53BP2 COMPLEXES

Abstract: The present invention discloses complexes of the 53BP2 protein with proteins identified as interacting with 53BP2 (53BP2-IPs) by a yeast two hybrid assay system. The proteins which were demonstrated to interact with 53BP2 are: beta -tubulin, p62, hnRNP G, and three gene products, 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3, which are encoded (in part) by the EST R72810 sequence. Thus, the present invention discloses complexes of 53BP2 and beta -tubulin, p62, hnRNP G, 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3, and derivatives, fragments and analogs thereof. The present invention also discloses the 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3 genes and proteins, as well as derivatives, fragments and analogs thereof. Methodologies for screening the aforementioned complexes for efficacy in treating and/or preventing certain diseases and disorders (particularly, cancer, autoimmune disease and neurodegenerative disease) are also provided by the present invention.

Description: 53BP2 COMPLEXES RELATED PATENT APPLICATIONS AND GRANT SUPPORT This application claims priority to United States Utility Patent Application Serial No. 08/935,450, originally filed on September 23, 1997, which is entitled "53BP2 COMPLEXES" and is hereby incorporated in its entirety by reference herein. The invention disclosed herein was made with United States Government support under award number 70NANB5H1066 awarded by the National Institute of Standards and Technology. Accordingly, the United States Government has certain rights in the present invention. FIELD OF THE INVENTION The field of the present invention relates to the complexes of the 53BP2 protein with various other proteins, including, but not limited to, complexes of the 53BP2 protein with β-tubulin, p62, hnRNP G, IP-1, IP-2 .and IP-3 proteins. The present invention also relates to the production of .antibodies specific for complexes of the 53BP2 protein and the aforementioned proteins, and their use in, inter alia, screening, diagnosis, prognosis and therapy. Additionally, the present invention further relates to 53BP2.IP-1, 53BP2.IP-2 and 53BP2.IP-3 genes and proteins, as well as derivatives, fragments and analogs, thereof. BACKGROUND OF THE INVENTION It should be noted that the novel complexes of the present invention, which will be disclosed infra, comprising complexes of the 53BP2 protein with β-tubulin, p62, hnRNP G, IP-1, IP-2, or IP-3 have heretofore not been described. Accordingly, citation of a reference herein shall not be construed as an admission that such is prior art to the present invention. (1) THE 53BP2 PROTEIN The human Bel 2/p53 binding protein, also known as 53BP2, or BEP [GenBank Ace. Number U58334] has been demonstrated to impede cell cycle progression from G2 to M phase, as well directly competing with Bel 2 for binding to p53, a critical tumor suppressor protein Introduction (W.H. Freeman and Co., New York, NY). Accordingly, 53BP2 serves a critical role in the modulation of p53 function and thus, mediates cell cycle progression. See e.g., Naumovski & Cleary, 1996. Mol. Cell. Biol. 16:3884-3892. The 53BP2 protein has been shown to bind to the central DNA binding domain of p53 via two adjacent ankryin repeats and an 5H3 domain, thus supporting its ability to modulate, inter alia, the DNA binding-ability and stability of the p53 protein and thus, its tumor suppression functions. See e.g., Iwabuchi, et al, 1994. Proc. Natl. Acad. Sci. USA 9J_: 6098-6102). With respect to the genesis of human neoplasia. the most frequent, observed p53 mutations maps to the 53BP2 binding domain. See e.g., Gorina & Pavletich, 1996. Science 274: 1001-1005). 53BP2 also modulates the dephosphorylation status (and thus the function of p53) by the binding of protein phosphatase 1 (PP1) to the carboxyl-terminal region of 53BP2 containing the aforementioned, critical ankyrin and 5H3 binding domains. See e.g., Helps, et al.. 1995. FEBS Letts. 377:295-300. The binding of 53BP2 to PP1 inhibits the latter protein's ability to dephosphorylate the p53 protein. Although PP1 -mediated phosphorylation of p53 at multiple sites has been demonstrated to affect the transcriptional activation/inhibition of the protein, this interaction is highly complex and difficult to elucidate in a quantitative, predictable manner. See e.g., Hecker, et al, 1996. Oncogene 12:953-961. Accordingly, 53BP2 serves an important role in the control of cell cycle progression, transcriptional regulation, cellular apoptosis and differentiation, intracellular signal transduction, and tumorigenesis. (2) β-TUBULIN The human β-tubulin protein [GenBank Ace. No. X79535] has been shown to exist in at least six different isoforms which are expressed from separate genes in a tissue-specific manner. See e.g., Ranganathan, et al., 1997. Prostate 30: 263-268. The tubulin proteins are critical to the enzymatically-mediated conversion of ATP hydrolysis to mechanical/molecular movement along microtubules. The carboxyl-terminus of β-tubulin (specifically the last 12 amino acid residues) interacts with kinesin motors to modulate microtubule polymerization, dynamics, and drug sensitivity. See e.g., Tucker & Goldstein, 1997. J. Biol. Chem. 272:9481—9488. Interestingly, these aforementioned functions of β-tubulin may have pathophysiological significance, as type IV β-tubulin is highly expressed in adenocarcinomas of the prostate and type II tubulin expression is up-regulated in adenocarcinomas which become malignant. See e.g.. Ranganathan, et al., 1997. Prostate 30: 263-268. Colchicine, which specifically interacts with β-tubulins to arrest cellular outgrowth, ahs been shown to function as an effective anti-tumor agent. See e.g., Banerjee, 1997. Biochem. Biophys. Res. Commun. 231 :698-700. Further, microtubules (possibly through β-tubulin binding to proteins which possess Src homology 2 (SH2) domains) play important roles in the assembly of signaling molecular complexes involved in cellular transformation processes. See e.g., Itoh, et al, 1996. J. Biol. Chem. 217:27931-27935. Therefore, in summary, β-tubulin serves a role in tumorigenesis and tumor progression, cell structure and intracellular protein transport, cell differentiation, and intracellular signaling (3) THE P62 PROTEIN The human p62 protein [GenBank Ace. No. M88108] is a 62 kD tyrosine-specific kinase which displays significant homology to the hnRNP protein GRP33. See e.g., Wong, et al, 1992. Cell 69:551 -558. The p62 protein has been demonstrated to associate with the p2P af GTPase- activating protein (GAP), wherein the binding of p62 is dependent upon its phosphorylation state, and occurs via the SH2 domains within GAP. See e.g., Wong, et al, 1992. Cell 69:551 - 558. In addition, the p62 protein also has been shown to associate with the 5H3 domains possessed by the family of Src tyrosine kinases. As p62 possesses the ability to simultaneously interact with multiple proteins, via a plurality of SH3 binding domains, the p62 protein serves to physically link Src kinase activity with downstream effectors including, but not limited to, GRB2 and phospholipase C γ-1. See e.g., Richard, et al, 1995. Mol. Cell Biol. 15: 186-197. Furthermore, in its dephosphorylated state, p62 has been demonstrated to specifically interact with RNA via a KH domain. See e.g., Wang, et al, 1995. J. Biol. Chem. 270:2010- 2013. Phosphorylation severely impairs p62 binding to RNA, thus suggesting that the binding of the p62 protein to RNA is regulated by a phosphorylation/dephosphorylation mechanism in vivo. p62 is known to specifically interact with the ubiquitin protein, via an 80 amino acid residue domain at its carboxyl-terminus (see e.g., Vadlamudi, et al, 1996. J. Biol. Chem. 271 :20235- 0237), thus implicating p62 in ubiquitin-mediated proteolysis. The p62 protein also specifically interacts with CSK (a cytosolic tyrosine kinase which negatively-regulates the Src family of tyrosine kinases). It has been hypothesized that the binding of p62 to CSK mediates the interaction (i.e., docking) of proteins (e.g., CSK and GAP) to cytoskeletal and membranal regions upon c-Src activation. See e.g., Neet & Hunter, 1995. Mol. Cell. Biol. 15:4908-4920. Intracellular levels of phosphorylated p62 (as detected by Western blotting), are markedly increased in v-abl transformed lymphoblasts (a cell model of leukemia) which subsequently reach advanced stages of feeder-layer-independent agar growth. See e.g., Clark & Liang, 1995. Leukemia 9:165-174. Hence, in summary, the p62 protein serves an important role in the processes of cell transformation and tumor progression, intracellular signaling and cellular activation by c-Src, ubiquitin-mediated proteolysis, and mRNA binding and metabolism. (4) THE hnRNP G PROTEIN The human hnRNP G protein [GenBank Ace. No. Z23064] is an RNA-binding protein whose homolog (ρ43) was originally identified as an auto-antigenic nuclear protein in canine models a systemic lupus erythematosus (SLE)-like syndrome. See e.g., Soulard, et al, 1993. Nuc. Acids Res. 2J_:4210-4217. The hnRΝP G protein is a glycosylated component of heterogeneous nuclear ribonucleoprotein (RΝP) complexes which contains an RΝA-specific binding domain at its amino-terminus and a carboxyl-terminal domain which is rich in serine, arginine, and glycine amino acid residues. See e.g., Soulard, et al, 1993. Nuc. Acids Res. 2λr. 4210-4217. Likely biological functions for the hnRΝP G protein include regulation of cell division, translational, and transcription. Additionally, hnRΝP G may also function in various autoimmune diseases, such as SLE and rheumatoid arthritis. The novel 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3 proteins of the present invention are encoded, in part, by a nucleotide sequence identified within the GenBank Database as EST R72810 [GenBank Ace. No. 157775] initially obtained from the Soares (human) breast library 2NbHBst. Over a span of 54 nucleotides, the EST R72810 sequence displays a 74% homology to the Simian immunodeficiency virus (SIV) ptS gene [GenBank Accession No. U05129], but otherwise displays no significant homology to other characterized proteins. SUMMARY OF THE INVENTION The present invention discloses both compositions and methods of production for protein complexes of the 53BP2 protein with various other proteins which interact with 53BP2. It should be noted that proteins which interact with the 53BP2 protein are hereinafter designated as 53BP2 interacting-protein "53BP2-IP" and complexes of the 53BP2 protein with a given 53BP2- IP are hereinafter designated as "53BP2«53BP2-IP." More specifically, the present invention relates to complexes of the 53BP2 protein " (and derivatives, fragments and analogs thereof) with: (i) β-tubulin, (ii) p62, (Hi) hnRNP G, (z ' v) 53BP2:IP-1, (v) 53BP2:IP-2 and (vi) 53BP2:IP-3. (and their derivatives, analogs and fragments). The present invention further provides methodologies for the screening of proteins which interact with the 53BP2 protein (or derivatives, fragments or analogs thereof), wherein the preferable screening methodology is a yeast two hybrid assay system, or a modification thereof. The present invention further relates to the nucleotide sequences of 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3 genes (e.g., human 53BP2:IP-1, 53BP2:IP-2. and 53BP2:IP-3 genes and homologs of other species), as well as derivatives, fragments and analogs thereof. Also disclosed herein are nucleic acids which are complementary to the aforementioned nucleotide sequence including, but not limited to, the inverse complement. The present invention also relates to 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3 (and derivatives, fragments and analogs thereof) which are biologically and functionally active (i.e., are capable of displaying one or more known functional activities of a wild-type 53BP2:IP-1, 53BP2TP-2 or 53BP2:IP-3 proteins). Such functional activities include, but are not limited to: (/) the ability to bind with, or compete for binding with, the 53BP2 protein, (ii) antigenicity (i.e.. the ability to bind with, or compete with, 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 for binding) to an anti-53BP2:IP-l, anti- 53BP2:IP-2 or anti-53BP2:IP-3 antibody, respectively) and/or (Hi) immunogenicity (i.e., the ability to generate an antibody which binds 53BP2.-IP-1, 53BP2:IP-2 or 53BP2:IP-3, respectively). Methods of production of the 53BP2-53BP2-IP complexes and of 53BP2:IP-1, 53BP2:IP- 2 and 53BP2:IP-3 proteins, as well as derivatives, fragments and analogs of the complexes and proteins (e.g., by recombinant means), are also disclosed by the present herein. Pharmaceutical compositions utilizing the 53BP2 protein and the aforementioned 53BP2»53BP2-IP complexes are also disclosed. The present invention further provides methodologies for the modulation (i.e., the inhibition or enhancement) of the activity of 53BP2*53BP2-IP complexes, more specifically modulation of the 53BP2«β-tubulin, 53BP2«p62, 53BP2«hnRNP G, 53BP2«53BP2:IP-1, 53BP2«53BP2:IP-2 or 53BP2»53BP2:IP-3 complexes. The various protein components of these complexes have been implicated in cellular functions which include, but are not limited to: control of cell cycle progression, cellular differentiation and apoptosis, tumorigenesis and tumor progression, regulation of transcription and translation, control of intracellular signal transduction (e.g., c-Src signaling), control of ubiquitin-mediated protein degradation, and processing involving mRNA binding and stability. Accordingly, the present invention provides methodologies for the screening 53BP2»53BP2-IP complexes (and derivatives, fragments and analogs thereof) for the ability to alter cell functions, particularly those cell functions in which the 53BP2 protein and/or a 53BP2-IP have been implicated. These cellular function include, but are not limited to: (/ ' ) cell proliferation, differentiation and apoptosis; (ii) tumorigenesis and cell transformation; (Hi) intracellular signal transduction; (iv) gene expression (v) ubiquitin-mediated protein degradation and (vi) mRNA stability. The present invention also discloses therapeutic and prophylactic, as well as diagnostic, prognostic and screening methodologies and compositions which are based upon 53BP2*53BP2- IP complexes (and the nucleic acids encoding the individual proteins which participate in the complexes) as well as 53BP2:IP-1; 53BP2:IP-2 and 53BP2:IP-3 proteins and nucleic acids. Therapeutic compounds of the present invention include, but are not limited to: (i) 53BP2»53BP2-IP complexes and complexes where one or both members of the complex is a derivative, fragment or analog of the 53BP2 protein. 53BP2-IP. 53BP2:IP-1, 53BP2:IP-2 or 53BP2-IP-3 proteins (and derivatives, fragments and analogs thereof); (ii) antibodies specific for the aforementioned proteins; (Hi) nucleic acids encoding the aforementioned proteins and (iv) antisense nucleic acids to the nucleotide sequences encoding the complex components and 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3 antisense nucleic acids. Diagnostic, prognostic and screening kits are also provided herein. The present invention also discloses animal models and methodologies for the screening of modulators (i.e., agonists, antagonists and inhibitors) of the activity of 53BP2»53BP2-IP complexes and 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3 proteins. Methodologies for the identification of molecules which inhibit or, alternatively, which increase the formation of 53BP2»53BP2-IP complexes are also provided herein. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 : The nucleotide sequence of 53BP2 [GenBank Ace. No. U58334; SEQ ID NO: 1] and its associated, inferred amino acid sequence [SEQ ID NO:2]. The amino-terminal start site of the sequence (utilized as bait in the assays described in Section 6, infra) is indicated by the arrow labeled "A". Figure 2: The nucleotide sequence [SEQ ID NO:3] and associated, inferred amino acid sequence [SEQ ID NO:4] of β-tubulin (GenBank Accession No. X7953 5). Prey sequence A begins at nucleotide 820 and amino acid residue 253 which are denoted by the arrow labeled "A". Prey sequence B begins at nucleotide 895 and amino acid residue 278 which are denoted by the arrow labeled "B." Figure 3: The nucleotide sequence [SEQ ID NO. 5] and associated, inferred amino acid sequence [SEQ ID NO. 6] of the p62 protein (GenBank Ace. No. M88108). The amino-terminal start site of the prey sequence (utilized as bait in the assays described in Section 6, infra) is indicated by the arrow labeled "A." Figure 4: The nucleotide sequence [SEQ ID NO: 7] and associated, inferred amino acid sequence [SEQ ID NO: 8] of the hnRNP G protein. The amino-terminal start site of the prey sequence (utilized as bait in the assays described in Section 6, infra) is indicated by the arrow labeled "A." Figure 5: The nucleotide sequence of EST R72810 [SEQ ID NO:9]. The entire sequence was utilized as a prey sequence in the assays described in Section 6, infra. Figure 6: A schematic diagram of the portions of the 53BP2 protein, β-tubulin, p62, hnRNP G, 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3 (i.e.. the proteins potentially encoded, at least in part, by the extended EST R72810 sequence) which interact to from a 53BP2«53BP2:IP complex in the yeast two hybrid assay system. The sequences of the 53BP2 protein, β-tubulin, p62, hnRNP G and EST R78210 proteins are depicted as bars positioned at the starting and ending amino acid residues (as depicted for each protein in Figures 1-4, 9 and 10A — F (SEQ ID NOS: 2, 4, 6, 8, 11, 12 and 13, respectively). The portions of each sequence either used as bait (in the case of 53BP2) or identified in the assay ("prey sequence"). Similarly, the sequences of the β-tubulin, p62, hnRNP G and EST R78210 encoded proteins are blackened, and the first amino acid residue number of the bait or prey sequence, as the case may be, is indicated above each bar. Additionally, for β-tubulin, the amino-terminal portion of a second, longer interacting sequence is indicated by a horizontal line (with the first amino acid of this extension indicated above the bar). For 53BP2:IP-1 and 53BP2:IP-3, the first amino acid is denoted by ">1" as the actual amino-terminus of the protein is predicted to extend beyond the 5 '-terminus of the assembled nucleotide sequence. Figure 7: A matrix of results of yeast two hybrid system assays. The yeast expressing hybrids of the bait proteins Bl, MDM2 and 53BP2 are indicated in the rows designated Bl, MDM2 and 53BP2 mated with yeast cells expressing hybrids of the prey proteins PI, P2, PPlα, p62 and β-tubulin ("β-tub."), as indicated by the rows designated as PI, P2, PPlα, p62 and β-tub, are depicted. A positive interaction for a bait and prey proteins is indicated as "+" in the box forming the intersection between the particular bait and prey proteins; whereas a lack of interaction is designated by an empty box. Boxes labeled A, B, C and D indicate the results of matings of yeast expressing Bl and PPlα, 53BP2 and PPW, 53BP2 and p62, and 53BP2 and β-tubulin, respectively. Figure 8: An illustration of the general procedure utilized to assemble the longest possible contiguous nucleic acid sequence from a particular EST sequence. The starting EST nucleic acid sequence (denoted as the line labeled as "B") is analyzed with the NCBI. "BLAST" Program and compared to all sequences within the "nr" database. Sequences which demonstrated homology > 95% (at the nucleic acid level) over their termini of at least 30 bases were utilized if the said alignment resulted in a 5 '-extension (Sequence A) or 3 '-extension (Sequence C) of the starting EST sequence. Figure 9: The nucleotide sequence of EST R72810 and 25 contiguous EST sequences [SEQ ID NO:10] is depicted. The original EST R72810 sequence is shown in bold lettering. A 5'-terminus extension was achieved with EST C17385, and is denoted by the underline sequence. Similarly, 3 '-terminus extensions were made, first from EST AA464793 (denoted by boxed lettering) and secondly with EST AA479761 (denoted by bold, italic lettering). The 5'-terminus of the prey interacting sequence is denoted by "A"; whereas the 3 '-terminus of the sequence itself is denoted by a starred arrow. Figures 10A-F: The predicted open reading frames (ORFs) and translation of the open reading frames, in all three possible reading frames, of the nucleotide sequence of SEQ ID NO: 10 (A and B). The carboxyl-terminus of 53BP2:IP-3 [SEQ ID NO: 13], which is encoded by Translation Frame +1 at the 5 '-terminus of the assembled nucleotide sequence, is depicted graphically in Panel A. Panel B represents the nucleotide and associated, inferred amino acid sequence of the carboxyl-terminus of 53BP2:IP-3. 53BP2:IP-2 [SEQ ID NO: 12], which is encoded by Translation Frame +2 from nucleotides 44-652. is depicted in Panel C. Panel D represents the nucleotide and associated, inferred amino acid sequence of 53BP2:IP-2. 53BP2:IP-1 [SEQ ID NO: 11], which is encoded in Translation Frame +2 from nucleotides 44- 652, is depicted in Panel E. Panel F represents the nucleotide and associated, inferred amino acid sequence of 53BP2:IP-1. DETAILED DESCRIPTION OF THE INVENTION The present invention disclosed herein relates to the identification of proteins which interact with the 53BP2 protein (the 53BP2-interacting proteins are hereinafter referred to as "53BP2-IPs") by the utilization of an improved, modified form of the yeast two hybrid system, β-tubulin, ρ62, hnRNP G, and 53BP2:IP-1. 53BP2:IP-2 and 53BP2:IP-3 were demonstrated to form complexes under physiological conditions with the 53BP2 protein (the complexes of the 53BP2 protein with a 53BP2-IP are hereinafter referred to as "53BP2»53BP2-IP" complexes"). These 53BP2«53BP2-IP complexes, by virtue of the interaction, are implicated in the modulation of the functional activities of the 53BP2 protein and its associated binding partners (i.e., 53BP2- IPs). Such functional activities include, but are not limited to, cell cycle control, transcriptional regulation, cellular apoptosis and differentiation, intracellular signal transduction. tumorigenesis and tumor progression, protein transport and cell structure, cell differentiation, cellular activation by c-Src. ubiquitin-mediated proteolysis, mRNA binding and metabolism, translational regulation, and autoimmune disease. The present invention also relates to methodologies for the screening of proteins which interact with the 53BP2 protein. In a specific embodiment, the present invention discloses 53BP2 complexes, in particular complexes of the 53BP2 protein with one or more of the following proteins: β-tubulin, p62, hnRNP G, 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3. Another specific embodiment of the present invention relates to complexes of the 53BP2 protein (or derivatives, fragments or analogs thereof) with β-tubulin, p62, hnRNP G, 53BP2:IP-1, 53BP2TP-2 or 53BP2:IP-3 (or derivatives, fragments and analogs thereof. In another specific embodiment, these aforementioned complexes bind an anti-53BP2»53BP2-IP complex antibody. In yet another specific embodiment of the present invention, complexes of the 53BP2 protein with a protein which is not protein phosphatase lα (PP lα) or p53 are disclosed. The present invention additionally provides methodologies for the production and - isolation of the 53BP2»53BP2-IP complexes. In a specific embodiment, the present invention discloses methodlogies for the recombinant expression of both the 53BP2 protein and its binding partner, 53BP2-IP (or fragments, derivatives or homologs of one or both members of the complex); wherein either both binding partners are under the control of a single heterologous promoter (i.e., a promoter not naturally associated with the native gene encoding the particular complex component) or where each is under the control of a separate heterologous promoter. In yet another embodiment, the present invention provides the nucleotide sequences of 53BP2:IP-1, 53BP2-IP-2 and 53BP2-IP-3, as well as the associated, inferred amino acid sequences of their respective encoded proteins. The present invention further relates to 53BP2:IP-1, 53BP2-IP-2 and 53BP2-IP-3 proteins (or derivatives, fragments, analogs and homologs thereof) as well as nucleic acids encoding the 53BP2:IP-1, 53BP2:IP-2 and 53BP2-IP-3 proteins (or, derivatives, fragments, analogs and homologs thereof). The present invention also provides 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3 proteins and the nucleic acid sequences encoding these proteins derived from many different species, preferably from vertebrates, and more preferably from mammals. In the most preferred embodiment, the 53BP2:IP-1, 53BP2-IP-2 and 53BP2:IP-3 proteins and genes are of human origin. Production of the aforementioned proteins and nucleic acid sequences by recombinant methodologies is provided herein. The present invention further relates to 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3 proteins (and derivatives and analogs thereof) which are functionally active (i.e., are capable of displaying one or more of the known, functional activities associated with the wild-type 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3. Such functional activities include, but are not limited to: (i) the ability to form a complex with the 53BP2 protein; (ii) antigenicity (i.e.. the ability to bind, or compete with, 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 for binding to an anti-53BP2:IP-l, anti- 53BP2-IP-2 or anti-53BP2:IP-3 antibody) and (Hi) immunogenicity (i.e., the ability to generate an antibody which binds to 53BP2:IP-1, 53BP2TP-2 or 53BP2TP-3). Methods of diagnosis, prognosis, and screening for diseases and disorders which are associated with aberrant levels of 53BP2«53BP2-IP complexes or of 53BP2:IP-1, 53BP2-IP-2 or 53BP2-IP-3, are also provided herein. The present invention also discloses methodologies for the therapeutic or prophylactic treatment of diseases or disorders which are associated with aberrant levels of 53BP2»53BP2-IP complexes or 53BP2:IP-1, 53BP2TP-2 or 53BP2TP-3 or, similarly, aberrant levels of the activity of one or more of the components of the complex. Treatment may be facilitated by, but is not limited to, the administration of: (/) 53BP2»53BP2-IP complexes, 53BP2TP-1, 53BP2:IP-2 53BP2:IP-3, (ii) modulators of 53BP2»53BP2-IP complex formation or activity (e.g., antibodies which bind the 53BP2*53BP2-IP complex, the non- complexed 53BP2 protein or 53BP2-IP, or a derivative or fragment thereof-which preferably possesses the region containing the portion of 53BP2 or the 53BP2-IP that is directly involved in complex formation); (Hi) mutants of the 53BP2 protein or the 53BP2-IP which increase or decrease binding affinity; (iv) small molecule inhibitors/enhancers of complex formation and (v) antibodies which either stabilize or neutralize the complex. Methodologies for assaying 53BP2«53BP2-IP complexes, 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 for biological activity as therapeutics or diagnostics, as well as methodologies for the screening of 53BP2»53BP2-IP complexes, 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 modulators (i.e., inhibitors, agonists and antagonists) are also disclosed herein. It should be noted that, for clarity of disclosure, and not by way of limitation, the detailed description of the present invention is divided into the subsections which follow, infra. (1) 53BP2»IP COMPLEXES AND 53BP2.IP-1. 53BP2TP-2 AND 53BP2:IP-3 PROTEINS The present invention relates to 53BP2*53BP2-IP complexes, and, in specific embodiments, complexes of the 53BP2 protein and β-tubulin, p62, hnRNP G, 53BP2TP-1, 53BP2:IP-2 and 53BP2:IP-3. In a preferred embodiment, the 53BP2 protein is complexed with a protein which is not a PPlα or a p53 protein. In another preferred embodiment, the 53BP2»53BP2-IP complexes are complexes of human proteins. The present invention also relates to complexes of the 53BP2 proteins and 53BP2-IP wherein one or both members of the complex are fragments, derivatives or analogs of the wild-type 53BP2 or 53BP2-IP protein. Preferably, the 53BP2»53BP2-IP complexes possess one or both members which are functionally-active fragments, derivatives or analogs of the wild-type protein(s). The term "functionally-active 53BP2»53BP2-IP complex," as utilized herein, refers to those complexes which display one or more of the known functional attributes of a complex of full-length 53BP2 protein with a full-length 53BP2-IP (e.g., β-tubulin, p62, hnRNP G, 53BP2:IP-1, 53BP2TP-2 or 53BP2:IP-3). These functional activities include, but are not limited to: (i) cell cycle control, (ii) modulation of cell apoptosis and differentiation; (Hi) control of transcriptional and translational regulation; (iv) effects on intracellular signal transduction, protein transport, and c-Src activation; (v) effects on tumorigenesis and tumor progression; (iv) ubiquitin-mediated proteolysis; (vi) effects on mRNA binding and metabolism; (vii) binding to an anti 53BP2«53BP2-IP complex antibody and (viii) various other biological activities well-known within the art. For example, the derivatives or analogs of the 53BP2 protein which possess the desired immunogenicity or antigenicity may be utilized in immunoassays, as immunogens for antibody production, for inhibition of 53BP2*53BP2-IP complex activity, and the like. Similarly, derivatives or analogs which retain, or alternatively lack or inhibit, a specific property of interest (e.g., participation in the formation of a 53BP2*53BP2-IP complex) may be used as inducers or inhibitors, respectively, of such a property and its physiological correlates. Such derivatives or analogs of 53BP2»53BP2-IP complexes may be screened for the desired biological activity by any of the procedures well-known within the art. In specific embodiments of the present invention, 53BP2«53BP2-IP complexes comprising fragments of one or both members of the complex are disclosed. In a preferred embodiment, fragments of various 53BP2-IPs which have been shown to form complexes with the 53BP2 protein by use of the yeast two hybrid assay methodology are disclosed. These aforementioned fragments may consist of but are not limited to: (i) the carboxyl-terminal domain of the 53BP2 protein (amino acid residues 704-1005) as depicted in Figure 1 [SEQ ID NO:2]; (ii) amino acid residues 253-445 or 278-445 of β-tubulin, as depicted in Figure 2 [SEQ ID NO:4]; (Hi) amino acid residues 275-443 of p62, as depicted in Figure 3 [SEQ. ID NO:6]; (iv) amino acid residues 88-439 of hnRNP G, as depicted in Figure 4 [SEQ ID NO:8]; (v) amino acid residues 8-173 of 53BP2:IP-1, as depicted in Figure 10F [SEQ ID NO:ll]; (vz) amino acid residues 1-70 of 53BP2:IP-2, as depicted in Figure 10D [SEQ ID NO: 12] and (vii) and amino acid residues 8-33 of 53BP2:IP-3. as depicted in Figure 10B [SEQ ID NO: 13]. The nucleic acid sequences (i.e., genes) encoding the aforementioned proteins, as well as derivatives, fragments and analogs thereof, are also disclosed by the present invention. The nucleotide and associated amino acid sequences of the human 53BP2 protein (GenBank Ace. No. U58334); β-tubulin (GenBank Ace. No. X79535); p62 (GenBank Ace. No. M88108) and hnRNP G (GenBank Ace. No. Z23064) have been previously elucidated, and are provided in Figures 1-4 and SEQ ID NOS:l, 3, 5 and 7, respectively. The nucleic acid sequences encoding the 53BP2 protein, β-tubulin, p62 or hnRNP G may be obtained by any method known within the art (e.g., by polymerase chain reaction-mediated amplification using synthetic primers hybridizable to the 3'- and 5 '-termini of the sequence of interest and/or by cloning from a cDNA or genomic library using an oligonucleotide which is specific for the gene sequence of interest). Homologs (i.e., nucleic acids encoding the 53BP2 protein, β-tubulin, p62, and hnRNP G of species other than human) or other related sequences (e.g., paralogs) may be obtained by low, moderate or high stringency hybridization with all or a portion of the particular human sequence as a probe utilizing methodologies for nucleic acid hybridization and cloning which are well- known within the art. The 53BP2, β-tubulin, p62, hnRNP G, and 53BP2:IP-1, 53BP2.-IP-2 or 53BP2:IP-3 proteins (either alone or in a complex) may be obtained by methods well-known within the art for protein purification and recombinant protein expression. For recombinant expression of one or more of the proteins, the nucleic acid containing all or a portion of the nucleotide sequence encoding the protein of interest may be inserted into an appropriate expression vector (i.e., a vector which contains the requisite elements for the transcription and translation of the inserted protein coding sequence). These necessary transcriptional and translational signals may also be supplied by the native promoter for the 53BP2 gene or any of the genes encoding the 53BP2-IPs and/or their flanking regions. A variety of host-vector systems may be utilized to express the protein coding sequence including, but not limited to: (z) mammalian cell systems infected with virus (e.g., vaccinia virus, adenovirus, and the like); (ii) insect cell systems infected with virus (e.g., baculovirus)or (Hi) microorganisms such as yeast containing yeast vectors or bacteria transformed with bacteriophage, plasmid or cosmid DNA. Accordingly, depending upon the specific host-vector system utilized, any one of a number of suitable transcription and translation elements may be used in the practice of the present invention. In a preferred embodiment, the 53BP2«53BP2-IP complexes are obtained by expression of the entire 53BP2 and 53BP2-IP coding sequences within the same cell, either under the control of the same promoter or two separate promoters. In another preferred embodiment, a derivative, fragment or homolog of the 53BP2 protein and/or a derivative, fragment or homolog of a 53BP2-IP are recombinantly expressed. Preferably the derivative, fragment or homolog of the 53BP2 protein and/or the 53BP2-IP possess the ability to form a complex with a binding partner identified by a binding assay (e.g., the modified yeast two hybrid system). Any of the methods well-known within the art for the insertion of DNA fragments into a vector may be utilized to construct expression vectors containing a chimeric gene consisting of appropriate transcriptional/translational control signals and protein coding sequences. These methods may include in vitro recombinant DNA and synthetic techniques and in vivo recombinants (genetic recombination). Expression of nucleic acid sequences encoding the 53BP2 protein and a 53BP2-IP (e.g., β-tubulin, p62, hnRNP G. 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3), or derivatives, fragments or homologs thereof, may be regulated by a second nucleic acid sequence such that the genes or fragments thereof are expressed in a host transformed with the recombinant DNA molecule(s). In a specific embodiment, the promoter is not native to the genes for the 53BP2 protein or the 53BP2-IP. Promoters which may be utilized include, but are not limited to: (i) the SV40 early promoter (see e.g., Bernoist & Chambon, 1981. Nature 290:304-310); (ii) the promoter contained in the 3'-terminus long terminal repeat of Rous sarcoma virus (see e.g., Yamamoto, et al, 1980. Cell 22:787-797); (Hi) the Herpesvirus thymidine kinase promoter (see e.g., Wagner, et al, 1981. Proc. Natl. Acad. Sci. USA 78:1441-1445); (iv) the regulatory sequences of the metallothionein gene (see e.g., Brinster, et al, 1982. Nature 296:39-42); (v) prokaryotic expression vectors such as the β-lactamase promoter (see e.g., Villa-Kamaroff, et al, 1978. Proc. Natl Acad. Sci. USA 75:3727-3731) or (vi) the tac promoter (see e.g., DeBoer, et al, 1983. Proc. Natl Acad. Sci. USA 80:21-25. In addition, animal transcriptional control regions which exhibit tissue specificity and have been utilized in transgenic animals may also be utilized. These transcriptional control regions include, but are not limited to: (i) the elastase I gene control region which is active in pancreatic acinar cells (see e.g., Swift, et al, 1984. Cell ^8:639-646; (ii) the insulin gene control region which is active in pancreatic β-cells (see e.g., Hanahan. et al, 1985. Nature 315:115-122); (Hi) the immunoglobulin gene control region which is active in lymphoid cells (see e.g., Alexander, et al, 1987. Mol. Cell Biol. 7:1436-1444); (iv) the mouse mammary tumor virus control region which is active in testicular, breast, lymphoid and mast cells (see e.g., Leder, et al, 1986. Cell 45:485-495); (v) the α-fetoprotein gene control region which is active in liver (see e.g., Krumlauf, et al, 1985. Mol. Cell. Biol. 5:1639-1648); (vi) the β-globin gene control region which is active in myeloid cells (see e.g., Kollias, et al, 1986. Cell 46:89-94) and (vii) the myosin light chain-2 gene control region which is active in skeletal muscle (see e.g., Shani, 1985. Nature 314:283-286). In a specific embodiment of the present invention, a vector is utilized which comprises: (z) a promoter operably-linked to nucleic acid sequences encoding the 53BP2 protein and/or a 53BP2-IP (e.g., β-tubulin, p62, hnRNP G, 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3), or a fragment, derivative or homolog thereof; (ii) one or more origins of replication and optionally, (Hi) one or more selectable markers (e.g., an antibiotic resistance gene). In a preferred embodiment of the present invention, a vector is utilized which comprises a promoter operably-linked to nucleic acid sequences encoding both the 53BP2 and a 53BP2-IP, one or more origins of replication, and one or more selectable markers. For example, in a specific embodiment, an expression vector containing the coding sequences, or portions thereof, of the 53BP2 protein and a 53BP2-IP, either together or separately, is produced by subcloning the aforementioned gene sequences into the EcoRI restriction site of each of the three pGEX vectors (glutathione 5-transferase expression vectors; see e.g.. Smith & Johnson, 1988. Gene 7:31-40), thus allowing the expression of products in the correct reading frame. Expression vectors containing the sequences of interest may be identified by three general approaches: (i) nucleic acid hybridization, (ii) presence or absence of "marker" gene function and (ii) expression of the inserted sequences. In the first approach, the 53BP2 protein, β-tubulin, p62, hnRNP G, 53BP2:IP-1, 53BP2:IP-2, 53BP2.IP-3, or other 53BP2-IP sequences may be detected by nucleic acid hybridization utilizing probes comprising sequences which are homologous and complementary to the inserted sequences of interest. In the second approach, the recombinant vector/host system may be identified and selected based upon the presence or absence of certain "marker" functions (e.g., binding to an anti-53BP2, anti-53BP2-IP or anti- 53BP2«53BP2-IP complex antibody, resistance to antibiotics, occlusion body formation in baculovirus, and the like) caused by the insertion of the sequence(s) of interest into the vector. For example, if the 53BP2 or a 53BP2-IP gene (or portion thereof) is inserted within the marker gene sequence of the vector, recombinants containing the 53BP2 or 53BP2-IP fragment will be identified by the absence of the marker gene function. In the third approach, recombinant expression vectors may be identified by assay for the 53BP2 protein, β-tubulin, p62. hnRNP G, 53BP2:IP-1, 53BP2:IP-2, 53BP2:IP-3, or other 53BP2-IP products which may be expressed by the recombinant vector. Such assays can be based, for example, on the physical or functional properties of the interacting species in in vitro assay systems (e.g., formation of a 53BP2«53BP2- IP complex, immunoreactivity to antibodies specific for the protein and the like). Once a recombinant 53BP2, β-tubulin, p62. hnRNP G. 53BP2:IP-1. 53BP2:IP-2, or 53BP2:IP-3, or other 53BP2-IP molecule is identified and the complexes or individual proteins subsequently isolated, various methodologies which are well-known within the art may be utilized to "amplify" them. For example, in one embodiment of the present invention, once a suitable host system and growth conditions have been established, recombinant expression vectors are then propagated and amplified in quantity. As previously described, the expression vectors or derivatives which may be used include, but are not limited to: human or animal viruses such as vaccinia virus or adenovirus, insect viruses such as baculovirus, yeast vectors, bacteriophage vectors such as lambda phage, and plasmid and cosmid vectors. In addition, a host cell strain may be chosen which modulates the expression of the inserted sequences, or modifies or processes the expressed proteins in the specific fashion desired. The use of certain promoters allows the expression of the desired sequences to be elevated in the presence of certain inducers. Accordingly, the expression of the genetically-engineered 53BP2 and/or 53BP2-IP may be controlled. Furthermore, different host cells have characteristic and specific mechanisms for the translational and post-translational processing and modification (e.g., glycosylation, phosphorylation, and the like) of proteins. Appropriate cell lines or host systems may be selected to ensure the desired modification and processing of the foreign protein is achieved. For example, expression in a bacterial system can be used to produce an non-glycosylated core protein, while expression within mammalian cells ensures "native" glycosylation of a heterologous protein. In other specific embodiments, the 53BP2 and/or 53BP2-IPs (or derivatives, fragments or homologs thereof) may be expressed as fusion or chimeric protein products comprising the protein (or derivative, fragment or homolog thereof) joined via a peptide bond to a heterologous protein sequence of a different protein. These aforementioned chimeric products may be generated by the ligation of the appropriate nucleic acid sequences encoding the desired amino acids to one another (in the proper "reading frame") and expressing the chimeric products in a suitable host by methodologies which are well-known with the relevant art. Alternatively, chimeric product may be produced by protein synthetic techniques (e.g., by use of a peptide synthesizer). Chimeric genes comprising portions of the 53BP2 protein and/or a 53BP2-IP, or 53BP2:IP-1, 53BP2TP-2 or 53BP2:IP-3 which are fused to any heterologous protein-encoding sequences may be constructed in the practice of the present invention. A specific embodiment of the present invention relates to a chimeric protein comprising a fragment of the 53BP2 protein and/or a 53BP2-IP, or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 of at least six amino acid residues. In another specific embodiment of the present invention, fusion proteins are provided which contain the interacting domains of the 53BP2 protein and a 53BP2-IP (e.g., β-tubulin, p62, hnRNP G, 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3) and, optionally, a peptide linker between the two domains, where such a linker promotes the interaction of the 53BP2 and 53BP2-IP binding domains. These aforementioned fusion proteins may be particularly useful where the stability of the interaction is desirable (due to the formation of the complex as an intramolecular reaction), for example in production of antibodies specific to the 53BP2»53BP2-IP complex. In yet another specific embodiment of the present invention, derivatives of the 53BP2 protein and/or 53BP2-IP or 53BP2:IP-1, 53BP2:IP-2 or 53BP2TP-3 may be produced by the alteration of their sequences by substitutions, additions or deletions which provide for functionally-equivalent molecules. As a function of the degeneracy of nucleotide coding sequences, other DNA sequences which encode substantially the same amino acid sequence as a 53BP2 or 53BP2-IP or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 gene may be utilized in the practice of the present invention. These nucleotide sequences include, but are not limited to, the sequences comprising all or portions of the 53BP2 protein, β-tubulin, p62. hnRNP C, 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3, or other 53BP2-IP genes which are altered by the substitution of different codons that encode a functionally equivalent amino acid residue within the sequence, thus producing a "silent" substitution. Similarly, the 53BP2. 53BP2-IP, 53BP2:IP-1, 53BP2:IP-2 and 53BP2TP-3 derivatives of the present invention include, but are not limited to, those derivatives containing, as a primary amino acid sequence, all or part of the amino acid sequence of 53BP2 or a 53BP2-IP or 53BP2:IP-1, 53BP2-IP-2 or 53BP2-IP-3. including altered sequences in which functionally-equivalent amino acid residues are substituted for residues within the sequence resulting in a "silent" substitution. For example, one or more amino acid residues within the sequence can be substituted by another amino acid of a similar polarity which acts as a functional equivalent. Substitutes for an amino acid within the sequence may be selected from other members of the class (i.e., hydrophobic or hydrophilic) to which the amino acid residue belongs. A specific embodiment of the present invention discloses the nucleic acid sequences which encode the proteins and proteins consisting of or comprising a fragment of the 53BP2 protein or a 53BP2-IP or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 consisting of at least 6 (continuous) amino acid residues. In other specific embodiments of the present invention, the fragment consists of at least 10, 20, 30, 40, or 50 amino acid residues of the 53BP2 protein. 53BP2-IP, 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3. In yet another specific embodiments, such fragments are not larger than 35, 100 or 200 amino acid residues. Derivatives or analogs of the 53BP2 protein and 53BP2-IPs or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 include, but are not limited to, molecules comprising regions which are substantially homologous to the 53BP2 protein, 53BP2-IPs, 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 in various embodiments, and demonstrated homologies ranging from 35-95%, with preferable homology of 85%. more preferable homology of 90% and most preferable homology of 95%>, to an amino acid sequence of identical size or when these aforementioned derivatives or analogs are compared to an aligned sequence in which the alignment is performed by a computer homology program known in the art or whose encoding nucleic acid is capable of hybridizing to a sequence encoding the 53BP2 protein, a 53BP2-IP, 53BP2:IP-1, 53BP2TP-2 or 53BP2:IP-3, under stringent, moderately stringent, or non-stringent hybridization conditions. Homology algorithms utilized in the present invention include, but are not limited to, the BLASTN BLASTX, BLASTP and FASTA. The 53BP2, 53BP2-IP, 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3 derivatives and analogs of the present invention may be produced by various methods known within the art and the manipulations which result in their production may occur at the gene or protein level. The cloned 53BP2, 53BP2-IP, 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 gene sequences may be modified by any of numerous strategies known within the art. See e.g., Maniatis, T., 1990. Molecular Cloning, A Laboratory Manual, 2d ed. (Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York). For example, the nucleic acid sequences of interest may be cleaved at appropriate sites with restriction endonuclease(s), followed by further enzymatic modification (if required), isolated, and ligated in vitro. In the production of the nucleic acid sequence encoding a derivative or analog of the 53BP2 protein or a 53BP2-IP, care is taken to ensure that the modified sequence retains the original translational reading frame, uninterrupted by translational stop signals, in the "region" where the desired biological activity is encoded. Additionally, the 53BP2- and/or 53BP2-IP-encoding nucleic acid sequences, as well as the 53BP2:IP-1-, 53BP2:IP-2- or 53BP2:IP-3-encoding nucleic acid sequences may be mutated in vitro or in vivo, so as to create and/or destroy translation, initiation, and/or termination sequences, or to create variations in coding regions and/or form new restriction endonuclease sites or destroy pre-existing ones, to facilitate further in vitro modification. Any technique for mutagenesis known within the art may be utilized including, but not limited to, chemical mutagenesis and in vitro site-directed mutagenesis (see e.g., Hutchinson. et al, 1978. J. Biol. Chem. 253:6551-6558), use of TAB* linkers (Pharmacia), and the like. Once a recombinant cell expressing the 53BP2 protein and/or a 53BP2-IP, or 53BP2TP-1, 53BP2:IP-2 or 53BP2:IP-3 protein (or a derivative, fragment or analog thereof) is identified, the individual gene product or protein complex may be isolated and analyzed. This is achieved by utilization of assays which are based upon the physical and/or functional properties of the protein or protein complex, including, but not limited to, radioactive labeling of the gene product followed by gel electrophoretic analysis, immunoassay, cross-linking to marker-labeled product, and the like. The 53BP2-53BP2-IP complexes and 53BP2:IP-1, 53BP2TP-2 and 53BP2:IP-3 proteins may be isolated and purified by standard methods well-known within the art (either from natural sources or recombinant host cells expressing the proteins or protein complexes). These methodologies including, but not limited to: (i) chromatography (e.g., ion exchange, affinity, gel exclusion, reversed-phase high pressure, fast protein liquid, etc.); (ii) differential centrifugation; (Hi) differential solubility or any other standard technique utilized for the purification of proteins. Functional properties may then be evaluated using any suitable assay known within the art. Alternatively, once a 53BP2-IP (or its derivative) is identified, the associated amino acid sequence of the protein may be deduced from the nucleic acid sequence of the chimeric gene from which it was originally encoded. As a result, the protein or its derivative may then be synthesized by standard chemical methods known within the art. See e.g., Hunkapiller, et al, 1984. Nature 310:105-111. In a specific embodiment of the present invention, the 53BP2*53BP2-IP complexes and 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3 proteins (whether produced by recombinant DNA techniques, chemical synthesis methods or by purification from native sources) include, but are not limited to those which possess, as a primary amino acid sequence, all or part of the amino acid sequences substantially as depicted in Figures 1-4, and 1OB, D and F [SEQ ID NOS:2, 4, 6, 8, 13, 12 and 11], respectively. Manipulations of the 53BP2 protein and/or 53BP2-IP sequences or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 sequences, may be performed at the protein level. Included within the scope of the present invention are complexes of 53BP2 or 53BP2-IP derivatives, fragments or analogs, as well as 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3 derivatives, fragments and analogs, which are differentially-modified during or after translation, (e.g., by glycosylation, acetylation, phosphorylation, amidation, derivatization by known protecting/blocking groups, proteolytic cleavage, linkage to an antibody molecule or other cellular ligand, and the like). Any of numerous chemical modifications may be carried out by known techniques including, but not limited to, specific chemical cleavage by cyanogen bromide, trypsin, chymotrypsin, papain, V8 protease, NaBH 4 , acetylation, formylation, oxidation, reduction, metabolic synthesis in the presence of tunicamycin, etc. In specific embodiments, the 53BP2 protein and/or 53BP2-IP sequences may be modified to include a detectable label which may include, but are not limited to, radioactive fluorescent, chemiluminescent, colorimeteric, and enzymatic labels. In another specific embodiment, the 53BP2 protein and/or the 53BP2-IP are modified to include a heterofunctional reagent, which may be utilized to cross-link the various proteins to other members of the complex or to other 53BP2-IPs. In addition, complexes of analogs and derivatives of the 53BP2 protein and/or a 53BP2-IP, as well as analogs and derivatives of 53BP2TP-1, 53BP2:IP-2 or 53BP2:IP-3 may be chemically synthesized. For example, a peptide corresponding to a portion of the 53BP2 protein, 53BP2-IP. 53BP2TP-1, 53BP2:IP-2 and/or 53BP2:IP-3, which comprises the desired domain or which mediates the desired activity in vitro (e.g., 53BP2«53BP2-IP complex formation), may be synthesized by use of a peptide synthesizer. Furthermore, if so desired, non-classical ami o acids or chemically-modified amino acid analogs may be introduced as either a substitution or addition into the 53BP2 protein, 53BP2-IP, 53BP2:IP-1, 53BP2:IP-2 and/or 53BP2:IP-3 amino acid sequences. Non-classical amino acids include, but are not limited to: the D-isomers of the common amino acids, α-amino isobutyric acid, 4-aminobutyric acid, Abu, 2-aminobutyric acid, 6-amino hexanoic acid, Aib, 2-amino isobutyric acid, 3-amino propionoic acid, omithine, norleucine, norvaline, hydroxyproline, sarcosine, citrulline, cysteic acid, t-butylglycine, t-butylalanine, phenylglycine, cyclohexylalanine and the like. Furthermore, the incoφorated amino acid residue may be D (dextrorotary) or L (levorotary) isomers. In cases where natural products are suspected of being mutants or are isolated from new species, the amino acid sequence of the 53BP2 protein, 53BP2-IP, 53BP2TP-1, 53BP2:IP-2 or 53BP2:IP-3 isolated from the natural source, as well as those expressed in vitro, or from synthesized expression vectors in vivo or in vitro, may be determined from analysis of the nucleic acid sequence, or alternatively, by direct amino acid sequencing of the isolated protein. Such analysis may be performed by manual sequencing or through use of an automated amino acid sequenator. The 53BP2»53BP2-IP complexes and 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 proteins may also be analyzed by hydrophilicity analysis (see e.g., Hopp & Woods, 1981. Proc. Natl. Acad. Sci. USA 78:3824-3828) which can be utilized to identify the hydrophobic and hydrophilic regions of the proteins and help predict their orientation in designing substrates for experimental manipulation (e.g., binding experiments, antibody synthesis, and the like). In addition, secondary structural analysis may also be performed to identify regions of the 53BP2 protein, 53BP2-IP, 53BP2:IP-1, 53BP2:IP-2 and/or 53BP2:IP-3, which assume specific structural motifs. See e.g., Chou & Fasman, 1974. Biochemistry 13:222-23. It should be noted that manipulation, translation, secondary structure prediction, hydrophilicity and hydrophobicity profiles, open reading frame (ORF) prediction and plotting, and determination of sequence homologies, may be accomplished utilizing the computer software programs currently available in the art. Other methods of structural analysis including, but not limited to: (i) X-ray crystallography (see e.g., Engstrom, 1974. Biochem. Exp. Biol 11:7-13); (ii) mass spectroscopy and gas chromatography (see e.g., Methods in Protein Science 1997. (J. Wiley and Sons, New York, NY)) and (Hi) computer modeling (see e.g., Fletterick & Zoller, 1986. Computer Graphics and Molecular Modeling, In: Current Communications in Molecular Biology (Cold Spring Harbor Laboratory Press, Cold Spring Harbor Press, NY)) may also be employed. (2) IDENTIFICATION AND ISOLATION OF 53BP2:IP-1. 53BP2:IP-2 AND 53BP2:IP-3 GENES The present invention relates to the nucleotide sequences of nucleic acids encoding 53BP2:IP-1, 53BP2TP-2 and 53BP2TP-3. In specific embodiments, the 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3 nucleic acids comprise the sequence set forth in SEQ ID NO:10 (or the coding regions thereof) or nucleotide sequences encoding, in whole or in part, a 53BP2:IP-1, 53BP2TP-2 and 53BP2TP-3 protein (e.g., a protein comprising the sequence of SEQ ID NOS:ll, 12 and 13, respectively). The present invention also provides purified nucleic acids consisting of at least 8 continuous nucleotides (i.e., a sequence which is capable of undergoing hybridization) of a 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3 sequence. In yet other embodiments, the nucleic acids consist of at least 25 (continuous) nucleotides. 50 nucleotides, 100 nucleotides, 150 nucleotides, or 200 nucleotides of a 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3 sequence, or a full-length 53BP2:IP-1, 53BP2TP-2 and 53BP2:IP-3 coding sequence. In still another embodiment of the present invention, the nucleic acids are smaller than 35, 200 or 500 nucleotides in length. The aforementioned nucleic acids may be single- or double-stranded. The present invention also discloses to nucleic acids which are hybridizable or complementary to the aforementioned sequences; in particular the present invention provides the inverse complement to nucleic acids hybridizable to these foregoing sequences. In specific embodiments, nucleic acids are disclosed which comprise a sequence complementary to (specifically are the inverse complement of) at least 10, 25, 50, 100. or 200 nucleotides, or the entire coding region of a 53BP2:IP-1, 53BP2TP-2 and 53BP2:IP-3 gene. In a specific embodiment of the present invention, a nucleic acid which is hybridizable to a 53BP2TP-1, 53BP2:IP-2 and 53BP2:IP-3 nucleic acids (e.g., possessing sequence SEQ ID NO:10), or to a nucleic acid encoding a 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3 derivative, under conditions of low stringency are provided. By way of example and not of limitation, procedures utilizing such conditions of low stringency hybridization are as follows (see e.g., Shilo & Weinberg, 1981. Proc. Natl Acad. Sci. USA 78:6789-6792): filters containing the nucleic acid sequences of interest were pre-hybridized for 6 hours at 40°C in a solution containing 35%> formamide, 5X SSC, 50 mM Tris-HCl (pH 7.5), 5 mM EDTA, 0.1% PVP, 0.1% Ficoll, 1% BSA, and 500 μg/ml denatured salmon sperm DNA. Hybridizations were performed in the same solution with the following modifications: 0.02%> PVP, 0.02%, Ficoll, 0.2% Bovine serum albumin (BSA), 100 μg/ml salmon sperm DNA and 10%> (wt/vol) dextran sulfate. In addition, 5-20 x 10 6 cpm of 32 P- labeled probe was used. Filters were incubated in the hybridization mixture for 18-20 hours at 40°C and washed for 1.5 hours at 55°C in a solution containing 2X SSC, 25 mM Tris-HCl (pH 7.4), 5 mM EDTA and 0.1% SDS. The wash solution was then replaced with fresh solution and incubated an additional 1.5 hours at 60°C. Filters were blotted dry and exposed to X-ray film for autoradiography. If necessary, filters were washed for a third-time at 65-68°C, and re-exposed to film. Other conditions of low stringency hybridization which may be used are well-known in the art (e.g., as employed for cross-species hybridizations). In a second specific embodiment of the present invention, a nucleic acid, which is hybridizable to a 53BP2:IP-1, 53BP2TP-2 or 53BP2:IP-3 nucleic acids under conditions of moderate stringency are disclosed. By way of example, but not of limitation, the procedures using such conditions of moderate stringency hybridization are as follows: filters containing the nucleic acids of interest were pre-hybridized for 6 hours at 55°C in a solution containing 10X SSC, 5X Denhardt's solution, 0.5%o SDS and 100 μg/ml denatured salmon sperm DNA. Hybridizations were performed in the same solution and 5-20 x 10 6 cpm of 32 P-labeled probe was used. Filters were incubated in the hybridization mixture for 18-20 hours at 55°C and washed twice for 30 minutes at 60°C in a solution containing IX SSC and 0.1%) SDS. The filters were then blotted dry and exposed to X-ray film for autoradiography. Other conditions of moderate stringency which may be used are well-known within the art. In another specific embodiment of the present invention, a nucleic acid which is hybridizable to a 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3 nucleic acids under conditions of high stringency are provided. By way of example, and not of limitation, procedures using such conditions of high stringency hybridization are as follows: pre-hybridization of filters containing the nucleic acid of interest was performed for 8 hours to overnight at 65°C in buffer composed of 6X SSC. 50 mM Tris-HCl (pH 7.5), 1 mM EDTA, 0.02% PVP, 0.02% Ficoll, 0.02% BSA and 500 μg/ml denatured salmon sperm DNA. Filters were hybridized for 48 hours at 65°C in pre- hybridization mixture containing 100 μg/ml denatured salmon sperm DNA and 5-20x 0" cpm of 32 P-labeled probe. Washing of filters was performed at 37°C for 1 hour in a solution containing 2X SSC, 0.01% PVP, 0.01% Ficoll, and 0.01% BSA. This was then followed by a wash in 0.1 X SSC at 50°C for 45 minutes prior to autoradiography. Other conditions of high stringency which may be utilized in the practice of the present invention are well-known within the art. Nucleic acids which encode derivatives and analogs of 53BP2TP-1, 53BP2:IP-2 or 53BP2:IP-3 proteins, as well as 53BP2TP-1, 53BP2:IP-2 or 53BP2:IP-3 53BP2:IP-1, 53BP2TP-2 or 53BP2:IP-3 antisense nucleic acids are additionally provided herein. Fragments of 53BP2:IP- 1, 53BP2TP-2 or 53BP2:IP-3 nucleic acids comprising regions conserved between (with " homology to) other 53BP2TP-1, 53BP2:IP-2 or 53BP2:IP-3 nucleic acids, of the same or different species, are also provided. Nucleic acids species which were predicted to encode (at least in part) 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 were identified as encoding a protein or proteins which interact with the 53BP2 protein using the improved, modified version yeast two hybrid system. As disclosed in the present invention, the 5 '-terminus of this identified nucleic acid (illustrated in Figure 9) possesses a nucleotide sequence which is identical to the nucleotide sequence of the EST sequence EST R72810. EST sequences are part of human DNA databases (e.g., the GenBank Database "dbest"). These sequences typically represent incomplete fragments of putative genes not yet ascribed to encode a known protein or RNA species. However, these aforementioned sequences generally do not encode a full-length protein because they generally: (z) lack a methionine codon to act as a site of translational initiation; (ii) lack a translational stop codon and/or (Hi) do not contain an open reading frame (ORF) to code for a protein longer than approximately 60 amino acid residues in length (this is shorter than the smallest currently-known tr.anslated protein). The EST databases contain many overlapping sequences, thus it is generally possible to find contiguous sequences to assemble a longer sequence representative of a larger original sequence found in nature. Common in silico procedures which may be used to detect homologies between nucleic acid sequences in the databases which are well-known within the art include, but are not limited to, the utilization of the "BLAST" family of programs available through the National Center for Biotechnology Information (NCBI). In order to account for potential sequencing errors, silent mutations, and the like, which are inherently present in all sequence homology computer databases, the term "significant homology," as utilized herein, may be generally defined as a nucleic acid species of interest which possesses 95-100%) homology over a region of 20, 25, 30, 35, 40, or greater span of nucleotide overlap. The homology detection paradigm may allow for a limited number of single or, at most, double nucleotide insertion or deletion mismatches, particularly in regions of sequences known to be difficult to sequence, (e.g., very high G + C content, multiple contiguous G residues, and the like). These in silico procedures allow for the "assembly" of two sequences which overlap non- identical regions spans of a common sequence. This assembled sequence, may then be utilized to identify further-related sequences by the same procedure. The 5'- and 3 '-termini of the assembled sequence are extended until significant homology to sequences within available databases cannot be detected. The assembled EST sequence are then subjected to a final search of available databases to detect homologies to known protein sequences which were not initially detected over the shorter span of the original EST sequence. The present invention discloses several EST sequences which overlap with EST R72810 at both the 5'- and 3'-termini. These aforementioned sequences are depicted in Figures 8 and 9. The assembled EST sequence may be analyzed by the utilization of any of a number of nucleic acid analysis computer programs which are currently available within the art, to ascertain and characterize possible protein translation products of the assembled nucleic acid sequence. It should be noted that translation in all six frames were performed in order to identify possible open reading frames (ORFs), which are contiguous spans of amino acids codons which lack a stop codon. In the case where EST sequences are derived from directionally cloned libraries, only the three forward (5' to 3') translations are required because the sense (i.e., coding) strand of the EST had already been previously defined. As per standard convention, the presence of ATG start codons. which define possible sites for the initiation of protein translation, were used to identify the beginning of such an open reading frame (ORF). If an ORF (which extends to the 5 '-terminus of the assembled nucleic acid sequence) was found to be longer than 60 amino acid residues in length, the assembled EST sequence was classified as a protein which potentially encodes a carboxyl-terminal region of the protein within that given reading frame (i.e., a protein which is missing one or more amino-terminal amino acid residues. In silico analysis of the assembled EST sequence revealed three possible translation products: 53BP2:IP-1 (denoting 53BP2-Interacting Protein 1); 53BP2:IP-2 (denoting 53BP2-Interacting Protein 2) and 53BP2:IP-3 (denoting 53BP2-Interacting Protein 3). Any methodology currently available within the art may be used to obtain a full length (i.e., encompassing the entire coding region) cDNA or genomic DNA clone encoding 53BP2:IP-1, 53BP2:IP-2 and or 53BP2:IP-3. In particular, the polymerase chain reaction (PCR) may be used to amplify the sequence assembled derived from the initial EST sequences in a genomic or cDNA library. Oligonucleotide primers which hybridize to sequences at the 3'- and 5 '-termini of the assembled EST sequences may be used as primers to PCR-amplify sequences from a nucleic acid sample (RNA or DNA) of interest. The nucleic acid sample is, preferably, derived from a cDNA library from an appropriate source (e.g., the sample from which the initial cDNA library for the yeast two hybrid assay fusion population was derived). PCR amplification may be performed by use of an automated thermal cycler (e.g., a Perkin-Elmer Cetus ® thermal cycler) and Taq polymerase. The nucleic acid sample being amplified can include, but is not limited to, mRNA, cDNA or genomic DNA from any eukaryotic species. One can choose to initially synthesize several different degenerate primers, for use in the PCR amplification reactions. It is also possible to vary the stringency of hybridization conditions utilized in the annealing of the primers in the PCR reactions to facilitate the amplification of nucleic acid homologs (e.g., to obtain 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3 sequences from species other than humans or to obtain human sequences which possess homology to 53BP2:IP-1, 53BP2TP-2 and or 53BP2:IP-3) by allowing for greater or lesser degrees of nucleotide sequence homology between the known nucleotide sequence and the nucleic acid homolog of interest. Generally, for cross species hybridization, low stringency hybridization conditions are preferred. For same species hybridization, moderately stringent conditions are preferred. Following the successful amplification of the nucleic acid containing: (z) all or a portion of the sequence assembled from the EST sequences or (ii) a nucleic acid encoding all or a portion of a 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 homolog, the nucleic acid segment may be cloned, sequenced and utilized as a probe to isolate a complete cDNA or genomic clone. This, in turn, will permit the determination of the gene's complete nucleotide sequence, the analysis of its expression, and the production of its protein product for functional analysis, as described infra. In this manner, the nucleotide sequences of the entire 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 genes as well as additional genes encoding proteins and analogs thereof, may also be identified. Any eukaryotic cell potentially can serve as the nucleic acid source for the molecular cloning of the 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 genes. DNA may be obtained by standard procedures known within the art, from cloned DNA (e.g., a DNA library), by chemical synthesis, by cDNA cloning, or by the cloning of genomic DNA (or fragments thereof) purified from the desired cell. See e.g., Glover, D.M., 1985. DNA Cloning: A Practical Approach (MRL Press, Ltd., Oxford, U.K). Clones which are derived from genomic DNA may contain both regulatory and intronic DNA regions, in addition to the exonic coding regions; whereas clones derived exclusively from cDNA will contain only exonic (coding) sequences. In the molecular cloning of the gene from genomic DNA, DNA fragments are generated by cleavage with one or more restriction endonucleases (REs). Alternatively, one may use DNAse I in the presence of manganese to fragment the genomic DNA, or the DNA may be mechanically-sheared (e.g., by sonication). The linear DNA fragments are then separated as a function of their molecular size by standard techniques including, but not limited to, agarose and polyacrylamide gel electrophoresis, column chromatography and the like. Once the DNA fragments are generated, identification of the specific DNA fragment containing the desired gene may be accomplished in a variety of ways. For example, a portion of the 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 gene (e.g., a PCR amplification product obtained as described above or an oligonucleotide having a sequence of a portion of the known nucleotide sequence) or its specific RNA (or a fragment thereof) may be purified and the resulting DNA may be screened by nucleic acid hybridization to a detectably-labeled probe. See e.g., Benton & Davis, 1977. Science 196:180-186. It is also possible to identify the appropriate fragment by: (/) restriction enzyme digestion(s) and comparison of fragment sizes with those expected according to a known restriction map; (ii) DNA sequence analysis and comparison to the known nucleotide sequence of 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 and/or (Hi) by the elucidation/ differentiation of the specific "properties" of the gene. Alternatively, the presence of the gene may be detected by assays based upon the physical, chemical, or immunological properties of its expressed product. For example, cDNA clones, or DNA clones which hybrid-select the proper mRNAs. may be selected on the basis of their production of a protein which, for example, possesses similar or identical electrophoretic migration, isolectric focusing behavior, proteolytic digestion maps, or antigenic properties or ability to bind the 53BP2 protein. These aforementioned properties have been ascertained in the case of 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3. Alternately, if an anti-53BP2:IP-l, anti-53BP2:IP-2 or anti-53BP2:IP-3 antibody is available, the protein may be identified by binding of labeled antibody to the putatively 53BP2:IP-1-, 53BP2:IP-2- or 53BP2:IP-3-synthesizing clones by utilization of an enzyme-linked immunosorbent assay (ELISA)-mediated procedure. Alternatives to isolating 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 genomic DNA include, but are not limited to, chemically synthesizing the gene sequence itself from a known sequence or generating cDNA to the mRNA which encodes the 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 protein. For example, RNA for cDNA cloning of the 53BP2:IP-1, 53BP2:IP-2 or 53BP2TP-3 gene may be isolated from cells expressing the protein. The identified and isolated nucleic acids may then be ligated into an appropriate cloning vector. A large number of vector/host systems including, but are not limited to, bacteriophages (e.g., lambda derivatives) or plasmids such as pBR322 or pUC plasmid derivatives or the Bluescript vector (Stratagene; La Jolla. CA), may be utilized in the practice of the present invention. Insertion of the sequence of interest into a cloning vector may be accomplished by: (i) ligating the DNA fragment into a cloning vector which has complementary cohesive termini; (ii) enzymatic modification of the termini if the complementary restriction sites used to fragment the DNA are not present in the cloning vector; (Hi) ligating nucleotide sequences (linkers) onto the DNA termini which comprise specific chemically-synthesized oligonucleotides possessing restriction endonuclease recognition sequences or (iv) modification of the insert termini by homopolymeric tailing with terminal deoxynucleotidyl transferase (TdT). The recombinant molecules may be introduced into the host cells via transformation, transfection, infection, electroporation, and the like. In an alternative embodiment of the present invention, the desired gene may be identified and isolated following its insertion into a suitable cloning vector by use of a "shot-gun" cloning approach. It should be noted, however, that enrichment for the gene of interest may be accomplished, for example, by size fractionation prior to insertion into the cloning vector. In specific embodiments, transformation of host cells with recombinant DNA molecules that incorporate the isolated 5 53BP2:IP-1, 53BP2:IP-2 or 535P2-IP-3 gene, cDNA, or synthesized DNA sequence enables generation of multiple copies of the gene. Thus, the gene may be obtained in large quantities by growing transformants, isolating the recombinant DNA molecules from the transformants and, when necessary, retrieving the inserted gene from the isolated recombinant DNA. The 53BP2:IP-1, 53BP2TP-2 or 53BP2:IP-3 sequences disclosed within the present invention include those nucleotide sequences: (z) encoding substantially the same amino acid sequences as found in native 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 proteins; (ii) encoding amino acid sequences with functionally-equivalent amino acids and (Hi) encoding other 53BP2:IP-1, 53BP2TP-2 or 53BP2TP-3 derivatives or analogs. (3) ANTIBODIES TO 53BP2«53BP2-IP COMPLEXES AND 53BP2:IP-1, 53BP2TP-2 AND 53BP2:IP-3 PROTEINS As disclosed by the present invention, the 53BP2«53BP2-IP complexes (e.g., 53BP2-IP complexes with β-tubulin, p62, hnRNP G, 53BP2: IP-1, 53BP2:IP-2 or 53BP2:IP-3 (or fragments, derivatives or homologs thereof), as well as 53BP2:IP-1, 53BP2TP-2 or 53BP2:IP-3 protein (or fragments, homologs and derivatives thereof) may be utilized as immunogens in the generation of antibodies which immunospecifically-bind such these aforementioned immunogens. Such antibodies include, but are not limited to, polyclonal, monoclonal, chimeric, single chain, F ab fragments, and an F ab expression library. In a specific embodiment of the present invention, methodologies for the production of antibodies specific for complexes of the human 53BP2 protein and human 53BP2-IPs are disclosed. In another specific embodiment, complexes formed from fragments of the 53BP2 protein and a 53BP2-IP (wherein the fragments possess the protein domain which interacts with the other member of the complex) are used as immunogens for the production of antibodies. In yet another specific embodiment of the present invention, 53BP2:IP-1, 53BP2TP-2 or 53BP2:IP-3 (or fragments, derivatives, analogs or homologs thereof) are utilized as immunogens. Various procedures well-known within the art may be used for the production of polyclonal antibodies to a 53BP2»53BP2-IP complex (or derivatives, fragments or analogs thereof) or to a 53BP2:IP-1, 53BP2TP-2 or 53BP2TP-3 protein (or derivatives, fragments or analogs thereof). For production of the specific antibody, various host animals may be immunized by injection with the native 53BP2«53BP2-IP complex, or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 protein, or a synthetic version or a derivative of the foregoing (e.g., a cross-linked 53BP2»53BP2-IP complex). Host animals which may be used in the production of antibodies include, but are not limited to rabbits, mice, rats, and the like. In addition, adjuvants may be utilized to increase the immunological response. For preparation of monoclonal antibodies directed towards a 53BP2»53BP2-IP complex, or a 53BP2TP-1, 53BP2:IP-2 or 53BP2:IP-3 protein (or derivatives, fragments or analogs thereof) any technique which provides for the production of antibody molecules by continuous cell lines in in vitro culture may be used. Culture techniques include, but are not limited to: (z) the hybridoma technique (see e.g., Kohler & Milstein, 1975. Nature 256:495-497); (ii) the trioma technique; (Hi) the human B-cell hybridoma technique (see e.g., Kozbor, et al, 1983. Immunology Today 4:72) and the EBV hybridoma technique to produce human monoclonal antibodies (see e.g., Cole, et al, 1985. In: Monoclonal Antibodies and Cancer Therapy (Alan R. Liss, Inc.). In an additional embodiment of the invention, monoclonal antibodies can be produced in germ-free animals utilizing a recently developed technology (see e.g., PCT Patent Publication U590/02545). As disclosed in the present invention, techniques described for the production of single- chain antibodies (see e.g., U.S. Patent No. 4,946,778) may be adapted to produce 53BP2-53BP2- IP complex-specific and 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3-specific single-chain antibodies. An additional embodiment of the invention utilizes the techniques described for the construction of F ab expression libraries (see e.g., Huse, et al, 1989. Science 246:1275- 1281) to allow rapid and efficacious identification of monoclonal F ab fragments with the desired specificity for 53BP2: β-tubulin, p62, hnRNP G, 53BP2:IP-1, 53BP2TP-2 or 53BP2:IP-3 complexes, or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 (or derivatives or analogs thereof). Non- human antibodies may be "humanized" by known methods (see e.g., U.S. Patent No. 5,225.539). In the production of antibodies, screening for the desired antibody may be accomplished by techniques known within the art (e.g., enzyme-linked immunosorbent assay; ELISA)). To select antibodies specific for a particular domain of the 53BP2*53BP2-IP complex or 53BP2:IP- 1. 53BP2:IP-2 or 53BP2:IP-3, one may screen the generated hybridomas for a product which binds to the fragment of the 53BP2-53BP2 complex or 53BP2:IP-1, 53BP2:IP-2 or 53BP2TP-3 that possesses such a domain. Similarly, for selection of an antibody which specifically-binds a 53BP2«53BP2-IP complex but does not specifically-bind to the individual proteins of the 53BP2-IP complex, one can select on the basis of positive binding to the 53BP2«53BP2-IP complex and a lack of binding to the individual 53BP2 and 53BP2-IP proteins. In a preferred embodiment of the present invention, antibodies specific to a domain of the 53BP2»53BP2-IP complex are provided, as are antibodies to specific domains of 53BP2TP-1, 53BP2:IP-2 and 53BP2:IP-3. The foregoing antibodies may be utilized in methods well-known within the art relating to the localization and or quantitation of 53BP2«53BP2-IP complexes and 53BP2:IP-1, 53BP2TP-2 and 53BP2:IP-3 proteins of the invention (e.g., for imaging these proteins, measuring levels thereof in appropriate physiological samples, in diagnostic methods, and the like). In another embodiment of the invention anti-53BP2«53BP2-IP complex antibodies and fragments thereof, or anti-53BP2:IP-l, anti-53BP2:IP-2, and anti-53BP2:IP-3 (or derivatives and fragments thereof). (4) DIAGNOSTIC. PROGNOSTIC. AND SCREENING USES OF 53BP2«2-IP COMPLEXES AND 53BP2:IP-1. 53BP2:IP-2 AND 53BP2TP-3 PROTEINS 53BP2*53BP2-IP complexes (particularly the 53BP2 protein complexed with β-tubulin, p62, hnRNP G, 53BP2:IP-1, 53BP2TP-2 or 53BP2:IP-3), as well as 53BP2TP-1, 53BP2TP-2 or 53BP2:IP-3 proteins, may function as "markers" of specific disease states involving the disruption of cell cycle progression, cellular apoptosis and/or differentiation, intracellular signal transduction, protein transport, and/or c-Src activation, transcriptional or translational regulation, tumorigenesis and tumor progression, ubiquitin-mediated proteolysis, mRNA binding and metabolism, and effects on autoimmune processes, and thus have potential diagnostic utility. Further, classification and differentiation of particular groups of patients with elevations or deficiencies of a 53BP2«53BP2-IP complex, as well as the 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 protein may potentially lead to new nosological classifications of diseases, furthering diagnostic ability. Detecting levels of 53BP2»53BP2-IP complexes, or individual proteins that have been shown to form complexes with 53BP2, or the 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 proteins, or detecting levels of the mRNA encoding the components of the 53BP2»53BP2-IP complexes, or the 53BP2: IP-1, 53BP2TP-2 or 53BP2:IP-3 proteins, may be utilized in prognosis, to follow the course of disease states, to follow therapeutic response, and the like. 53BP2»53BP2-IP complexes and the individual components of the 53BP2«53BP2-IP complexes (e.g., 53BP2. B-tubulin, p62, hnRNP G, 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3, and derivatives, analogs and sub-sequences thereof) 53BP2 and/or 53BP2-IP, 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3 nucleic acids (and sequences complementary thereto), and anti-53BP2«53BP2-IP complex antibodies and antibodies directed against the individual components which can form 53BP2-53BP2-IP complexes and anti-53BP2:IP-l, anti-53BP2:IP-2 and anti-53BP2:IP-3 antibodies, have potential uses in diagnostics. These aforementioned molecules may be utilized used in assays, such as immunoassays, to detect, prognose, diagnose, or monitor various conditions, diseases, and disorders characterized by aberrant levels of 53BP2»53BP2-IP complexes or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 proteins, or monitor the treatment thereof. In a specific embodiment of the present invention, a 53BP2»53BP2-IP complex is detected that is not a complex of the 53BP2 protein and PPlα or p53. In one embodiment of the present invention, the immunoassay methodology is comprised of contacting a sample derived from a patient with an anti-53BP2«53BP2-IP complex antibody or an anti-53BP2:IP-l, anti-53BP2:IP-2 or anti-53BP2:IP-3 antibody under conditions such that immunospecific binding may occur, and subsequently detecting or measuring the amounfof any " immunospecific binding by the aforementioned antibodies. In a specific embodiment, the binding of antibody (within tissue sections) may be utilized to detect aberrant localization of the 53BP2»53BP2-IP complex or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 protein and/or aberrant (i.e., high, low or absent) levels of the 53BP2-53BP2-IP complex or 53BP2:IP-1, 53BP2TP-2 or 53BP2:IP-3 protein. In another specific embodiment of the present invention, an antibody specific for the 53BP2«53BP2-IP complex may be used to screen a patient tissue or serum sample for the presence of 53BP2*53BP2-IP complex; wherein an aberrant level of the 53BP2»53BP2-IP complex is indicative of a pathological condition. In yet another embodiment, antibodies specific for the 53BP2:IP-1, 53BP2:IP-2 or 53BP2TP-3 proteins may be utilized to screen a patient tissue or serum sample for the presence of these aforementioned proteins; wherein an aberrant level of 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 proteins is an indication of a diseased condition. "Aberrant levels," as used herein, is defined as increased or decreased levels of the protein(s) relative to a standard level representing those levels which are present in an analogous sample from a portion of the body or from a subject not having the disease or disorder. The immunoassays which may be used in the practice of the present invention include, but are not limited to, competitive and non-competitive immunoassay systems using methodologies techniques such as Western blots, radioimmunoassay (RIA), enzyme linked immunosorbent assay (ELISA), "sandwich" immunoassays, immunoprecipitation assays, precipitin reactions, gel diffusion precipitin reactions, immunodiffusion assays, agglutination assays, complement- fixation assays, immunoradiometric assays, fluorescent immunoassays, protein A immunoassays, and the like. Nucleic acids encoding the components of the 53BP2»53BP2-IP complexes (e.g., the 53BP2 protein, β-tubulin, p62, hnRNP G, 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3), as well as the 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3 proteins and related nucleic acid sequences and subsequences (including complementary sequences), may also be used in hybridization assays. The 53BP2 protein, 53BP2-IP, 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3 nucleic acid sequences (or subsequences thereof comprising at least 8 nucleotides) may be used as hybridization probes. Hybridization assays may be used to detect, prognose, diagnose, or monitor conditions, disorders, or disease states associated with aberrant levels of the mRNAs encoding the components of a 53BP2-53BP2-IP complex or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 protein as described, supra. In a preferred embodiment, the hybridization assay is carried out using nucleic acid probes capable of hybridizing to the 53BP2 protein and to a binding partner of the 53BP2 protein (e.g., β-tubulin, p62, hnRNP G, 53BP2TP-1, 53BP2TP-2 or 53BP2:IP-3) to measure concurrently the expression of both members of a 53BP2»53BP2-IP complex. (5) THERAPEUTIC UTILIZATION OF 53BP2*53BP2-IP COMPLEXES AND 53BP2:IP-1. 53BP2TP-2 AND 53BP2:IP-3 The present invention provides for treatment or prevention of various diseases and disorders by administration of a therapeutic compound (hereinafter defined as a "Therapeutic"). Such Therapeutics include, but are not limited to: (i) 53BP2»53BP2-IP complexes (e.g., the 53BP2 protein complexed with β-tubulin, p62, hnRNP G, 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3), the 53BP2 protein alone and the individual 53BP2-IPs proteins (e.g., β-tubulin, p62, hnRNP G, 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3) and derivatives, fragments and analogs of the foregoing; (ii) antibodies thereto; (Hi) nucleic acids encoding the 53BP2 protein and/or the 53BP2-IP and 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3, and analogs or derivatives, thereof; (iv) 53BP2, 53BP2-IP, 53BP2TP-1, 53BP2:IP-2 and 53BP2:IP-3 antisense nucleic acids and (v) 53BP2-53BP2-IP complex and 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3 modulators (i.e., inhibitors, agonists and antagonists). The 53BP2 protein and several of its binding partners, as identified herein, (e.g., β-tubulin, p62 and hnRNP G) are implicated in disorders of cell cycle progression, cell differentiation, and transcriptional control, including cancer and tumorigenesis and tumor progression. Disorders of neurodegeneration resulting from altered cellular apoptosis, mRNA destabilization and ubiquitin-mediated proteolysis, may also involve these same proteins. For example, HnRNP G is specifically implicated in autoimmune disorders. A wide range of cell diseases affected by intracellular signal transduction, including c-Src signaling, and translational regulation may be therapeutically or prophylactically treated by the administration of a Therapeutic which modulates (i.e., inhibits, antagonizes or promotes) the activity of the 53BP2-53BP2-IP complex, 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3. Similarly, diseases and disorders associated with aberrant levels of 53BP2*53BP2-IP complex levels or activity or aberrant levels of the 53BP2, 53BP2-IP, 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 proteins may be treated or prevented by the administration of a Therapeutic which modulates 53BP2*53BP2-IP complex formation or activity or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 activity. In a specific embodiment of the present , the activity or levels of the 53BP2 protein is modulated by administration of a 53BP2-IP. Diseases and disorders which are characterized by either increased or decreased (relative to a subject not suffering from the disease or disorder) 53BP2«53BP2-IP levels or activity, or increased or decreased 53BP2TP-1, 53BP2:IP-2 or 53BP2:IP-3 levels or activity, may be treated by the administration of a Therapeutics which antagonize (i.e., reduces or inhibits) or increases 53BP2»53BP2-IP complex formation or activity, or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 levels or activity, respectively. Therapeutics which can be used include, but are not limited to: (z) the 53BP2 or a 53BP2- IP proteins (or analogs, derivatives or fragments thereof); (ii) anti-53BP2*53BP2-IP complex antibodies (e.g., antibodies which are specific for complexes of the 53BP2 protein with β-tubulin, p62, hnRNP G, 53BP2:IP-1, 53BP2TP-2 or 53BP2TP-3 complexes) and fragments and derivatives thereof containing the binding region thereof; (Hi) nucleic acids encoding the 53BP2 or 53BP2-IP proteins; (iv) concurrent administration of 53BP2 and a 53BP2-IP antisense nucleic acid or a 53BP2:IP-1, 53BP2:IP-2 or 53BP2TP-3 anti-sense nucleic acid and (v) 53BP2 and/or 53BP2-IP, or 53BP2:IP-1, 53BP2TP-2 or 53BP2:IP-3 nucleic acids, which are dysfunctional (e.g., due to a heterologous non-53BP2, non-53BP2-IP, non-53BP2:IP-l, non-53BP2:IP-2 and/or non-53BP2TP-3 insertion within the aforementioned proteins coding sequences) which are used to "knockout" endogenous 53BP2, 53BP2-IP, 53BP2TP-1, 53BP2:IP-2 or 53BP2:IP-3 function by homologous recombination (see e.g., Capecchi, 1989. Science 244:1288-1292). In specific embodiments of the present invention, nucleic acids containing a portion of a 53BP2, 53BP2-IP, 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 gene in which these aforementioned sequences flank (i.e., are both 5' and 3' to) a different gene sequence, are utilized as antagonists so as to promote 53BP2, 53BP2-IP, 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 inactivation by homologous recombination. See e.g., Roller & Smithies, 1989. Proc. Natl Acad. Sci. USA 86:8932-8935. In an additional embodiment, mutants or derivatives of a first 53BP2-IP protein which possesses greater affinity for the 53BP2 protein than the wild-type, first 53BP2-IP may be administered to compete with a second 53BP2-IP protein for binding to the 53BP2 protein, thereby reducing the levels of complexes which contain the 53BP2 protein with the second 53BP2-IP. Other Therapeutics which inhibit 53BP2-53BP2-IP complex or 53BP2:IP-1, 53BP2:IP-2 or 53BP2TP-3 function may be identified by use of in vitro assays which are well-known within the art. In specific embodiments of the present invention, Therapeutics which antagonize 53BP2«53BP2-IP complex formation and/or activity or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 activity are administered in a therapeutic or prophylactic manner: (i) in diseases or disorders involving an increased (i.e., relative to normal or desired) level of 53BP2«53BP2-IP complex or 53BP2:IP-1, 53BP2:IP-2 or 53BP2TP-3, for example, in patients where these complexes or proteins .are overactive or over-expressed or (ii) in diseases or disorders wherein in vitro or in vivo assays indicate the utility of 53BP2-53BP2-IP complex or 53BP2:IP-1. 53BP2TP-2 or 53BP2TP-3 antagonist administration. Increased levels of 53BP2-associated complexes or proteins may be readily detected (e.g., by quantifying protein, RNA or cDNA generated from RNA) by obtaining a patient tissue sample (e.g., from biopsy tissue) and performing in vitro screening for RNA or protein levels, structure and/or activity of the expressed 53BP2»53BP2-IP complex (or the 53BP2 and 53BP2-IP mRNA) or 53BP2:IP-1, 53BP2:IP-2 or 53BP2TP-3 protein or mRNA. Various methodlogies within the art may be employed including, but not limited to: (i) immunoassays to detect and/or visualize 53BP2»53BP2-IP complexes or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 (e.g., via Western blot, immunoprecipitation followed by sodium dodecyl sulfate polyacrylamide gel electrophoresis, immunocytochemistry and the like) and/or hybridization assays to detect concurrent expression of 53BP2, 53BP2-IP. 53BP2:IP-1, .53BP2:IP-2 or 53BP2:IP-3 mRNA (e.g., via Northern assays, dot blots, in situ hybridization and the like). A specific embodiment of the present invention includes methods of reducing 53BP2«53BP2-IP complex expression (i.e., the expression of the two components of the 53BP2-53BP2-IP complex and or formation of the complex) or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 expression, by targeting mRNAs which express these protein moieties. RNA therapeutics is currently differentiated into three classes: antisense species, ribozymes or RNA aptamers. See e.g., Good, et al, 1997. Gene Therapy 4:45-54. Antisense oligonucleotides have been the mode most widely utilized and, by way of example but not of limitation, antisense oligonucleotide methodology to reduce 53BP2 complex formation will be fully disclosed, infra. Ribozyme therapy involves the administration, induced expression and the like, of small RNA molecules which possess enzymatic ability to cleave, bind or otherwise inactivate specific RNAs to reduce or eliminate expression of particular proteins. See e.g., Grassi & Marini, 1996. Ann. Med. 28:499-510. At present, however, the design of "hairpin" and "hammerhead" RNA ribozymes remains necessary so as to specifically-target a particular mRNA (e.g., the 53BP2 mRNA). RNA aptamers are specific RNA ligands for proteins, such as for Tat and Rev RNA (see e.g., Good, et al, 1997. Gene Therapy 4:45-54) that can specifically inhibit their translation. Aptamers specific for the 53BP2, 53BP2-IP, 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 proteins may be identified by many methods which well-known within the art including, but not limited to, the protein-protein interaction assay described, infra. In another embodiment, the activity or levels of 53BP2 is reduced by the administration of a 53BP2-IP, a nucleic acid which encodes the 53BP2-IP, an antibody which immunospecifically-binds the 53BP2-IP or a fragment or derivative of the antibody which contains the binding domain thereof. Additionally, the levels or activity of a 53BP2-IP maybe reduced by administration of 53BP2, a nucleic acid which encodes 53BP2, an antibody which immunospecifically-binds 53BP2 or a fragment or derivative of the antibody which contains the binding domain thereof. In specific embodiment of the present invention, diseases or disorders which are associated with increased levels of 53BP2 or a particular 53BP2-IP (e.g., β-tubulin, p62, hnRNP G, 53BP2.IP-1, 53BP2TP-2 or 53BP2:IP-3) may be treated or prevented by administration of a Therapeutic which increases 53BP2»53BP2-IP complex formation if the complex formation acts to reduce or inactivate 53BP2 or the particular 53BP2-IP through the 53BP2»53BP2-IP complex formation. Such diseases or disorders can be treated or prevented by administration of one member of the 53BP2»53BP2-IP complex, including mutants of a member of the 53BP2»53BP2- IP complex that has increased affinity for the other member of the 53BP2«53BP2-IP complex (so as to cause increased complex formation), administration of antibodies or other molecules that stabilize the 53BP2»53BP2-IP complex and the like. Diseases and disorders associated with under-expression of a 53BP2«53BP2-IP complex, 53BP2, 53BP2-IP, 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 may be treated or prevented by the administration of a Therapeutic which promotes (i.e., increases or supplies) 53BP2»53BP2-IP complex or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 function. Examples of such a Therapeutic include, but are not limited to. 53BP2»53BP2-IP complexes and 53BP2:IP-1, 53BP2TP-2 and 53BP2:IP-3 proteins and derivatives, analogs and fragments thereof which are functionally active (i.e., possess the ability to form 53BP2»53BP2- IP complexes), non-complexed 53BP2 and 53BP2-IP proteins and derivatives (and analogs or fragments thereof) and nucleic acids encoding the members of a 53BP2«53BP2-IP complex or encoding 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3, or functionally active derivative or fragment thereof (e.g., for use in gene therapy). In other specific embodiments of the present invention, Therapeutics which promote 53BP2«53BP2-IP complex or 53BP2TP-1, 53BP2:IP-2 or 53BP2:IP-3 function, are administered in a therapeutic or prophylactic manner: (z) in diseases or disorders involving an absence or decreased (i.e., relative to normal or desired) level of 53BP2»53BP2-IP complex or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 proteins, for example, in patients where the complexes (or the individual components necessary to form the complexes) or proteins are lacking, genetically defective, biologically inactive or under-active, or under-expressed or (ii) in diseases or disorders wherein in vitro or in vivo assays indicate the utility of 53BP2*53BP2-IP complex or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 agonist administration. The absence or decreased level in 53BP2»53BP2-IP complex or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 protein and/or function may be readily detected (e.g., by obtaining a patient tissue sample from biopsy tissue) and performing in vitro screening for RNA, cDNA generated from mRNA, protein levels, structure and or activity of the expressed 53BP2*53BP2-IP complex (or for the concurrent expression of mRNA encoding the two components of the 53BP2-53BP2-IP complex) or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 RNA or protein. Various methodologies well-known withm the art may be employed to detect and/or visualize 53BP2«53BP2-IP complexes (or the individual components of 53BP2-53BP2-IP complexes) or 53BP2:IP-1, 53BP2:IP-2 or 53BP2TP-3 (e.g., via Western blot, immunoprecipitation followed by sodium dodecyl sulfate polyacrylamide gel electrophoresis, immunocytochemistry and the like) and/or hybridization assays to detect expression of the mRNA encoding the individual protein components of the 53BP2»53BP2-IP complexes or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 by detecting and/or visualizing 53BP2 and a 53BP2-IP concurrently, or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 mRNA (e.g., Northern assays, dot blots, in situ hybridization, and the like). In specific embodiment of the present invention, the activity or levels of 53BP2 are increased by administration of a 53BP2-IP (or a derivative or analog thereof), a nucleic acid encoding a 53BP2-IP, or an antibody which immunospecifically-binds a 53BP2-IP, or a fragment or derivative of the antibody which possesses the binding domain thereof. In another specific embodiment, the activity or levels of a 53BP2-IP are increased by administration of 53BP2 (or a derivative or analog thereof), a nucleic acid encoding 53BP2, or an antibody which immunospecifically-binds 53BP2. or a fragment or derivative of the antibody which possesses the binding domain thereof. Generally, administration of products of a species origin or species reactivity (in the case of antibodies) that is the same species as that of the patient is preferred. Thus, in a preferred embodiment, a human 53BP2»53BP2-IP complex or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 protein (or a derivative or analog thereof), nucleic acids encoding the members of the human 53BP2»53BP2-IP complex or human 53BP2:IP-1, human 53BP2:IP-2 or human 53BP2:IP-3 (or a derivative or analog thereof), an antibody to a human 53BP2«53BP2-IP complex or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 (or a derivative thereof), is therapeutically or prophylactically administered to a human patient. Preferably, suitable in vitro or in vivo assays are utilized to determine the effect of a specific Therapeutic and whether its administration is indicated for treatment of the affected tissue. In various specific embodiments, z z vitro assays may be performed with representative cells of the specific cell type(s) involved in a patient's disorder so as to determine whether a given Therapeutic has the desired effect upon such cell types. Prior to administration to humans, in vivo testing may be performed utilizing any animal model system known within the art. (6) MALIGNANCIES Various components of the 53BP2«53BP2-IP complexes (i.e., 53BP2, β-tubulin, p62 and hnRNP G) have been implicated in the regulation of cell proliferation. Accordingly, Therapeutics of the present invention may prove useful in treating or preventing diseases or disorders associated with cell over-proliferation or loss of control of cell proliferation, particularly cancers, malignancies and tumors. Therapeutics of the present invention may be assayed by any method known within the art for efficacy in treating or preventing malignancies and related disorders. Such assays include, but are not limited to, in vitro assays using transformed cells or cells derived from a tumor of a patient or in vivo assays using animal models of cancer or malignancies, or any of the assays described, infra. Potentially effective Therapeutics may function, but are not limited, to inhibit proliferation of tumor or transformed cells in culture or cause regression of tumors in animal models in comparison to controls. Accordingly, once a malignancy has been found to be amenable to treatment by modulation (i.e., inhibit, antagonize or agonize) of 53BP2«53BP2-IP complex activity, or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 activity, that specific malignancy may be treated or prevented by administration of a Therapeutic which modulates the formation of the 53BP2»53BP2-IP complex (e.g., supplying 53BP2«53BP2-IP complexes and the individual binding partners of a 53BP2.53BP2-IP complex, such as 53BP2, β-tubulin, p62, hnRNP G, 53BP2:IP-1. 53BP2:IP-2 and 53BP2:IP-3), or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 function. For example, in specific embodiments of the present invention, malignancy or dysproliferative changes (i.e., metaplasias and dysplasias) or hyperproliferative disorders, are treated or prevented in the bladder, breast, colon, lung, melanoma, pancreas, or uterus. In other specific embodiments, sarcoma, or leukemia is treated or prevented. (7) PRE-MALIGNANT CONDITIONS The Therapeutics of the invention that are effective in treating cancer or malignancies (e.g. as described above) may also be administered so as to treat pre-malignant conditions and to prevent their possible progression to a neoplastic or malignant state. Such prophylactic or therapeutic use is indicated in conditions known or suspected of preceding progression to neoplasia or cancer, in particular where non-neoplastic cell growth (i.e., hyperplasia. metaplasia or, most particularly, dysplasia) has occurred. See e.g., Robbins & Angell, 1976. Basic Pathology, 2d Ed. (W.B. Saunders Co., Philadelphia, PA). Hyperplasia is a form of controlled cell proliferation involving an increase in cell number in a tissue or organ, without significant alteration in structure or function. One example, endometrial hyperplasia, often precedes endometrial cancer. Metaplasia is a form of controlled cell growth in which one type of fully-differentiated (i.e., adult) cell substitutes for another type of fully-differentiated cell. Metaplasia can occur in epithelial or connective tissue cells. Atypical metaplasia involves a somewhat disorderly metaplastic epithelium. Dysplasia, frequently a forerunner of cancer, is found mainly in the epithelia and is the most disorderly form of non-neoplastic cell growth, involving a loss in individual cell uniformity and in the architectural orientation of cells. Dysplastic cells often have abnormally large, deeply stained nuclei, and exhibit pleomorphism. Dysplasia characteristically occurs where there exists chronic irritation or inflammation, and is often found in the cervix, respiratory passages, oral cavity, and gall bladder. Alternatively, or in addition to the presence of abnormal cell growth characterized as hyperplasia, metaplasia, or dysplasia, the presence of one or more characteristics of a transformed phenotype, or of a malignant phenotype, displayed in vivo or displayed in vitro by a cell sample from a patient, may be indicative of the desirability of prophylactic/ therapeutic administration of a Therapeutic of the present invention which modulates 53BP2»53BP2-IP complex activity or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 activity. The characteristics of a transformed phenotype include, but are not limited to, morphology changes, looser substratum attachment, loss of contact inhibition, loss of anchorage dependence, protease release, increased sugar transport, decreased serum requirement, expression of fetal antigens, disappearance of the 250 kD cell surface protein and the like. In a specific embodiment of the present invention, leukoplakia (a benign- appearing hyperplastic or dysplastic lesion of the epithelium) or Bowen's disease (a carcinoma in situ) are pre-neoplastic lesions which are amenable to prophylactic intervention by administration of a Therapeutic of the present invention. In another specific embodiment, fibrocystic disease (e.g., cystic hyperplasia, mammary dysplasia, adenosis, and benign epithelial hyperplasia) is also amenable to prophylactic intervention. In other embodiments of the present invention, a patient which exhibits one or more of the following predisposing factors for malignancy is treated by administration of an therapeutically-effective amount of a Therapeutic: (i) a chromosomal translocation associated with a malignancy (e.g., the bcr/abl translocation in chronic myelogenous leukemia; (ii) t(14,18) for follicular lymphoma; (Hi) familial polyposis or Gardner's syndrome (possible precursors of colon cancer); (iv) monoclonal gammopathy of undetermined significance (MGUS; a possible precursor of multiple myeloma) and (v) a first degree kinship with persons having a cancer or pre-cancerous disease showing a Mendelian inheritance pattern (e.g., familial polyposis of the colon, Gardner's syndrome, hereditary exostosis, polyendocrine adenomatosis, medullary thyroid carcinoma with amyloid production and pheochromocytoma, Peutz-Jeghers syndrome, neurofibromatosis of Von Recklinghausen, retinoblastoma, carotid body tumor, cutaneous melanocarcinoma, intraocular melanocarcinoma, xeroderma pigmentosum, ataxia telangiectasia, Chediak-Higashi syndrome, albinism, Fanconi's aplastic anemia, and Bloom's syndrome). See e.g., Robbins & Angell, 1976. Basic Pathology, 2d Ed. (W.B. Saunders Co., Philadelphia, PA). In yet another specific embodiment, a Therapeutic of the present invention is administered to a human patient to prevent progression to breast, colon, lung, pancreatic, or uterine cancer, or melanoma or sarcoma. (8) HYPERPROLIFERATIVE AND DYSPROLIFERATIVE DISORDERS In another specific embodiment of the present invention, a Therapeutic is administered so to treat or prevent hyperproliferative or benign dysproliferative disorders. Therapeutics of the present invention may be assayed by any method known within the art for efficacy in treating or preventing hyperproliferative diseases or disorders (e.g., in vitro cell proliferation assays, in vitro or in vivo assays utilizing animal models of hyperproliferative diseases or disorders or the like). Functions of potentially effective Therapeutics include, but are not limited to, promoting cell proliferation in in vitro culture or causing growth or cell proliferation in animal models in comparison to controls. Accordingly, once a hyperproliferative disorder has been shown to be amenable to treatment by modulation of 53BP2»53BP2-IP complex activity or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 activity, that hyperproliferative disease or disorder may be treated or prevented by administration of a Therapeutic which modulates 53BP2»53BP2-IP complex formation (e.g., supplying 53BP2«53BP2-IP complexes and the individual binding partners of a 53BP2-53BP2-IP complex, such as 53BP2, β-tubulin, p62, hnRNP G, 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3) or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 function. Specific embodiments of the present invention are directed towards the treatment or prevention of hepatic cirrhosis (a condition in which scarring has overtaken normal liver regeneration processes); treatment of keloid or hypertrophic scar formation (causing a disfiguring of the skin in which the scarring process interferes with normal renewal); psoriasis (a common skin condition characterized by excessive proliferation of the skin and delay in proper cell-fate determination); benign tumors; fibrocystic conditions and tissue hypertrophy (e.g., prostatic hyperplasia). (9) NEURODEGENERATΓVE DISORDERS The 53BP2 protein and certain binding partners thereof (e.g., β-tubulin and p62) have been implicated in the deregulation of cellular maturation and apoptosis, which are characteristic of neurodegenerative disease. Accordingly, Therapeutics of the present invention, particularly those which modulate the levels or activity of 53BP2«β-tubulin or 53BP2»p62 complexes, may be effective in treating or preventing neurodegenerative diseases or disorders. These Therapeutics may be screened for efficacy in treating or preventing such neurodegenerative diseases and disorders by any assay known within the art including, but not limited to, in vitro assays for regulated cell maturation or inhibition of apoptosis or in vivo assays using animal models of neurodegenerative diseases or disorders. Potentially effective Therapeutics, for example but not by way of limitation, promote regulated cell maturation and prevent cell apoptosis in culture or reduce neurodegeneration in animal models in comparison to controls. Once a neurodegenerative disease or disorder has been shown to be amenable to treatment by modulation of 53BP2»53BP2-IP complex activity or 53BP2:IP-1, 53BP2:IP-2 or 53BP2TP-3 activity, that specific neurodegenerative disease or disorder may be treated or prevented by administration of a Therapeutic which modulates 53BP2«53BP2-IP complex formation (including supplying 53BP2-53BP2-IP complexes, such as 53BP2«β-tubulin and 53BP2«ρ62 complexes) or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 function. (10) AUTOIMMUNE DISORDERS The 53BP2-interacting protein, hnRNP G, has been implicated in autoimmune disorders. Therapeutics of the present invention, particularly those which modulate or supply 53BP2»hnRNP G complex activity may be effective in treating or preventing autoimmune diseases or disorders. Therapeutics which are effective in treating or preventing such autoimmune diseases and disorders may be screened for such efficacy by any assay known within the art including, but not limited to, in vitro assays for using cell culture models or in vivo assays using animal models of autoimmune diseases or disorders. Potentially effective Therapeutics, for example but not by way of limitation, reduce autoimmune responses in animal models in comparison to controls. Accordingly, once an autoimmune disease or disorder has been shown to be amenable to treatment by modulation of 53BP2»53BP2-IP complex activity or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 activity, that autoimmune disease or disorder may be treated or prevented by administration of a Therapeutic which modulates 53BP2»53BP2-IP complex formation (including supplying 53BP2«53BP2-IP complexes) or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 function. (11) GENE THERAPY In embodiments of the present invention, nucleic acids comprising a sequence encoding 53BP2 and a 53BP2-IP, or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 (or functional derivatives thereof) are administered to modulate 53BP2«53BP2-IP complex or 53BP2.-IP-1, 53BP2:IP-2 or 53BP2:IP-3 function, by way of gene therapy. In specific embodiments, a nucleic acid or nucleic acids encoding both 53BP2 and a 53BP2-IP (e.g., β-tubulin, p62, hnRNP G, 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3) or functional derivatives thereof, are administered by way of gene therapy. Gene therapy, as utilized herein, refers to therapy performed by the administration of a nucleic acid to a subject. In this embodiment of the present invention, the nucleic acid produces its encoded protein(s) which serves to mediate a therapeutic effect by modulating 53BP2»53BP2- IP complex or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 function. Any of the methods for gene therapy known within the art may be utilized in the practice of the present invention. See e.g., Goldspiel, et al, 1993. Clin. Pharmacy 12:488-505; Wu & Wu, 1991. Biotherapy 3: 87-95; Mulligan, 1993. Science 260:926-932. In a preferred embodiment of the present invention, the Therapeutic comprises a 53BP2 and a 53BP2-IP nucleic acid or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 nucleic acid which is part of an expression vector that expresses the proteins 53BP2 and a 53BP2-IP or expresses 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 (or fragments or chimeric proteins thereof) in a suitable host. In particular, such a nucleic acid possesses a promoter operably-linked to the 53BP2 and the 53BP2-IP coding region(s) or, less preferably, two separate promoters operably-linked to the 53BP2 and the 53BP2-IP coding regions separately or linked to the 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 coding region, wherein said promoter is inducible or constitutive and, optionally, tissue-specific. In another particular embodiment, a nucleic acid molecule is used in which the 53BP2 and 53BP2-IP coding sequences or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 coding sequences, and any other desired sequences, are flanked by regions which promote homologous recombination at a desired site in the genome, thus providing for intra-chromosomal expression of the 53BP2 and the 53BP2-IP nucleic acids or 53BP2:IP-1, 53BP2TP-2 or 53BP2:IP-3 nucleic acids. See e.g., Koller & Smithies, 1989. Proc. Natl Acad. Sci. USA 86:8932-8935; Zijlstra, et al, 1989. Nature 342:435-438. Delivery of the nucleic acid into a patient may be either direct, in which case the patient is directly exposed to the nucleic acid or nucleic acid-carrying vector or indirect, in which case, cells are first transformed with the nucleic acid in vitro, then transplanted into the patient. These two approaches are known, respectively, as in vivo or ex vivo gene therapy. In a specific embodiment, the nucleic acid is directly administered in vivo, where it is expressed to produce the encoded product. This may be accomplished by any of numerous methods known in the art including, but not limited to, constructing it as part of an appropriate nucleic acid expression vector and administering it so that it becomes intracellular by: ( ) infection using a defective or attenuated retroviral or other viral vector (see e.g., U.S. Patent No. 4,980,286); (ii) direct injection of naked DNA; (Hi) use of microparticle bombardment (e.g., a gene gun - Biolistic, DuPont); (iv) coating with lipids or cell-surface receptors or transfecting agents, encapsulation in liposomes, microparticles, or microcapsules; (v) by administering it in linkage to a peptide which is known to enter the nucleus; (vi) administering it in linkage to a ligand subject to receptor-mediated endocytosis (see e.g., Wu & Wu, 1987. J. Biol. Chem. 262:4429-4432) which can be used to target cell types specifically-expressing the receptors and the like. In another embodiment, a nucleic acid-ligand complex can be formed in which the ligand comprises a fusogenic viral peptide to disrupt endosomes, allowing the nucleic acid to avoid lysosomal degradation. In yet another embodiment, the nucleic acid may be targeted in vivo for cell specific uptake and expression, by targeting a specific receptor. See e.g., PCT Publications WO 93/14188; WO 93/20221. Alternatively, the nucleic acid may be introduced intracellularly and incoφorated within host cell DNA for expression, by homologous recombination. See e.g., Koller & Smithies, 1989. Proc. Natl. Acad. Sci. USA 86:8932-8935; Zijlstra, et al, 1989. Nature 342:435-438. In a specific embodiment, a viral vector which contains the 53BP2 and/or the 53BP2-IP nucleic acids or 53BP2:IP-1, 53BP2:IP-2 or 53BP2TP-3 nucleic acid is utilized. For example, a retroviral vector may be used (see e.g., Miller, et al, 1993. Meth. Enzymol 217:581- 599) which have been modified to delete retroviral sequences that are not necessary for packaging of the viral genome and integration into host cell DNA. The 53BP2 and/or 53BP2-IP (preferably both 53BP2 and 53BP2-IP) nucleic acids or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 nucleic acids, to be used in gene therapy is/are cloned into the vector, which facilitates delivery of the gene into a patient. Adenoviruses are other viral vectors that can be used in gene therapy. Adenoviruses are especially attractive vehicles for delivering genes to respiratory epithelia where the virus naturally infect to cause a mild disease. Other targets for adenovirus-based delivery systems are liver, the central nervous system, endothelial cells, and muscle. In addition, adenoviruses have the advantage of being capable of infecting non-dividing cells. See e.g., Kozarsky & Wilson, 1993. Cwrr. Opin. Genet. Develop. 3:499-503. Adeno-associated virus (AAV) has also been proposed for use in gene therapy. See e.g., Walsh, et al, 1993. Proc. Soc. Exp. Biol. Med. 204:289-300. Another approach to gene therapy involves transferring a gene into cells in tissue culture by such methods as electroporation, lipofection, calcium phosphate-mediated transfection, or viral infection. Generally, the method of transfer includes the transfer of a selectable marker to the cells which are then placed under selection to isolate those cells which have taken-up and are expressing the transferred gene and only those selected cells are then delivered to a patient. In this embodiment, the nucleic acid is introduced into a cell prior to administration in vivo of the resulting recombinant cell. Such introduction can be carried out by any method known in the art including, but not limited to, transfection, electroporation, micro injection, infection with a viral or bacteriophage vector containing the nucleic acid sequences, cell fusion, chromosome-mediated gene transfer, microcell-mediated gene transfer, spheroplast fusion, and the like (see e.g., Loeffler & Behr, 1993. Meth. Enzymol. 217:599-618; Cohen, et al, 1993. Meth. Enzymol. 217:618-644) and may be used in accordance with the present invention, provided that the necessary developmental and physiological functions of the recipient cells are not disrupted. The technique chosen should provide for the stable transfer of the nucleic acid to the cell, so that the nucleic acid is expressible by the cell and preferably heritable and expressible by its cell progeny. The resulting recombinant cells can be delivered to a patient by various methods known in the art. In a preferred embodiment, epithelial cells are injected (e.g., subcutaneously). In another embodiment, recombinant skin cells may be applied as a skin graft onto the patient. Recombinant blood cells (e.g., hematopoietic stem or progenitor cells) are preferably administered intravenously. The amount of cells envisioned for use depends on the desired effect, patient state, etc., and may be determined by one skilled within the art. Cells into which a nucleic acid can be introduced for puφoses of gene therapy encompass any desired, available cell type .and include, but are not limited to: epithelial cells, endothelial cells, keratinocytes, fibroblasts, muscle cells, hepatocytes, blood cells such as T lymphocytes, B lymphocytes, monocytes, macrophages, neutrophils, eosinophils, megakaryocytes, granulocytes, various stem or progenitor cells, in particular hematopoietic stem or progenitor cells (e.g., as obtained from bone marrow, umbilical cord blood, peripheral blood, fetal liver, etc). In a preferred embodiment, the cell used for gene therapy is autologous to the patient. In an embodiment in which recombinant cells are used in gene therapy, a 53BP2 and/or a 53BP2-IP (preferably both a 53BP2 and a 53BP2-IP) nucleic acid or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 nucleic acid is/are introduced into the cells such that the gene or genes are expressible by the cells or their progeny, and the recombinant cells are then administered in vivo for therapeutic effect. In a specific embodiment, stem or progenitor cells are used. Any stem and/or progenitor cells which can be isolated and maintained in vitro can potentially be used in accordance with this embodiment of the present invention. Such stem cells include, but are not limited to, hematopoietic stem cells (HSC), stem cells of epithelial tissues such as the skin and the lining of the gut, embryonic heart muscle cells, liver stem cells (see e.g., PCT Publication WO 94/08598) and neural stem cells (see e.g., Stemple & Anderson, 1992. Cell 21:973-985). Epithelial stem cells (ESCs) or keratinocytes can be obtained from tissues such as the skin and the lining of the gut by known procedures. See e.g., Rheinwald, 1980. Meth. Cell Bio. 21:229-237. In stratified epithelial tissue such as the skin, renewal occurs by mitosis of stem cells within the germinal layer, the layer closest to the basal lamina. Stem cells within the lining of the gut provide for a rapid renewal rate of this tissue. ESCs or keratinocytes obtained from the skin or lining of the gut of a patient or donor can be grown in tissue culture. See e.g., Pittelkow & Scott, 1986. Mayo Clinic Proc. 6 771-782. If the ESCs are provided by a donor, a method for suppression of host versus graft reactivity (e.g., irradiation, drug or antibody administration to promote moderate immunosuppression) may also be used. With respect to hematopoietic stem cells (HSC), any technique which provides for the isolation, propagation, and maintenance in vitro of HSCs may be used in this embodiment of the present invention. Techniques by which this may be accomplished include, but are not limited to: (z) the isolation and establishment of HSC cultures from bone marrow cells isolated from the future host, or a donor or (ii) the use of previously established long-term HSC cultures, which may be allergenic or xenogeneic. Non- autologous HSC are used preferably in conjunction with a method of suppressing transplantation immune reactions of the future host/patient. In a specific embodiment of the present invention, human bone marrow cells can be obtained from the posterior iliac crest by needle aspiration. See e.g., Kodo, et al, 1984. J. Clin. Invest. 73: 1377-1384. In a preferred embodiment, the HSCs may be made highly enriched or in substantially pure form. This enrichment may be accomplished before, during or after long-term culturing, and may be performed by any techniques known in the art. Long-term cultures of bone marrow cells may be established and maintained by using, for example, modified Dexter cell culture techniques (see Dexter, et al, 1977. J. Cell Physiol. £1:335) or Witlock-Witte culture techniques (see Witlock & Witte, 1982. Proc. Natl. Acad. Sci. USA 79:3608-3612). In a specific embodiment, the nucleic acid to be introduced for puφoses of gene therapy comprises an inducible promoter operably linked to the coding region, such that expression of the nucleic acid is controllable by controlling the presence or absence of the appropriate inducer of transcription. Additional methods can be adapted for use to deliver a nucleic acid encoding the 53BP2 and/or 53BP2-IP proteins or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 proteins, or functional derivatives thereof. (12) USE OF ANTISENSE OLIGONUCLEOTIDES FOR SUPPRESSION OF 53BP2«53BP2-IP COMPLEXES AND 53BP2:IP-1. 53BP2:IP-2 AND 53BP2:IP-3 In a specific embodiment of the present invention, 53BP2»53BP2-IP complex function or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 protein function is inhibited by use of antisense nucleic acids for 53BP2 and/or a 53BP2-IP (e.g., β-tubulin, p62, hnRNP G, 53BP2:IP-1, 53BP2:IP-2 and 53BP2TP-3), preferably both 53BP2 and the 53BP2-IP or antisense nucleic acids for 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3. The present invention provides the therapeutic or prophylactic use of nucleic acids of at least six nucleotides which are antisense to a gene or cDNA encoding 53BP2 and/or a 53BP2-IP or encoding 53BP2TP-1, 53BP2:IP-2 or 53BP2:IP-3, or portions thereof. A 53BP2, 53BP2-IP, 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 "antisense" nucleic acid as used herein refers to a nucleic acid capable of hybridizing to a portion of a 53BP2, 53BP2-IP, 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 RNA (preferably mRNA) by virtue of some sequence complementarity. The antisense nucleic acid may be complementary to a coding and/or noncoding region of a 53BP2, 53BP2-IP, 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 mRNA. Such antisense nucleic acids have utility as Therapeutics which inhibit 53BP2»53BP2-IP complex formation or activity or 53BP2:IP-1. 53BP2:IP-2 or 53BP2:IP-3 function or activity, and may be used in the treatment or prevention of disorders as described, supra. The antisense nucleic acids of the present invention may be oligonucleotides that are double- stranded or single-stranded RNA or DNA (or a modification or derivative thereof) which can be directly administered to a cell, or which can be produced intracellularly by transcription of exogenous, introduced sequences. In another embodiment, the invention is directed to methods for inhibiting the expression of 53BP2 and a 53BP2-IP nucleic acid sequence or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 nucleic acid sequence in a prokaryotic or eukaryotic cell comprising providing the cell with an effective amount of a composition comprising an antisense nucleic acid of 53BP2 and 53BP2-IP, or an antisense nucleic acid of 53BP2:IP-1, 53BP2:IP-2 or 53BP2TP-3 (or derivatives thereof) of the present invention. The 53BP2, 53BP2-IP, 53BP2TP-1, 53BP2:IP-2 and 53BP2TP-3 antisense nucleic acids are of at least six nucleotides and are preferably oligonucleofides (ranging from 6 to about 200 oligonucleofides). In specific embodiments, the ohgonucleotide is at least 10 nucleotides, at least 15 nucleotides, at least 100 nucleotides, or at least 200 nucleotides. The oligonucleofides may be DNA or RNA or chimeric mixtures or derivatives or modified versions thereof, single- stranded or double-stranded. The ohgonucleotide may be modified at the base moiety, sugar moiety, or phosphate backbone. In addition, the ohgonucleotide may include other appending groups such as: (z) peptides or agents facilitating transport across the cell membrane (see e.g., PCT Publication No. WO 88/09810) or blood-brain barrier (see e.g., PCT Publication No. WO 89/10134); (ii) hybridization-triggered cleavage agents (see e.g., Krol, et al, 1988. BioTechmques 6:958- 976) or (Hi) intercalating agents (see e.g., Zon, 1988. Pharm. Res. 5:539- 549). In a preferred aspect of the invention, a 53BP2, 53BP2-IP, 53BP2:IP-1, 53BP2TP-2 or 53BP2:IP-3 antisense ohgonucleotide is provided, preferably as single-stranded DNA. In yet another embodiment, the ohgonucleotide is an anomeric ohgonucleotide, forming specific double-stranded hybrids with complementary RNA in which (contrary to the usual B -units) the strands run parallel to one another. See e.g., Gautier, et al, 1987. Nucl. Acids Res. 15:6625- 6641. The oligonucleofides may also be conjugated to another molecule (e.g., a peptide, hybridization triggered cross-linking agent, transport agent, hybridization-triggered cleavage agent, etc). Oligonucleofides of the present invention may be synthesized by standard methods known in the art, for example, by use of an automated DNA synthesizer such as are commercially available from Biosearch, Applied Biosystems. As an example, but not of a limitation, phosphorothioate oligonucleofides may be synthesized by the method of Stein, et al, 1988. Nucl. Acids Res. 16:3209); 5-methylphosphonate oligonucleofides may be prepared by use of controlled pore glass polymer supports (Sarin, et al, 1988. Proc. Natl, Acad. Sci. U.S.A. 85:7448-7451), and the like. In a specific embodiment, the 53BP2, 53BP2-IP, 53BP2:IP-1, 53BP2TP-2 or 53BP2TP-3 antisense oligonucleofides comprise catalytic RNAs, or ribozymes. See e.g., Sarver, et al, 1990. Science 247:1222-1225. In another embodiment, the ohgonucleotide is a 2'-O-methylribonucleotide (see e.g., Inoue, et al, 1987. Nucl. Acids Res. 15:6131-6148) or a chimeric RNA-DNA analog (see e.g., Inoue, et al, 1987. FEBSLett. 215:327-330). In yet another embodiment, the 53BP2, 53BP2-IP, 53BP2TP-1, 53BP2:IP-2 or 53BP2:IP- 3 antisense nucleic acids of the present invention are produced intracellularly by transcription from an exogenous sequence. For example, a vector can be introduced in vivo such that it is taken up by a cell, within which cell the vector or a portion thereof is transcribed, producing an antisense nucleic acid (RNA) of the invention. Such a vector would contain a sequence encoding 53BP2, 53BP2-IP (preferably, a 53BP2 and a 53BP2-IP anti-sense nucleic acid), 53BP2TP-1, 53BP2:IP-2 or 53BP2TP-3 antisense nucleic acids. Such a vector can remain episomal or become chromosomally integrated, as long as it can be transcribed to produce the desired antisense RNA. These aforementioned vectors may be constructed by recombinant DNA technology methods standard within the art. The vectors can be plasmid, viral, or others known in the art, used for replication and expression in mammalian cells. Expression of the sequences encoding the 53BP2, 53BP2-IP, 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 antisense RNAs may be by any promoter known in the art to act in mammalian, preferably human, cells. Such promoters can be inducible or constitutive and include, but are not limited to, the SV40 early promoter region; the promoter contained in the 3' long terminal repeat of Rous sarcoma virus; the Heφesvirus thymidine kinase promoter; the regulatory sequences of the metallothionein gene and the like. The antisense nucleic acids of the invention comprise a sequence complementary to at least a portion of an RNA transcript of a 53BP2, 53BP2-IP, 53BP2:IP-1, 53BP2TP-2 or 53BP2TP-3 gene, preferably a human gene. However, absolute complementarity (although preferred) is not required. A sequence said to be "complementary to at least a portion of an RNA," as referred to herein, means a sequence possessing sufficient complementarity to be able to hybridize with the RNA, forming a stable duplex, in the case of double-stranded 53BP2, 53BP2-IP, 53BP2:IP-1, 53BP2TP-2 or 53BP2TP-3 antisense nucleic acids, a single strand of the duplex DNA may thus be tested, or triplex formation may be assayed. The ability to hybridize will depend on both the degree of complementarity and the length of the antisense nucleic acid. Generally, the longer the hybridizing nucleic acid, the more base mismatches with a 53BP2, 53BP2-IP, 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 RNA it may contain and still form a stable duplex (or triplex). One skilled in the art may ascertain a tolerable degree of mismatch by use of standard procedures to determine the melting point of the hybridized complex. The 53BP2 and 53BP2-IP antisense nucleic acid or 53BP2:IP-1, 53BP2TP-2 or 53BP2:IP- 3 antisense nucleic acids can be used to treat (or prevent) disorders of a cell type which expresses, or preferably over-expresses, the 53BP2«53BP2-IP complex or 53BP2:IP-1, 53BP2TP-2 or 53BP2:IP-3 protein. In a preferred embodiment, a single-stranded DNA antisense 53BP2 and 53BP2-IP antisense ohgonucleotide, or single-stranded DNA antisense 53BP2TP-1, 53BP2:IP-2 or 53BP2:IP-3 ohgonucleotide, is used. Cell types which express or overexpress 53BP2 and 53BP2-IP RNA, or 53BP2:IP-1, 53BP2:IP-2 or 53BP2TP-3 RNA, may be identified by various methods known in the art including, but are not limited to, hybridization with 53BP2- and 53BP2-IP-specific nucleic acids, or 53BP2:IP-1-, 53BP2TP-2- or 53BP2:IP-3-specifιc nucleic acids (e.g., by Northern hybridization, dot blot hybridization, in situ hybridization, etc.) or by observing the ability of RNA from the cell type to be translated in vitro into 53BP2 and the 53BP2-IP, or into 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3, by immunohistochemistry. In a preferred embodiment of the present invention, primary tissue from a patient may be screened for 53BP2 or 53BP2-IP expression, or for 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 expression, prior to treatment. Pharmaceutical compositions of the present invention comprising an effective amount of a 53BP2 and a 53BP2-IP antisense nucleic acid, or a 53BP2:IP-1, 53BP2TP-2 or 53BP2:IP-3 antisense nucleic acid in a pharmaceutically-acceptable carrier, may be administered to a patient having a disease or disorder which is of a type that expresses or over-expresses 53BP2*53BP2-IP complexes or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 RNA or protein. The amount of antisense nucleic acid which will be effective in the treatment of a particular disorder or condition will depend upon the nature of the disorder or condition, and may be quantitatively determined by standard clinical techniques. Where possible, it is preferable to determine the antisense cytotoxicity in vitro, and then in useful animal model systems prior to testing and use in humans. In a specific embodiment of the present invention, pharmaceutical compositions comprising 53BP2 and 53BP2-IP antisense nucleic acids, or 53BP2:IP-1, 53BP2:IP-2 or 53BP2TP-3 antisense nucleic acids, are administered via liposomes, microparticles or microcapsules. In various embodiments of the invention, it may be useful to use such compositions to achieve sustained release of the 53BP2 and 53BP2-IP antisense nucleic acids, or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 antisense nucleic acids. In another specific embodiment, it may be desirable to utilize liposomes targeted via antibodies to specific identifiable central nervous system cell types. See e.g., Leonetti, et αl, 1990. Proc. Nαtl Acαd. Sci. U.S.A. 87:2448-2451. (13) ASSAYS OF 53BP2«53BP2-IP COMPLEXES, 53BP2:IP-1. 53BP2:IP-2 AND 53BP2:IP-3 AND DERIVATIVES AND ANALOGS The functional activity of 53BP2«53BP2-IP complexes and 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3 proteins (and derivatives, fragments and analogs thereof) may be assayed by various methods well-known within the art. Potential modulators (i.e., inhibitors, agonists and antagonists) of 53BP2*53BP2 complex activity or 53BP2.TP-1, 53BP2TP-2 or 53BP2:IP-3 activity (e.g., anti-53BP2»53BP2-IP complex; anti-53BP2-IP or anti-53BP2:IP-l, anti-53BP2:IP- 2 and anti-53BP2:IP-3 antibodies and 53BP2, 53BP2-IP, 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3 antisense nucleic acids, may be assayed for their ability to modulate 53BP2«53BP2- IP complex formation and or activity or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 activity. As an example, but not of a limitation, in one embodiment of the present invention, where one is assaying for the ability to bind or compete with wild-type 53BP2«53BP2-IP complexes or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3, for binding to an anti-53BP2»53BP2-IP complex antibody or anti-53BP2:IP-l, anti-53BP2:IP-2 or anti-53BP2:IP-3 antibodies, various immunoassays known within the art may be used including, but not limited to, competitive and non-competitive assay systems using techniques such as radioimmunoassay (RIA), enzyme linked immunosorbent assay (ELISA), "sandwich" immunoassays, immunoradiometric assays, gel diffusion precipitin reactions, immunodiffusion assays, in situ immunoassays (using colloidal gold, enzyme or radioisotope labels, for example), Western blots, precipitation reactions, agglutination assays (e.g., gel agglutination assays, hemagglutination assays), complement fixation assays, immunofluorescence assays, protein-A assays, immunoelectrophoresis assays, and the like. In one embodiment of the present invention, antibody binding is detected by detecting a label on the primary antibody. In another embodiment, the primary antibody is detected by detecting binding of a secondary antibody or reagent to the primary antibody. In a further embodiment, the secondary antibody is labeled. Numerous means are known within the art for detecting binding in an immunoassay and are encompassed within the scope of the present invention. The expression of the 53BP2, 53BP2-IP, 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3 genes (both endogenous genes and those expressed from cloned DNA containing these genes) may be detected using techniques known in the art including, but not limited to, Southern hybridization, Northern hybridization, restriction endonuclease mapping and DNA sequence analysis. In addition, polymerase chain reaction amplification (PCR; see e.g., U.S. Patent Nos. 4,683,202, 4,683,195, and 4,889,818; Loh, et al., 1989. Science 243:217-220) followed by Southern hybridization or RNase protection with probes specific for 53BP2, 53BP2-IP, or 53BP2:IP-1, 53BP2TP-2 or 53BP2:IP-3 genes in various cell types. Methods of amplification, other than PCR, are well-known within the art .and can be employed in the practice of the present invention. In one specific embodiment, Southern hybridization may be used to detect genetic linkage of 53BP2, 53BP2-IP, 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 gene mutations to physiological or pathological states. Various cell types, at various stages of development, may be characterized for their expression of 53BP2 and a 53BP2-IP (particularly concomitant expression of 53BP2 and 53BP2-IP within the same cells) or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 expression. The stringency of the hybridization conditions for northern or Southern blot analysis can be manipulated to ensure detection of nucleic acids with the desired degree of relatedness to the specific probes used. Modifications to these methods and other methods commonly-known within the art may also be utilized. Derivatives (e.g., fragments and analogs) of 53BP2-IPs, including 53BP2:IP-1, 53BP2TP-2 and 53BP2:IP-3 (and fragments and other derivatives and analogs of 53BP2-IPs) may be assayed for binding to 53BP2 by any method known in the art, for example, the modified yeast two hybrid assay system, immunoprecipitation with an antibody which binds to 53BP2 in a complex followed by analysis by size fractionation of the immunoprecipitated proteins (e.g., by denaturing or nondenaturing polyacrylamide gel electrophoresis), Western analysis, non- denaturing gel electrophoresis, and the like. One embodiment of the present invention provides a methodology for screening a derivative or analog of 53BP2 for biological activity comprising contacting the derivative or analog of 53BP2 with a protein which is selected from the group consisting of β-tubulin, p62, hnRNP G, 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3, and detecting the formation of a complex between the aforementioned derivative or analog of 53BP2 and the selected protein, and where detecting formation of the complex indicates that said derivative or analog of 53BP2 possesses biological (e.g., binding) activity. Another embodiment discloses a method for screening a derivative or analog of a protein selected from the group consisting of β-tubulin, p62, hnRNP G, 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3 for biological activity which is comprised of contacting the derivative or analog of the selected protein with 53BP2, and detecting the formation of a complex between said derivative or analog of said protein and 53BP2, wherein detecting the formation of said complex indicates that said derivative or analog of said protein has biological activity. The present invention also provides methods of modulating the activity of a protein that can participate in a 53BP2«53BP2-IP complex (e.g., 53BP2, β-tubulin, p62. hnRNP G, 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3) by administration of a binding partner of that protein or derivative or analog thereof. 53BP2 (and derivatives and analogs thereof, can be assayed for the ability to modulate the activity or levels of a 53BP2-IP by contacting a cell or administering an animal expressing a 53BP2-IP gene with a 53BP2 protein, or a nucleic acid encoding a 53BP2 protein or an antibody that immunospecifically binds the 53BP2 protein or a fragment or derivative of said antibody containing the binding domain thereof and measuring a change in 53BP2-IP levels or activity, wherein a change in 53BP2-IP levels or activity indicates that 53BP2 possesses the ability to modulate 53BP2-IP levels or activity. Alternatively, a 53BP2-IP can be assayed for the ability to modulate the activity or levels of a 53BP2 protein by contacting a cell or administering an animal expressing a gene encoding said protein with 53BP2, or a nucleic acid encoding 53BP2, or an antibody that immunospecifically-binds 53BP2, or a fragment or derivative of said antibody possessing the binding domain thereof, wherein a change in 53BP2 levels or activity indicates that the 53BP2-IP possesses the ability to modulate 53BP2 levels or activity. 53BP2, as well as several of the identified binding partners of 53BP2 (e.g., β-tubulin, p62 protein and hnRNP G have been demonstrated to have roles in the control of cell proliferation and, therefore, cell-transformation and tumorigenesis. Accordingly, the present invention discloses methods for screening 53BP2-53BP2-IP complexes and 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3 proteins (and fragments, derivatives and analogs thereof) for activity in altering cell proliferation, cell transformation and/or tumorigenesis in vitro and in vivo. The 53BP2»53BP2- IP complexes, 53BP2.-IP-1, 53BP2TP-2 and 53BP2TP-3 proteins (and derivatives, fragments and analogs thereof) may be assayed for activity to alter (i.e., either increase or decrease) cell proliferation in cultured cells in vitro using methods which are well-known within the art for measuring cell proliferation. Specific examples of cell culture models include, but are not limited to: lung cancer primary rat lung tumor cells (see e.g., Swafford, et al, 1997. Mol. Cell. Biol. 17:1366-1374) and large-cell undifferentiated cancer cell lines (see e.g., Mabry, et al, 1991. Cancer Cells 3:53-58); colorectal cell lines for colon cancer (see e.g., Park & Gazdar, 1996. J. Cell Biochem. Suppl. 24:131-141); multiple established cell lines for breast cancer (see e.g., Hambly, et al, 1997. Breast Cancer Res. Treat. 43:247-258) ); continuous human bladder cancer cell lines for genitourinary cancers (see e.g., Ribeiro, et al, 1997. Int. J. Radiat. Biol. 72:11-20) and established cell lines for leukemias and lymphomas (see e.g., Drexler, 1994. Leuk. Res. 18:919-927). For example, but not by way of limitation, the present invention discloses methodologies for the assay of cell proliferation comprising; measuring 3 H-thymidine incoφoration, by direct cell count, by detecting changes in transcriptional activity of known genes such as proto- oncogenes (e.g., fos, myc) or cell cycle markers, etc. Accordingly, one embodiment of the present invention provides a method of screening 53BP2«53BP2-IP complexes, 53BP2TP-1, 53BP2:IP-2 and 53BP2:IP-3 proteins (and fragments, derivatives and analogs thereof) for activity in altering proliferation of cells in vitro, which is comprised of contacting the cells with a 53BP2-53BP2-IP complex or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 protein (or derivative, analog or fragment thereof) measuring the proliferation of cells which have been so contacted, and comparing the proliferation of the cells so contacted with a complex or protein of the invention with the proliferation of cells not so contacted with the complex or protein of the invention, wherein in a change in the level of proliferation in said contacted cells indicates that the complex or protein of the invention possess activity to alter cell proliferation. The 53BP2»53BP2-IP complexes and 53BP2:IP-1 , 53BP2:IP-2 and 53BP2:IP-3 proteins (and derivatives, fragments and analogs thereof) may also be screened for activity in inducing or inhibiting cell transformation (or progression to malignant phenotype) in vitro. The complexes and proteins of the invention can be screened by contacting either cells with a normal phenotype (for assaying for cell transformation) or a transformed cell phenotype (for assaying for inhibition of cell transformation) with the complex or protein of the invention and examining the cells for acquisition or loss of characteristics associated with a transformed phenotype (a set of in vitro characteristics associated with a tumori genie ability in vivo), including, but not limited to: colony formation in soft agar, a more rounded cell moφhology, looser substratum attachment, loss of contact inhibition, loss of anchorage dependence, release of proteases such as plasminogen activator, increased sugar transport, decreased serum requirement, expression of fetal antigens, disappearance of the 250 kD surface protein, and the like. See e.g., Luria, et al, 1978. General Virology, 3d Ed., (John Wiley & Sons, New York, NY). The 53BP2-53BP2-IP complexes and 53BP2:IP-1, 53BP2TP-2 and 53BP2:IP-3 proteins (and derivatives, fragments and analogs thereof) may also be screened for activity to promote or inhibit tumor formation in vivo in non-human test animal. For example, the complexes and proteins of the invention may be administered to a non-human test animal (preferably a test animal predisposed to develop a type of tumor) and the non-human test animals subsequently examined for an increased incidence of tumor formation in comparison with controls not administered the complex or protein of the invention. Alternatively, the complexes and proteins of the invention can be administered to non-human test animals having tumors (i.e., animals in which tumors have been induced by introduction of malignant, neoplastic, or transformed cells or by administration of a carcinogen) and subsequently examining the tumors in the test animals for tumor regression in comparison to controls. The 53BP2-53BP2-IP complexes and 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3 proteins, (and derivatives, analogs and fragments thereof) may also be screened for activity in modulating the activity of 53BP2 and the 53BP2 binding partners (i.e., the 53BP2-IPs, particularly β-tubulin, p62, hnRNP G, 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3) involved in specific 53BP2-53BP2-IP complexes. For ex.ample, 53BP2 has been shown to bind a specific domain of the p53 protein and, by virtue of 53BP2-binding, enhance the tumor suppressor activity of p53. Accordingly, the complexes and proteins of the invention can be screened for the ability to modulate (i.e., either increase or decrease) 53BP2 binding to p53 or the 53BP2-binding domain of p53 (see e.g., Naumovski & Cleary, 1996. Mol. Cell. Biol. 16:3884-3892) or for the ability to modulate the tumor suppressive activity of p53 by a protein binding assay known within the art (see e.g., Iwabuchi, et al, 1994. Proc. Natl. Acad. Sci. USA 91:6098-6102). 53BP2 has also been demonstrated to affect the phosphorylation and dephosphorylation of p53 by 53BP2's binding to protein phosphatase 1 (PPl). Thus, the complexes and proteins of the present invention may be screened by assaying for changes in the level of p53 phosphorylation (see e.g., Milne, et al, 1994. J. Biol Chem. 269:9253-9260) or the level of 53BP2 binding to PPl (e.g., by methods described supra), β-tubulin has also been shown to be up-regulated in adenocarcinoma cells and, possibly, to bind proteins with Src homology 2 (SH2 domains), such as the PDGF receptor. See e.g., Shaffhausen, 1995. Biochem. Biophys. Acta 1242:61-75. Thus, the complexes and proteins of the invention can be screened by assaying for changes in β-tubulin levels (e.g., by immunoassays with anti- β-tubulin antibodies) or for changes in β-tubulin binding to proteins with SH2 domains. Additionally, the protein p62 associates with the p21waf GTPase-activating protein (GAP), Src family tyrosine kinase 5H3 domains in signaling proteins, binds RNA, interacts with ubiquitin, and also interacts with the cytosolic protein tyrosine kinase that negatively regulates the Src family protein kinases. Further, p62 may also play a role in docking certain proteins to the cytoskeleton or membrane upon c-Src activation. Thus, the complexes and proteins of the invention may also be screened by measuring changes in p62 binding to GAP (see e.g., Wong, et al, 1992. Cell 69:551-558); p62 binding to proteins with 5H3 domains, p62 binding to RNA (see e.g., Wang, et al, 1995. J. Biol. Chem. 270:2010-2013); interaction with ubiquitin (see e.g., Vadlamudi, et al, 1996. J. Biol. Chem. 271:20235-20237) or interaction with CSK (see e.g., Neet & Hunter, 1995. Mol. Cell. Biol. 15:4908-4920). Finally, the human hnRNP G protein binds RNA, thus, the complexes and proteins of the invention may be screened by measuring their affect on the levels of hnRNP G protein binding to RNA. The 53BP2 -binding partners, β-tubulin and p62, have been implicated in the processes of cellular apoptosis, mRNA destabilization and ubiquitin-mediated proteolysis associated with neurodegenerative disease. The 53BP2»53B2-IP complexes, particularly the 53BP2β-tubulin and 53BP2«p62 complexes (and derivatives, analogs and fragments thereof), nucleic acids encoding the 53BP2 and 53BP2-IP genes; anti-53BP2»53BP2-IP complex antibodies and various other modulators of 53BP2«53BP2-IP complex activity may be tested for activity in treating or preventing neurodegenerative disease in in vitro and in vivo assays. In one embodiment of the present invention, a Therapeutic may be assayed for activity in treating or preventing neurodegenerative disease by contacting cultured cells that exhibit an indicator of a neurodegenerative disease including, but not limited to, hypersecretion of B-A4 peptide (see e.g., Nakajima, et al, 1985. Proc. Natl Acad. Sci. USA 82:6325- 6329) in vitro with the Therapeutic, and comparing the level of said indicator in the cells contacted with the Therapeutic, with said level of said indicator in cells not so contacted, wherein a lower level in said contacted cells indicates that the Therapeutic has activity in treating or preventing neurodegenerative disease. Specific examples of such cultured models for neurodegenerative disease include, but are not limited to: cultured rat endothelial cells from affected and nonaffected individuals (see e.g., Maneiro, et al, 1997. Methods Find. Exp. Clin. Pharmacol. 19:5-12); P19 murine embryonal carcinoma cells (see e.g., Hung, et al, 1992. Proc Natl Acad. Sci USA 89:9439-9443) and dissociated cell cultures of cholinergic neurons from nucleus basalis of Meynert (see e.g., Nakajima, et al, 1985. Proc Natl Acad. Sci USA 82:6325-6329). In another embodiment of the present invention, a Therapeutic may also be assayed for activity in treating or preventing neurodegenerative disease by administering the Therapeutic to a test animal that exhibits symptom of a neurodegenerative disease including, but not limited to, cognitive dysfunction in behavior maze test, or that is predisposed to develop symptoms or a neurodegenerative disease, and measuring the change in said symptoms of the neurodegenerative disease after administration of said Therapeutic, wherein a reduction in the severity of the symptoms of the neurodegenerative or prevention of the symptoms of the neurodegenerative disease indicates that the Therapeutic has activity in treating or preventing neurodegenerative disease. Such a test animal can be any one of a number of animal models known in the art for neurodegenerative disease. These models, including those for Alzheimer's Disease and mental retardation of trisomy 21, accurately mimic natural human autoimmune diseases. See e.g.; Farine, 1997. Toxicol. 119:29-35. The 53BP2-binding partner, hnRNP G, has also been implicated in autoimmune disease. Accordingly, 53BP2»53BP2-IP complexes, particularly 53BP2»hnRNP G complexes (.and derivatives, analogs and fragments thereof), nucleic acids encoding the 53BP2 and 53BP2-IP genes; anti-53BP2*53BP2-IP complex antibodies and various other modulators of the 53BP2«53BP2-IP complex activity, may be assayed for activity in treating or preventing neurodegenerative disease in in vitro and in vivo assays. In one embodiment, a Therapeutic of the present invention may be assayed for activity in treating or preventing autoimmune disease by contacting cultured cells that exhibit an indicator of an autoimmune reaction in vitro, such as but not limited to, secretion of chemokines (see e.g., Kunkel, et al, 1996. J. Leukocyte Biol. 59:6-12) with the Therapeutic, and comparing the level of said indicator in the cells contacted with the Therapeutic with said level of said indicator in cells not so contacted, wherein a lower level in said contacted cells indicates that the Therapeutic has activity in treating or preventing autoimmune disease. In another embodiment, a Therapeutic of the present invention may be assayed for activity in treating or preventing autoimmune disease by administering said Therapeutic to a test animal exhibiting an autoimmune reaction or which test animal does not exhibit an autoimmune reaction and is subsequently challenged with an agent that elicits an autoimmune reaction, and measuring the change in the autoimmune reaction after the administration of said Therapeutic, wherein a reduction in said autoimmune reaction or a prevention of said autoimmune reaction indicates that the Therapeutic has activity in treating or preventing an autoimmune disease. A number of animal models of autoimmune disease are known within the art. These models, including those for arthritis, systemic lupus erythematosus, diabetes, thyroiditis, encephalitis and the like, accurately mimic natural human autoimmune diseases. See e.g., Farine, 1997. Toxicol. 1 19:29-35. (14) SCREENING FOR ANTAGONISTS AND AGONISTS OF 53BP2«53BP2-IP COMPLEX AND 53BP2:IP-1. 53BP2:IP-2. AND 53BP2:IP-3 53BP2«53BP2-IP complexes, 53BP2:IP-1, 53BP2:IP-2 53BP2:IP-3 (and derivatives, fragments and analogs thereof), as well as nucleic acids encoding 53BP2 and 53BP2-IPs and 53BP2:IP-1, 53BP2TP-2 and 53BP2:IP-3 (as well as derivatives, fragments and analogs thereof) may be utilized to screen for compounds which bind to 53BP2»53BP2-IP complexes and 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3 nucleic acids, proteins or derivatives, and thus have potential use as agonists or antagonists of 53BP2»53BP2-IP complex or 53BP2:IP-1, 53BP2TP-2 or 53BP2:IP-3 protein function. The present invention thus provides assays to detect molecules that specifically bind to 53BP2 and 53BP2-IP, and 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3 nucleic acids, proteins or derivatives. For example, recombinant cells expressing both 53BP2 and 53BP2-IP nucleic acids or 53BP2:IP-1, 53BP2TP-2 or 53BP2:IP-3 nucleic acids may be used to recombinantly produce the complexes or proteins in these assays, to screen for molecules that bind or interfere with 53BP2»53BP2-IP complexes or 53BP2:IP-1, 53BP2TP-2 or 53BP2TP-3 function. In preferred embodiments, polypeptide analogs that have superior stability (but retain the ability to form 53BP2-53BP2-IP complexes), for example, 53BP2 and 53BP2-IPs which have been modified to be resistant to proteolytic degradation in the binding assay buffers, or to be resistant to oxidative degradation are used to screen for modulators (e.g., molecules generated by substitution of amino acids at proteolytic cleavage sites, the use of chemically derivatized amino acids at proteolytic susceptible sites, and replacement of amino acid residues subject to oxidation, such as methionine and cysteine). Molecules (e.g., putative binding partners of a 53BP2«53BP2-IP complex or of 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3) are contacted with the 53BP2-53BP2-IP complex or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 proteins (or fragment thereof) under conditions conducive to binding, and then molecules that specifically bind to 53BP2»53BP2-IP complexes or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 proteins are identified. Similar methods may be utilized to screen for molecules which bind to 53BP2*53BP2-IP or 53BP2:IP-1, 53BP2:IP-2 or 53BP2TP-3 nucleic acids or derivatives thereof. A particular aspect of the invention relates to identifying molecules that inhibit or promote formation or degradation of a 53BP2»53BP2-IP complex (e.g., using the method described for screening inhibitors using the modified yeast two hybrid assay described infra .and in U.S. Patent Application Nos. 08/663,824 and 08/874,825, both entitled "Identification and Comparison of Protein-Protein Interactions that Occur in Populations and Identification of Inhibitors of These Interactions,", by Nandabalan, et al, which are incoφorated by reference herein in their entireties. In one embodiment of the present invention, a molecule which modulates activity of 53BP2 or a protein selected from the group consisting of β-tubulin, p62, hnRNP G, 53BP2:IP-1, 53BP2TP-2 and 53BP2TP-3 (or a complex of 53BP2 and said protein) is identified by contacting one or more candidate molecules with 53BP2 in the presence of said protein, and measuring the amount of complex that forms between 53BP2 and said protein, wherein an increase or decrease in the amount of complex that forms relative to the amount that forms in the absence of the candidate molecules indicates that the molecules modulate the activity of 53BP2 or said protein or said complex of 53BP2 and said protein. In preferred embodiments, the modulators are identified by administering the candidate molecules to a transgenic, non-human animal expressing both 53BP2 and a 53BP2-IP from promoters which are not the native 53BP2 or the native 53BP2-IP promoters, and more preferably where the candidate molecules are also recombinantly expressed in the transgenic, non-human animal. Alternatively, the method for identifying such modulators can be carried out in vitro, preferably with purified 53BP2, purified 53BP2-IP and purified candidate molecules. Methodologies which can be used to carry out the foregoing are well-known within the art. Agents to be screened can be provided as mixtures of a limited number of specified compounds, or as compound libraries, peptide libraries and the like. Agents to be screened may also include all forms of antisera, antisense nucleic acids, etc. which possess the ability to modulate 53BP2«53BP2-IP complex activity or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 activity. By way of example, and not of limitation, diversity libraries (e.g., random or combinatorial peptide or non-peptide libraries) may be screened for molecules which specifically bind to a 53BP2«53BP2-IP complex or 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 protein. Many libraries are known within the art and include, but are not limited to, chemically-synthesized libraries, recombinant (e.g., phage display libraries) and in vitro translation-based libraries. Screening the libraries may be accomplished by any of a variety of commonly known methodologies. In a specific embodiment, screening may be performed by contacting the library members with a 53BP2-53BP2-IP complex or a 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 protein (or nucleic acid or derivative) which has been immobilized on a solid phase and harvesting those library members which bind to the protein (or nucleic acid or derivative). Examples of such screening methods, termed "panning" techniques are described by way of example, but not of limitation, in Fowlkes, et al, 1992. BioTechniques 13:422-427; PCT Publication No. WO 94/18318. In yet another specific embodiment of the present invention, fragments and/or analogs of 53BP2 or a 53BP2-IP, especially peptidomimetics, may be screened for activity as competitive or non-competitive inhibitors of 53BP2«53BP2-IP complex formation, and as a result concomitantly inhibit 53BP2*53BP2-IP complex activity. In a preferred embodiment, molecules which bind to 53BP2-53BP2-IP complexes and 53BP2:IP-1, 53BP2TP-2 and 53BP2:IP-3 proteins may be screened for using the modified, yeast two hybrid system described herein infra. In one embodiment, agents which modulate (i.e., inhibit, .antagonize or agonize) 53BP2*53BP2- EP complex activity may be screened using a binding inhibition assay, wherein agents are screened for their ability to inhibit formation of a 53BP2*53BP2-IP complex under physiological binding conditions, in which 53BP2*53BP2-IP complex formation occurs in the absence of the agent to be tested. Agents which interfere with the formation of 53BP2»53BP2-IP complexes are identified as antagonists of said complex formation. Methods for screening may also involve labeling the complex proteins with: (z) radioligands (e.g., ,25 I or 3 H); (ii) magnetic ligands (e.g., paramagnetic beads covalently attached to photobiotin acetate); (Hi) florescent ligands (e.g., fluorescein or rhodamine) or (iv) enzyme ligands (e.g., luciferase or β-galactosidase). The reactants which bind in an aqueous solution (i.e., under physiological conditions) may then be isolated by one of many techniques known in the art including, but not limited to, co-immunoprecipitation of the labeled moiety using antisera against the unlabeled binding partner (or labeled binding partner with a distinguishable marker from that used on the labeled moiety) protein, immunoaffmity chromatography, size exclusion chromatography, and gradient density centrifugation. In a preferred embodiment, one binding partner is a small fragment or peptidomimetic that is not retained by a commercially available filter. Upon binding, the labeled species is then unable to pass through the filter, providing for a simple assay of complex formation. Methods commonly known in the art are used to label at least one of the members of the 53BP2«53BP2-IP complex. Suitable labeling includes, but is not limited to: (z) radiolabeling by incoφoration of radiolabeled amino acids (e.g., 3 H-leucine or 35 S-methionine, radiolabeling by post-translational iodination with ,25 I or I using the chloramine-T method, Bolton-Hunter reagents, etc., or labeling with 32 P using phosphorylase and inorganic radiolabeled phosphorous; (ii) biotin labeling with photobiotin-acetate and (iv) UV exposure, and the like. In cases where one of the members of the 53BP2»53BP2-IP complex is immobilized on a solid-support, the free species is labeled. Where neither of the interacting species is immobilized, each can be labeled with a distinguishable marker such that isolation of both moieties can be followed to provide for more accurate quantitation, and to distinguish the formation of homomeric from heteromeric complexes. Methods which utilize accessory proteins that bind to one of the modified interactants to improve the sensitivity of detection, increase the stability of the complex, etc. are also provided herein. Typical binding conditions are, for example, but not by way of limitation, in an aqueous salt solution of 10-250 mM NaCl, 5-50 mM Tris-HCl, pH 5.8, 0.5% Triton X-100 or other detergent which improves specificity of interaction. Metal chelators and/or divalent cations may be added to improve binding and/or reduce proteolysis. Reaction temperatures may include 4, 10, 15, 22, 25, 35, or 42 degrees Celsius, and time of incubation is typically at least 15 seconds, but longer times are preferred to allow binding equilibrium to occur. Particular 53BP2»53BP2- IP complexes can be assayed using routine protein binding assays to determine optimal binding conditions for reproducible binding. The physical parameters of complex formation may be analyzed by quantitation of complex formation using assay methods specific for the label used (e.g., liquid scintillation counting for radioactivity detection, enzyme activity measurements for enzyme label, etc). The reaction results are then analyzed utilizing Scatchard analysis, Hill analysis, and other methods well-known within the arts. See e.g., Proteins, Structures, and Molecular Principles 1984. (W.H. Freeman and Company, New York, NY). In a second common approach to binding assays, one of the binding species is immobilized on a solid support (e.g., on a filter, in a microtiter plate well, in a test tube, to a chromatography matrix, and the like) either covalently or non-covalently. Proteins may be covalently immobilized using any method well known in the art including, but not limited to, linkage to a cyanogen bromide-derivatized substrate such as CNBr-Sepahrose 4B. See e.g., Kadonaga & Tjian, 1986. Proc. Natl. Acad. Sci. USA 83.5889-5893. Where needed, the use of spacers can reduce steric hindrance from the substrate. Non-covalent attachment of proteins to a substrate include, but are not limited to, attachment of a protein to a charged surface, binding with specific antibodies, binding to a third unrelated IP, and the like. In one specific embodiment of the present invention, immobilized 53BP2 is used to assay for binding with a radioactively-labeled 53BP2-IP in the presence and absence of a compound to be tested for its ability to modulate 53BP2*53BP2-IP complex formation. The binding partners are allowed to bind under aqueous, or physiological, conditions (i.e., the conditions under which the original interaction was detected). Conversely, in another embodiment, the 53BP2-IP is immobilized and contacted with the labeled 53BP2 protein (or derivative thereof) under binding conditions. Assays of agents (including cell extracts or library pool) for competition for binding of one member of a 53BP2«53BP2-IP complex (or derivatives thereof) with the other member of the 53BP2«53BP2-IP complex, are disclosed herein to screen for competitors of 53BP2«53BP2- IP complex formation. In specific embodiments, blocking agents to inhibit non-specific binding of reagents to other protein components, or absoφtive losses of reagents to plastics, immobilization matrices, etc., are included in the assay mixture. Blocking agents include, but are not restricted to, bovine serum albumin (BSA), β-casein, nonfat dried milk, Denhardt's reagent, Ficoll, polyvinylpyrolidine, non-ionic detergents(e.g., NP40, Triton X-100, Tween 20, Tween 80, and the like), ionic detergents (e.g., SDS, LDS, etc.), polyethyleneglycol, etc. Appropriate " blocking agent concentrations allow 53BP2«53BP2-IP complex formation. After binding is performed, unbound, labeled protein is removed in the supernatant, and the immobilized protein with any bound, labeled protein is washed extensively. The amount of label bound is then quantitatively determined using standard methods in the art to detect the label as described supra. (15) ASSAYS FOR PROTEINS -PROTEIN INTERACTIONS One aspect of the present invention provides methods for assaying and screening fragments, derivatives and analogs of derivatives, analogs and fragments of 53BP2-interacting proteins (for binding to 53BP2 peptides). Derivatives, analogs and fragments of 53BP2-IPs which interact with the 53BP2 protein may be identified by means of a yeast two hybrid assay system. See Fields & Song, 1989. Nature 340: 245-246; U.S. Patent No. 5,283,173. or, more preferably, an improvement thereof as described in U.S. Patent Application Nos. 08/663,824 and 08/874,825, both entitled "Identification and Comparison of Protein-Protein Interactions that Occur in Populations and Identification of Inhibitors of These Interactions," by Nandabalan, et al, which are incoφorated by reference herein in their entireties. Because the interactions are screened for in yeast, the intermolecular protein interactions detected in this system generally occur under physiological conditions that mimic the conditions in mammalian cells. See e.g., Chien, et al., 1991. Proc. Natl. Acad. Sci. USA 88-9578-9581. Identification of interacting proteins by the improved yeast two hybrid system is based upon the detection of the expression of a reporter gene ("Reporter Gene"), the transcription of which is dependent upon the reconstitution of a transcriptional regulator by the interaction of two proteins, each fused to one half of the transcriptional regulator. The "bait" (53BP2 or a derivative or analog) and "prey" (proteins to be tested for ability to interact with the bait) proteins are expressed as fusion proteins to a DNA binding domain, and to a transcriptional regulatory domain, respectively, or vice versa. In various specific embodiments of the present invention, the prey has a complexity of at least 50, 100, 500, 1,000, 5,000, 10,000, or 50,000, or has a complexity in the range of 25 to 100,000, 100 to 100,000, 50,000 to 100,000, or 10,000 to 500,000. For example, the prey population can be one or more nucleic acids encoding mutants of a 53BP2-IP (e.g., as generated by site-directed mutagenesis or another method of making mutations in a nucleotide sequence). Preferably, the prey populations are proteins encoded by DNA (e.g., cDNA, genomic DNA or synthetically generated DNA). For example, the populations can be expressed from chimeric genes comprising cDNA sequences from an non-characteπzed sample of a population of cDNA from mammalian RNA Preferably, the prey population are proteins encoded by DNA (e g , cDNA, genomic DNA or synthetically generated DNA). In a specific embodiment, recombinant biological hbraπes expressing random peptides may be used as the source of prey nucleic acids In another specific embodiment, the invention provides methods for screening for inhibitors of the interacting proteins identified herein In bπef, the protem-protem interaction assay may be performed as descπbed herein, except that it is done in the presence of one or more candidate molecules An increase or decrease in Reporter Gene activity relative to that present when the one or more candidate molecules are absent indicates that the candidate molecule has an effect on the interacting pair In a preferred embodiment, inhibition of the interaction is selected for (z e , inhibition of the interaction is necessary for the cells to survive), for example, where the interaction activ ates the URA3 gene, causing yeast to die in medium containing the chemical 5-fluoroorotιc acid See e g , Rothstein, 1983 Meth Enz\mol 101 167-180 The identification of inhibitors of such interactions can also be accomplished, for example, but not by way of limitation, using competitive inhibitor assays, as descπbed supra In general, proteins of the bait and prey populations are provided as fusion (chimeπc) proteins (preferably by recombinant expression of a chimeric coding sequence) containing each protein contiguous to a pre-selected sequence For one population, the pre-selected sequence is a DNA binding domain The DNA binding domain may be any DNA binding domain, so long as it specifically recognizes a DNA sequence withm a promoter For example, the DNA binding domain is of a transcπptional activator or inhibitor For the other population, the pre-selected sequence is an activator or inhibitor domain of a transcπptional activator or inhibitor, respectn ely The regulatory domain alone (not as a fusion to a protein sequence) and the DNA- binding domain alone (not as a fusion to a protein sequence) preferably do not detectably interact, so as to avoid false-positives in the assay results The assay system of the present invention further includes a Reporter Gene operably- linked to a promoter which possesses a binding site for the DNA binding domain of the transcπptional activator (or inhibitor) Accordingly, in the embodiment of the invention, binding of a 53BP2 fusion protein to a prey fusion protein leads to reconstitution of a transcπptional activator (or inhibitor) which activates (or inhibits) expression of the Reporter Gene The activation of transcπption of the Reporter Gene occurs intracellularly (e g , in prokaryotic or eukaryotic cells, preferably m cell culture) The promoter which is operably-linked to the Reporter Gene nucleotide sequence may be a native or non-native promoter of the nucleotide sequence, and the DNA binding site(s) which are recognized by the DNA binding domain portion of the fusion protein can be native to the promoter (if the promoter normally contains such binding site(s)) or non-native. Thus, for example, one or more tandem copies (e.g., 4 or 5 copies) of the appropriate DNA binding site can be introduced upstream of the TATA box in the desired promoter (e.g., in the area of position -100 to -400). In a preferred embodiment, 4 or 5 tandem copies of the 17 bp UAS (GAL4 DNA binding site) are introduced upstream of the TATA box in the desired promoter, which is upstream of the desired coding sequence for a selectable or detectable marker. In another preferred embodiment, the GALl-b promoter is operably fused to the desired nucleotide sequence, the GALl-b promoter already contains binding sites for GAL4. Alternatively, the transcriptional activation binding site of the desired gene(s) may be deleted and replaced with GAL4 binding sites. See e.g., B artel, et al, 1993. BioTechniques 14(6):920-924. The Reporter Gene preferably contains the sequence encoding a detectable or selectable marker the expression of which is regulated by the transcriptional activator, such that the marker is either turned on or off in the cell in response to the presence of a specific interaction. Preferably, the assay is carried out in the absence of background levels of the transcriptional activator (e.g., in a cell that is mutant or otherwise lacking in the transcriptional activator). In one embodiment, more than one Reporter Gene is used to detect transcriptional activation (e.g., one Reporter Gene encoding a detectable marker and one or more Reporter Genes encoding different selectable markers). The detectable marker may be any molecule that can give rise to a detectable signal, such as a fluorescent protein or a protein that can be readily visualized or that is recognizable by a specific antibody. The selectable marker may be any protein molecule that confers ability to grow under conditions that do not support the growth of cells not expressing the selectable marker (e.g., the selectable marker is an enzyme that provides an essential nutrient and the cell in which the interaction assay occurs is deficient in the enzyme and the selection medium lacks such nutπent). The Reporter Gene may either be under the control of the native promoter that naturally contains a binding site for the DNA binding protein, or under the control of a heterologous or synthetic promoter. The activation domain and DNA binding domain used in the assay may be derived from a wide variety of transcriptional activator proteins, so long as these transcriptional activators have separable binding and transcriptional activation domains. For example, the GAL4 protein of S. cerevisiae; the GCN4 protein of S. cerevisiae (see e.g., Hope & Struhb, 1986. Cell 46:885-894); the ARDl protein of S. cerevisiae (see e.g.. Thukral. et al, 1989. Mol Cell Biol. 9:2360-2369) and the human estrogen receptor (see e.g., Kumar, et al. 1987. Cell 51:941-951) all possess separable DNA binding and " activation domains. Moreover, the DNA binding domain and activation domain that are employed in the fusion proteins need not be from the same transcriptional activator. In a specific embodiment of the present invention, a GAL4 or LEXA DNA binding domain is employed. In another specific embodiment, a GAL4 or heφes simplex virus VP16 (see e.g., Triezenberg, et al. 1988. Genes Dev. 2:730-742) activation domain is employed. In another specific embodiment, amino acid residues 1-147 of GAL4 (see e.g., Ma, et al, 1987. Cell 48:847-853) comprises the DNA binding domain; whereas amino acid residues 41 1-455 of VP16 (see e.g., Triezenberg, et al, 1988. Genes Dev. 2:730-742) comprises the activation domain. In a preferred embodiment of the present invention, the yeast transcription factor GAL4 is reconstituted by the protein-protein interaction and the host strain is mutant for GAL4. In another preferred embodiment, the DNA-binding domain is Acel and or the activation domain is Acel, the DNA binding and activation domains of the Acel protein, respectively. Acel is a yeast protein that activates transcription from the CURL operon in the presence of divalent copper. CUP1 encodes metallothionein, which chelates copper, and the expression of CUP1 protein allows growth in the presence of copper, which is otherwise toxic to the host cells. The Reporter Gene may also be a CUPl-lacZ fusion which expresses the enzyme β-galactosidase (which is detectable by routine chromogenic assay) upon binding of a reconstituted AcelN transcriptional activator. See e.g., Chaudhuri, et al, 1995. FEBS Letters 357:221-226. In another specific embodiment, the DNA binding domain of the human estrogen receptor is used, with a Reporter Gene driven by one or three estrogen receptor response elements (see e.g., Le Douarin, et al, 1995. Nucl. Acids. Res. 23:876-878). The DNA binding domain and the transcription activator/inhibitor domain each preferably has a nuclear localization signal (see e.g., Ylikomi, et al, 1992. EMBO J. 11:3681-3694) functional in the cell in which the fusion proteins are to be expressed. To facilitate the subsequent isolation of the encoded proteins, the fusion constructs can further contain sequences encoding "affinity tags" (e.g., glutathione-S-transferase, maltose-binding protein or an epitope of an available antibody) for affinity purification. See e.g., Allen, et al, 1995. TIBS 20:51 1-516. In yet another embodiment, the fusion constructs further comprise bacterial promoter sequences for recombinant production of the fusion protein in bacterial cells. See e.g., Allen, et al, 1995. TIBS 20:511-516. The host cell in which the interaction assay occurs can be any cell, prokaryotic or eukaryotic, in which transcription of the Reporter Gene can occur and be detected including, but not limited to, mammalian (e.g., monkey, chicken, mouse, rat, human, bovine), bacteria, insect cells, or. preferably, a yeast cell. Expression constructs encoding and capable of expressing the binding domain fusion proteins, the transcriptional activation domain fusion proteins, and the Reporter Gene product(s) are provided within the host cell, by mating of cells containing the expression constructs, or by cell fusion, transformation, electroporation, microinjection. etc. In a specific embodiment of the present invention in which the assay is carried out in mammalian cells (e.g., hamster cells), the DNA binding domain is the GAL4 DNA binding domain, the activation domain is the heφes simplex virus VP16 transcriptional activation domain, and the Reporter Gene contains the desired coding sequence operably-linked to a minimal promoter element from the adenovirus E1B gene driven by several GAL4 DNA binding sites (see e.g., Fearon, et al, 1992. Proc. Natl. Acad. Sci. USA 89:7958-7962). The host cell used should not express an endogenous transcription factor that binds to the same DNA site as that recognized by the DNA binding domain fusion population. Also, preferably, the host cell is mutant or otherwise lacking in an endogenous, functional form of the Reporter Gene(s) used in the assay. Various vectors and host strains for expression of the two fusion protein populations in yeast are known and may be utilized. See e.g., U.S. Patent No. 5,1468,614: Fields & Sternglanz. 1994. TIG 10:286-292. By way of example but not limitation, yeast strains or derivative strains made therefrom, which may be utilized include: ITIOS, N106R, N1051, N106R1, and YULH, although numerous other strains commonly-known and available within the art can be used. If not already lacking in endogenous Reporter Gene activity, cells mutant in the Reporter Gene may be selected by known methods, or the cells can be made mutant in the target Reporter Gene by known gene-disruption methods prior to introducing the Reporter Gene. See e.g.. Rothstein. 1983. Meth. Enzymol 101 :202-21 1. In a specific embodiment of the present invention, plasmids encoding the different fusion protein populations can be both introduced into a single host cell (e.g., a haploid yeast cell) containing one or more Reporter Genes, by co- transformation, to conduct the assay for protein-protein interactions. Or, preferably, the two fusion protein populations are introduced into a single cell either by mating (e.g., of yeast cells) or by cell fusions (e.g., of mammalian cells). In a mating type assay, conjugation of haploid yeast cells of opposite mating type that have been transformed with a binding domain fusion expression construct (preferably a plasmid) and an activation (or inhibitor) domain fusion expression construct (preferably a plasmid). respectively, delivers both constructs into the same diploid cell. The mating type of a yeast strain may be manipulated by transformation with the HO gene See e g , Herskowitz & Jensen, 1991 Meth Enzymol 194 132-146 In a preferred embodiment, a yeast interaction mating assay is employed, using two different types of host cells, strain-types (a and alpha) of the yeast Saccharomvces cerevisiae. The host cell preferably contains at least two Reporter Genes, each with one or more binding sites for the DNA-bindmg domain (e g , of a transcπptional activator) The activator domain and DNA binding domain are each parts of chimeπc proteins formed from the two respective populations of proteins One set of host cells, for example the a strain cells, contains fusions of the library of nucleotide sequences with the DNA-bmding domain of a transcπptional activator, such as GAL4 The hybπd proteins expressed in this set of host cells are capable of recognizing the DNA-binding site on the Reporter Gene The second set of yeast host cells, for example alpha strain cells, contains nucleotide sequences encoding fusions of a library of DNA sequences fused to the activation domain of a transcπptional activ ator In a preferred embodiment, the fusion protein constructs are introduced into the host cell as a set of plasmids These plasmids are preferably capable of autonomous replication in a host yeast cell and preferably can also be propagated in E coli The plasmid contains a promoter directing the transcription of the DNA binding or activation domain fusion genes, and a transcπptional termination signal The plasmid also preferably contains a selectable marker gene, permitting selection of cells containing the plasmid The plasmid may be smgle-copy or multi-copy Single-copy yeast plasmids that have the yeast centromere may also be used to express the activation and DNA binding domain fusions See e g , Εlledge, et al 1988 Gene 70 303-312 In another embodiment, the fusion constructs are introduced directly into the yeast chromosome via homologous recombination The homologous recombination for these puφoses is mediated through yeast sequences that are not essential for vegetatn e growth of yeast (e g , the MΕR2, MER, ZIPI, REC102 or MEM genes) Bacteriophage vectors may also be utilized to express the DNA binding domain and/or activation domain fusion proteins. Libranes can generally be prepared faster and more easily from bacteπophage vectors than from plasmid vectors In a specific embodiment, the invention provides a method for the detection of one or more protem-protein interactions compπsing (i) recombmantly expressing 53BP2 (or a deπvative or analog thereof) in a first population of yeast cells being of a first mating type and compπsing a first fusion protein containing the 53BP2 sequence and a DNA binding domain, wherein said first population of yeast cells contains a first nucleotide sequence operably-linked to a promoter dπven by one or more DNA binding sites recognized by said DNA binding domain such that an interaction of said first fusion protein with a second fusion protein, said second fusion protein compπsing a transcπptional activation domain, results in increased transcπption of said first nucleotide sequence, (u) negatively- selecting to eliminate those yeast cells in said first population in which said increased transcπption of said first nucleotide sequence occurs in the absence of said second fusion protein, (m) recombinantly-expressmg in a second population of yeast cells of a second mating type different from said first mating type, a plurality of said second fusion proteins, each second fusion protein compπsmg a sequence of a fragment, deπvatn e or analog of a 53BP2-IP and an activation domain of a transcπptional activator, m which the activation domain is the same m each said second fusion protein, (zv) mating said first population of yeast cells with said second population of yeast cells to form a third population of diploid veast cells, wherein said third population of diploid yeast cells contains a second nucleotide sequence operably-linked to a promoter driven by a DNA binding site recognized by said DNA binding domain such that an interaction of a first fusion protein with a second fusion protein results in increased transcπption of said second nucleotide sequence, in which the first and second nucleotide sequences can be the same or different and (v) detecting said increased transcπption of said first and or second nucleotide sequence, thereby detecting an interaction between a first fusion protein and a second fusion protein In a preferred embodiment of the present invention, the bait 53BP2 sequence and the prey library of chimeπc genes are combined by mating the two yeast strains on solid media for a peπod of approximately 6-8 hours In a less prefeπed embodiment, the mating is performed in liquid media The resulting diploids possess both types of chimeπc genes (z e the DNA-bmdmg domain fusion and the activation domain fusion) Prefeπed Reporter Genes include, but are not limited to, URA3. HIS3 and/or the lacZ genes (see e g , Rose & Botstem. 1983 Meth 101 167-180) operably-linked to GAL4 DNA-bmdmg domain recognition elements Other reporter genes compπse the functional coding sequences for. but not limited to. Green Fluorescent Protein (GFP. see e g , Cubitt, et al 1995 Trends Biochem Sci 20 448-455), luciferase, LEU2. LYS2, ADE2, TRP1, CANi, CYH2, GUS. CUP1 or chloramphemcol acetyl transferase (CAT) Expression of LEU2, LYS2, ADE2 and TRP1 are detected b> growth in a specific, defined media, GUS and CAT may be monitored b\ well-known enzyme assays and CANi and CYH2 are detected by selection in the presence of canavanine and cycloheximide With respect to GFP, the natural fluorescence of the protein is detected In a specific embodiment of the present invention, transcπption of the Reporter Gene is detected by a linked replication assay For example, expression of SV40 large T antigen is under the control of the E1B promoter responsive to GAL4 binding sites See e g , Vasavada. et al , 1991 Proc Natl Acad Sci USA 88.10686-10690 The replication of a plasmid containing the SV40 oπgm of replication, indicates the reconstruction of the GAL4 protein and a protein- protem interaction Alternatively, a polyoma virus rephcon can be employed See e g , Vasavada, et al , 1991 Proc Natl Acad Sci lβ.4 88 10686-10690 In another embodiment, the expression of Reporter Genes that encode proteins can be detected by immunoassay (z e by detecting the immunospecific binding of an antibody to such protein, which antibody can be labeled, or alternatively, which antibody can be incubated with a labeled binding partner to the antibody, so as to yield a detectable signal) Alam & Cook, (1990 Anal Biochem 188 245-254) disclose non-limiting examples of detectable marker genes that can be operably linked to a transcπptional regulatory region responsn e to a reconstituted transcπptional activator, and thus used as Reporter Genes The activation of Reporter Genes like URA3 or HIS3 enables the cells to grow in the absence of uracil or histidine. respectively, and hence serves as a selectable marker Thus, after mating, the cells exhibiting protein-protem interactions are selected by the ability to grow in media lacking a nutπtional component, such as uracil or histidme. respectively (referred to as -URA (minus E1BA) and -HIS (minus HIS) medium, respectively) The -HIS medium preferably contains 3-amιno-l,2,4-tπazole (3-AT), w hich is a competitive inhibitor of the HIS3 gene product and thus requires higher levels of transcπption in the selection See e g , Durfee. et al , 1993 Genes De\ 7 555-569 Similarly, 6-azauracιl. w hich is an inhibitor of the URA3 gene product, may also be included in -URA medium See e g Le Douaπn, et al , 1995 Nucl Acids Res 23 876-878 URA3 gene activity can also be detected and/or measured by determining the activity of its gene product, orotidine monophosphate decarboxylase See e g , Pierrat, et al , 1992. Gene 1 19 237-245 In other embodiments of the present invention, the activities of the reporter genes like lacZ or GFP are monitored by measuring a detectable signal (e g , fluorescent or chromogemc) which results from the activation of these Reporter Genes For example, lacZ transcπption can be monitored by incubation m the presence of a chromogemc substrate, such as X-gal (5-bromo- 4-chloro-3-ιndolyl-a-D-galactosιde), for its encoded enzyme, β-galactosidase The pool of all interacting proteins isolated by this manner from mating the 53BP2 sequence product and the library identifies the "53BP2 interactive population " In a preferred embodiment of the present invention, false positives arising from transcπptional activation by the DNA binding domain fusion proteins in the absence of a transcπptional activator domain fusion protein are prevented or markedly reduced by negative selection for such activation withm a host cell containing the DNA binding fusion population, pπor to exposure to the activation domain fusion population By way of example, and not of limitation, if such cell contains URA3 as a Reporter Gene, negative selection is earned out by incubating the cell in the presence of 5-fluoroorotιc acid (5- FOA) which kills URA+ cells See e g . Rothstem. 1983 Meth Enzymol 101 - 167-180 Hence, if the DNA-bmdmg domain fusions by themseh es activate transcπption. the metabolism of 5-FOA will lead to cell death and the removal of self-activatmg DNA-bmdmg domain hybnds Negative selection involving the use of a selectable marker as a Reporter Gene and the presence in the cell medium of an agent toxic or growth inhibitory to the host cells in the absence of Reporter Gene transcπption is prefeπed, since it allows a higher rate of processing than other methods As will be apparent, negative selection can also be earned out on the activation domain fusion population prior to interaction with the D\A binding domain fusion population, by similar methods, either alone or m addition to negative selection of the D\A binding fusion population Negative selection may also be earned out on the recovered 53BP2»53BP2-IP complexes by know methods (see e g Bartel, et al , 1993 BioTechmques 14 920-924), although pre- negative selection (i e , pπor to the interaction assay), as descπbed supra, is prefeπed For example, each plasmid encoding a protein (peptide or polypeptide) fused to the activation domain (one-half of a detected interacting pair) may be transformed back into the original screening strain, either alone or with a plasmid encoding only the DNA-bmding domain, the DNA-binding domain fused to the detected interacting protein, or the D\ Vbindmg domain fused to a protein that does not affect transcription or participate in the protein-protein interaction, a positive interaction detected w ith any plasmid other than that encoding the DNA- bmding domain fusion to the detected interacting protein is deemed a false positπ e and eliminated from the screen In a prefeπed embodiment of the present invention, the 53BP2 plasmid population is transformed in a yeast strain of a first mating type (a or alpha), and the second plasmid population (containing the library of DNA sequences) is transformed in a yeast strain of different mating t\pe Both strains are preferably mutant for URA3 and HIS3, and contain HIS3, and optionallv lacZ, as a Reporter Genes The first set of yeast cells are positu ely-selected for the 53BP2 plasmids and are negatively-selected for false positives by incubation in medium lacking the selectable marker (e g , tryptophan) and containing 5-FOA Yeast cells of the second mating type are then transformed with the second plasmid population, and are positively selected for the presence of the plasmids containing the library of fusion proteins The selected cells are subsequently pooled and mating is allowed to occur on a solid phase. The resulting diploid cells are then transfeπed to selective media that selects for the presence of each plasmid and for activation of Reporter Genes In another prefeπed embodiment of the present invention, after an interactive population is obtained, the DNA sequences encoding the pairs of interactive proteins are isolated by a method w herein either the DNA-binding domain hybπds or the activation domain hybπds are amplified, in separate respective reactions Preferably, the amplification is earned out by polymerase chain reaction (PCR, see e g , U S Patent Nos 4,683,202, 4,683,195 and 4,889,818 and Gyllenstein. et al , 1988 Pioc Natl Acad Sci USA 85 7652-7656) using pairs of ohgonucleotide pπmers specific for either the DNA-binding domain hybπds or the activation domain hvbnds This PCR amplification reaction may also be performed on pooled cells expressing interacting protein pairs, preferably pooled aπays of mteractants Other amplification methods which are well-known withm the art may also be utilized in the practice of the present invention including, but not limited to ligase chain reaction, Q/3 rephcase. or vanous other methods enumerated in Kπcka, et al 1995 Molecular Probing, Blotting and Sequencing (Academic Press, New York, NY) The plasmids encoding the DNA-binding domain hybrid and the activation domain hybnd proteins can also be isolated and cloned by any of the methods well-know n withm the art For example, but not by way of limitation, if a shuttle (yeast to E coli) vector is used to express the fusion proteins, the genes can be recovered by transforming the yeast DNA into E coli and recoveπng the plasmids from E coli See e g Hoffman, et al , 1987 Gene 57 267-272 Alternatn ely, the yeast vector can be isolated, and the insert encoding the fusion protein subcloned into a bactenal expression vector, for growth of the plasmid in Ε coli (16) PHARMACEUTICAL COMPOSITIONS AND THERAPEUTIC ROPHYLACTIC ADMINISTRATION The present invention discloses methods of treatment (and prophylaxis) by administration to a subject of an effective amount of a Therapeutic In a prefeπed embodiment, the Therapeutic is substantially puπfied The subject is preferably an animal including, but not limited to. animals such as cows, pigs, horses, chickens, cats, dogs, etc., and is preferably a mammal, and most preferably human In another specific embodiment, a non-human mammal is the subiect Formulations and methods of administration that can be employed when the Therapeutic compnses a nucleic acid are descnbed supra, and additional appropπate formulations ana routes of administration may be selected from among those descnbed herein below Vanous delivery systems are known and can be used to administer a Therapeutic of the invention including, but not limited to encapsulation m liposomes, microparticles, microcapsules, recombinant cells capable of expressing the Therapeutic, receptor-mediated endocytosis (see e g , Wu & Wu, 1987 J Biol Chem 262 4429-4432), construction of a Therapeutic nucleic acid as part of a retroviral or other vector, and the like Methods of introduction include, but are not limited to mtradermal, intramuscular, mtrapeπtoneal, intravenous, subcutaneous, intranasal, epidural. and oral routes The compounds may be 10 administered by any convenient route, for example by infusion or bolus injection, by absoφtion through epithelial or mucocutaneous linings (e g , oral mucosa, rectal and intestinal mucosa, etc ) and ma\ be administered together with other biologicallv active agents Administration may be either svstemic or local Furthermore, it may be desirable to introduce the pharmaceutical compositions of the invention into the central nervous system by any suitable route, including I-* intraventπcular and intrathecal injection, mtraventπcular injection may be facilitated by an intraventπcular catheter, for example, attached to a reservoir (e g an Ommaya reservoir) Pulmonary administration may also be employed (e g , by use of an inhaler or nebulizer, and formulation with an aerosolizing agent) In another specific embodiment of the present invention, it may be desirable to administer 20 the pharmaceutical compositions of the invention locally to the area in need of treatment, this may be achieved by, for example, and not bv way of limitation, local infusion dunng surgery, topical application (e g in conjunction with a wound dressing after surgery, by injection, by means of a catheter, by means of a suppository, or by means of an implant, said implant being of a porous, non-porous, or gelatinous matenal. including membranes, such as sialastic 25 membranes, or fibers) In one embodiment, administration can be by direct injection at the site (or former site) of a malignant tumor or neoplastic or pre-neoplastic tissue In another embodiment, the Therapeutic may be deh\ ered in a vesicle, in particular a hposome (see e g , Treat, et al , In Liposomes in the Therapy of Infectious Disease and Cancer (Liss. New York, NY) 30 In yet another embodiment, the Therapeutic may be delivered m a controlled release system In one specific embodiment, a pump may be utilized See e g , Sefton, 1987. CRC Crit Ref Biomed Eng 14 201 In another embodiment, polymeric matenals can be used (see e g , Medical Applications of Controlled Release 1984 (CRC Pres . Boca Raton, FL) In yet another embodiment, a controlled release system can be placed in proximity of the therapeutic target (e.g., the brain), thus requiring only a fraction of the systemic dose. In a specific embodiment where the Therapeutic is a nucleic acid encoding a protein Therapeutic, the nucleic acid may be administered in vivo to promote expression of its encoded protein, by constructing it as part of an appropriate nucleic acid expression vector and administering it so that it becomes intracellular, (e.g., by use of a retroviral vector; see U.S. Patent No. 4,980,286), or by direct injection; or by use of microparticle bombardment (e.g., a gene gun, Biolistic, DuPont), or coating with lipids or cell-surface receptors or transfecting agents; or by administering it in linkage to a homeobox-like peptide which is known to enter the nucleus (see e.g., Joliot, et al, 1991. Proc. Natl Acad. Sci. USA 8 : 1864-1868), and the like. Alternatively, a nucleic acid Therapeutic can be introduced intracellularly and incoφorated within host cell DNA for expression, by homologous recombination. The present invention also provides pharmaceutical compositions. Such compositions comprise a therapeutically effective amount of a Therapeutic, and a pharmaceutically acceptable carrier. In a specific embodiment, the term "pharmaceutically acceptable," as used herein, means approved by a regulatory agency of the Federal or a state government or listed in the U.S. Pharmacopoeia or other generally recognized pharmacopoeia for use in animals, and more particularly, in humans. The term "earner," as used herein, refers to a diluent, adjuvant, excipient. or vehicle with which the therapeutic is administered. Such pharmaceutical carriers can be sterile liquids, such as water and oils, including those of petroleum, animal, vegetable or synthetic origin, such as peanut oil. soybean oil, mineral oil, sesame oil and the like. Water is a prefeπed carrier when the pharmaceutical composition is administered intravenously. Saline solutions and aqueous dextrose and glycerol solutions can also be employed as liquid carriers, particularly for injectable solutions. Suitable pharmaceutical excipients include starch, glucose, lactose, sucrose, gelatin, malt, rice, flour, chalk, silica gel, sodium stearate, glycerol monostearate, talc, sodium chloride, dried skim milk, glycerol, propylene. glycol. water, ethanol and the like. The composition, if desired, can also contain minor amounts of wetting or emulsifying agents, or pH buffering agents. These compositions can take the form of solutions, suspensions, emulsion, tablets, pills, capsules, powders, sustained-release formulations and the like. The composition can be formulated as a suppository, with traditional binders and carriers such as triglycerides. Oral formulation can include standard carriers such as pharmaceutical grades of mannitol. lactose, starch, magnesium stearate, sodium saccharine, cellulose, magnesium carbonate, etc. Examples of suitable pharmaceutical earners are described in "Remington's Pharmaceutical Sciences" by E.W. Martin (1965). Such compositions will contain a therapeutically effective amount of the Therapeutic (preferably in a substantially purified form) together with a suitable amount of carrier so as to provide the form for proper administration to the patient. The formulation should suit the mode of administration. In a prefeπed embodiment, the composition is formulated in accordance with routine procedures as a pharmaceutical composition adapted for intravenous administration to human beings. Typically, compositions for intravenous administration are solutions in sterile isotonic aqueous buffer. Where necessary, the composition may also include a solubilizing agent and a local anesthetic (e.g., lignocaine) to ease pain at the site of the injection. Generally, the ingredients are supplied either separately or mixed together in unit dosage form, for example, as a dry lyophilized powder or water free concentrate in a hermetically sealed container such as an ampoule or sachet indicating the quantity of active agent. Where the composition is to be administered by infusion, it can be dispensed with an infusion bottle containing sterile pharmaceutical grade water or saline. Where the composition is administered by injection, an ampoule of sterile water for injection or saline can be provided so that the ingredients may be mixed prior to administration. The Therapeutics of the invention can be formulated as neutral or salt forms. The amount of the Therapeutic of the present invention which will be effective in the treatment of a particular disorder or condition will depend on the nature of the disorder or condition, and may be determined in a quantitative manner by standard clinical techniques. In addition, in vitro assays may optionally be employed to help identify optimal dosage ranges. The precise dose to be employed in the formulation will also depend on the route of administration, and the seriousness of the disease or disorder, and should be decided according to the judgment of the practitioner and each patient's circumstances. However, suitable dosage ranges for intravenous administration are generally about 20-500 μg of active compound/kg of patient body weight. Suitable dosage ranges for intranasal administration are generally about 0.01 pg/kg body weight to 1 mg/kg body weight. Effective doses may be extrapolated from dose-response curves derived from in vitro or animal model test systems. Suppositories generally contain active ingredient in the range of 0.5%o to 10%> by weight: whereas oral formulations preferably contain 10%) to 95%o active ingredient. The present invention also provides a pharmaceutical pack or kit comprising one or more containers filled with one or more of the ingredients of the pharmaceutical compositions of the invention. Optionally associated with such container(s) can be a notice in the form prescribed by a governmental agency regulating the manufacture, use or sale of pharmaceuticals or biological products, which notice reflects approval by the agency of manufacture, use or sale for human administration. SPECIFIC EXAMPLES (A) IDENTIFICATION OF 53BP2»53BP2-IP COMPLEXES A modified, improved yeast two hybrid system was utilized to identify protein interactions. Yeast is a eukarvote, and therefore any intermolecular protein interactions detected in this type of system demonstrate protein interactions that occur under physiological conditions. Expression vectors were constructed to encode two hybrid proteins. For a "forward" screen, one hybrid consisted of the DNA binding domain of the yeast transcriptional activator Gal4 fused to a portion of 53BP2. The other hybrid consisted of the Gal4 activator domain fused to "prey " protein sequences encoded by a mammalian cDNA library. In a "reverse " screen, the portion of 53BP2 was fused to the Gal4 activator domain, and the prey protein sequences of the mammalian cDNA library were fused to the DNA binding domain, but the assay was otherwise identically performed. Each of the vectors was inserted into complementary (a and alpha) mating types of yeast using methods known in the art and mating was then carried out to express both vector constructs within the same yeast cells, thus allowing interaction to occur. Interaction between the bait and prey domains led to transcriptional activation of reporter genes containing cis-binding elements for Gal4. The Reporter Genes encoding the indicator protein (β-galactosidase) and metabolic markers for uracil and histidine auxotrophy, were included in specific fashion in one or the other of the yeast strains used in the mating. In this manner, yeast were selected for successful mating, expression of both fusion construct, and expression of 53BP2-IPs. Yeast clones which possessed interacting regions were picked and grown in individual wells of microtiter plates. The plasmids containing the 53BP2-IPs were then isolated and characterized. The prey cDNAs were obtained from a fetal brain cDNA library of 1.5 x 10 10 independent isolates. The library was synthesized from Xho l-dT 15 -primed fetal brain mRNA (from five male/female 19-22 week fetuses) which was directionally cloned into pBD-Gal4 (a yeast Gal4 DNA binding domain cloning vector including the TRYP gene for selection in yeast deficient in tryptophan biosynthesis). A reverse screen was used to test the interaction of prey cDNA products against an aπay of 22 bait proteins, one of which was encoded by the 53BP2 nucleotide sequence of nucleotides 2866-3771 as depicted in Figure 1 [SEQ. ID NO 1], including amino acid residues 704-1005 of the 53BP2 amino acid sequence at the carboxyl-terminus of 53BP2, as depicted in Figure 1 [SEQ. ID NO 2] The bait fragment was amplified from a λgtl 1 library (Clontech) by polymerase chain reaction (PCR) using the forward pπmer "GGACTAGGCCGAGGTGGCCTCTCCAGGCCT TGATTATGAGCCTG 3 ' [SEQ ID NO 14] and the reverse pnmer "GGACTAGGCCTCCTCGGCCCTACCTCTGCACTATGTCACTGATTTX [SEQ ID NO:15], by standard techniques The resulting amplification fragment as cloned into the Sfi I site of the vector pACT-Sfi I, constructed by introducing an Sfi I-contaimng polylmker into the vector pACT2 (Clontech) This vector is a yeast activation domain cloning vector which contains the LEU2 gene for selection in yeast strains deficient in leucine biosynthesis The bait was sequenced to confirm that PCR amplification reproduced an accurate copy of the 53BP2 sequence (see Figure 1 ) This analysis determined that, as predicted, the bait sequence encoded an interacting domain identical to the human 53BP2 beginning at amino acid residue 704 (see Figure 1) The bait was then transformed by a lithium acetate/polyethylene glycol transformation protocol (see Ito, et al 1983 J Bacterwl 153 163-168) into the yeast strain NlO6r (mating type a, ura3. hιs3, ade2, trpl. Ieu2, gal4, galsO, cyhr, Lys2..GALl- , n XATA" l D ura 3.GAL1U- GALTATA-lacZ), while the prey sequences were transformed into the yeast strain YULH (mating type alpha. ura3, hιs3, lys2. Ade2. trpl, leu2, gal4, galBO, GALl-lacZ, GAL1-URA3) The two transformed populations were then mated using standard methods within the art Bπefly, cells were grown until mid-to-late log phase on media that selected for the presence of the appropπate plasmids The tw o mating strains (alpha and a) were then diluted in YAPD media ( see e g , Sherman, et al , 1991 Getting Started with Yeast, Vol 194 (Academic Press, New York, NY), filtered onto nitrocellulose membranes, and incubated at 30"C for 6-8 hours The cells were then transfeπed to media selective for the desired diploids (z e , yeast possessing Reporter Genes for β-galactosidase. uracil auxotrophy, and histidine auxotrophy. and expression of the vectors encoding the bait and prey The mating products were plated on SC (synthetic complete, see Kaiseret. et al 1994 Methods in Genetics (Cold Spπng Harbor Press, New York, NY) media lacking adenme and lysine (to select for successful mating), leucine and tryptophan (to select for expression of genes encoded by both the bait and prey plasmids), and uracil and histidine (to select for protein interactions) This medium is hereinafter refeπed to as SCS medium, for SC Selective medium Selected clones were tested for expression of β-galactosidase to confirm the formation of a 53BP2»53BP2-IP interaction. Filter-lift β-galactosidase assays were performed as modified from the protocol of Breeden and Nasmyth, 1985. Cold Spring Harbor Quant. Biol 50-643-650 Colonies were patched onto SCS plates, grown overnight, and replica-plated onto Whatman No. 1 filters. The filters were then assayed for β-galactosidase activity; wherein colonies which were "positive" turned a visible blue. Cells in colonies positive for protein interaction contained a mixture of DNA-bmding and activation-domain plasmids. These cells were individually plated, and regrown as single isolates in individual wells of 96-well microtiter plates. Approximately 10 μl of each isolate was then lysed, the inserts withm the pACT2 and pASSPiI plasmids were amplified by PCR using pnmers specific for the flanking sequences of each vector, and approximately 200 ammo-termmal nucleotides of each insert was determined using an ABI 377 sequenator Compaπson to known sequences was made using the "Blast" program publicly available through the National Center for Biotechnology Information (NCBI). Two of the inserts were identified as β-tubuhn, the others identified as p62, hnRNP G, and the insert encoding 53BP2.TP-1, 53BP2:IP-2 or 53BP2.IP-3 Specifically, the inserts contained nucleotides 830-1398 and 895-1398 of the coding sequence for β-tubuhn, as depicted in Figure 2 [SEQ. ID NO 3]; nucleotides 929-1435 of the nucleotide sequence of p62, as depicted in Figure 3 [SEQ. ID NO'5], nucleotides 273-1322 of hnRNP G, as depicted in Figure 4 [SEQ. ID NO:7] and the sequence depicted in Figure 5 (encoding m-part 53BP2.IP-1, 53BP2.IP- 2 and 53BP2.IP-3). The determined nucleic acid sequences and corresponding, inferred amino acid sequences of β-tubuhn, p62. hnRNP G. 53BP2 IP-1, 53BP2:IP-2 and 53BP2 IP-3 are illustrated in Figures 2-4 and 9-13. respectively A summary of the 53BP2 and 53BP2-IP interacting domains are shown in Figure 6 (B) VERIFICATION OF THE SPECIFICITY OF THE 53BP2+B-TUBULIN. p62. hnRNP G AND 53BP2»IP-1. -2 and -3 INTERACTIONS In order to ascertain the specificity of baifprey interaction, two general tests were first performed. In the first test, N106 cells were created that express the individual plasmids encoding 53BP2. β-tubulm, p62, hnRNP G, and the sequences encoding 53BP2:IP-1, 53BP2.IP-2 and 53BP2:IP-3 These yeast cells were plated on SCS plates, grown overnight, and examined for growth. No growth was found for all five proteins, confirming that they were not "self-activating" proteins (i e , these proteins require interaction with a second protein domain for a functional activation complex). In the second test, plasmids containing β-tubulin, p62. hnRNP G, and 53BP2:IP-1, 53BP2:IP-2 or 53BP2:IP-3 inserts were transformed into strain YULH (mating type alpha) and mated with yeast strain N106 (mating type a) expressing proteins other than 53BP2. Promiscuous binders (i.e., inserts able to bind with many other proteins in a non-specific fashion) would interact non-specifically with non-53BP2 domains, and would be discarded as non-specific interactants. 53BP2 was demonstrated to fail to interact with pRb (GenBank Ace. No. 1428419; Lee, et al, 1987. Nature 329: 642-645); the trk oncogene (GenBank Ace. No. X03541 ; Martin-Zanca, et al, 1986. Nature 319:743-748); EST M62042 (Adams, et al, 1991. Science 252: 1651-1656); Ral GDS (GenBank Ace. No. U14417; Hofer, et al, 1994. Proc. Natl. Acad. Sci. U.S.A. 9k 1 1089-1 1093) or E2F (GenBank Ace. No. X86096). In addition, β-tubulin, p62, hnRNP G, and the sequences encoding 53BP2.TP-1, 53BP2TP-2 or 53BP2:IP-3 also did not interact with MDM2 15 (GenBank Ace. No. M92424); CAS (GenBank Ace. No. U33286: Brinkmann. et al. 1995. Proc. Natl Acad. Sci. U.S.A. 92: 1042"- 10431 ) and PA9 (GenBank Ace. No. S82076; Yang, et al, 1996. Carcinogenesis 17:563-567). Specifically. lack of growth for the p62 and β-tubulin interactions with MDM2 is depicted in Figure 7. To recapitulate the detected interactions, and further demonstrate their specificity, the isolated bait plasmid for 53BP2. along with bait plasmids for MDM2 and human bait protein 1 (Bl) were utilized to transform yeast strain N106Rτ (mating type a). The interacting domains from p62 and β-tubulin were transformed into strain YULH (mating type alpha). The transformants were re-amplified, and a mating performed to recapitulate the identified 53BP2«53BP2-IP complex formation. 53BP2 complexed specifically with β-tubuim and p62. but not with two human proteins. HI and H2. As illustrated in Figure 7. the intersection of the 53BP2 row (bottom) with the β-tubulin and p62 columns indicates growth (i.e., a positive interaction), but the intersection of the 53BP2 row with the columns for HI and H2 indicates no growth (i.e., no protein interaction). The known interaction between 53BP2 and PPl-α (see e.g., Helps, et al, 1995. FEBS Letts. 377:295-300) was confirmed, as shown in Figure " . intersection of column 3, row 3. As previously described above, β-tubulin and p62 failed to interact with MDM2 and Bl. Mating of PPl-α and Bl confirmed an interaction previously found in our studies (Figure 7. and Nandabalan, et al, 1997. unpublished). (C) ASSEMBLY OF THE SEQUENCE ENCODING 53BP2:IP-1. 53BP2:IP-2 AND " 53BP2TP-3 One identified prey sequence was identical to EST R72810 (GenBank data base "dbes '). The database contained other EST sequences which were found to overlap the EST R72810 sequence. Hence, it was possible to find contiguous sequences to extend the nucleotide sequence both 3'- and 5 '-termini of the EST R72810. The general procedure utilized is illustrated in Figure 8. The National Center for Biotechnology Information (NCBI) "Blast" Program was used to compare the EST R72810, and compared to all sequences in the non-redundant nucleotide data bases "NRDB," a compilation of GenBank + EMBL + DDBJ + PDB sequences (but no EST, STS, GSS, or HTGS sequences), as defined in the NCBI Blast program, "month." which includes all new or revised GenBank + EMBL + DDBJ - 1 - PDB sequences released within the last 30 days, and "dbest," a non-redundant database of GenBank + EMBL - DDBJ + EST divisions. Sequences which aligned with 95% or greater identity at the nucleic acid level over their termini of at least 30 bases, were utilized if the alignment resulted in either a 5 '-extension or 3'-extension of the EST R72810 sequence. Once this first assembly was complete, the extended sequence was again subject to the Blast comparison, so as to detect possible, new homologies to the added extensions. Specifically, the sequence was extended in both directions until new related sequences that allowed extension of the assembled sequence were no longer detected. The extended EST R72810 sequence is illustrated in Figure 9 and the nucleic acid sequence of the original EST R72810 sequence is shown in bold lettering. For 5 '-extension, a long overlap was found with EST C 17385, the nucleotide sequence of which is denoted by bold underline (Fujiwara et al. GenBank direct submission, Sept. 9.1996). For 3'-extension. overlap with EST AA464793 (Hillier, et al, 1997. Wash Univ.-Merck EST Project), shown in boxed lettering, was detected. Additional overlap between EST AA464793 and EST AA479761 (Hillier, et al, 1997. Wash Univ.-NCI Human EST Project), shown in bold, italic lettering, was utilized for further 3 '-extension, to complete the EST assembly process. The complete assembled sequence of 915 nucleotides is shown in Figure 9. The assembled EST sequence was then subjected to a further 10 searches of both the NRDB and "month" nucleic acid data bases to detect possible homologies to known protein sequences which were not previously detected over the shorter-span of the original EST sequence. This step was necessary where significant homology was not detected during the EST assembly process to proteins in the NRDB and "month" data bases, as was the case with the assembled EST R72810. However, no significant homologies to known proteins were detected for the extended EST R72810 utilizing this aforementioned analysis. In addition, the sequence was analyzed by the NCBI program "ORF Finder," that performed translations in all three forward reading frames of the assembled DNA sequence (Figures 10 A-F). EST R72810 (Hillier, et al, 1995. GenBank Direct Submission. June 2, 1995) was obtained from the directionally-cloned Soares breast library 2NbHBst. and thus the direction of 25 translation of the extended EST is known as 5' to 3'. Within the three translations, three possible open reading frames ("ORFs") were identified. Open reading frames greater than 60 amino acid residues in length following an initiator codon or an ORF with no initiator methionine encoded at the 5' end were determined to be possible protein products, and were submitted for Blast searching against the protein data base NRDB. a non-redundant compilation of GenBank CDS translations + PDB + SwissProt + PIR Swiss Prot sequences, and "month," which includes all new or revised GenBank CDS translation + PDB + Swiss Prot - PIR sequences released within the last 30 days. Three possible protein candidates were identified by the hypothetical translation. The first candidate, encoded in Translation Frame #3 (Figure 10 F), encompasses an ORF from amino acid residue 1 (Arg) to amino acid residue 286 (Gin) which directly precedes an opal translational stop codon. This aforementioned translational frame has no initiator methionine codon (ATG), and hence must extend further 5' than the assembled sequence. The second protein candidate, encoded in Translation Frame #2 (Figure 10 D). extends from the initiator codon ATG at amino acid residue position 147 (Met) to a Gin residue, 69 amino acids downstream, which precedes an amber translational stop codon. The third protein candidate, encoded in Translation Frame #1 (Figure 10 B), extends from a Gly residue at amino acid residue position 1 (no initiation methionine codon was found in this reading frame) to a Gly amino acid residue located at position 33, which precedes a TAA stop codon. It should be noted that none of these aforementioned proteins displayed significant homology to any known protein at either the nucleic acid or amino acid levels. The present invention is not to be limited in scope by the specific embodiments described herein. Indeed, numerous modifications of the invention, in addition to those described herein, will become apparent to those individuals skilled within the relevant arts from the foregoing description and accompanying figures. Such modifications are intended to fall within the scope of the appended claims. Various publications are cited herein, the disclosures of which are incoφorated by reference in their entireties.

Claims: WHAT IS CLAIMED IS: 1. A purified complex of a 53BP2 protein and a 53BP2-IP protein, wherein the 53BP2-IP protein is not PPl-α or p53. 2. The purified complex of claim 1, wherein said 53BP2-IP protein is selected from the group consisting of β-tubulin protein, p62 protein, and hnRNP G protein. 3. The purified complex of claim 1, wherein said 53BP2-IP protein is a 53BP2:IP-1 protein. 4. The purified complex of claim 1, wherein said 53BP2-IP protein is a 53BP2:IP-2 protein. 5. The purified complex of claim 1 , wherein said 53BP2-IP protein is a 53BP2:IP-3 protein. 6. The purified complex of claim 1, in which said proteins are human proteins. 7. A purified complex selected from the group consisting of: a complex of a fragment of a 53BP2 protein and a full-length 53BP2-IP protein, a complex of a full-length 53BP2 protein and a fragment of a 53BP2-IP protein, and a complex of a fragment of a 53BP2 protein and a fragment of a 53BP2-IP protein, in which the fragment of the 53BP2 protein possesses the 53BP2-IP binding domain of the 53BP2 protein and the fragment of the 53BP2-IP protein possesses the 53BP2 binding domain of the 53BP2-IP protein, in which the 53BP2-IP is selected from the group consisting of: β-tubulin, p62, hnRNP G, 53BP2.TP-1, 53BP2:IP-2 and 53BP2:IP-3. 8. A purified complex selected from the group consisting of: a complex of a derivative of a 53BP2 and a 53BP2-IP protein, a complex of a 53BP2 protein and a derivative of a 53BP2-IP, and a complex of a derivative of a 53BP2 and a derivative of a 53BP2-IP. in which said derivative of the 53BP2 protein is capable of forming a complex with a wild-type 53BP2-IP protein and said derivative of the 53BP2-IP is able to form a complex with a wild-type 53BP2 protein, in which the 53BP2-IP is selected from the group consisting of: β-tubulin. p62, hnRNP G, 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3. 9 The puπfied complex of claim 8, wherein which said deπvative of the 53BP2 protein and/or the 53BP2-IP protein is fluorescently-labeled 10 A chimeπc protein compnsing a fragment of a 53BP2 protein consisting of at least 6 ammo acid residues fused, via a covalent bond, to a fragment of a 53BP2-IP protein consisting of at least 6 amino acids 1 1 The chimenc protein of claim 10 herein said fragment of the 53BP2 protein is a fragment capable of binding the 53BP2-IP protein and wherein said fragment of the 53BP2-IP protein is a fragment capable of binding the 53BP2 protein 12 The chimenc protein of claim 1 1 herein said fragment of the 53BP2 protein and said fragment of the 53BP2-IP protein form a 53BP2»53BP2-IP complex 13 An antibody which immunospecifically-binds a complex of a 53BP2 protein and a 53BP2-IP protein, or a fragment or deπvatπ e of said antibody possessing the binding domain thereof, m which the 53BP2-IP is selected from the group consisting of β-tubuhn, p62, hnRNP G 53BP2 IP-1. 53BP2 IP-2 and 53BP2-IP-3 14 The antibody of claim 13, which does not lmmunospecificallv-bmd a 53BP2 protein or a 53BP2-IP protein which are not part of a 53BP2»53BP2-IP complex 15 An isolated nucleic acid or an isolated combination of nucleic acids compπsing a nucleotide sequence encoding a 53BP2 protein and a nucleotide sequence encoding a 53BP2-IP protein selected from the group consisting of β-tubuhn, p62, hnRNP G, 53BP2 IP-1, 53BP2 IP-2 and 53BP2 IP-3 16 The isolated nucleic acid or isolated combination of nucleic acids of claim 15 which are nucleic acid vectors 17 The isolated nucleic acid or isolated combination of nucleic acids of claim 16 wherein the 53BP2 protein-coding sequence and the 53BP2-IP protem-codmg sequence are operably-linked to a promoter 18 An isolated nucleic acid that compπses a nucleotide sequence encoding the chimenc protein of claim 12 19 A recombinant cell containing said nucleic acid of claim 15 20 A recombinant cell containing said nucleic acid of claim 17 21 A recombinant cell containing said nucleic acid of claim 18 22 A puπfied protein selected from the group consisting of 53BP2 IP-1, 53BP2 IP-2 and 53BP2 IP-3 23 The protein of claim 22 which is a human protein 24 The protein of claim 23 which compπses an amino acid sequence selected from the group consisting of SEQ ID NO 11. SEQ ID NO 12 and SEQ ID NO 13 25 A purified protein encoded by a nucleic acid hybndizable to the i erse complement of a DNA possessing a nucleotide sequence consisting of SEQ ID NO 10 26 A purified derivative or analog of the protein of claim 22. herein said deriv ative or analog can bind 53BP2 27 The denvative or analog of claim 26 which is able to be bound by an antibody directed against a protein selected from the group consisting of 53BP2 IP-1. 53BP2 IP-2 and 53BP2 IP-3 28 A nuπfied fragment of the protein of claim 22. wherein said fragment compπses a 53BP2 binding domain 29 A puπfied protein compnsmg an ammo acid sequence possessing at least 60% identity to the protein of claim 22, wherein the percentage identity is determined over an ammo acid sequence of identical size to said protein of claim 22 30. A chimeric protein comprising a fragment of the protein of claim 22, said fragment consisting of at least 6 amino acids, fused via a covalent bond to an amino acid sequence of a second protein, wherein the second protein is not said protein of claim 22. 31. An antibody which immunospecifically-binds the protein of claim 22, or a fragment or derivative of said antibody possessing the binding domain thereof. 32. An isolated nucleic acid comprising a nucleotide sequence encoding said protein of claim 22. 33. An isolated nucleic acid comprising the nucleotide sequence of SEQ. ID NO:10. 34. An isolated nucleic acid hybridizable to the inverse complement of the coding sequence of SEQ. ID NO: 10. 35. A recombinant cell containing said nucleic acid of claim 34. 36. A pharmaceutical composition comprising a therapeutically- or prophylactically-effective amount of a complex of a 53BP2 protein and a 53BP2-IP protein, wherein said 53BP2-IP is selected from the group consisting of: β-tubulin, p62, hnRNP G, 53BP2.TP-1, 53BP2TP-2 and 53BP2:IP-3, and a pharmaceutically-acceptable carrier. 37. The pharmaceutical composition of claim 36 in which the proteins are human proteins. 38. A pharmaceutical composition comprising a therapeutically- or prophylactically-effective amount of a complex selected from the group consisting of: a complex of a fragment of a 53BP2 protein and a full-length 53BP2-IP protein, a complex of a full-length 53BP2 protein and a fragment of a 53BP2-IP protein, and a complex of a fragment of a 53BP2 protein and a fragment of a 53BP2-IP protein, wherein the fragment of said 53BP2 protein possesses the 53BP2-IP binding domain of the 53BP2 protein and the fragment of said 53BP2-IP protein possesses the 53BP2 binding domain of said 53BP2-IP protein, and wherein the 53BP2-IP is selected from the group consisting of: β-tubulin, p62. lrnRNP G, 53BP2.TP-1, 53BP2:IP-2 and 53BP2-IP-3, and a pharmaceutically-acceptable carrier. 39. A pharmaceutical composition comprising a therapeutically- or prophylactically-effective amount of a chimeric protein comprising a fragment of a 53BP2 protein consisting of at least 6 amino acids fused via a covalent bond to a fragment of a 53BP2-IP protein consisting of at least 6 amino acids, and a pharmaceutically-acceptable carrier. 40. The pharmaceutical composition of claim 39 wherein the fragment of the 53BP2 protein is a fragment capable of binding the 53BP2-IP protein and wherein the fragment of the 53BP2-IP protein is capable of binding the 53BP2 protein. 41. The pharmaceutical composition of claim 40 wherein the fragment of the 53BP2 protein and the fragment of the 53BP2-IP protein form a 53BP2*53BP2-IP complex. 42. A pharmaceutical composition comprising a therapeutically- or prophylactically-effective amount of an antibody which immunospecifically-binds a complex of a 53BP2 protein and a 53BP2-IP protein, or a fragment or derivative of said antibody possessing the binding domain thereof, wherein the 53BP2-IP protein is selected from the group consisting of: β-tubulin, p62, hnRNP G, 53BP2.TP-1, 53BP2:IP-2 and 53BP2-IP-3, and a pharmaceutically-acceptable carrier. 43. The pharmaceutical composition of claim 42 wherein the antibody does not immunospecifically-bind a 53BP2 protein or a 53BP2-IP protein which are not part of a 53BP2«53BP2-IP complex. 44. A pharmaceutical composition comprising a therapeutically- or prophylactically-effective amount of a nucleic acid comprising a nucleotide sequence encoding a 53BP2 protein and a nucleotide sequence encoding a 53BP2-IP protein, wherein the 53BP2-IP is selected from the group consisting of: β-tubulin, p62, hnRNP G, 53BP2.TP-1, 53BP2:IP-2 and 53BP2-IP-3. and a pharmaceutically-acceptable carrier. 45. A pharmaceutical composition comprising a therapeutically- or prophylactically-effective amount of said isolated nucleic acid of claim 18, and a pharmaceutically-acceptable carrier. 46 A pharmaceutical composition compπsing a therapeutically- or prophylactically-effective amount of said recombinant cell of claim 21, and a pharmaceutically-acceptable earner 47 A pharmaceutical composition compπsing a therapeutically- or prophylactically-effective amount of a 53BP2 IP-1 protein, 53BP2 IP-2 protein or 53BP2 IP-3 protein, and a pharmaceuticallv-acceptable earner 48 The pharmaceutical composition of claim 47, wherein the 53BP2 IP-1 protein compπses the ammo acid sequence as set forth in SEQ ID NO 11, the 53BP2 IP-2 protein compπses the ammo acid sequence as set forth in SEQ ID NO 12 and the 53BP2 IP-3 protein compπses the amino acid sequence as set forth in SEQ ID NO 13 49 A pharmaceutical composition compπsing a therapeutically- or prophylactically-effective amount of an antibody which immunospecificallv-bmds a protein selected from the group consisting of a 53BP2 IP-1 protein, a 53BP2 IP-2 protein and a 53BP2 IP-3 protein, or a fragment or den\ ative of said antibody possessing the binding domain thereof, and a pharmaceutically-acceptable earner 50 A pharmaceutical composition compπsing a therapeutically- or prophylactically-effective amount of a nucleic acid compπsing a nucleotide sequence encoding a protein selected from the group consisting of 53BP2 IP-1. 53BP2 IP-2 and 53BP2 IPX and a pharmaceutically-acceptable earner 51 A pharmaceutical composition compπsing a therapeutical - or prophylactically-effective amount of a recombinant cell containing said nucleic acid of claim 50, and a pharmaceutically- acceptable earner 52 A method of producing a complex of a 53BP2 protein and a 53BP2-IP protein compπsing growing a recombinant cell containing the nucleic acid of claim 15. such that the encoded 53BP2 and 53BP2-IP proteins are expressed and bind to one another, and recoveπng the expressed complex of said 53BP2 protein and said 53BP2-IP protein 53 A method of producing a protein selected from the group consisting of 53BP2 IP-1, 53BP2 IP-2 and 53BP2 IP-3 compπsing growing a recombinant cell containing a nucleic acid encoding said protein such that the encoded protein is expressed, and reco\ enng the expressed protein 54 A method of diagnosing or screening for the presence of or a predisposition for developing a disease or disorder characteπzed by an abeπant level of a complex of 53BP2 protein and a 53BP2-IP protein, wherein said 53BP2-IP is selected from the group consisting of β-tubulm. p62, hnRNP G 53BP2 IP-1. 53BP2 IP-2 and 53BP2 IP-3, in a subject compπsing measunng the level of said complex, RNA encoding the 53BP2 and 53BP2-IP proteins, or functional activity of said complex in a sample deπved from the subject, in which an increase or decrease in the level of said complex, said RNA encoding 53BP2 and 53BP2-IP, or functional activity of said complex in the sample relative to the level of said complex, said RNA encoding 53BP2 and 53BP2-IP or functional acm itv of said complex found in an analogous sample not having the disease or disorder or a predisposition for developing the disease or disorder, indicates the presence of the disease or disorder or a predisposition for developing the disease or disorder 55 A method of diagnosing or screening for the presence of or a predisposition for developing a disease or disorder characteπzed by an abeπant level of a protein or RNA selected from the group consisting of 53BP2 IP-1. 53BP2 IP-2 or 53BP2 IP-3 protein or RNA in a subject, compπsmg measunng the level of said protein, said RNA or the functional activity of said protein in a sample deπved from the subject, wherein an increase or decrease in the le\ el of said protein, said RNA, or said functional activity in the sample, relative to the level of said protein, said RNA. or said functional ity found in an analogous sample not having the disease or disorder or a predisposition for developing the disease or disorder, is indicative of the presence of the disease or disorder or a predisposition for developing the disease or disorder 56 A kit compnsmg, in one or more containers, a substance selected from the group consisting of a complex of 53BP2 and a 53BP2-IP. an antibody against said complex, nucleic acid probes capable of hybπdizmg to RNA of said 53BP2 and RNA of said 53BP2-IP, or pairs of nucleic acid pnmers capable of pnmmg amplification of at least a portion of a gene for said 53BP2 and a gene for said 53BP2-IP, in which said 53BP2-IP is selected from the group consisting of β-tubulin, p62, hnRNP G, 53BP2 IP-1, 53BP2 IP-2 and 53BP2 IP-3 57 A method of treating or preventing a disease or disorder involving aberrant levels of a complex of 53BP2 and 53BP2-IP. in which said 53BP2-IP is selected from the group consisting of β-tubulm, p62, hnRNP G, 53BP2 IP-1, 53BP2 IP-2 and 53BP2-IP-3, m a subject compnsmg admimsteπng to a subject in which such treatment or prevention is desired a therapeutically effective amount of a molecule or molecules which modulate the function of said complex 58 The method of claim 57 in which said disease or disorder involves decreased levels of said complex and said molecule or molecules promote the function of the complex of 53BP2 and 53BP2-IP and are selected from the group consisting of a complex of 53BP2 and 53BP2-IP. a deπvative or analog of a complex of 53BP2 and 53BP2-IP. which complex is more stable or more active than the wild-type complex, nucleic acids encoding the 53BP2 and 53BP2-IP proteins, and nucleic acids encoding a denvative or analog of 53BP2 and 53BP2-IP that form a complex that is more stable or more active than the wild-type complex 59 The method of claim 57 m which said disease or disorder involves increased levels of said complex and said molecule or molecules inhibit the function of said complex and are selected from the group consisting of an antibody against said complex or a fragment or deπvative thereof containing the binding region thereof, 53BP2 and 53BP2-IP antisense nucleic acids, and nucleic acids compπsing at least a portion of a 53BP2 and a 53BP2-IP gene into which a heterologous nucleotide sequence has been inserted such that said heterologous sequence inactivates the biological activity of the at least a portion of the 53BP2 and 53BP2-IP genes, wherein the 53BP2 and the 53BP2-IP gene portions flank the heterologous sequences so as to promote homologous recombination with genomic 53BP2 and 53BP2-IP genes 60 A method of treating or prev enting a disease or disorder involving an abeπant level of a 53BP2-IP selected from the group consisting of 53BP2 IP-1. 53BP2 IP-2 and 53BP2 IP-3 in a subject comprising admmisteπng to a subject in which such treatment or prevention is desired a therapeutically-effective amount of a molecule which modulates the function of said 53BP2-IP 61 The method of claim 60 in which said disease or disorder involves a decreased level of the 53BP2-IP and said molecule promotes the function of the 53BP2-IP and is selected from the group consisting of the 53BP2-IP protein, a deπvative or analog of the 53BP2-IP which is active in binding 53BP2. a nucleic acid encoding the 53BP2-IP protein, and a nucleic acid encoding a derivative or analog of the 53BP2-IP which is active in binding 53BP2 62. The method of claim 60 in which said disease or disorder involves an increased level of the 53BP2-IP and said molecule inhibits the 53BP2-IP function and is selected from the group consisting of an anti-53BP2-IP antibody, or a fragment or derivative thereof possessing the binding region thereof, a 53BP2-IP antisense nucleic acid, and a nucleic acid comprising at least a portion of the 53BP2-IP gene into which a heterologous nucleotide sequence has been inserted such that said heterologous sequence inactivates the biological activity of the at least a portion of the 53BP2-IP gene, wherein the 53BP2-IP gene portion flanks the heterologous sequence so as to promote homologous recombination with a genomic 53BP2-IP gene. 63. A method of screening a purified complex of 53BP2 and a 53BP2-IP selected from the group consisting of: tubulin, p62. hnRNP G, 53BP2:IP-1. 53BP2:IP-2 and 53BP2:IP-3, or a derivative of said complex, or a modulator of the activity of said complex for anti-neoplastic activity comprising measuring the survival or proliferation of cells from a cell line which is derived from or displays characteristics associated with malignant disorder, which cells have been contacted with the complex, derivative, or modulator, and comparing the survival or proliferation in the cells contacted with the complex, derivative or modulator with said survival or proliferation in cells not so contacted, wherein a lower level in said contacted cells indicates that the complex, derivative or modulator possesses anti-neoplastic activity. 64. A method of screening a purified complex of 53BP2 and a 53BP2-IP selected from the group consisting of: tubulin. p62, hnRNP G. 53BP2.TP-1. 53BP2:IP-2 and 53BP2:IP-3. or a derivative of said complex, or a modulator of the activity of said complex for anti-neoplastic activity by a method comprising administering the complex, derivative or modulator to a test animal, which test animal has a tumor, or which test animal does not have a tumor and is subsequently challenged with tumor cells or tumorigenic agents, and measuring tumor growth or regression in said test animal, wherein decreased tumor growth or increased tumor regression or prevention of tumor growth in test animals administered said complex, derivative or modulator compared to test animals not so administered indicates that the complex, derivative or modulator possesses anti-neoplastic activity. 65. A method for screening a purified complex of 53BP2 and a 53BP2-IP selected from the group consisting of; tubulin, p62. hnRNP G, 53BP2.TP-1. 53BP2:IP-2 and 53BP2:IP-3, or a derivative of said complex, or a modulator of the activity of said complex, for activity in treating or preventing autoimmune disease compnsmg contacting cultured cells that exhibit an indicator of an autoimmune reaction in vitro with said complex, denvative or modulator, and compaπng the level of said indicator in the cells contacted w ith the complex, derivative, or modulator with said level of said indicator in cells not so contacted, wherein a lower level m said contacted cells indicates that the complex, deπvative or modulator possesses activity in treating or preventing autoimmune disease 66 A method for screening a puπfied complex of 53BP2 and a 53BP2-IP selected from the group consisting of β-tubuhn, p62, hnRNP G. 53BP2 IP-1, 53BP2 IP-2 and 53BP2 IP-3, or a deπvative of said complex, or a modulator of the activity of said complex for activ ity in treating or preventing autoimmune disease compnsmg administering said complex, deπvative or modulator to a test animal, which test animal exhibits an autoimmune reaction, or hich test animal does not exhibit an autoimmune reaction and is subsequently challenged w ith an agent that elicits an autoimmune reaction, and measunng the change in the autoimmune reaction after the administration of said complex, deπvative or modulator, wherein a reduction in said autoimmune reaction or prevention of said autoimmune reaction indicates that the complex, deπvativ e or modulator possesses activity in treating or preventing an autoimmune disease 67 A method for screening a puπfied complex of 53BP2 and a 53BP2-IP selected from the group consisting of β-tubulm, p62, hnRNP G. 53BP2 IP-1. 53BP2 IP-2 and 53BP2 IPX or a deπvativ e of said complex, or a modulator of the activity of said complex for activ ity in treating or preventing neurodegenerative disease, compnsmg contacting cultured cells that exhibit an indicator of a neurodegenerative disease in vin o w ith said complex, deπv ative or modulator, and companng the lev el of said indicator in the cells contacted with the complex, deπv ativ e. or modulator with said level of said indicator m cells not so contacted, wherein a lower level in said contacted cells indicates that the complex, deπv ative or modulator possesses activ ity in treating or preventing neurodegenerative disease 68 A method for screening a puπfied complex of 53BP2 and a 53BP2-IP selected from the group consisting of β-tubuhn, p62, hnRNP G, 53BP2 IP-1, 53BP2 IP-2 and 53BP2— IP-3. or a denvative of said complex, or a modulator of the activity of said complex, for activ ity in treating or preventing neurodegenerative disease compnsmg admmisteπng said complex, αenvativ e or modulator to a test animal, which test animal exhibits symptoms of a neurodegenerative disease or which test animal is predisposed to develop symptoms of a neurodegenerative disease, and measunng the change in said symptoms of the neurodegenerative disease after administration of said complex, derivative, or modulator, wherein a reduction in the seventy of the symptoms of the neurodegenerative disease or prevention of the symptoms of the neurodegenerative disease indicates that the complex, denvative or modulator possesses activity in treating or preventing neurodegenerative disease. 69. A method of screening for a molecule that modulates, directly or indirectly, the formation of a complex of 53BP2 and 53BP2-IP, in which said 53BP2-IP is selected from the group consisting of: β-tubulin, p62, hnRNP G, 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3. compπsing measunng the levels of said complex formed from 53BP2 and 53BP2-IP proteins in the presence of said molecule under conditions conducive to formation of the complex, and companng the levels of said complex with the levels of said complex that are formed m the absence of said molecule, wherein a lower or higher level of said complex in the presence of said molecule indicates that the molecule modulates formation of said complex. 70. A recombinant, non-human animal in which both an endogenous 53BP2 gene and an endogenous 53BP2-IP gene selected from the group consisting of : β-tubuhn, p62. hnRNP G, 53BP2.-IP-1 , 53BP2TP-2 and 53BP2:IP-3. have been deleted or inactivated by homologous recombination or msertional mutagenesis of said animal or an ancestor thereof. 71. A recombinant. non-human animal containing both a 53BP2 gene and a 53BP2-IP gene selected from the group consisting of: β-tubuhn. p62. hnRNP G, 53BP2.TP-1 , 53BP2:IP-2 and 53BP2-IP-3, wherein the 53BP2 gene is under the control of a promoter that is not the native 53BP2 gene promoter and the 53BP2-IP gene is under the control of a promoter that is not the native 53BP2-IP gene promoter. 72. A recombinant, non-human animal containing a transgene compnsmg a nucleic acid sequence encoding the chimenc protein of claim 11. 73. A recombinant, non-human animal m which an endogenous 53BP2-IP gene, selected from the group consisting of: a 53BP2TP-1 gene, a 53BP2:IP-2 gene and a 53BP2:IP-3 gene, has been deleted or inactivated by homologous recombination or insertional mutagenesis of said animal or an ancestor thereof. 74. A method of modulating the activity or levels of 53BP2 by contacting a cell with, or administering to an animal expressing a 53BP2 gene, a protein selected from the group consisting of: β-tubulin, p62, hnRNP G, 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3. or a nucleic acid encoding said protein or an antibody that immunospecifically-binds said protein or a fragment or derivative of said antibody possessing the binding domain thereof. 75. A method of modulating the activity or levels of a protein, selected from the group consisting of: β-tubulin, p62, hnRNP G, 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3. by contacting a cell with, or administering to an animal expressing a gene encoding said protein. 53BP2. or a nucleic acid encoding 53BP2. or an antibody that immunospecifically-binds 53BP2, or a fragment or derivative of said antibody possessing the binding domain thereof. 76. A method of modulating the activity or levels of a complex of 53BP2 and a protein selected from the group consisting of: β-tubulin. p62, hnRNP G, 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3, by contacting a cell with, or administering to an animal expressing and forming said complex, a molecule that modulates the formation of said complex. 77. A method for identifying a molecule that modulates activity of 53BP2, or a protein selected from the group consisting of: β-tubulin. p62, hnRNP G, 53BP2:IP-1, 53BP2:IP-2 and 53BP2:IP-3, or a complex of 53BP2 and said protein, which is comprised of contacting one or more candidate molecules with 53BP2 in the presence of said protein, and measuring the amount of complex which forms between 53BP2 and said protein; wherein an increase or decrease in the amount of complex which forms relative to the amount of complex which forms in the absence of the candidate molecules is indicative of the molecules possessing the ability to modulate the activity of 53BP2. or said protein, or said complex of 53BP2 and said protein. 78. The method of claim 77, wherein said contacting is carried out by administering the candidate molecules to the recombinant. non-human animal of claim 71. 79 The method of claim 77, wherein the candidate molecules are recombmantly-expressed m the recombinant, non-human animal of claim 71 80 The method of claim 77, wherein said contacting is earned out in vitro, and wherein 53BP2, said protein, and said candidate molecules are substantially punfied 81 A method for screening a deπvative or analog of 53BP2 for biological activity which is compπsed of contacting said denvative or analog of 53BP2 with a protein selected from the group consisting of β-tubuhn, p62, hnRNP G, 53BP2 IP-1, 53BP2 IP-2 and 53BP2 IP-3, and detecting the formation of a complex between said deπvative or analog of 53BP2 and said protein, wherein detecting formation of said complex is indicative of said denvati e or analog of 53BP2 possessing biological activity 82 A method for screening a denvative or analog of a protein selected from the group consisting of β-tubuhn, p62, hnRNP G, 53BP2 IP-1, 53BP2 IP-2 and 53BP2 IPX for biological activity compnsmg contacting said deπvativ e or analog of said protein with 53BP2, and detecting the formation of a complex between said denvative or analog of said protein and 53BP2, wherein detecting the formation of said complex is indicative of said deπv ative or analog of said protein possessing biological activity 83 A method of monitoring the efficacy of a treatment of a disease or disorder charactenzed by an abeπant level of a complex of the 53BP2 protein and a 53BP2-IP protein in a subject which has been administered said treatment for said disease or disorder, which is comprised of measunng the level of said complex, PITA encoding the 53BP2 and 53BP2-IP proteins, or functional activity of said complex within a sample deπved from said subject, wherein said sample is taken from said subject after the administration of said treatment and compared to (z) said level in a sample taken from said subject pπor to the administration of the treatment or (u) a standard level associated with the pre-treatment stage of the disease or disorder, m which the change, or lack of change in the level of said complex, said RNA encoding 53BP2 and 53BP2-IP, or functional activity of said complex withm said sample taken after the administration of said treatment relative to the level of said complex, said RNA encoding 53BP2 and 53BP2-IP or functional activity of said complex in said sample taken before the administration of said treatment or to said standard level is indicative of whether said administration is effective for treating said disease or disorder 84 A method of treating or preventing cancer or a cell proliferation disorder in a subject w hich is compπsed of administenng to a subject in which such treatment or prevention is αesired. a therapeutically-effective amount of a molecule that modulates the function of a complex of 53BP2 and a 53BP2-IP protein selected from the group consisting of β-tubuhn. p62, hnRNP G. 53BP2 IP-1, 53BP2 IP-2 or 53BP2 IP-3, or a combination of any one or more of the foregoing 85 A method of treating or preventing neurodegenerative disease in a subject which is comprised of administenng to a subject in which such treatment or prevention is desired, a therapeutically-effective amount of a molecule that modulates the function of a complex of 53BP2 and a 53BP2-IP protein selected from the group consisting of β-tubuhn, p62, hnRNP G, 53BP2 IP-1, 53BP2 IP -2 and 53BP2 IPX or a combination of any one or more of the foregoing 86 A method of treating or preventing autoimmune disease in a subject which is compnsed of administenng to a subject in which such treatment or prevention is desired, a therapeutically- effective amount of a molecule that modulates the function of a complex of 53BP2 and hnRNP G 8 " A purified fragment of a protein selected from the group consisting of β-tubuhn, p62 and hnRNP G. wherein said fragment binds 53BP2

Inventors: NANDABALAN KRISHNAN, SCHULZ VINCENT PETER, YANG MEIJA, NANDABALAN, KRISHNAN, SCHULZ, VINCENT, PETER, YANG, MEIJA
Applicants: CURAGEN CORP, NANDABALAN KRISHNAN, SCHULZ VINCENT PETER, YANG MEIJA, CURAGEN CORPORATION, NANDABALAN, KRISHNAN, SCHULZ, VINCENT, PETER, YANG, MEIJA
Application year: 1998
Main classification: C12N15
IPC codes: A01K67, A61K38, A61K39, A61K48, A61P13, A61P17, A61P25, A61P35, A61P37, C07K14, C07K16, C12N1, C12N5, C12N15, C12Q1, G01N33