APOPTOSIS ASSOCIATED PROTEIN BBK

Abstract: The present invention is directed to an isolated Bbk protein, nucleotide sequences coding for and regulating expression of the protein, antibodies directed against the protein, and recombinant vectors and host cells containing the genetic sequences coding for and regulating the expression of the protein sequence. The invention is also directed to genomic DNA, cDNA, and RNA encoding the Bbk protein sequence and to corresponding antisense RNA sequences. Antibodies can be used to detect Bbk in biological specimens, including, for example, human tissue samples. The present invention is further directed to methods of treating degenerative disorders characterized in inappropriate cell proliferation or inappropriate cell death. The present invention is further directed to methods for diagnosing degenerative disorders characterized in inappropriate cell proliferation or inappropriate cell death, as well as methods for monitoring the progress of such degenerative disorders.

Description: APOPTOSIS ASSOCIATED PROTEIN BBK Field of the Invention The present invention i dales generally to the field ol cell physiology, and more particularly, to apoptosis Even more pailicularly. the present invention is related to the novel apoptosis associated protein Bbk. to nucleotide sequences encoding Bbk; to products and processes involved in the cloning, preparation and expression ol genes and nucleotide sequences encoding Bbk. to antibodies with specilicity to Bbk; and lo diagnostic and therapeutic uses ol the above Background of the Invention "Apoptosis" rclcrs lo cell suicide thai proceeds by an active, physiological process (Kerr, J.F., et ul , Bt J. Cancel 26.239-257 ( 1972), Wylhe, A H., Natuie 2^:555-556 ( 1980)) Cells that die by apoptosis undergo characteristic morphological changes, including cell shrinkage, and nuclear condensation and Iragmcntation Apoptosis plays an important role in developmen¬ tal processes, including moiphogcnesis, maturation ol the immune system, and tissue homeostasis whereby cell numbers aic limited in tissues that arc continually renewed by cell division (Ellis, R E., et ol., Annu Rev. Cell. Biol. 7 663-698 ( 1991), Oppenheim, R.W., et al., Neurosci. 74 453-501 ( 1991 ); Cohen. J.J., et al., Annu. Rev. Immunol 7(9:267-293 ( 1992). Raff, M C, Nature 356:397-400 ( 1992)) Apoptosis is an important cellular safeguard against tumoπgcncsis (Williams, G T , Cell 65: 1097-1098 ( 1991); Lane, D P. Nature 562:786-787 (1993)). Detects in the apoploiic pathway may contπbute lo the onset or progression of malignancies Under certain conditions, cells undergo apoptosis in response to Jorced expression ot oncogencs, or other genes that drive cell prohtcration, (Askew. D , et al , Oncogene 6 195- 1922 ( 1991), Evan, G I , et al , Cell 69 1 19- 128 (1992), Rao, L , et al , Proc Natl Acad Set USA #9 7742-7746 ( 1992), Smeyne, R i , et al . Natuie 361 166- 169 ( 1993)) A vancty ot degenerative disorders may involve aberrant apoptosis, resulting in premature or inappropriate cell death (Barr, P J . et al , Biotechnology 72 487-493 (1994)) Productive infection by certain viruses may depend on suppression ol host tell death by anti-apoptotic viral gene product (Rao, L , et al , Pioc Natl Acad Sci USA 897742-7746 (1992), Ray, C A , et al , Cell 69 597-604 ( 1992), White, E , et al , Mol Cell Biol 12 2570-2580 (1992), Vaux, D L , et al , Cell 76 111-119 ( 1994) and inhibition ot apoptosis can alter the course (l c lytic vs latent) ol vnal lnlcction, (Levinc. B et al , Natitie 361 739-742 (1993)) Widespicad apoptosis ol T lymphocytes tπggeied by HIV intcction may, at least in pan, be responsible tor the immune syslem lailure associated with AIDS (Gougcon M , et al , Science 260 1269- 1270 ( 1993)) The roles ot apoptosis in normal and pathological cell cycle events are reviewed in Holbrook, N J , e t al , Eds , Cellular Aϋing and Cell Death, Wiley-Liss, Ine , Publisher, New York, N Y (1996) The bcl-2 gene product has been intensively studied as a potent suppressor ot apoploiic cell death The bcl-2 gene was originally ldentiticd al ihe 1( 14 18) translocation breakpoint that occurs trequently in human B cell tolhcular lymphomas (Bakhshi, A , et al , Cell 41 899-906 (1985), Cleary, M L . et at , Pioc Nat! Acad Sci USA 82 (1985), Tsuμmoto, Y , et al , Science 229 1390-1393 (1985)) This translocation results in the constitutive activauon ot bcl-2 gene expression due to luxtaposition with the immunoglobulin heavy chain locus Bcl-2 tunctions as an oncogcne in this disease by inappropriately suppressing apoptosis that would normally limit the accumulation ot these cells (McDonnell, T J et al , Cell 5779-88 ( 1989), Ht^ :nbcι v D et al , Natitie 148 334-336 ( 1990)) Consequently B cells accumulate during the indolent stage ol the lymphoma due to their iailure to die rather than by uncontrolled proliferation. The anti-apoptotic activity of Bcl-2 is not restricted to B cells. A large number ot studies have demonstrated that cctopic Bcl-2 expression can suppress apoptosis triggered by diverse stimuli in a multitude ot cell lineages (Vaux, D.L., et al.. Nature 355:440-442 ( 1988); Scntman, C.L., et al., Cell 67:879-888 ( 1991 ); Strasser, A., et al , Cell 67:889-899 ( 1991 ). Hockenbery, D.M., et al.. Cell 75:241 -251 ( 1993)). Bcl-2 blocks cell death induced by growth factor withdrawal, DNA damage, oncogcne expression, oxidative stress, and viral infection. The ability ol Bcl-2 lo block apoptosis in virtually every system suggests that Bcl-2 is closely connected with the machinery that actually carries out the death program. This view is further supported by the conservation ol Bcl-2 lunclion across species. The ced9 gene in the nematode C. elegans t unctions to suppress programmed death in certain cell lineages ot the developing worm (Ellis, H.M., et al, Cell 44:817-829 (1986)) Ced9 appears to be a tunctional homologue of Bcl-2, since Bcl-2 can complement ccd9 in transgenic worms (Vaux, D L., et a!.. Science 255: 1955- 1957 ( 1991 )). Bcl-2 can also function in insect cells as demonstrated by the ability of Bcl-2 to suppress apoptosis induced by Baculovirus intcction (Alnemπ, E.S., et al., Proc. Natl. Acad Sci. USA 89:1295-1299 ( 1992)). The molecular mechanism whereby Bcl-2 operates to block cell death is poorly understood. Additional cellular genes thai exhibit significant sequence homology with Bcl-2 have been identified and, where tested, these genes appear also to t unction as regulators of apoptotic cell death. One Bcl-2 relative, Bcl-X, was isolated by low stringency DNA hybridization to the Bcl-2 gene (Boise, L.H., et al., Cell 74:597-608 (1993)). The Bcl-X RNA is differentially spliced to produce a long torm, termed Bcl-X, , and a shorter torm, Bcl-X s , bearing a short internal deletion. Bcl-X, f unctions to suppress cell death, much like Bcl-2, whereas the deleted torm, Bcl-X s , can inhibit protection by Bcl-2 and may function as a "dominant negative" species. A second Bcl-2 relative, Bax, was ldcntilied biochemically as protein found in co-immunoprecipitatcs with Bcl-2 (Ollvai, Z.N., et al.. Cell 74-609-619 (1993)). Isolation ol ihe corresponding cDNA revealed dial the Bax protein shows substantial sequence homology tt) Bcl-2. Bax forms heterodimcrs with Bcl-2 and appears lo induce apoptosis and function as a negative regulator ol Bcl-2 function Eclopic expression of Bax was shown to block the protection against apoptosis at lorded by Bcl-2 expression Two additional cellular Bcl-2 relatives, Mel- 1 and Al (Ko/.opas, K M., et al., Proc. Natl. Acad Sci. USA 903516-3520 ( 1993). Lin. E.Y., et al . J Immunol 151' 1979- 1988 (1993)) were originally isolated as mRNAs induced in response to spccilic stimulr phorbol ester induced dillcrcntiation ol myeloid leukemia cells (Mel- 1 ); and GM-CSF treatment of muπnc bone marrow cells (A l ). It is not yet known whelhcr eilhcr Mcl- 1 oi A I can modulate apoptosis. In addition to these cellular Bcl-2 relatives, a number ol Bcl-2 homologucs encoded by DNA viruses have been identified The Epstein-Barr virus BHRF- 1 gene product was noted to contain sequence homology lo Bcl-2 and has subsequently been shown to function as a suppressor ol apoptosis (Henderson, et al , Pioc. Natl. Acad Set USA 90.8479-8488 ( 1993)). Likewise, the Alncan swine lever virus LMW5-HL gene encodes a protein structurally similar to Bcl-2 (Netlan, J.G., et al.. J Virol 67:4391-4394 ( 1993)) The Adenovirus Elb 19kD protein appears to be functionally equivalent to Bcl-2, although the primary sequence homology is quite limited (White, E.. et al., Mol. Cell. Biol. 72:2570-2580 ( 1992)). It is likely that these genes function to ensure replication ot viral DNA by preventing apoptosis ol the infected cell. The finding that unrelated DNA viruses have evolved genes that apparently function to mimic the action of Bcl-2, supports die conclusion that Bcl-2 represents an important apoptosis resiulator. The isolation and characterization ot a bcl-2 related gene, termed hak, is descnbed in co-pending United Stales application Serial Number 08/321,071, tiled 1 1 October 1994. which is a continuation-in-parl ol United States application Serial Number 08/287,427, tiled 9 August 1994 (hak is rclcrrcd lo ihciein as hcl-v), the disclosures ot which arc incorporated herein by reference Ectopic Bak expression accelerates the death ol an IL-3 dependent cell line upon cytokine withdrawal, and opposes the protection against apoptosis allorded by Bcl-2 In addition, entorccd expression ol Bak is sufficient to induce apoptosis ol serum deprived libroblasLs, raising the possibility lhal Bak directly activates, or is lLsell a component ot, the cell death machinery Known ccllulai Btl-2 lelated genes, where analyzed, have distinct patterns ot expression and thus may tunction in dillcreni tissues The cell death program is in place in all tissues and may be regulated by dillcrcnt BL1-2 related genes While Bcl-2 expression is required tor maintenance ol the mature immune system, it is desirable to identity other genes which may govern apoptotic cell death in other lineages From the perspective ol pharmaceutical development, it would be desirable to identity or develop agenLs dial either activate or suppress apoptosis, depending on the clinical setting Summary of the Invention The present inventor has surprisingly discovered a novel composition ot matter which has been isolated and characterized, and which is described in a number ol embodiments herein. Referred to herein as "Bbk," n appears to be a member ot die Bcl-2 lamily, and can, inter alia, induce apoptosis in cells and oppose the tunction ol Bcl-2 and related cell death suppresors in cells Isolation ol a lull lonmh human Bbk cDNA revealed that the deduced Bbk amino acid sequence shares homology with Bcl-2. Bbk mRNA appeals to be widely expressed in primary human tissues Bbk is an important regulator ol apoptosis in human tissues anuVor tumor cells. Expression ol Bbk accelerates apoptosis when expressed in normal rat tibroblasts (Ratl), and in human tumor cell lines including HcLa and BT549 cells The co-expression ot Bak and Bbk in Rat 1 cells docs not block the induction ot apoptosis. suggesung that their ability lo bind each other does not inhibit their ability to promote apoptosis Their coexpression may result in cooperative induction ol cell death The apoptotic tunction ol Bbk can be reversed by the coexpression ot the known survival proteins, Bcl-2, Bcl-x, and Epstcin-Barr virus BHRF 1. Increasing fhc ratio ot Bbk iclativc to the survival proteins may icstorc apoptosis as has been previously shown with the apoptosis promoting protein Bik The present invention thus relates to an apoptosis associated protein Bbk, products and processes involved in the cloning, preparation and expression ol genes lor Bbk; antibodies with specificity to Bbk; and nucleotide probes corresponding to die Bbk nucleotide sequence or portions thereot. The Bbk poiypcplide is usetul tor producing antibodies thereto The antibodies and probes are useful tor detecting and isolating Bbk in biological specimens including tor example, cells trom all human tissues including heart tissue, lung tissue, tumor cells, placenla, liver, skeletal muscle, kidney, and pancreas The picsent invention further relates to species homologs and viral homologs ot Bbk. The present invention relates to the identification, characterization and sequencing ol cDNAs and genomic fragments which encode the Bbk that is present in human cells. According to ihe present invention, there arc provided genetic sequences encoding Bbk The instant invention also provides lor expression vectors containing such genetic sequences, hosts transformed with such expression vectors, and methods lor producing the genetically engineered or recombinant Bbk The present invention also provides antibodies which specifically recognize Bbk The Bbk cDNA and recombinant protein are useful tor making antibodies which specifically recognize Bbk Such antibodies aie uselul lor delecting and isolating Bbk in a biological specimen The prescnl Bbk protein is also useful as a regulator ol apoptosis. A small cDNA trom an EBV-translormed B-ccll line has been isolated The ammo acid sequence ol the Bbk protein shares sequence homology with Bcl-2 domains The present invention lurther relates to a method lor isolating Bbk partial clones using polymerase chain reaction (PCR) cloning, trom diverse human tumor cell lines. The present invention is turthcr directed to methods lor inducing or suppressing apoptosis in individuals sul leπng trom dcgcneiative disorders characterized by inappropriate cell prolileration or inappropriate cell death, respectively. Degenerative disorders characterized by inappropnate cell prolileration include, lor example, inflammatory conditions, cancer, including lymphomas, gcnolypic tumors, etc. Degenerative disorders characlcnzed by inappropnate cell death include, lor example, autoimmune diseases, acquired immunodeficiency disease (AIDS), cell death due to radiation therapy or chemotherapy, etc. The present invention also relates to methods for detecting the presence ot Bbk protein, as well as methods directed to the diagnosis ol degenerative disorders, which disorders are associated widi an increased or decreased level ol expression or mutations ot Bbk, as compared to the expected level of Bbk expression in the normal cell population. The present invention is further directed to methods tor monitoring the progress of degenerative disorders associated with increased or decreased levels ot expression of Bbk, by monitoring Bbk expression. The present invention also relates lo methods lor determining whether a disease/degenerative disorder is linked to abnormal Bbk expression, as well as methods tor determining the etiect of over-expression or loss ol expression ol Bbk in animal models such as transgcnic mice and/or homozygous null mice. Methods lor determining whether a disease/degenerative disorder is linked to abnormal Bbk expression include analyzing Bbk expression in diseased tissue as compared to normal tissue by for example, Northern and/or Western blots, as well as by other assay methods readily chosen and employed by those ol ordinary skill in the art. The present invention relates to hybrids of Bbk for therapeutic use. The present invention also relates lo methods lor modulating apoptotic ettects by administering the prescnl Bbk protein, mutant protein or hybrids to an individual suffenng trom a degenerative disorder characlcnzed by inappropriate cell prolileralion or inappropriate cell death in order to stabilize inappropriate cell prolileration ( I e . induce apoptosis) or stabilize inappropriate cell death (i.e., suppress apoptosis), respectively, and/or in either case lo restore normal cell behavior. Fig. 3 illustrates levels of Bbk mRNA expressed in a variety of healthy fetal and adult tissues. The present invention lurther relates lo functional equivalents including functional fragments of Bbk including, for example, peptides of Bbk such as BH 1 and BH2, and other regions of homology recognized by the present inventor between Bbk and other apoptosis related proteins including Bcl-2 and Bax. In a particular aspect, the invention is directed to a novel protein domain which has been identified and mapped to a short subsequence in the central portion ot the Bbk molecule. This novel protein domain, which the inventor has designated the "Bbk BH3 domain," is essential both to Bbk's interaction with Bak, and to Bbk's cell killing tunction. Truncated Bbk species encompassing the Bbk BH3 domain arc themselves sufficient to kill cells in transfection assays. The Bbk BH3 domain shares less than twenty-five percent identity with the GD Domain first described in Bak in United Slates application Serial Number 08/440,391, filed 12 May 1995 (BH3 is rctciTcd to therein as the GD domain) However, as observed with respect to the GD Domain in Bak, mutation ol Bbk BH3 domain elements in Bbk diminishes cell killing and protein binding tunction Thus, the Bbk BH3 domain is responsible tor mediating key protein/protein interactions ol signiticancc to the actions ol multiple cell death regulatory molecules In one aspect, then, the invention is directed to punlicd and isolated peptides comprising die Bbk BH3 domain and to molecules thai mimic its structure and/or tunction, uselul tor inducing or modulating the apoploiic stale ol a cell Chemical compounds that disrupt the tunction ot the Bbk BH3 domain have utility as apoptosis-modulating agents Accordingly, in another aspect, the invention is duecied lo agents capable ol disrupting Bbk BH3 domain tunction Such agents include, but aie not limited to. molecules that bind to the Bbk BH3 domain, molecules that interfere wiih the interaction ol the Bbk BH3 domain with other proleιn(s), and molecules compnsmg the Bbk BH3 domain which is altered in some mannei The invention provides methods to identif y molecules that modulate apoptosis by disrupting the function ot the Bbk BH3 domain, which accordingly comprise additional contemplated embodiments. In additional aspects, the present invention relates lo products and processes involved in the cloning, preparation and cxpicssion ol peptides comprising the Bbk BH3 domain; antibodies with specificity to the Bbk BH3 domain; and nucleotide sequences encoding the Bbk BH3 domain or portions thcreot Peptides comprising the Bbk BH3 domain are useful tor producing antibodies thereto. Such antibodies arc uselul lor detecting and isolating proteins comprising the Bbk BH3 domain in biological specimens including, tor example, cells trom all human tissues including heart tissue, lung tissue, tumor cells, brain tissue, placenta, liver, skeletal muscle, kidney, and pancreas, as well as tor modulating the apoptotic activity ot proteins comprising the Bbk BH3 domain in and trom such biological specimens, and constitute additional aspects ol ihc invention In yet another aspect, the invention provides tor expression vectors containing genetic sequences, hosts translormed with such expression vectors, and methods tor producing the recombinant Bbk BH3 domain peptides ot the invention The prescnl invention is lurther directed to methods tor inducing or suppressing apoptosis in the cells and/or tissues ot individuals sutlcπng trom degenerative disorders charactcnzed by inappropriate cell prolileration or inappropriate cell dcalh, respectively. Degenerative disorders characterized by inappropriate cell prolileration include, lot example, inflammatory conditions, cancer, including lymphomas. such as prostate hyperplasia, genolypic tumors, etc. Degenerative disorders characterized by inappropriate cell death include, lor example, autoimmune diseases, acquired immunodcliciency disease (AIDS), cell death due to radiation therapy or chemotherapy, ncurodcgcncrative diseases, such as Alzheimer's disease and Parkinson's disease, etc. The present invention also relates to methods tor detecting the presence ot the Bbk BH3 domain peptide, as well as methods directed to the diagnosis ol degenerative disorders, which disorders arc associated with an increased or decreased level ot expression ot proteins compnsmg the Bbk BH3 domain, as compared to the expected level ol expression ol such proteins in the normal cell population The present invention relates to the therapeutic use ol peptides comprising the Bbk BH3 domain. The present invention also relates to methods for modulating the apoptotic state of a cell by administering peptides comprising the Bbk BH3 domain peptide, or mutants thereof, to an individual suttcnng trom a degenerative disorder characterized by inappropnate cell prolileration or inappropnate cell dcatii. in order to stabilize inappropnate cell prolileration (i.e., induce apoptosis) or stabilize inappropriate cell death (1 c , suppress apoptosis). respectively, and/or in either case to restore normal cell behavior The present invention is also directed to nucleotide probes which can be used to determine the presence ol Bbk as well as to identity and isolate homologs including species homologs and viral homologs These and other objects and aspects ot the invention will be apparent to those ol skill trom the description which lollows Description of the Figures Figure I Features ol the yeast two-hybrid system (adapted liom Clonfech manual) Figure 1(A) A schematic illusliation ol the yeast GAL4 protein showing the DNA binding domain (bd) that interacts with the GALI upstream activating sequence (UAS) and the transcription activation domain (ad) that stimulates transcription Figure 1(B) The GAL4 bd luscd to piotcin X can bind lo the GALI UAS but cannot stimulate transcription due to the lack ol an activation domain The GAL4 ad luscd to piotcin Y also tails lo stimulate transcnption due lo tailuie to localize to the promoter Figure 1(C) The interaction ol GAL4 bd/prolein X lusion with the GAL I UAS and its additional interaction with the GAL4 ad/protem Y tusion allows the reconstitution ot GAL4 tunction and the stimulation ot transcription Figure 2. The nucleotide sequence and putative open reading tramc (ORF) ot clone Bbk (SEQ ID NOS: 9-μ\ Arrows indicate the slart points ol several related clones also isolated by ihe iwo-hybnd analysis The position ol an AAG insert idcntilicd in several clones is also indicated. Figuic 3 Northern blot analysis ol human tctal and adult tissues (Clontech) The blots were hybndizcd with 12 P-labcled Bbk DNA (top panel) and β-actin DNA as a control Size markers are as deltned by the manulacturcr Figure 4 Expression ol Bbk piotcin Figure 4(A) In vitro translation ol "S-labeled Bbk m rabbit rciiculocyte lysate. Controls include translation ol lucitcrasc protein was resolved by SDS gel electrophoresis and visualized by auloradiography The gel mobilities ol prc-staincd protein molecular weight markers (Amersham) are shown Figure 4(B). Expression ol Bbk in transtectcd cells Plasmids expressing the hcmagglutinin (HA) cpitopc-tagged Bax or Bbk were transtectcd into COS7 cells Lysalcs were prepared 48 hrs alter transaction Lysatcs ol untranstccled COS7 cells aic included as a negative control. Proteins were detected by SDS gel electrophoresis and Western blot ot cell lysates with the anti-HA monoclonal antibody I2CA5 (Boehringer Mannheim) The Bax and Bbk proteins are indicated with arrows. Figure 5. Eftect of Bbk expression on viability ol Ratl cells Cells were transfected with plasmids as indicated with a plasmid expressing β-galactosidase (pRcCMV/βgal, 0 16 μg). Cells were stained 24 hrs posl-tianslection to identity live and dead β-galactosidasc expressing cells Values trom tnphcatc expcnmcnts were averaged and plotted with enor bars representing SEM Figure 5(A) Etlecl ol transient expression ot vector (0 42 μg pRcCMV), Bak (0.21 μg pcDNAI/HABak + 0 21 μg pRcCMV), Bbk (0 21 μg pcDNA3/HABbk + 0 21 μg pRcCMV), or Bak + Bbk (0 21 μg pcDNA3/HABak + 0 21 μg pcDNA3/HABbk) in Ratl cells. Figure 5(B) Ef fect ol the survival prolcins Bcl-2 (0.21 μg pcDNA3/HABbk + 0.21 μg pRcCMV/Bcl-2). Bcl-x, (0 21 μg pcDNA3/HABbk + 0 21 μg pRcCMV/Bcl-x, ), or Epstein Ban- virus BHRF1 (0 21 μg pcDNA3/HABbk + 0 21 μg pRcCMV/BHRFl ) upon Bbk induction ol apoptosis in Rai l cells Figure 6 Ef fect til Bbk expression on viability ol HeLa cells and BT549 cells Figure 6(A) HeLa cells wcic iranslcclcd with pRcCMV/βgal (0 16 μg) plus vector (0 42 μg pRcCMV), Bak (0 21 μg pcDNA I/HABak + 0 21 μg pRcCMV), or Bbk (0.21 μg pcDNA3/HABbk + 0 21 μg pRcCMV) Stained cells were scored and plotted as described in Figure 5 Figure 6(B) BT549 cells weie transtected as described in panel (A) Figure 7 Interaction ot Bbk with Bcl-2 family members A glutathione S-transterase (GST) tusion protein of Bbk was produced in E coli and purified on glutathione agarose Puπhed Bbk or GST control protein was incubated with "S labeled in vitro translated (IVT) HA-tagged Bak, Bax, Bdc or Flag-tagged Bcl-x, Complexes were captured on gluiaϋuonc agarose beads, subjected to SDS gel elctrophorcsis, and visualized by autoradiograhy Captured complexes are compared to an aliquot ot the input IVT material. Figure 8 Sequence alignment of Bbk with Bcl-2 family member BH2 and BH3 domains. Figure 8(A). The BH2 domain sequences ol Bak [SEQ ID NO. 13], Bax ISEQ ID NO. 14], Bik [SEQ ID NO 15], Bcl-2 [SEQ ID NO. 16] and Bcl-x, [SEQ ID NO. 17] are aligned with the homologous regions ol Bbk |SEQ ID NO 12]. Residues thai arc identical or conservative in at least three ol the proteins arc boxed Black boxes indicate identical residues while grey boxes indicate conservative lesidues Numbering indicates ihc position ot the first ammo acid residue shown lor each sequence Figure 8(B). The BH3 domain sequences ot Bak [SEQ ID NO. 19], Bax [SEQ ID NO. 20], Bik [SEQ ID NO. 21 ], Bcl-2 [SEQ ID NO. 22] and Bcl-x, [SEQ ID NO. 23] arc aligned with the homologous regions ol Bbk Shading and numbcnng arc as described in panel (A). Figure 9. Deletion and point mutation analysis ot Bbk [SEQ ID NO. 18] in Rat I cells. Figure 9(A). Ratl cells were transtectcd with pRcCMV/βgal (0 16 μg) plus vector (0.42 μg pRcCMV), full length Bbk (0 42 μg pcDNA3/HABbk), or deletion mutants of Bbk (0.42 μg pcDNA3/HAΔ 1-105 or 0.42 μg pcDNA3/HAΔ 142-249) Stained cells were scored and plotted as descnbed in Figure 5. Figure 9(B). Alaninc point mutants ot the Bbk BH3 domain (PM-LVLEE [SEQ ID NO. 25], PM-V [SEQ ID NO. 26], PM-L [SEQ ID NO. 27], PM-EE [SEQ ID NO. 28]) arc compared to the wild type Bbk BH3 domain [SEQ ID NO 24] The shading is as described in Figure 8 with Alanine substitutions indicated as outlined boxes Figure 9(C) The alanine point mutants shown in panel (B) (0 42 μg each pcDNA3/HAPM-LVLEE, pcDNA3/HAPM-V, pcDNA3/HAPM-L, pcDNA3/HAPM-EE plus 0 16 μg pRcCMV/βgal) were translected into Ratl cells and compared to cells transfected with vector control plasmid or wild type Bbk as descnbed in panel (A) Stained cells weie scored and plotted as described in Figure 5 Figure 10 Effect of Bbk BH3 domain expression on the viability of Rat l cells Rat l cells were transfected with pRcCMV/bβgal (0 16 mg) plus vector (0 42 mg pRcCMV), full length Bbk (0 42 mg pRcCMV/HABbk), or Bbk BH3 domain (0 42 mg pRcCMV/HABbkBH3) Stained cells were scored and plotted as described in Figure 5 Figure 1 1 Interaction of Bbk point mutants with Bak analyzed by yeast two-hybrid system. Bak bait plasmid (pAS2/BakΔC) was co-transformed into yeast with plasmids expressing Gal4 activation domain fusions of alanine point mutations of Bbk (pACT/PM-LVLEE, pACT/PM-V, pACT/PM-L, and pACT/PM-EE) and wild type Bbk (pACT/Bbk) As a positive control, plasmids supplied by the manufacturer (Clontech) expressing p53 bait (pVA3) and SV40 T antigen (pTD l ) were co-transformed as above For a negative control, pACT/Bbk was co-transformed with pAS2, which expresses only the Gal4 activation domain as bait Three individual colonies from each transformation were analyzed in triplicate for β-galactosidase activity usmg the liquid culture assay described by the manufacturer (Clontech) The mean of triplicate measurements from each of the tliree colomes were then averaged to generate a smgle value for each pair of interacting proteins. The data are plotted as units of β-galactosidase (Miller, J H., Experiments in Molecular Genetics. Cold Spring Harbor Laboratory Press, Planvicw, New York ( 1972)) with error bars representing the SEM Detailed Description of the Invention Technical and scientific terms used herein have the meanings commonly understood by one ol ordinary skill in the art lo which the present invention pertains, unless otherwise detincd. Reference is made herein lo vaπous methodologies known to those ot skill in the art Publications and other materials selling forth such known methodologies to which rctcrence is made aie incorporated herein by rclcrcncc in their entireties as though set forth in lull Standard rclcrcncc woiks selling loiih the general principles ol iccombinant DNA technology include Sambrook, J , et al . Molcculai Cloninϋ A Lahoialoiv Manual. 2d Ed , Cold Spring Harbor Laboratory Picss, Planvicw, New York ( 1989). McPhcrson, M J , Ed , Directed Mulauencsis- A Practical Approach. IRL Press, Oxford ( 1991 ). Jones, J , Amino Acid and Pentide Synthesis. Oxlord Science Publications, Oxlord ( 1992). Austen, B M and Wcstwood, O. M R., Protein Tart'Clinti and Secretion. IRL Press. Oxloid ( 1991 ) Any suitable materials and/or methods known to those ol skill can be utilized in carrying out the ptescnl invention, however, prclerrcd materials and/oi methods aic described Matcnals. leagenls and the like to which rctcrence is made in the following description and examples arc obtainable trom commercial sources, unless otherwise noted This invention is directed most generally to a novel protein designated "Bak binding killer" protein or "Bbk" based upon its ability to bind spccilically to the protein Bak and to kill immortalized human tumoi cells Accordingly, this invention comprises amino acid sequences ot Bbk or Bbk mutants, genetic sequences coding lot such amino acid sequences, expression vehicles containing the genetic sequences, hosts tianstoπncd tlvicwith and recombinant Bbk and antisense RNA produced by such transformed host expression The invention turthcr compnses antibodies dnecicd against Bbk and/or tragmcnts thereof or against Bbk mutants. The process tor genetically engineering such protein sequences, according to the invention, is facilitated through the cloning ol genetic sequences which arc capable ol encoding the peptide and through the expression ol such genetic sequences As used herein, the term "genetic sequences" is intended lo icier lo a nucleic acid molecule (pictcrably DNA) Genetic sequences which are capable ol encoding the proteins are dcπved trom a variety of sources These sources include genomic DNA, cDNA, synthetic DNA, and combinations thereof The prclened source ol the genomic DNA oi mRNA is human tissue including heart, lung, tumor cells, placenta, liver, skeletal muscle, and pancreas The mRNA may then be used lo obtain cDNA by techniques known to those skilled in the an Probes may be synthesized based on the nucleotide sequence ol Bbk by methods known in the art The Bbk protein or Iragmcnl genomic DNA ol the invention may or may not include naturally occurnng introns Moreover, such genomic DNA may be obtained in association with the 5' promoter region ot ihc Bbk prolcin gene sequences and/or with the 3' transcnptional termination region Further, such genomic DNA may be obtained in association with the genetic sequences which encode the 5' non-translated region ol the Bbk prolcin mRNA and/or with the genetic sequences which encode the 3' non-translated region. To the extent that a host cell can recognize the transcnptional and/or iranslauonal regulatory signals associated with the expression of the mRNA and piotcin, the 5' and/or 3' non-transcribed regions ot the native gene, and/or the 5' and/or 3' non-translated regions of the mRNA, may be retained and employed for transcnptional and translalional regulation. Bbk protein genomic DNA can be extracted and punticd trom human tissue by means well known in the art (tor example, see Berger, S.L., et al , Eds . Guide lo Molecular Cloning Techniques, Academic Press ( 1987)) Alternatively, mRNA can be isolated trom any cell which produces or expresses the protein, and used to produce cDNA by means well known in the art (lor example, see Bcrgcr, S L., et al., Eds . Guide lo Moleculai Cloning Techniques, Academic Piess ( 1987)) Pieterably, Ihe mRNA preparation used will be enriched in mRNA coding tor such Bbk protein, either naturally, by isolation trom cells which arc pioducing large amounts ot the protein, or in vitro, by techniques commonly used lo cnπch mRNA preparations ot specif ic sequences, including tor example sucrose gradient ccntπtugation, or PCR cDNA can then be prepared lor example, by reverse transcription The cDNA can then be amplified by PCR using suitable pπmers For cloning into a vector, such suitable DNA preparations (either human genomic DNA or cDNA) arc randomly sheared or cnzymatically cleaved, icspectivcly, and ligated into appropriate vectois to toim a recombinant gene (either genomic oi cDNA) hbraiy A DNA sequence encoding the Bbk protein or us tunctional equivalents may be inserted into a DNA vector in accordance with conventional techniques, including blunt-ending or staggcred-endmg termini tor ligation, restriction enzyme digestion to provide appropnate termini, tilling in ot cohesive ends as appropriate, alkaline phosphatasc treatment lo avoid undesirable pining, and ligation with appropriate hgascs Techniques lor such manipulations are disclosed, lor example, by Sambrook, J , et al , Moleculai Cloning- A Laboratory Manual. 2d Ed , Cold Spring Harbor Laboratory Press, Planview, New York ( 1989), and are well known in the art Libranes containing the Bbk protein clones may be screened and a Bbk clone identified by any means which specifically selects tor Bbk protein DNA such as, lor example, (a) by hybndization with an appropnate nucleic acid probe(s) containing a sequence specific tor the DNA ot this protein, or (b) by hybridization-selected translational analysis in which native mRNA which hybridizes to the clone in question is translated in vino and the lianslalion products aie lurther characterized, or, (c) it the cloned genetic sequences are themselves capable ot expressing mRNA, by immunoprecipitation ot a translated Bbk or fragment product produced by the host containing ihc clone Oligonucleotide probes specific tor the protein which can be used to identity clones lo this protein can be designed trom knowledge ot the amino acid sequence ot the Bbk protein. The sequence ot amino acid residues in a peptide is designated herein either through the use ot their commonly employed three-letter designations or by their single-letter designations A listing ot these thrcc-Icitcr and one-letter designations may be tound in textbooks such as Biochemistry. 2cd , Lchnmgcr, A , Worth Publishers, New York, NY ( 1975) When the amino acid sequence is listed honzontally, the amino terminus is intended lo be on the lclt end whereas the cat boxy terminus is intended lo be at the right end The residues ol amino acids in a peptide may be separated by hyphens Such hyphens arc intended solely to lacilitale the presentation of a sequence Because the genetic code is degenerate, more than one codon may be used lo encode a particular amino acid (Watson, J.D.. In: Molecular Biology of the Gene, 3rd Ed., W.A. Beniamin, Inc., Mcnlo Park, CA ( 1977), pp. 356-357) The peptide tragments are analyzed to identity sequences ot ammo acids which may be encoded by ohgonucleotides having the lowest degree ot degeneracy This is prctcrably accomplished by identitymg sequences lhal contain amino acids which arc encoded by only a single codon Although occasionally an amino acid sequence may be encoded by only a single oligonucleotide sequence, trequenUy the amino acid sequence may be encoded by any ot a sel of similar ohgonucleotides Importantly, whereas all ot the members ot this set contain oligonucleotide sequences which arc capable ot encoding me same peptide fragment and, thus, potentially contain the same oligonucleotide sequence as the gene which encodes the peptide lragmcnt, only one member ot the sel contains the nucleotide sequence that is identical to the exon coding sequence ot the gene. Because this member is prescnl within the set. and is capable ol hybridizing lo DNA even in the presence ol the other members of the sel, it is possible lo employ the unlractionatcd set of ohgonucleotides in the same manner in which one would employ a single oligonucleotide to clone the gene that encodes the peptide. Using the genetic code (Watson, J.D., In- Moleculai Biology of the Gene. 3rd Ed., W.A. Benjamin, Inc., Menlo Park. CA ( 1977)), one or more diltcrcnt ohgonucleotides can be ldcntilicd lrom the amino acid sequence, each ol which would be capable ol encoding the present Bbk or fragment protein The probability that a particular oligonucleotide will, in tact, constitute the actual prolcin coding sequence can be estimated by considering abnormal base pairing relationships and the Ircqucncy with which a particulai codon is actually used (lo encode a particular amino acid) in cukaryotic cells Such "codon usage rules" are disclosed by Lathe, et al., J Molec Biol 183 1-12 (1985) Using the "codon usage rules" ol Lathe, a single oligonucleotide sequence, or a set ol oligonucleotide sequences, that contains a theoretical "most probable" nucleotide sequence capable ol encoding the Bbk protein sequences is identified. The suitable oligonucleotide, or set ot ohgonucleotides, which is capable ot encoding a tragmcnt ot the Bbk protein gene (or which is complementary to such an oligonucleotide, or set ol ohgonucleotides) may be synthesized by means well known in the art (see, lor example, S.A. Narang, Ed., Synthesis and Application ol DNA and RNA. Academic Press, San Diego, CA) and employed as a probe to identity and isolate the cloned Bbk protein gene by techniques known in the art Techniques ol nucleic acid hybridization and clone identification are disclosed by Maniatis, et al., Eds , Molecular Cloning, A Laboratory Manual, Cold Spring Harbor Laboratories, Cold Spring Harbor, NY, (1982); Bcrger, et al , Eds., Guide to Molecular Cloning Techniques. Academic Press, San Diego, CA, ( 1988); Sambrook. J , et al., Molecular Cloning- A Laboratory Manual. 2d Ed.. Cold Spring Harbor Laboratory Picss, Planvicw, New York (1989); and by Hamcs, et al., Eds., Nucleic Acid Hybridization. A Practical Approach. IRL Press, Washington, DC. ( 1985). which references arc herein incorporated by reference. Those members ol the abovc-descπbcd gene library which are lound to be capable of such hybridization arc then analyzed to determine the extent and nature ol the Bbk protein encoding sequences which they contain To facilitate the detection ol the desired Bbk or fragment protein DNA encoding sequence, the above -described DNA probe is labeled with a detectable group or label. Such detectable group or label can be any material having a detectable physical or chemical property. Such materials have been well-developed in the field ot nucleic acid hybridization and in general most any label uselul in such methods can be applied to the present invention. Particularly useful arc radioactive labels, such as >2 P, Η, l4 C, ,S S, n \, or the like. Any radioactive label may be employed which provides for an adequate signal and has asufficient half-life. The oligυnuclcoiidc may be radioactively labeled, tor example, by "nick-translation" by well-known means, as described in. tor example, Rigby, et al., J. Mol. Biol. 113:231 (1977) and by T4 DNA polymerase replacement synthesis as descnbed in, for example, Deen, et al., Anal. Biochem. 135:456 (1983) Alternatively, polynucleotides arc also useful as nucleic acid hybridization probes when labeled with a non-radioactive marker such as biolin, an enzyme or a fluorescent or chemiluminescent group. Sec. tor example, Leary, et al., Proc. Natl. Acad. Sci, USA 50:4045 ( 1983); Renz, et al., Nucl. Acids Res. 72:3435 ( 1984); and Renz, M., EMBO J. 6:817 (1983). Thus, the actual identification of the Bbk protein sequences permits the identification of a theoretical "most probable" DNA sequence, or a set of such sequences, capable of encoding such a peptide. By constructing an oligonucleotide complementary to this theoretical sequence (or by constructing a set of ohgonucleotides complementary to the set of "most probable" ohgonucleotides), one obtains a DNA molecule (or set ol DNA molecules), capable ot lunctioning as a probe(s) lor the identification and isolation ol clones containing the Bbk protein gene In an alternative way ol cloning the Bbk protein gene, a library is prepared using an expression vector, by cloning DNA or, more prelcrably, cDNA prepared trom a cell capable ol expressing the Bbk prolcin, into an expression vector The library is then screened lor members which express the Bbk protein, tor example, by screening the library with antibodies to the Bbk protein The above discussed methods are. therctorc, capable ol identifying genetic sequences which aie capable oi encoding Bbk proteins or tragmcnls thereol. In order to further characterize such genetic sequences, and, in order to produce the recombinant protein, it is desirable to express ihc proteins which these sequences encode Such expression identifies those clones which express pioteins possessing characlcπstics ol the Bbk proteins Such characteristics may include the ability to specifically bind antibody to the Bbk protein and the ability to elicit the production ol an antibody or antibodies which arc capable ot binding to the Bbk protein To express die Bbk protein oi a lunctional equivalent, or mutant thereof transcnptional and iranslauonal signals recognizable by an appropriate host are necessary The cloned Bbk encoding sequences, obtained, lor example, through the methods descnbed above, and preferably in a double-stranded torm, may be operably linked to sequences controlling transcnptional expression in an expression vector, and introduced into a host cell, either prokaryotic or eukaryotic, lo produce recombinani Bbk protein or a functional equivalent thereof Depending upon which strand of the Bbk encoding sequence is operably linked to the sequences controlling transcπplional expression, it is also possible to express Bbk antisense RNA or a functional equivalent thcreot Expression ol Bbk in diltcrent hosts may icsull in different post-translalional modifications which may alter the properties of the Bbk. The present invention encompasses the expression of the Bbk protein, or lunctional equivalent thereof or Bbk mutant, in prokaryotic or eukaryotic cells, and particularly, eukaryotic expression is prelened. Preferred prokaryotic hosts include bactena such as E colt, Bacillus, Streptomyces, Pseudomonas, Salmonella, Seiratia, etc. The most pretcrrcd prokaryotic host is E coli. Omer enterobactcπa such as Salmonella h'phimunum or Serratia marcescens. and various Pseudomonas species may also be utilized Under such conditions, the protein may not be glycosylatcd The prokaryotic host must be compatible with the rcphcon and control sequences in the expression plasmid To express the Bbk protein (or a functional equivalent thcreot) or Bbk mutant in a prokaryotic cell (such as, lor example, E. coli, B subtilis, Pseudomonas, Streptomyces, etc.), it is necessary to operably link the Bbk encoding sequence to a lunctional prokaryotic promoter. Such promoters may be cither constitutive or, more preferably, rcgulatablc 0 c, inducible or dcrepressible) Examples ol constitutive promoters include the int promoter ot bacteπophage lambda, the hla promoter ot the β-lactamasc gene ot pBR322, and the CAT promoter ot the chloramphenicol acetyl transterase gene of pBR325, etc. Examples ot inducible prokaryotic promoters include the major righl and left promoters of bacteπophage lambda (P L and P R ), the trp, recA. lacZ, lad, and gal promoters of E. coli, the α-amylase (Ulmanen, I., et al., J. Bacterial. 762: 176-182 ( 1985)) and the sigma-28-specιfic promoters of B. subtilis (Gilman, M.Z.. et al.. Gene 32:1 1-20 ( 1984)), the promoters ot the bacteπophages ot Bacillus (Gryczan, T.J., The Molecular Biology ol the Bacilli. Academic Press, Inc., NY ( 1982)), and Streptomyces promoters (Waid, J M., et al , Mol Gen Genet 20i:468-478 ( 1986)) Prokaryotic promoters are reviewed by Ghck, B R , ( / bid Microbiol 7.277-282 ( 1987)). Cenaliempo. Y (Biochimie 65-505-516 ( 1986)), and Gottesman, S (Ann Rev Genet 18 415-442 ( 1984)) Proper expression in a prokaryotic cell also requires the picsencc ol a πbosome binding site upstream ot the gene-encoding sequence Such πbosome binding sues arc disclosed, tor example, by Gold. L , et al (Ann Rev Miaobiol 35 365-404 ( 1981)) Especially prcleircd eukaryotic hosts include mammalian cells cither in vivo, in animals or in tissue culture Gcncial principles ol mammalian cell culture are known in ihe art and are described, lor example, in Bullet. M and Dawson. M , Eds . Cell Culture LahFax, Bios Scientific Publishers Ltd , Oxloid. UK and Academic Picss, Ine . San Diego, CA, Publishers ( 1992), and rctcrcnccs cued therein Expression ol the Bbk in eukaryotic hosts requires the use ol regulatory regions functional in such hosts, and preferably eukaryotic regulatory systems A wide vanety ol transcnptional and translational regulatory sequences can be employed, depending upon the nature ot the eukaryotic host The transcnptional and translational regulatory signals can also be derived trom the genomic sequences ol viruses which lnlect eukaryotic cells, such as adenovirus, bovine papilloma vn us, Simian vnus, herpes virus, oi the like Prctcrably, these regulatory signals are associated with a particular gene which is capable ol a high level ot expression m the host cell In eukaryotes, where transcription is not linked to translation, such control regions may or may not provide an initiator melhioninc (AUG) codon, depending on whether the cloned sequence contains such a methtonine Such regions will, in general, include a promoter region sufticicnt lo direct the initiation ol RNA synthesis in the host cell Promoters trom hcterologous mammalian genes which encode mRNA product capable ot translation are prclcrrcd, and especially, strong promoters such as the promolct lor actin, collagen, myosin, etc., can be employed piovidcd they also tunction as promoters in the host cell. Piclerred eukaryotic promoters include the promoter ol the mouse mctallothionein 1 gene (Hamcr, et al., J Mol Appl Gen 7.273-288 ( 1982)); the TK promoter ol Herpes virus (McKmght, S.. Cell ^7 :355-365 ( 1982)), the SV40 early promoter (Benoist, et al., Natitie (London) 290 304-310 ( 1981)); and the HCMV promoter (Boshart, et al., Cell 47:521 ( 1985)): in yeast, the yeast gal4 gene promoter (Johnston et al . Pioc Natl Acad. Sci USA 79:6971-6975 (1982); Silver, et al, Proc. Natl. Acad Sn USA HI 5951 -5955 ( 1984)) or a glycolytic gene promoter may be used. As is widely known, translation ol eukaryotic mRNA is initiated at Ihe codon which encodes the lust melhioninc Foi this reason, it is prclerablc to cnsuie that the linkage between a eukaryotic promoter and a DNA sequence which encodes the Bbk protein, or a lunctional equivalent thercol, does not contain any intervening codons which arc capable ol encoding a methiomne The presence ol such codons results cither in the tormalion ot a tusion protein (if the AUG codon is in the same leading Irame as ihe Bbk encoding DNA sequence) or a trame- shift mutation (it the AUG codon is not in the same reading lrame as the Bbk encoding sequence) If desired, a tusion pioduct ol the Bbk may be constructed For example, the sequence coding lor ihe Bbk or Iragment thercol may be liked lo a signal sequence which will allow secretion ot the protein trom or the compartmentahzalion of the protein in, a particular host. Such signal sequences may be designed with or without specific protease sites such that the signal peptide sequence is amenable to subsequent removal Transcnptional initiation regulatory signals can be selected which allow tor repression or activation, so that expression ol the operably linked genes can be modulated Ot interest are regulatory signals which aie lempciatutc-sensitivc, such that by varying the temperature, is expression can be repressed or initialed, or which aie sub|ccl to chemical regulation, e.g., by a metabolite Also ot interest are constructs wherein the Bbk mRNA and antisense RNA are provided in a transcπhable torm, but with ditlcrent promoters or other transcnptional regulatory elements such thai induction ot Bbk mRNA expression is accompanied by repression of antisense RNA cxpicssion, and/or repression ol Bbk mRNA expression is accompanied by induction of aniisense RNA expression. Translational signals aie not necessary when it is desired lo express Bbk antisense RNA sequences. It desired, the non-iranscπbcd and/or non- translated regions 3' to ihc sequence coding lor the Bbk pioicin can be obtained by the abovc-dcscπbed cloning methods The 3'-non-lranscnbcd region may be retained lor its transcnptional termination regulatory sequence elements; the 3'-non-lranslalcd region may be retained loi its translation termination regulatory sequence elements, oi loi those elements which direct polyadenylation in eukaryotic cells. Where ihe native expression control sequence signals do not Junction satisfactorily in the host cell, then sequences functional in the host cell may be substituted. The vectors ot the invention may lurther comprise other operably linked regulatory elements such as enhancer sequences, or DNA elements which conlcr tissue or cell-type specific expression on an operably linked gene To transform a mammalian cell with the DNA constructs ot the invention many vector systems arc available, depending upon whether it is desired to insert the Bbk DNA construct into ihc host cell chromosomal DNA, or to allow it to exist in an extrachromosomal torm. It the bbk DNA encoding sequence and an operably linked promoter are introduced into a recipient eukaryotic cell as a non- replicating DNA (or RNA) molecule, which may either be a linear molecule or a closed covalent cucular molecule which is incapable ot autonomous replication, then the expression ot the Bbk protein may occur through the transient expression ol the introduced sequence Genetically stable iianstormants may be constructed with vector systems, or trans! ormation systems, whereby bak DNA is integrated into the host chromosome Such integration may occur de nova within the cell or, in a prctencd embodiment be assisted by transformation with a vector which functionally inserts itself into the host chromosome, tor example, with retroviral vectors, transposons or other DNA elements which promote integration ot DNA sequences into chromosomes A vector is employed which is capable ot integrating the desired gene sequences into a mammalian host cell chromosome Cells which have stably integrated the introduced DNA into iheir chromosomes are selected by also introducing one or more markers which allow lor selection ot host cells which contain the expression vector in the chromosome, lor example, ihc marker may provide biocidc resistance, e.g , resistance to antibiotics, or heavy metals, such as copper, or the like. The selectable marker gene can either be directly linked to the DNA gene sequences to be expressed, or introduced into the same cell by co-transtcction In another embodiment, the introduced sequence is incorporated into a plasmid or viral vector capable ot autonomous replication in the recipient host Any ol a wide vancty ol vectors may be employed tor this purpose, as outlined below Factors of importance in selecting a particular plasmid or viral vector include: the ease with which recipient cells that contain the vector may be recognized and selected trom those recipient cells which do not contain the vector; the number of copies ot the vector which are desired in a particular host; and whether it is desirable to be able to "shutUe" the vector between hosl cells ol ditlcrcnl species. Preferred eukaryotic plasmids include those derived trom the bovine papilloma virus, vaccinia virus, SV40, and, in yeast, plasmids containing the 2-mιcron circle, etc., or their derivatives Such plasmids arc well known in the art (Botslcin, et al., Miami Wntr. Svmp. 79:265-274 ( 1982); Broach. J.R., The Molecular Biology ol the Yeast Saccharomvccs: Life Cycle and Inheritance. Cold Spring Harbor Laboratory, Cold Spring Harbor. NY, pp. 445-470 ( 1981 ); Broach, J R., Cell 25.203-204 ( 1982); Bollon, et al., J Clin. Hematol. Oncol 70:39-48 ( 1980); Maniatis, T., "Gene Expression," In: Cell Biology A Comprehensive Treatise. Vol. 3, Academic Press, NY, pp. 563-608 ( 1980)), and arc commercially available. For example, mammalian expression vector systems which utilize the MSV-LTR promoter to dnvc expression ol the cloned gene, and in which it is possible lo coniranslcct with a helper virus to amphly plasmid copy number, and integrate the plasmid into the chromosomes ol host cells, have been described (Perkins, et al.. Mol Cell Biol. J: 1 123 ( 1983), Clontech, Palo Alto, California). Once the vector or DNA sequence containing the construct(s) is prepared for expression, the DNA construct(s) is introduced into an appropriate host cell by any ol a vanety oi suitable means, including transtection After the introduction ot the vector, recipient cells arc grown in a selective medium, which selects tor the growth ol vector-containing cells. Expression of the cloned gene scqucnce(s) results in the production ot the Bbk protein, or in the production of a fragment of this protein. This expression can take place in a continuous manner in the transformed cells, or in a controlled manner, for example, expression which follows induction of differentiation ol the translormed cells (for example, by administration ot bromodeoxyuracil to ncuroblastoma cells or the like). The expressed protein is isolated and purified in accordance with conventional conditions, such as extraction, precipitation, chromatography, allimty chromatography, electrophoresis, or the like. 2S Bbk can be purified by growing the translormed host cells under suitable conditions which arc well known in the art. the cells can be harvested and disrupted to extract total cellular protein. The protein can then, lor example, be placed on a sizing column such as scpharose or agarose beads, and proteins ol the concct molecular weight can be collected. The predicted molecular weight ol Bbk is 26.7 kD and it runs with an apparent molecular weight of approximately 37 kD on SDS polyacrylamidc gels. Further purification can be clfcclcd by use of an anli-Bbk antibody. Such an antibody can be used to immunoprccipitatc Bbk proteins trom the set of cellular proteins ot the correct approximate molecular weight Such antibodies can. lor example, be raised against polypcpudcs synthesized accoiding to the sequence or subsequences ol the sequence shown in Fig. 2. Alternatively, the antibodies can be raised against fusion proteins, which contain Bbk sequences as well as those ot other proteins. After immunoprecipitation. the Bbk proteins can be released trom the antibodies lo provide a substantially pure preparation of Bbk protein. The bbk DNA coding sequences, of the present invention may be used to obtain Bbk antisense RNA genetic sequences, inasmuch as die antisense RNA sequence will be that sequence lound on the opposite strand of the strand transcπbing the pepiide core's mRNA. The antisense DNA strand may also be operably linked lo a promoter in an expression vector such that transformation with this vector results in a hosl capable ol expression of a Bbk antisense RNA in the transformed cell. Antisense RNA and its expression may be used to interact with an endogenous bbk DNA or RNA in a manner which inhibits or represses transcription or translation of the bbk genes in a highly specific manner. Use ol antisense RNA probes to block gene expression is described, lor example, in Lichtenstein, C, Nature J3J:801-802 ( 1988). Identification, Characterization and Use of Bbk Fragment Compositions Comprising the Bbk BH3 Domain A novel domain within the Bbk molecule that appears to be both necessary and sufficient for the known biological activities of Bbk has been identified. This domain, designated herein as the "Bbk BH3 domain," is sufficient to mediate cell killing tunction and may be sutticicnt lor physical interaction with Bak. Mutation ot Bbk BH3 domain sequences has been demonstrated to reduce the apoptotic activity ol the Bbk prolcin in Ratl fibrobiast cells. These expcnmcnts demonstrate that the Bbk BH3 domain is required lor the cell killing and Bak binding activities ol the Bbk protein. These observations suggest ihat Bbk modulates or regulates apoptosis through a mechanism that involves the Bbk BH3 domain As those ot skill familiar with the present invention will appreciate, sequences compnsmg the Bbk BH3 domain arc useful in modulating apoptosis in cells. Similarly, compounds and compositions which are capable ot binding to the Bbk BH3 domain arc uselul as agents lor the modulation of apoptotic activity in cells. As used herein, the term "Bbk BH3 domain" refers to a protein domain first identified in Bbk, demonstrated herein to be essential tor the interaction of Bbk with Bak and lor Bbk's cell killing function, and lo peplidcs and/or molecules capable ol mimicking its structure and/or function. In a preferred embodiment, the present invention compπses a peptide having the following amino acid sequence: LRRLVALLEEEAE -[SEQ ID NO: 1 ]- corrcsponding lo amino acid residues 125- 137 of Bbk. as well as functional equivalents thcreot. By "functional equivalent" is meant a peptide possessing a biological activity or immunological Mi charactenstic substantially similar to that ol the Bbk BH3 domain, and is intended lo include "lragments". "variants", "analogs", "homologs", or "chemical derivatives" possessing such activity or characteristic Functional equivalents ol the Bbk BH3 domain, then, may not share an identical ammo acid sequence, and conservative or non-conservative amino acid substitutions ot conventional or unconventional ammo acids are possible Reference herein to "conservative" amino acid substitution is intended to mean die intcrchangeability ol ammo acid residues having similar side chains. For example, glycine, alanine, vahne, lcucinc and isolcucine make up a group ol amino acids having aliphatic side chains, scπnc and thiconinc aie amino acids having ahphatic-hydroxyl side chains; asparagine and glutamine arc amino acids having amide-containing side chains; phenylalanine, lyrosine and tryptophan arc amino acids having aromatic side chains; lysinc, arginme and histidinc arc amino acids having basic side chains; aspartic acid and glutamic acid arc amino acids having acidic side chains: and cysteinc and mcthionine are amino acids having sullur-containing side chains Interchanging one amino acid trom a given group with another amino acid trom mat same group would be considered a conservative substitution. Preterrcd conservative substitution groups include asparaginc-glutaminc, alanine-valinc, lysine-argininc. phenylalanine-tyrosmc and valinc-lcucine-isoleucine In additional embodiments ot the invention, there arc provided peptides having the following amino acid sequence: LRRLAALLEEEAE -[SEQ ID NO. 2]~ LRRLVALAEEEAE -[SEQ ID NO: 3] - LRRLVALLEAAAE -[SEQ ID NO: 4]~ corresponding to alanine point mutants as shown in Figure 9, which also demonstrate significant Bbk cell killing lunclion The Bbk BH3 domain disclosed herein is uniquely involved in both cell killing and Bak binding activity ol Bbk. The lunctional importance ol the Bbk BH3 domain is likely to be related lo its ability to mediate one or more piotcin/protcin interactions with other Bcl-2 family members, or with other as yet unidentilicd ccllulai pιotcιn(s) The present inventor does not intend to be bound by a particular theory; however, regardless ol its mechanιsm(s) ot action, the Bbk BH3 domain in Bbk is ol central importance lor mediating these prolcin/prolein interactions Agents capable ol modulating Bbk BH3 domain mediated protein/protein interactions may include peptides comprising the Bbk BH3 domain, as well as mutants ol the Bbk BH3 domain or ol proteins comprising the Bbk BH3 domain A "mutant" as used herein retcrs to a peptide having an ammo acid sequence which differs I mm thai ol the naturally υccumng peptide or protein by al least one amino acid Mutants may have the same biological and immunological activity as the nalurally occumng Bbk BH3 domain peptide or the naturally occurring protein However, die biological or immunological activity ol mutants may difter or be lacking For example, a Bbk BH3 domain mutant may lack the biological activity which characterizes nalurally occumng Bbk BH3 domain peptide. but may be uselul as an antigen tor raising antibodies against the Bbk BH3 domain or lor the detection or puntication ot antibodies against the Bbk BH3 domain, or as an agonist (competitive or non-competitive), antagonist, or partial agonist of the lunclion ol the naturally occumng Bbk BH3 domain peptide. Modulation ot Bbk BH3 domain mediated protein/protein interactions may be ettected by agonists or antagonists ol Bbk BH3 domain peptides as well Screening ol peptide libranes, compound libraries and other intormation banks to identity agonists or antagonists ol the tunction ot pioteins comprising ihc Bbk BIT3 domain is accomplished with assays lor detecting the ability ol potential agonists or antagonists to inhibit or augment Bbk BH3 domain binding, e.g., Bbk BH3 domain homodimeπzalion or hetcrodimeπzation. For example, high through-pul screening assays may be used lo identity compounds that modulate the protein binding lunclion ol the Bbk BH3 domain. Such screening assays facilitate the identiticaiion ol compounds thai accelerate or inhibit apoptosis by influencing pro- tcin/prolein interactions mediated by the Bbk BH3 domain. For example an //; vitro screen for compounds that disrupt the Bbk BH3 domain mleraclion with Bak compnses multiwell plates coated with Bak which arc incubated with a labeled Bbk BH3 domain peptide probe in the presence of one or more compounds lo be tested. Molecules thai specifically disrupt the interaction could, in pnnciple. bind lo either the Bbk BH3 domain "ligand" or to the "receptor" domain in Bak. Either class ol compound would be a candidate apoptosis-modulatmg agent. Thus, ihc invention provides a method ol screening lor an agent capable ot modulating apoptosis which comprises coating a multiwell plale with Bak and incubating the coated multiwell plate with a labeled Bbk BH3 domain peptide probe in the presence ol an agent which it is desired to test wherein disruption of Bbk BH3 domain interaction with Bak indicates that said agent is capable ol modulating apoptosis Agents identified by this mcUiod arc also contemplated embodiments ol the invention Suitable labels include a detectable label such as an enzyme, ladioactivc isotope, fluorescent compound, chemiluminescent compound, or bioluminescent compound. Those of ordinary skill in the art will know ol other suitable labels or will be able to ascertain such using routine experimentation Furthermore, the binding of these labels to the peptides is accomplished using standard techniques known in the art. A high speed screen toi agents lhat bind directly lo the Bbk BH3 domain may employ immobilized or "tagged" combinatorial iibraπes. Agents that bind spccilically to such libraries are candidates lo be tested lor their capacity to block Bbk7Bak interactions. As discussed above, such agents may lunction as suppressors ol apoptosis by cither directly inhibiting Bbk (and/or Bbk/Bak) lunction. or by increasing the cttective activity ot endogenous Bcl-2 (or other Bcl-2 lamily member) Such agents would be useful lor suppressing aberrant apoptosis in degenerative disorders or lollowing l.schcmic injury Antibodies against the Bbk BH3 domain peptides ot the invention may be used to screen cDNA expression libraries lot identifying clones containing cDNA inserts encoding structurally related, immunocrossreactivc proteins which may be members ol ihc Bbk BH3 domain lamily ol proteins Screening ol cDNA and mRNA expression libraries is known in the art Similarly, antibodies against Bbk BH3 domain peptides arc used lo identity ot punly immunociossreactive proteins related to this domain, oi to detect or determine ihc amount ol proteins containing the Bbk BH3 domain in a cell or cell population, tor example, in tissue or cells, such as lymphocytes, obtained trom a patient Known methods tor such measurements include immunoprccipitalion ot cell extracts tollowcd by PAGE, in situ detection by lmmunohtslochem- ical methods, and ELISA methods, all ol which are well known in die art. Modulation ol apoptosis according to the invention includes methods employing specitic antisense polynucleotides complimentary to all or part ot the nucleotide sequences encoding proteins comprising the Bbk BH3 domain disclosed herein Such complimentary antisense polynucleotides may include nucleotide additions, deletions, substitutions and transpositions, providing that specitic hybridization to the target sequence persists. Soluble antisense RNA or DNA ohgonucleotides which can hybridize specifically to mRNA species encoding proteins comprising ihc Bbk BH3 domain, and which prevent transcnplion ot the mRNA species and/or translation ol the encoded polypcptide arc contemplated as complimentary antisense polynucleotides according to the invention Ptoduclion ol proteins comprising the Bbk BH3 domain is inhibited by antisense polynucleotides according to the invention, and such antisense polynucleotides may inhibit apoptosis. senescence and the hkc. and/or reverse the translormed phenolype ol cells A hcterologous expression cassette maybe used to produce antisense polynucleotides in a transtcctant or transgemc cell Antisense polynucleotides also may be administered as soluble ohgonucleotides to the external environment ol the target cell, such as the culture medium ol cells in vitro or the interstitial fluid (c g., via the circulatory system) in vivo. Antisense polynucleotides and their use are known to those ol skill, and are descnbed, for example, m Mellon, D A . Ed, Antisense RNA and DNA, Cold Spring Harbor Laboratory Press, Cold Spnng Harbor, New York ( 1988) The predicted biological activity ot agents identified according to the invention varies depending on the assumptions made regarding the mechanism ol Bbk/Bak tunction For example, an agent which binds tightly to the Bbk BH3 domain would be predicted to inhibit Bbk (and perhaps Bbk/Bak) function Assuming Bbk (and/or Bbk/Bak) is the active cell death regulatory molecule, an agent that binds tightly to the Bbk BH3 domain may inhibit Bbk tunction. Such agents might, thcretorc, exhibit anti-apoptotic activity under conditions in which Bbk has a demonstrated apoptotic cltect Agents in this class could have utility in treating diseases characterized by excessive or inappropriate cell death, including, lor example, neuro-degenerative diseases and injury resulting trom ischemia. Peptidomimetics of Bbk BH3 domain peptide are also provided by the present invenuon, and can act as drugs tor the modulation ol apoptosis by, tor example, blocking the tunction ot proteins comprising the Bbk BH3 domain or interfering with Bbk BH3 domain mediated interations Peptidomimetics are commonly understood in the pharmaceutical industry to include non-pcptide drugs having properties analogous to those ot those ol the mimicked peptide The principles and practices ot pcpudomimetic design arc known in the art and are described, for example, in Faucherc J., Adv. Drug Res. 15: 29 ( 1986); and Evans et al., J. Med. Chem. 30: 1229 ( 1987). Peptidomimetics which bear structural similarity lo therapeutically useful peptides may be u.sed to produce an equivalent therapeutic or prophylactic effect. Typically, such peptidomimetics have one or more peptide linkages optionally replaced by a linkage which may convert desirable properties such as resistance lo chemical breakdown in vivo. Such linkages may include -CH 2 NH-, -CH.S-, -CH 3 -CH ? - t -CH=CH-, -COCH : -, - CH(OH)CH,-, and -CH 2 SO-. Peptidomimetics may exhibit enhanced pharmacological properties (biological half life, absorption rates, etc.), dilterenl speciticity, increased stability, production economies, lessened anligenicity and the like which makes their use as therapeutics particularly desirable Immunization ol animals with peptides comprising the Bbk BH3 domain alone or in conjunction with adjuvants by known methods can produce antibodies specific for the Bbk BH3 domain peptide. Antiscrum obtained by conventional procedures may be utilized for this purpose. For example, a mammal, such as a rabbit, may be immunized with a peptide comprising the Bbk BH3 domain, thereby inducing the lormation of polyclonal antibodies thcreagainst. Monoclonal antibodies also may be generated using known procedures. Such antibodies can be used according to the invenuon to delect the piescncc and amount ol peptides comprising the Bbk BH3 domain. The Bbk BH3 domain peptides of ihc invention may be used for the detection of Bbk and other proteins by means ol standard assays including radioimmunoassays and enzyme immunoassays. It will be appreciated by those of skill that the precise chemical structure of peptides comprising the Bbk BH3 domain will vary depending upon a number of factors. For example, a given protein may be obtained as an acidic or basic salt, or in neutral form, since ionizable carboxyl and amino groups arc lound in the molecule For the purposes ot the invention, then, any torm ot ihe peptides comprising the Bbk BH3 domain which retains the therapeutic or diagnostic activity ol the naturally occurring peptide is intended to be within the scope ot the present invention. The term "substantially homologous" as used herein rctcrs to the ability ol a first DNA sequence encoding Bbk to hybridize to a second DNA sequence encoding the loregoing. under stringent conditions, lor example, at about 0. Ix sodium citrale sodium chloride butter (SSC) at a temperature ol about 65 C The term "substantially pure" means that the protein or molecule ol interest is essentially Irec trom any other detectable biological constituents A "Iragment" ol a molecule such as Bbk is meant lo rclcr to any variant ot the molecule which possess ihe biological activity ol the Bbk protein A "variant" ol a molecule is meant to reler to a molecule substantially similar in structure and biological activity or immunological characteristics to either the entire molecule, or lo a Iragment thereot Thus, provided that two molecules possess a similai activity, they are considered variants as that term is used herein even it the composition or secondary, tertiary, or quaternary structure ot one ot the molecules is not identical to that lound in the other, or it the sequence ol amino acid residues is not identical An "analog" ol a molecule is meant to rclcr to a molecule substantially similar in tunction to either the enure molecule or to a Iragment thereof As used herein, a molecule is said to be a "chemical dcπvalivc" ol another molecule when it contains additional chemical moieties not normally a part ol the molecule Such moieties may improve the molecule's solubility, absorption, biological half lite, etc The moieties may alternatively decrease the toxicity of the molecule eliminate or attenuate any undesirable side effect ot the molecule, etc Moieties capable ol mediating such effects are described, lor example, in Remington's Pharmaceutical Sciences ( 1980) Pmcedurcs lor coupling such moiclies to a molecule arc well known in the art By the term "modulate" is intended, for the purposes of the present invention, the induction of apoptosis by the administration of the Bbk protein of the invention, an active fragment thereof, a functional equivalent thereof, and/or the suppression or induction of apoptosis by the administration of a Bbk hybrid or Bbk mutant, or the administration of a vector containing cDNA encoding any of the foregoing, to the particular cells of an individual suffering from any degenerative disorder which results in inappropriate cell growth, for example, including lymphomas, genotypic tumors, cancer, or, disorders characterized by inappropriate cell death, for example, including AIDS which results in T-cell death, in order to stabilize mappropπate cell proliferation or inappropriate cell death and preferably to restore normal cell behavior By the term "administration" is intended any mode of administration which results in the delivery of the therapeutic agent across the cell membrane and into the desired cell. The site of administration and cells will be selected by one of ordinary skill in the art based upon an understanding of the particular degenerative disorder being treated. In addition, the dosage, dosage frequency, and length of course of treatment, can be determined and optimized by one of ordinary skill in the art depending upon the particular degenerative disorder being treated. The particular mode of administration can also be readily selected by one of ordinary skill in the art and can mclude, for example, oral, intravenous, subcutaneous, intramuscular, etc., with the requirement that the therapeutic agent cross the cell membrane The therapeutic agent of the present mvention can be the Bbk protein and/ or functional equivalents thereof and/or Bbk hybrids or Bbk mutants and/or a vector containing cDNA encoding the foregoing. By the term "therapeutic agent" is intended the present Bbk protein, fragments, functional equivalents and/or hybrids or mutants thereof as well as vectors containing cDNA encoding any of the foregoing. The present therapeutic agent can be administered alone or in combination with and/or 3X concurrently with other suitable drugs and/or courses of therapy By the term "degenerative disorder" is intended for purposes of this mvention, any disorder characterized by inappropriate cell proliferation or inappropriate cell death or in some cases, both By the term "inappropriate cell proliferation" is intended a statistically significant increase in cell number as compared to the proliferation of that particular cell type in the normal population Also included are disorders whereby a cell is present and/or persists in an inappropriate location, e.g , the presence of fibroblasts in lung tissue after acute lung injury. For example, such cells include cancer cells which exhibit the properties of invasion and metastasis and are highly anaplastic Such cells include but are not limited to, cancer cells including, for example, tumor cells By the term "inappropriate cell death" is intended a statistically significant decrease in cell number as compared to the presence of that particular cell type in the normal population Such undenepresentation may be due to a particular degenerative disorder, including, for example, AIDS (HIV), which results in the inappropriate death of T-cells, autoimmune diseases which are characterized by inappropriate cell death. By the term "autoimmune disease" is intended a disorder caused by an immune response directed against self antigens. Such diseases are characterized by the presence of circulating autoantibodies or cell-mediated immunity against autoantigens m conjunctions with inflammatory lesions caused by immunologically competent cells or immune complexes in tissues containing the autoantigens Such diseases include systemic lupus erythematosus (SLE), rheumatoid arthritis. By the term "suppression" is intended for the purposes of this invention the result achieved by administering an amount of a therapeutic agent containing Bbk hybrids or Bbk mutants thereof effective to suppress apoptosis in an individual suffering from a degenerative disorder characterized by inappropriate cell death. Suppression of apoptosis is achieved when the numbers ot the particular affected cell type remain stable or increase in number to a level within the range observed in the normal cell population By the term "stable" is intended the state achieved when a statistically significant decrease in cell number is no longer observed in the individual bemg treated, as compared to the cell number observed at the onset of the course of treatment By the term "induction" is intended for the purposes of this invention the result achieved by the administration of an amount of a therapeutic agent containing the Bbk of the mvention effective to induce apoptosis in cells of an individual suffering from a degenerative disorder characterized by inappropriate cell proliferation The induction of apoptosis is achieved when cell numbers remain stable or decrease to a level within the range observed in the normal cell population One of ordinary skill in the art can readily determine whether the induction of apoptosis has been achieved By the term "Bbk hybrid" is intended for the purposes of this invention, proteins which are hybrid proteins of the present Bbk proteins, fragments thereof, and/or functional equivalents or mutants thereof, with other apoptosis associated proteins encoded by genes including, for example, Bcl-2, Bax, c-myc, LMW5-HL, Bbk, Bcl-X, , Bcl-X s , BHRF- 1 , Mcl-1, A l and ced9, fragments thereof and/or functional equivalents thereof, in order to produce a protein which exhibits enhanced, decreased, or intermediate apoptosis induction or suppression activity as compared to the activity of Bbk alone Such hybrids can be produced, for example, by fusing the first half of the coding region ot the bbk cDNA with the second half of the coding region of the cDNA for bcl-2, or bax, or bcl-x L , or bcl-x s or vice versa Additionally, by adding or replacing segments of bcl-2, bax, bcl-x L or bcl-x s to the bbk cDNA, chimeπc gene products of therapeutic value can be generated. One of ordinary skill in the art can readily produce and employ such hybrids using techniques well known in the art One of ordinary skill in the art can readily determine whether a particular hybrid exhibits enlianced, decreased or intermediate apoptosis induction or suppression activity using known screening methods and as described 194 herein. By the term "normal cell behavior" is intended for the purposes of this invention, cells in which apoptosis proceeds normally. Normal cell behavior is observed in an organism which is able to remove senescent, damaged, or abnormal cells that could interfere with organ function or develop into tumors Apoptosis which proceeds normally represents a coordinated cellular response to noxious stimuli that are not immediately lethal. By the term "patient" or "individual" is intended for the purposes of the present mvention, animals, mcluding humans and mammals, who suffer from a degenerative disorder. By the term "Bbk mutant" is intended for the purposes of the present invention a mutant of Bbk which exhibits the reverse (apoptosis suppression) activity of the Bbk protein of the invention due to the substitution ot one or more ammo acids or corresponding nucleotides. By the term "apoptosis associated protein Bbk" is intended for the purposes of the present invention both the isolated naturally occurring and isolated recombmantly produced protein (i.e., synthetic Bbk) which exlubits, inter alia, apoptosis induction from human tissue including, for example, tumor cells and established human cell lines, and from tissues of other animals including mammals. This term includes any analog, homolog, mutant or derivative of isolated naturally occumng Bbk including fragments havmg less than the naturally occumng number of amino acids, such as partial fragments of natural or synthetic Bbk which retain the biological or immunological characteristics of the polypeptide disclosed in this application This term also includes any peptide which contains the sequence of an isolated naturally occurring Bbk protein, or analog or homolog thereof, together with one or more flanking ammo acids, which retains the biological or immunological characteristics of the Bbk protein of the invention. Construction and Identification of Antibodies Raised Against Bbk, Functional Equivalents, Fragments, Hybrids, or Mutants Thereof In the lollowing description, relercncc will be made to various methodologies well-known to those skilled in the art ol immunology Standard rclcrcncc works setting torth the general principles ol immunology include the work ol Catty, D , Antibodies. A Practical Approach. Vol I, IRL Press, Washington, DC ( 1988), Klein, J , Immunology The Science ol Cell-Nonccll Discrimination, John Wiley & Sons, New York (1982). Kennett, et al , Monoclonal Antibodies. Hyhπdoma- A New Dimension in Biological Analyses, Plenum Press, New York ( 1980). Campbell, A , "Monoclonal Antibody Technology." In Burdon, R., et al , Eds , Laboratory Techniques in Biochemistry and Moleculai Biology. Vol 13. Elsevier, Amsterdam ( 1984). and Eisen, H N , In Davis, B D , e t al , Eds . Microbiology, 3d cd . Harper & Row. Philadelphia ( 1980) An antibody is said lo be "capable ol binding" a molecule ii it is capable ol spccilically reading with the molecule to thereby bind the molecule to the antibody The term "epitope" is meant to rclcr to that portion ol a hapten which can be recognized and bound by an antibody An antigen may have one or more than one epitope An "antigen" is capable ol inducing an animal to produce antibody capable ol binding to an epitope ot that antigen The specitic reaction retened to above is meant to indicate lhat the antigen will react, in a highly selective manner, wilh its conesponding antibody and not with the multitude ol other antibodies which may be evoked by other antigens The term "antibody" (Ab) or "monoclonal antibody" (Mab) as used herein is meant to include intact molecules as well as tragmcnts thercol (such as, lor example, Fab and F(ab) : tragmcnts) which arc capable ot binding an antigen Fab and F(ab)-, tragmcnts lack ihe Fc tragment ol intact antibody, clear more rapidly trom the circulation, and may have less non-spccttic tissue binding ol an intact antibody (Wahl, et al., J Nucl. Med. 24: 16-325 (1983)). The antibodies ol the present invention have specificity to one or more epitopes present on die Bbk peptide, or an ldiolypc on the present Bbk The antibodies ot the invention can be polyclonal or monoclonal, provided that they arc made with the present Bbk polypeptide or tragment thcreot as ihc immunogen. Both ol these types ot antibodies can be utilized in the applications described herein The present antibodies can be used to detect the presence ot the present Bbk protein in a human tissue sample. The present Bbk protein can be delected by contacting the sample with an imaging-ctlectivc amount ol the present dctcctably labeled appiopπatc antibody and delecting the label, thereby establishing ihc presence ot the Bbk protein in the sample. Detection can be carried out by imaging in vivo. The Bbk protein can also be detected by known immunoassay techniques, including, lor example, RIA, ELISA. etc , using appropriate antibodies according to the invention. The antibodies ot the present invention arc prepared by any ot a variety ot known methods For example, cells expressing the Bbk protein can be administered to an animal in order to induce the production ol scrum containing polyclonal antibodies that arc capable ot binding the Bbk protein. For example, the Bbk protein or Iragment thercol is chemically synthesized and punticd by HPLC to render it substantially lree ot contaminants. Such a preparation is then introduced into an animal in order to produce polyclonal antisera of high specific activity. Polyclonal antibodies can be generated in any suitable animal including, lor example, mice, rabbits or goats The Bbk immunogcnic peptide or tragmcnl thcreot can be miccled by itself or linked to appropriate immunoaetivating carπcis, such as Keyhole limpet hcmocyanin (KLH). See Catty, D.. Ed.. Antibodies. A Practical Handbook. Vols. I and II, IRL Press, Washington. DC (1988) Monoclonal antibodies can be prepared in various ways using techniques well understood by ϋiosc having ordinary skill in the art. For example, monoclonal antibodies can be prepared using hybπdoma technology (Kohler, et al, Nature 256:495 ( 1975); Kohler, et al., Em: J. Immunol. 6:51 1 ( 1976); Kohler, et al . Eur. J Immunol 6:292 ( 1976); Hammeriing, et al.. In: Monoclonal Antibodies and T-Ccll Hvhπdomas. Elscviei , N Y., pp. 563-681 ( 1981)); Roger H Kennclt, et al., Eds., Monoclonal Antibodies - Hybndomas: A New Dimension in Biological Analysis. Plenum Picss ( 1980) In general, such procedures involve immunizing an animal with the present Bbk protein, or a tragment thercol The splenocyies ot such animals are extracted and luscd with a suitable myeloma cell line Any suitable myeloma cell line may be employed in accordance with the present invention Alter tusion, die resulting hybπdoma cells are selectively maintained in HAT medium, and then cloned by limiting dilution as described by Wands, et al , Gastroenterol WΛ225-232 ( 1981 ) The hybπdoma cells obtained through such a selection are then assayed to identity clones which secrete antibodies capable of binding the Bbk protein. Through application ol the above- described methods, additional cell lines capable ol producing antibodies which recognize epitopes ot the prescnl Bbk protein can be obtained. For example, additional hybndomas which produce monoclonal antibodies which enable the detection of the present Bbk protein can be easily produced and isolated with minimal screening Hybndomas producing monoclonal antibodies specific tor epitopes which are found on the present Bbk protein arc most effectively produced by tirst immunizing an animal from which hybndomas can be produced such as, tor example a Balb/c mouse, with initial subcutaneous inactions of Freund's ad|uvanl. lollowcd by booster in ctions within a lew days. The tusion can be earned out using any ol the techniques commonly known to those of ordinary skill in the art. The screening ot the hybndomas to determine which ones are producing monoclonal antibodies specific lor the present peptide is straightforward and can be accomplished in a standard ELISA or RIA formal. For example, in an RIA screening format the culture supernatant, or ascites lluid trom a hybndoma producing monoclonal antibody is reacted with l2<, I-pcpiιde The isolation ol other hybndomas secreting mAbs ot the same specificity as those described herein can be accomplished by the technique ot anti-idiotypic screening. Potocnηak, et al , Science 275: 1637 (1982) Briefly, an anti-idiotypic (anti-Id) antibody is an antibody which iccognizcs unique determinants generally associated with the antigen-binding site ol an antibody An Id antibody can be prepared by immunizing an animal ol the same species and genetic type (eg , mou.sc strain) as the source ol the mAb with the mAb raised against the prescnl Bbk prolcin or tragment thereof to which an anti-Id is being prepared The immunized animal will recognize and respond lo the idiotypic determinants of the immunizing antibody by pioducing an antibody to mese idiotypic determinants (the anti-Id antibody). By using an anti-Id antibody which is specific lor idiotypic determinants on a given mAb, it is then possible lo identity other B cell or hybπdoma clones sharing thai ldiotype. Idiotypic identity between the antibody product ol two clones makes it highly piobable that the antibody products ot the two clones tecognize the same antigenic epitopes. The anti-Id antibody may also be used as an "immunogen" to induce an immune response in yet another animal, producing a so-called anti-anti-Id antibody The anti-anti-Id may be epitopically identical to the original mAb which induced the anti-Id. Thus, by using antibodies lo the idiotypic determinants ol a mAb, it is possible to identity other clones expressing antibodies ol identical specificity Accordingly, mAbs generated against the present Bbk protein may be used to induce anti-Id antibodies in suitable animals, such as BALB/c mice Spleen cells trom such immunized mice arc used to produce anti-Id hybndomas secreting anti-Id mAbs. Further, the anti-Id mAbs can be coupled to a earner such as keyhole limpet hcmocyamn (KLH) and used to immunize additional BALB/c mice Sera trom these mice will contain anti-anti-Id antibodies that have the binding properties of the original mAb specific tor the antigen epitope The anti-Id mAbs thus have iheir own idiotypic epitopes, or "idiotopes" structurally similar to the epitope being evaluated For replication, the hybπdoma cells ot this invention may be cultivated m vitro or in vivo Production ol high liters ol mAbs in vivo production makes this the presently prelerred method ol production Briefly, cells trom the individual hybndomas arc ιn|ecled intrapcπloneally into pπstanc-pπmcd BALB/c mice to produce ascites fluid containing high concentrations ot die desired mAbs MAbs of isotype IgM or IgG may be purified trom such ascites fluids, or trom culture supernatants, using column chromatography methods well known to those of skill in the art. Ot special interest to the present invention arc antibodies which are produced in humans, or are "humanized" (i e, non- immunogemc in a human) by recombinant or other technology such that they will not be antigenic in humans, or will be maintained in the circulating serum of a recipient tor a longer period of time Humanized antibodies may be produced, for example by replacing an immunogemc portion ot an antibody with a corresponding, but non- immunogemc portion (i.e., chimenc antibodies) (Robinson, et al.. International Patent Publication PCT/US86/02269; Akira, et al., European Patent Application 184,187; Taniguchi, M., European Patent Application 171,496; Momson, et al , European Patent Application 173,494: Ncuberger, et al.. PCT Application WO 86/01533, Cabilly, et al, European Patent Application 125,023; Better, et al. Science 240:1041-1043 (1988); Liu, et al, Proc. Natl. Acad. Sci. USA #4:3439-3443 (1987): Liu, et al, J. Immunol 7J9:3521-3526 ( 1987); Sun, et al, Proc. Natl. Acad. Sci. USA #4:214-218 (1987); Nishimura, et al, Cane. Res. 47:999-1005 (1987); Wood, et al. Nature 314:446-449 ( 1985)); Shaw, et al, J. Natl Cancer Inst. #0: 1553-1559 (1988). General reviews of "humanized" chimcric antibodies are provided by Morrison, S.L. (Science. 229: 1202-1207 ( 1985)) and by Oi, et a!.. BioTechniques 4:214 ( 1986)). Suitable "humanized" antibodies can be alternatively produced as described by Jones, et al. Nature 321:552-525 (1986); Vcrhoeyan, et al. Science 234: 1534 (1988). and Bcidler, et al, J. Immunol /4/:4053-4060 ( 1988). The present Bbk protein, fragments thereof, hybrids thereof, Bbk mutants, or antibodies thereto can be utilized in immunoassays for die detection of the Bbk protein in a human tissue sample. For example, antibodies against the present Bbk protein can be used to detect the present Bbk protein in a human tissue sample The immunoassays can be competitive or sandwich, as is otherwise well known and they all depend on the formation of antibody-antigen immune complex. These assays are well known to those of skill in the art. For purposes of ihe assays, the antibody or antigen can be immobilized or labeled. There are many carriers to which the antibody/antigen can be bound for immobilization and which can be used in the present invention. Well-known carriers include but are not limited to glass, polystyrene, polypropylene, polyethylene, dextran, nylon, amylases, natural and modified celluloses, polyacrylamides, agaroses, and magnetite. The nature of the earner can be either soluble to some extent or insoluble for purposes of the invention. Those skilled in the art will know many other suitable earners for binding the antibody or antigen, or will be able to ascertain such, using routine experimentation. Depending on the particular embodiment ol me invention, one or more ot the antibodies or antιgen(s) peptιde(s) will be coupled wim a detectable label such as an enzyme, radioactive isotope, fluorescent compound, chemiluminescent compound, or biυluminesccnl compound. Those ol ordinary skill in the art will know ot other suitable labels lor binding to the antibodies or antιgcn(s) pcptιdc(s) or will be able to ascertain such using routine expenmcnta- Uon Furthermore, the binding ot these labels to die antibodies oi antιgen(s) can be done using standard techniques commonly known to those ol ordinary skill in the art The antibodies or antigen peplιdc(s) can be bound lo an enzyme This enzyme, in turn, when later exposed lo its substrate will react with the substrate in such a manner as to produce a chemical moiety which can be delected, as, lor example, by spectrophoiometnc or fluorometπc means. Examples ol enzymes that can be used to detcctably label are amylatc dehydrogcnase, staphylococcal nuclcase, dclta-5-steroιdιsomerase, yeast alcohυldehydrogenase, α-glycerophosphatc dehydrogcnase, tπose phosphate isomera.se, alkaline phosphatase, asparaginase, glucose oxidase, β-galactosidasc, nbonucleasc, urease, catalasc, glu¬ coses-phosphate dehydrogcnase, glucoamylase, and acctylchohnesicrase The presence ol an antibody or antigen can also be detected by labeling ihc antibody or antigen with a radioactive isotope The presence ol the radioactive isotope can be determined by such means as the use oi agamma counter or a scintillation counter. Isotopes which are particularly uselul are Η, n % 32 P, 3S S, ,4 C, M Cr, ,h Cl, w Co, s,, Fc, 7S Se, and 1S2 Eu. It is possible to delect the presence ot the antibody or antigen by labeling the antibody or antigen peptide with a fluorescent compound When the fluorescently labeled antibody or antigen peptide is exposed lo light ol the proper wavelength, its presence can then be detected due to fluorescence ol the dye Among the most common fiuoiesccnt labeling compounds are fluorcscein isothiocyanatc. rhodamine, phycoerylhπn, phycocyanin, allophycocyanin, o-phthaldehydc, and tluorcscaminc. Another way in which the antibody or antigen can be delectably labeled is by coupling it to a chemiluminescent compound The presence ol the chcmiluminescent-lagged antibody or antigen peptide is then determined by detecting the presence ol luminescence that aπses duπng the course ol a chemical reaction Examples ol particularly usctul chemiluminescent labeling compounds aie luminol, l.soluminol, aromatic-acπdinium ester, lmidaxolc, acπdimum salt, and oxaiate ester Likewise a biolumincsccnt compound may also be used lo label the antibody or antigen peptide Biolumincsccncc is a special type ot chcmiluminesccnce which is lound in biological systems and in which a catalytic piotcin increases the etlicicncy ot the chemiluminescent reaction The presence ol a biolumincsccnt binding partnei would be determined by detecting the presence ot luminescence Important biolummescent compounds lor purposes ol labeling are luciteπn, luciterasc. and acquoπn The antibodies or antigen peptιdc(s) lor use in the assay ol the invention arc ideally suited tor die preparation ol a kit Such a kit may compnse a earner means being compartmen¬ talized to receive in close confinement one or more container means such as vials, tubes, and the like, each ot said container means comprising one ol the separate elements to be used in the method For example, one ol the container means may comprise a first antibody bound to an insoluble or partly soluble camer. A second container may comprise soluble, detectably-labeled second antibody, in lyophilizcd torm or in solution The earner means may also contain a third container means compnsmg a delectably labeled third antibody in lyophilizcd torm or in solution. Such a kit can be used loi sandwich assays 4<> In addition, the earner means may also contain a plurality ol containers each ot which comprises dillcrcnt, predetermined amounts ot the present Bbk peptide. These latter containers can then be used to prepare a standard curve into which can be used lo interpolate the resultsoblained trom the sample containing the unknown amount of the prescnl Bbk protein. Imaging can be carried out in vitro or in vivo In vitro imaging can be done with the labels mentioned previously In vivo imaging is done with diagnostically etteciive labeled antibodies The term "diagnostically eltective" means mat the amount ot detectably labeled antibody administered is sufficient to enable detection ot the site ot Bbk protein presence when compared to a background signal Generally, the dosage ol detectably-labeled antibody or antιgen(s) lor diagnosis will vary depending on considerations such as age, condition, sex, and extent ol disease in the patient, counteπndications. it any, and other variables, to be adjusted by the individual physician. Dosage can very trom 001 mg/kg to 2,000 mg/kg, pretcrably 0.1 mg/kg to 1,000 mg/kg. The term "diagnostically labeled" means that the antibody has attached to it a diagnostically detectable label. There are many ditterent imaging labels and methods ol labeling known to those ot ordinary skill in the art Examples ot the types ol labels which can be u.sed in the present invention include radioactive isotopes and paramagnetic isotopes. For diagnostic in vivo imaging, the type ot detection instrument available is a major t actor in selecting a given radionuclide The radionucleotide chosen must have a type ot decay which is detectable tor a given type ot instrument. In general, any conventional method tor visualizing diagnostic imaging can be utilized in accordance with this invention. Another important tactor in selecting a ladionuchde lor in vivo diagnosis is that the halt-life ol a radionucleotide be long enough so that it is still detectable at the time ol maximum uptake by the target, but short enough so thai deleterious radiation upon the host is minimized Ideally, a radionuclide used tor in vivo imaging will lack a paniculate emission, but pioducc a large number ol photons in a 140-200 kc V lange, which may be readily detected by conventional gamma cameras For in vivo diagnosis, radionuclcotides may be bound to antibody or antigen eidier directly or indirectly by using an intermediary lunctional group Intermediary lunctional groups which are ottcn used to bind radioisotopes which exist as metallic ions to anubody or antigen are dicthylenctπaminepcntaacciic acid (DTPA) and cthlcnediaminetetracetic acid (EDTA) Typical examples ol metallic ions which can be bound to immunoglobulins arc Wn Tc, 12, I, "'In, π, I, " 7 Ru, 07 Cu. " 7 Ga, 72 As, ay Zr, and 2ϋ, Tl The antibodies used in the method ol the invention can also be labeled with paramagnetic isotopes lor purposes ol in vivo diagnosis Elements which arc particularly uselul (as in magnetic resonance imaging (MRI) techniques) in this manner include 1S7 Gd, ,s Mn, 152 Dy, ' 2 Cr, and 56 Fe Preparations ot the imaging antibodies tor administration include sterile aqueous or non-aqueous solutions, suspensions, and emulsions Examples ot non-aqueous solvents are propyleneglycol, polyethylencglycol, vegetable oil such as olive oil and ιn|cctablc organic esters such as ethyloleate. Aqueous earners include water, alcoholic/aqueous solutions, emulsions or suspensions, including saline and buttered media, parenteral vehicles including sodium chlonde solution, Ringer's dextrose, dextrose and sodium chloride, lactated Ringer's or fixed oils Intravenous vehicles include fluid and nutrient replemshers, electrolyte replenishes, such as those based on Ringer's dextrose, and the like. Preservatives and other additives may also be present, such as. lor example, antimicrobials, anti-oxidants, chclaling agents, and inert gases and the like Sec, generally, Remington's Phaunaceuttcal Science. 16th cd Mac Eds 1980 Ol course, the expressed Bbk protein is an lntraccllular protein. Accordingly, those ot skill will recognize that in vivo diagnostic and therapeutic methods employing the antibodies ot the invention may rcquuc some mechanism by which such antibodies can delect Bbk in die cell. One such method is lo introduce the antibodies or tragments thcreot into the cell itself across the cell membrane This may be accomplished, lor example, by attaching die antibody to a ligand lor which the target cell contains receptor sites. The antibody can thus be transported into the cell membrane or across ihc cell membrane along wilh the ligand. Suitable ligands include growth factors and cytokines that arc internalized upon receptor binding. Suitable growth 1 actors include epidermal growth factor (EGF), tumor growth factor alpha (TGF-α), fibrobiast growth laclor (FGF), insulin, and insulin-like giowth tactors 1 and 2 (IGF- 1 and 1GF-2) Suitable cytokines include G-CSF, GM-CSF, crythropυielin, IL- 1 and IL-2 It is noted that there arc also receptors that carry nutπents and vitamins into cells. These nutnents are suitable tor use as ligands in the present invention and include lolatc, dihydrofolate, tetrahydrotolate and vitamin B 12 The choice ot a carrier ligand will depend on several tactors, as those ot skill will appreciate. These include, lor example, the kinetics ot the ligand and its receptor, and of overall transport, which may include passive or active, with actively transported ligands pretened The means ot attaching the antibody to the ligand also will vary widnn limits, and may be, for example, covalent or ionic, beanng in mind fhat such attachment should noi unacceptably alter hgand-receptor affinity Examples of receptors suitable tor such applications include the receptor tor low density lipoproicin (LDL), which has been shown to contain all the intormation necessary for receptor endocytosis. Davis et al, J. Cell Biol 107(6/3). Abstr No. 31 12 (1988), as well as known brain-specific receptors such as those lor dopamine. In this regaid, ii will be appreciated that the ligand may itself be an antibody or Iragment specific lor the receptor, lo which may be con|ugalcd the antibody ol the invention Moreover, those ol skill may find n particularly desirable lo employ anubody fragments of the invention (such as. lor example, Fab or F(ab')-, fragments), which arc less likely to interfere with the hgand-rcccplor interaction, and may be more easily transported across the cell membrane Single-chain antibodies may prove prctcrablc lor these and other reasons, as will be appreciated by those ol skill. When an antibody is lo he transported into the cell's membrane or into the cell as de¬ scribed above, it will be preferred to diagnostically or therapeutically label the antibody in such a way that the label will be relatively moie el lcctivc when the antibody is bound lo its antigenic site on the Bbk prolcin. This may be accomplished, lor example, by employing a label which becomes active or delectable as a result til lormation of the antigen-antibody complex. Alterna¬ tively, the antibody ltscll may be labeled in such a way that antigen-antibody complex formation induces a conloπnatmnal change in the antibody to expose or more lully expose the previously uncxposed or less lully exposed label. All ol the above cπtcπa, and others, will be apparent to those ol skill in canying out these aspects ol the invention. It is also possible lo utilize hposomcs having the antibodies ol the present invention in their membranes to specifically deliver the antibodies lo the target area. These hposomcs can be produced so that they contain, in addition to the anubody, such therapeutic agents as drugs, radioisotopes, lcctms and toxins, which would act at the target site. Pharmaceutical Compositions Pharmaceutical compositions containing a therapeutically eflcclivc amount ol the present Bbk protein, lunctional equivalents. Iragmcnts and/or hybπds and/or mutants thereof as well as vcclois containing cDNΛ encoding one oi more ol ihc loiegoing, are usel ul lor ti eating S3 patients suffering trom degenerative disorders characterized by inappropriate cell death or inappropriate cell prolileration. Hybrids ol Bbk include hybrids ol Bbk and lor example Bcl-2, ccd-9, Bcl-X, , Bcl-X s , Bax, Mcl- 1 , c-myc, LMW5-HL, BHRF- 1, Bak, Bik and A l Such hybrids exhibit enhanced, decreased or intermediate apoptosis induction or suppression activity as compared to the activity of Bbk alone. These hybπds can be readily selected, produced and employed by one or ordinary skill in the art. Pharmaceutical compositions according ιo ihc invention thus will contain a therapeutically cllectivc amount ot the present Bbk protein, lunctional equivalents, Iragmcnts and/or hybrids and/or mutants thercol, and may optionally contain one or more pharmaceutically acceptable carriers and/oi cxcipicnts, known lo those ol ordinary skill in the art. Adminisiralion, dosage and lrcqucncy, and length ol ihc course ol treatment can be readily optimized for a particular patient by one ol ordinary skill in ihe ait For example, the present pharmaceutical composition can be lormulatcd as sterile aqueous oi non-aqueous suspensions or emulsions, as described above tor example for solutions lor intravenous administration. Therapeutic Applications Programmed cell dcalh is a process in which cells undeigo nuclear condensation and fragmentation during normal development of healthy tissues and organs The process is essential in maintaining the balance between growth ol new cells and elimination ot old cells. When apoptosis does not work properly, cither by causing cells to die prematurely or by preventing them I mm dying when scheduled, various disorders develop. The present apopiosis associated Bbk protein, lunctional equivalents. Iragmcnts and/or hybrids and/or mutants thercol as well as vectors containing cDNA encoding ihc foregoing are uselul for treating degeneraiive disorders, which disorders are chaiaclei ized by inappropriate cell death or inappropriate cell proliferation. Particular disorders may involve dittercnt cell types whereby it may be desirable to induce apoptosis in one cell type while suppressing apoptosis in the olhcr For example, ii may be desirable to suppress apoptosis in lung tissue cells in a patient sulteπng trom acute lung injury by administering the Bbk mutant protein ol the invenuon (or by ellecting expression ol such Bbk mutant protein in those cells) while inducing apoptosis in fibrobiast cells which may be present in the lung due to the inflammatory response by administeπng the Bbk protein oi the invention (or by ellecting Bbk protein expression in those cells) The mcrapculic agents ol the present invention can be administered as discussed above with the requirement that the agent must cross the cell membrane The therapeutic agent can be administered alone, in combination with or during the course ol ireatmcnt with other acceptable dierapics known in the art tor treating a particular disorder For example, the present therapeutic agents can be administered to induce apoptosis in a cancer patient who is also undergoing classic cancer therapy including, lor example, radiation therapy, chemotherapy, and treatment with anti-cancer drugs including, lor example, tυpoisomerasc inhibitors, alkylating agents, antimetaboliles. and hormone antagonists Further, the present therapeutic agents can also be administered concunently with gene therapy For example, the prescnl theiapcutic agents can be administered to a patient suffering trom a degenerative disorder ol the central nervous system while the patient is concunently undergoing gene therapy to replenish neutrophic hormones. Premature widespread apoptosis (inappropnate cell death) causes much ol the damage associated with degenerative disorders including, for example, AIDs, chemotherapy and radiation, and tissue atrophy. In AIDs patients, lymphocytes arc activated even in the asymptomatic phase ol the HIV infection, and those cells die prematurely by apoptosis Such disorders may admit ol treatment by administration ot a Bbk mutant protein Those ol skill will appreciate that administration ol the various proteins ol the invention lo particular target cells 01 tissues, as descnbed herein, is intended lo comprehend the administration ol the proteins themselves as well as the expression by ihe target cells or tissues of the nucleotide sequences encoding those proteins by various known means and in accordance with ihe teachings of the prescnl specification. Degenerative disorders characterized in inappropriate cell proliferation include cancer, autoimmune disorders, tissue hypertrophy, and inflammatory disorders including inflammation arising Irom acute tissue ιn|ury including, lor example, acute lung injury. These disorders can be treated by administering the present Bbk protein or lunctional equivalent. Cancers arise when changes in DNA cause the anomalous accumulation ol cells. The comparative rates ol cell division and cell deaths determine how last a cancer grows. Some cancer cells divide more slowly than normal cells, but the cancer may still expand because ot prolonged cell lite span. Apoptosis is an efficient method lor preventing malignant transformation because it removes cells with genetic lesions Detective apoptosis can promote cancer development, both by allowing accumulation ol dividing cells and by obstrucling removal ol genetic variants with enhanced malignant potential The present therapeutic agents, including the present Bbk protein, lunctional equivalents, fragments, and hybrids thereof, along with vectors containing cDNA encoding ihc one or more ol the loregomg, can be administered to cancer patients to induce apoptosis. Many types of cancer can be treated by the administration of the present therapeutic agents, including lor example, carcinomas, sarcomas, and Icukemia/lymphomas, including for example, carcinomas such as adenocarcmomas, squamous carcinomas, carcinoma ol the organs including breast, colon, head. neck, etc.; sarcomas including chondrosarcoma. melanosareoma, etc.: and leukemia and lymphomas including acute lymphomalic leukemia, acuic myelogenous leukemia, non- Hodgkin's lymphoma. Burkitt's lymphoma. B-cell lymphomas, T-cell lymphomas, etc. Other conditions amenable to treatment using the present therapeutic agent include fungal mleclions The present therapeutic agents can be used to treat autoimmune diseases. Random gene recombination and somatic hypcrmutalion can potentially generate aulorcactive T and B lymphocytes throughout hie Under normal conditions immature lymphocytes that bind autoantigens die by apoptosis However, a defect m the deletion ol these lymphocytes predisposes one lo aitloimmuniiy The present therapeutic agents can be administered to patients suflering trom autoimmune disorders to induce apoptosis in auloreactive T lymphocytes, tor example, in patients suffering sysiemic lupus crythcmalosus. Other autoimmune diseases amenable to treatment by suppressing or inducing apoplo.sis through the administration ot the present therapeutic agents include, lor example, rheumatoid arthritis, myasthcnia gravis. Grave's disease, Hashimoto's thyroidnis. lnsulin-resislcnt diabetes, allergic rhinitis, asthma, lunctional autonomic abnormalities, juvenile insulin-dependent diabetes, Addison's disease idiopalhic hypoparathy- roidism, spontaneous lnlcriility, premature ovanan failure, pemphigus, Bullous pcmphigoid, primary biliary cinhosis. autoimmune hemolytic anemia, idiopalhic thrombocylopenie purpura, idiopalhic neutropcnia. Goodpasturc's syndrome, rheumatoid arthπtis and Sjogren's syndrome. The prescnl therapeutic agents can be used to treat inflammation resulting from acute lung injury, by inducing apoptosis. The disease process begins with an explosive inflammatory response in the alveolar wall. In the attcrmalh of the resulting tissue destruction, extensive fibropioliferation of the alveolar air space ensues, consisting ol fibroblasts, capillaries and their connective tissue products Fukuda, Y , et al.. Am. J Pathol 726:171- 182 (1987). An important mechanism tor the systematic elimination ol the toregoing is apoptosis, i.e., programed cell death. The present therapeutic agents can also be used to ticat degeneraiive disorders due to premature or excessive cell loss dunng aging which can lead to organ dislunciion and disease Such degenerative disorders include degenerative diseases ol the central nervous system due to aging or other lactors which result in the death ot neurons The present therapeutic agents containing Bbk mutant protein or hybrids thereof can be administered to a patient suttcπng Irom such a degenerative disordei lo suppress apoptosis Furihei. the present therapeutic agents can be administcicd concurrently with gene therapy lo piovide genes encoding ncutrophic hormones including, lor example nerve giowth lactor Olhei conditions amenable lo treatment utilizing the present therapeutic agents include, lor example, Alzheimer's disease One ot ordinary skill in the art can readily identity other degenerative disorders characlcnzed by inappropriate cell death or inappropriate cell proliferation or bolh which are amenable lo treatment using the prescnl therapeutic agents The present therapeutic agents can include the Bbk protein itself as well as tragmcnts. lunctional equivalents and/or hybπds and/or mutants thereof which aie administered to a target cell Alternatively, therapeutic agents according to the invenuon can be administered by lnlecung the largcl cell with a vector containing cDNA encoding one or more ol the toregoing The present therapeutic agents can be administered to the desired target cell as discussed below, lor example, by choosing a receptor on the target cell surlacc which is specific tor that cell type The present therapeutic agents can be administered alone or in combination with other acceptable drug therapies. Further, the present therapeutic agents can be administered concurrently with other acceptable therapies specific lor the pailiculai degenciativc disordei being tieatcd For example, the ss present therapeutic agents can be administered concunently with ehcmoihcrapeutic agents, gene therapy, or the like Whether it is the Bbk protein itsell or the a vector encoding the protein, the therapeutic agent must cross the cell membrane One method lor introducing the Bbk prolcin or tragmcnts thercol into the cell's membrane or into the cell itsell is by attaching the protein to a ligand lor which the target cell contains receptor sites The protein can thus be transported into the cell membrane or across the cell membrane along with the ligand. The choice ol a carrier ligand will depend on several (actors, as discussed herein and known to those ol skill Suitable tissue- specific receptors include Brain: nerve growth 1 actor receptor (NGF-R). bicasl prolactin receptor, stomach gastπn receptor; skin: mclanocytc stimulating hormone receptor (MSH-R), liver: asialoglycoprotcin receptor; thyroid: thyroid stimulating hormone receptor (TSH-R); ovanes: lutcinizing hormoncrcccptor (LH-R). tcstis- human choπomc gonadotrophm receptor (hCG-R), T-cells: T-ccll receptors. B cells: CD 19; lung hyaluronate receptor CD44 nsolorm 4V (J. Cell. Biol. 124. 7182, 1994) In this regard, it will be appreciated that ihc ligand may be an antibody or Iragment specitic lor the receptor, to which may be conjugated the Bbk protein ol Ihc invention It may be desirable lo employ active Bbk Iragmcnts according lo the invention which are less likely to lnterlerc with the ligand- receptor interaction, and which may be more easily transported across the cell membrane. When a protein is to be transported across the cell's membrane or into the cell as de¬ scribed above and the ligand is an antibody, it will be prelerred lo diagnostically or thera¬ peutically label the protein in such a way that die label will be relatively more effective when the protein is bound, such as. lor example, by means analogous lo those described herein in the context ot antibody transport It is also possible to utilize hposomcs having the proteins ol the present invenuon in their membrane to specifically deliver the present Bbk proteins to the target area. These hposomcs can be produced so that ihcy contain, in addition lo the Bbk protein, such other therapeutic agents including drugs, radioisotopes, lectins and toxins, which would be released at the target site A prelerrcd manner lor adminisici mg the Bbk encoding nucleotide sequences (and Lheir lunctional equivalents and/or hybrids anuVor mutants) lor diagnostic or therapeutic purposes is by the use ot viral vectors. Suitable viral vectors tor gene transter include retroviruses (reviewed in Miller, et al . Methods Enzvmol 277:581-599 ( 1993)) including human immunodeficiency virus (HIV), adenovirus derivatives (lor examples see Erzurum, et al. Nucleic Acids Res 27: 1607- 12 ( 1993), Zabncr, et al, Nat. Genet. 6:75-83 ( 1994); Davidson, et al, Nat Genet. 3:219-223 ( 1993)), adcno-associatcd virus (AAV), (i.e.. see Flottc, et al, Proc. Natl. Acad. Sci. USA 90: 10613-7 ( 1993)) and Herpes virus vectors (i.e., see Anderson, et al, Cell Mol. Neurohiol 73:503- 15 ( 1993)) Other suitable viruses can be readily selected and employed by those ol ordinary skill in the art Other methods tor DNA delivery include hposomc mediated gene transfer (Alton, et al, Nat. Genet. 5- 135-42 ( 1993). Nabcl, et al, Proc. Natl. Acad. Sci. USA 90: 1 1307- 1 1 ( 1993)) The use ol viral vectors lor introduction ol genes into mammalian cells is also reviewed, tor example, in Varmus, Science 240(4858): \421 (1988); Eghtis et al, BioTechnuμtes 6.7:608 ( 1988); Jaenisch. Science 240(4858): 1468 ( 1988); and Bernstein et al. Genet. Eng (N Y. ) 7:235 (1985). For the purposes of the present invention, it may be prctcned to employ an attenuated viral or retroviral strain Thus, lor example it is possible lo use as vectors for the DNA sequences ol the invention retroviruses having attenuated cytopathicity. such as HIV- 2 ST (Kong et al . Science 240(48 ς >8) 1525 ( 1988)) or HIV-2 πn (Evans et al . Science 240(4858): 1523 ( 1988)), which enter neural cells by a CD4-dcpcndcnl mechanism (Funkc et al . J Exp Med. 765: 1230 ( 1987)) The ncurobiology ol HIV infections is described, loi example, in Johnson et al . FASEB J 2(14) 2910 ( 1988) Those ol skill will be able to targel diltercnt cell populations having known susceptibilities to viruses by the exercise ol routine skill For example, CD4 is known to have a variant iranscπpl in the human brain, with its highest content in lorebrain (Maddon et al , Cell 47 333 (1986) Possible methods to target retroviral gene expression to specific cell types arc reviewed by Boπs-Lawπc and H Temin Cun Opin Genet Dcv vol 3, p 102-9 ( 1993) Ideally, then, the choice ol a gene delivery system will be made by those ol skill, keeping in mind the objectives ot el ticicnt and stable gene transter. with an appropriate level ol gene expression, in a tissue-appropriate manner, and without any adverse ettccts See, lor example, Woilt et al . Rheum Dis Clm North Am 74(2) 459 ( 1988) With respect to delivery to a central nervous system target many viral vectors, including HIV, otter the advantage ot being able to cross the blood-brain bamer (Johnson et al , FASEB J 2(14)2910 ( 1988)) Diagnostic Applications Antibodies laised against the present Bbk protein, tragmcnts. lunctional equivalents, or hybπds or mutants thercol can be used to detect the Bbk protein m a human tissue sample, as well as lo diagnose degenerative disorders associated with the expression ot the Bbk proiein. Further, such antibodies can also be u.sed to monitor the pi ogress ot degenerative disorders associated with the expression ol the Bbk protein Any source ot human cells is suitable tor use in the diagnostic testing in the present invention The cells can be isolated iioin an\ human tissue including lot example, heart, lung, tumor cells, brain, placenta, liver, skeletal muscle, kidney and pancreas Extraction ol proteins trom the cell sample may be performed by any ol the many means known in the art. For example, cells may be lyscd by a detergent by mechanical means It desired, nucleic acids can be removed from the cell preparation by enzymatic digestion or by precipitation Such means aie well known in the art. Antibodies can be generated which aie immunorcaciivc with the Bbk proteins by the methods set torth herein Appropriate antibodies can then be screened using the natural gene products ot bbk The extracted proteins lrom the cell sample may be contacted wilh the anubody under suitable conditions lor anlibody-anligcn complex lormaiion Generally, such conditions arc physiological conditions The protein extract may be bound to a solid support such a nitroccllular filter or a microtiter plale The anubody will generally bear a label which is a radio label, a llorescent label, or an enzyme conjugate which under appropriate conditions produces. lor example, a colored reaction product Antibodies and anubody labeling are descnbed herein and known to those of skill. Alternatively, ii the antibody is not labeled, it can be detected by means ol a second anubody trom another species which is reacted with the first anubody Suitable assay techniques, labels and means ol detection aie discussed herein. A parallel sample to the test sample is employed to provide the control. The control sample consists ot an equivalent amount ot proteins extracted Irom cells, prctcrably in the same manner as those ot the test sample The amount ot protein can readily be determined by employing techniques well known in the art, including, tor example, the Lowry or Bradfoid techniques. The cells used lor preparing the conlrol sample may be selected lrom cells ol the same cell type as the test cells, isolated lrom a normal human not sutteπng trom the degenerative disorder lrom which the human lrom which the test sample was taken suiters, cells ot ihe same cell type as the test sample isolated lrom an established normal cell line, and cells lrom the human who is being tested, which cell type is dittercnt lrom the cell type ol the test cells. Test samples can also be screened tor elevated levels ol mRNA tianscnbed lrom the bbk gene, according to methods well known in the art For example, RNA extracted trom B-cells may be used, or alternatively mRNA may be isolated lrom total cellular RNA The mRNA may be purified, lor example, by altinity chromatography on oligo (dT cellulose) which binds to the poly (A) tract al the 3' end ot most mRNA. As is well known to those skilled in the art, it is essential that nbonuclcase acuviiy be minimized duπng picparalion and assaying A DNA probe may be selected lrom any ot the protein coding sequences ot the bbk gene Prctcrably, the probe will be selected Irom sequences ol the 5' or 1st exon ot the gene so that RNA can be detected Pielerably, the probe contains al lcasl 15 nucleotides ol the bbk sequence In order to perform the hybridization, it is desirable lhat the probe be single stranded Thus, it the probe is double stranded, it should be denatured to a single stranded lorm Means tor denaturing are well known in the art, including alkali or heat treatment The probe can then be contacted with the RNA derived lrom the cell sample under conditions where homologous RNA-DNA hybπds torm and arc stable Such conditions arc well known in the art. Means tor detecting hybnds are many and well known, but otten involve ihe use ol radiolabcicd probes and nucleases which degrade single stranded DNA Other methods known in the art may be used Control samples can be derived trom any of these cell sources described above tor use in the antibody diagnostic tests. Samples and controls should prcterably be prepared in parallel under similar conditions The diagnostic methods and compositions of the prescnl invention arc useful tor determining whether a discasc/degcncralive disorder is linked to abnormal Bbk expression, to the expression of Bbk mutants, as well as lor determining the eflcct ol over expression or loss ol expression ol Bbk in animal models such as transgcnic mice and/or homozygous null mice Methods lor determining whether a disease/degenerative disorder is linked to abnormal Bbk expression include analyzing Bbk expression in diseased tissue as compared to normal tissue by for example, Northern anuVor Western blots, as well as by other assay methods readily chosen and employed by those ol ordinary skill in the art Once it has been determined that a disease/degenerative disordei is linked to abnormal Bbk expression, the disease/disorder can be diagnosed in an individual. The following examples are oltered by way ol illustration, not by way ol limitation Examples A. Materials and Methods 1 Yeast two-hybrid analysis Components ol the yeast two-hybrid system were obtained from Cloniech Laboratories (Catalog numbers K 1605- 1 , K 1605-D. HL40O6AE) These included the GAL4 binding domain tusion vector pAS2. yeast strains Y 190 and Y 187, and human lymphocyte cDNA activauon domain library. Bak was subcloncd into the pAS2 vector using standard protocols (Sambrook, J., et al, Molecular Cloning: A Laboratory Manual, 2d Ed., Cold Spring Harbor Laboratory Press, Planvicw, New York ( 1989)) To create an in-trame fusion with Bak the pAS2 vector was modified by digesting with Ndel, making the ends blunt with Klenow Iragment of DNA polymerase I, and tc-ligating. The Bak gene was removed from pcDNA l/amp (described in co-pending United States application Serial Number 08/321 ,071 , filed 1 1 October 1994, which is a continualion-in-pai l ol United Stales application Serial Number 08/287,427, tiled 9 August 1994 (bak is rcfened lo ihercin as /;c/-v)) by digestion with BamHI and EcoRI. made blunt with the Klenow tragment ot DNA polymerase I, and ligated into the modified pAS2 vector that had been digested with Smal and treated with call intestinal phosphatasc lo remove terminal phosphates The Bak/GAL4 binding domain lusion vector (pAS2/BakΔC) was DNA sequenced across the fusion point lo venfy that the GAL4 reading trame had been preserved thiough the cloning |iιncuon and into the Bak open reading Iramc. Two-hybrid analysis, β-galaclosidasc filler assays, and detection ot false positives were pertormed using the Bak/GAL4 binding domain bait and lymphocyte cDNA GAL4 activation domain library lollowing the manulaclurcr's instructions Plasmid DNAs trom the positive clones were isolated and tianslormcd into E coli as described by the manulacturcr. Bactenal clones wcic analyzed lurther by restriction enzyme analysis and DNA sequencing. 2. Additional Plasmid Constructs All plasmid constructs were made using standard protocols (Sambrook, J., et «/., Molecular Cloning: A Laboratory Manual. 2d Ed., Cold Spnng Harbor Laboratory Press. Planvicw, New York ( 1989)). A modified torm of the mammalian expression plasmid pcDNA3 (Clontech) was created in which the influenza hemagglutanin (HA) epitope tag (MGYPYDVPDYASLS) had been inserted between the Hindlll and Xhol sites ol the polylinkcr cloning region lo generate pcDNA3/HA The Bbk gene obtained in the two-hybrid screen (pACT/Bbk) was removed lrom the GAL4 activauon domain plasmid on an Xhol fragment and subcloncd into the Xhol site of the pcDNA3/HA vector described above lo create pcDNA3/HABbk. This results in an in-trame tusion ol Bbk with the HA tag with the HA tag at the N-terminus of Bbk. The deletion mutant Δ 1- 105 was obtained directly lrom the two-hybrid screen and subcloned in a manner simlar to tull length Bbk to create pcDNA3/HAΔ l- l ()5. The mutant pcDNA3/HAΔ 142-249 was created by digesting pcDNA3/HABbk with PflMI and Xbal to remove sequences between nucleotides 338-958 and subsequently replacing the deleted sequences with a polymerase chain reaction (PCR) generated PflMI lo Xbal DNA tragment corresponding to Bbk nucleotides 338-476 An m-lramc stop codon was incorporated after The alanine point mutants pcDNA/HAPM-LVLEE (L P ,V I2) ,L | , 2 E| M E„, replaced with A icsidues), pcDNA/HAPM-V (V py lcplaced with A residue), pcDNA/HAPM-L (L,„ replaced with A lcsidue), pcDNA/HAPM-EE (E 1 M E,„ replaced with A residues) were created by replacing wild type Bbk sequences between nucleotides 338-476 (a PflMI tragment) with PCR- generatcd PtlMI tragmcnts that have incorporated alanine codons al Ihe designated positions Bbk genes canying the alanine point mutations were removed from the pcDNA/HA vectors and also cloned mto the Xhol polyhnker site of pACT to create pACT/PM-LVLEE, pACT/PM-V, pACT/PM-L, and pACT/PM-EE These plasmids generate an in-frame fusion between the Bbk mutants and the Gal4 activation domain for use in yeast two-hybrid analysis Plasmid pRcCMV/HABbkBH3 expressing Bbk amino acid residues 1 17-166, which encompass the Bbk BH3 domam, was constructed as described below A fragment of the Bbk gene encoding amino acid residues 1 17-166 was generated by PCR (incorporating a stop codon after ammo acid 166) and subsequently cloned into the Xhol site ot pcDNA3/HA (see above) that had been made blunt with the Klenow fragment of DNA polymerase The HA tag/Bbk BH3 fusion gene was then removed on an Hindlll/Xbal fragment and subcloned into the Hindll/Xbal sites of pRcCMV (Clontech) This clorung results m the m-frame fusion of the HA tag and the Bbk BH3 domain for use in mammalian cell transfections A control plasmid encoding wild type Bbk was similarly consructed by removing the Hindlll/Xbal fragment from pcDNA3/HABbk (see above) and subcloning into the Hindll/Xbal sites of pRcCMV A glutathione S-transteiasc tusion oi Bbk (GST-Bbk) was created by subcloning a Bglll to EcoRI Iragment ol Bbk into the BamHI to EcoRI sites ol the plasmid pGEX2TK (Pharmacia) The Bglll to EcoRI tragment ot Bbk was created in several steps First the initiating melhioninc ol Bbk was removed by replacing a Bglll lo Bsu36I tragment ol pcDNA3/HABbk with a double- stranded ohgonulcotidc adapter The Xbal site ot this modified pcDNA3/HABbk plasmid was then converted to an EcoRI site using EcoRI linkers Other plasmids expressing Bak. Bik, Bax, Bcl-x L , Bcl-2 and Epstein Barr virus BHRF1 have been previously descnbed (Boyd , J M , et al , Oncogene 11 Λ 921 ( 1995). Chittenden , T., EMBO J 74(22).5589 ( 1995): co-pending United Slates application Senal Number 08/321,071 , tiled 1 1 Octobet 1994, which is a coniinualion-in-part ol United States application Serial Number 08/287,427, filed 9 August 1994 (bak is referred to therein as bcl-v)) 3 Northern Blot Analysis Human fetal and adult multiple tissue Northern blots were purchased from Clontech Laboratories and hybridized sequentially lo ,2 P-labeled probes encompassing the entire coding regions of Bbk and β-actin following the supplier's protocol 4. In vitro translation "S-melhionine labeled proteins were synthesized in vitro using the TnT T7/T3 coupled rcticulocyte lysale system (Promega), tollowing the manutacturer's procedures Translation products were subjected to SDS polyacrylamide electrophoresis The gel was fixed, incubated in a tlourography enhancing solution (Amplify, Amersham), dned, and subjected to autoradiography al -70°C. 5 Western blot analysis COS7 cells were cultured in DMEM supplemented with 10% fetal calf serum and L-glutamine Cells were transtectcd with 2 μg of plasmid DNA using LipolcctAMINE (Gibco/BRL), and cell lysales were prepared 24 hours after transfection. Portions of the cells' extracts (approximately 100 mg) were electrophoresed on an SDS polyacrylamide gel. and transtcncd to a nylon membrane by standard methods (Harlow, E., et al , Antibodies- A Laboratory Manual ( 1988)) The blot was incubated with the anti-HA epitope monoclonal antibody 12CA5 (Klodzic), P.A , et al., Meth Enzvmol 194:508-519 ( 1991 )), which was subsequently detected with a secondary antibody using the ECL system (Amersham) 6. Tiansient transtcction analysis Ratl, HeLa. and BT549 cells were cultured at 37 l C, 7% C0 2 in DMEM with 109? lclal call scrum, 4nM L-gluiaminc, 50 units/ml penicillin, and 50 μg/ml streptomycin Cells were plated at 3 5 x 10 4 cells/well in 24 well tissue culture dishes 24 hours belore transtcction A plasmid encoding E coli β-galclosidase (pRcCMV/βgal, 0.16 μg) was mixed with a total ol 0 42 μg plasmιd(s) ol interest as defined in the figure legends The plasmid mixture was added to 25 μl OPTIMEM (Gibeo/BRL) and subsequently mixed with 27 μl LipolcctAMINE solution (2 μl stock solution diluted with 25 μl OPTIMEM) Alter a 30 minute incubation al room temperature the plasmid mixtures were diluted with 200 μl OPTIMEM and added lo cells that had been rinsed once with OPTIMEM. Alter 4 hours at normal growth conditions die cells were fed with 250 μl DMEM, 20% letal call scrum, 4 mM L-glulamme and then allowed to grow tor 24 hours under normal conditions. Cells were then washed with phosphate buttered saline (PBS), fixed with 0 2% gluteraldchyde, 2% paratormaldchydc. 49 2 mM sodium phosphate (pH 7.3) tor 5 minutes al 4'C and washed twice with PBS β-galactosidase-cxpressing cells are identified as blue cells alter a 1 -4 hour incubation with 80mM Na 2 HP0 4 , 20 mM NaH 2 P0 4 , 1 3 mM MgCl,, lmg/ml X-Gal (diluted trom a 20 mg/ml stock solution prepared in dimethyltormamide), 3 mM K ,Fe(CN) ft , 3 mM K 4 Fe(CN)J3H 2 0 Live blue cells are identified as those that retain a flat morphology while dead blue cells are round 7 In vitro prolcin interactions Glutathione S-transtcrasc tusion protein ol Bbk (GST-Bbk) was expressed in E coli trom plasmid pGEX2TK-Bbk and purified by affinity chromatogiaphy using glutathione agarose (Smith, D B and Johnson, K S., Gene 67.31-40 ( 1988)) "S-melhιonιnc labeled HA-cpitopc tagged Bak. Bax, Bik, and Flag-cpitope (Kodak) tagged Bcl-x, was expressed in vitio using a coupled transcription/translation system in rabbit reticulocyte lysaics (Promega) Labeled proteins were prcclcarcd with 10% glutathione- agarose in 10 mM HEPES butler (pH 7 2) containing 0 25% NP-40, 142 5 mM KC1, 5 mM MgCl 2 , 1 mM EGTA (Bultcr A) GST-Bbk was added (final conciliation 1-3 μM) and the mixtures incubaicd loi 60 minutes at 4"C Protein complexes were captured with 10% glulathionc-agarose and washed twice with butler A and once with buller A without NP-40 Proteins were eluted tiom the beads by incubation in SDS-PAGE sample butter at 100'C tor 5 minutes and loaded onto 4-20% SDS-polyacrylamidc gels (Novex) Following electrophoresis, gels were fixed and incubated in a flourography enhancing solution (Amplify, Amersham) The gels were dried and subjected to autoradiography at -70°C. 8 Liquid culture β-galaclosidase assays The affinity of Bbk/Bak and mutant Bbk/Bak interactions was quantitated usmg a liquid β-galactosidase assay with o-nitrophenylgalactoside (ONPG) as substrate as descnbed by the manufacturer's protocol (Clontech). Plasmids used for analysis are as stated in the figure legends. B Results 1. Identification ot Bak-interacting proteins by yeast two-hybrid analysis Bak is lound expressed in many cells (co-pending United States application Seπal Number 08/321 ,071 , filed 1 1 October 1994. which is a continuaiion-in-parl ol United Slates application Seπal Number 08/287,427, filed 9 August 1994 (bak is iclcπed lo therein as bcl-v); Kieler, M.C., et al, Nature 374:136 ( 1995)) Overcxprcssion ot Bak induces death by apoptosis It was believed that regulators or cltcctors ol apoptosis might bind to Bak. Proteins thai interact with Bak were ihcretorc identified using the yeast two-hybrid system (U.S. Patent No. 5,283, 173) The principle ot this methodology is summarized in Figure I . GAL4 is a yeast transcπpuonal activator protein lhat has two distinct domains, the DNA-binding domain and the transcription activation domain (Figure IA). The DNA-bindmg domain binds to a specific DNA sequence element in ihc GAL4 promoter, thus bringing die transcription activauon domain in proximity to the promoter where it t unctions to stimulate transcription It has been demonstrated that these domains aie separable, although when separated they cannol lunction to stimulate transcription Ti anscπplional activation can, however, be restored il a link between ihc iwo separated domains is made Such a link can be made by expressing the GAL4 domains as hybrid proteins where these domains are fused to hetcrologous proteins (prolcin X and prolcin Y in Figure I B,C) that arc known to interact. In the scenario shown in Figure 1 the GAL4 binding domain serves to bring protein X lo the GAL4 promoter and subsequent interaction with protein Y in turn brings the GAL4 activation domain to the promoter where it can stimulate transcription The GAL4 promoter, or a promoter containing the GAL4 DNA sequence element, can be used to direct the transcnption ot selectable marker genes (such as HIS3) and reporter genes (such as lacZ) The system described above can be used lo study the interaction ol proieins that are known to interact as well as lo identity and isolate novel interacting proteins. In die latter case, a protein of interest is fused to the GAL4 binding domain and used as "bait" to capture interacting proteins lhat arc expressed as GAL4 activation domain f usions. In the experiments described here a GAL4 DNA-bindmg domain/Bak f usion protein was used as the bait to isolate Bak-interacting proteins expressed as GAL4 activation domain lusions generated lrom a cDNA 7(1 library ot Epstein-Barr Virus-transiormed human B lymphocytes (Clontech) Two-hybπd analysis, selection tor interacting clones, β-galactosidasc filter assays, and identification ot lalsc positives were performed f ollowing the manufacturer's specif ications (Clontech) 2 Sequence analysis ot an avid Bak-binding clone, bbk. Eleven ol the most avidly binding clones (as judged by the intensity ot blue color in β-galaclosidase filter assays) were determined by DNA sequencing to be varying length clones ot the same gene. Restriction enzyme analysis was used lo identity the approximate sizes ot these clones Clone bbk was the largest ot the clones and was thcrelore chosen tor exhaustive DNA sequencing ol both the top and bottom strands The sequence ol clone bbk is shown in Figure 2 Six ol the eleven clones have the same sequence startpoint as bbk while there arc live clones that have deletions ol varying length (up to nucleotides 33, 151, 178, 242, and 364 ol clone bbk) Three ol the eleven clones have an intact 3' terminus as determined by the presence ol a polyadenylated (polyA) tail. The absence ol a polyA tail in the remaining clones is likely to be due to abbenant priming during cDNA synthesis due to the AT-πch nature ot the gene in this region Nonetheless, the remaining clones have 3' termini that are within 30 bases ot the true 3' terminus (including clone bbk, which is 10 bases short) The sequence ot bbk was compared to the Gcnbank database using the NCBI BLAST program This analysis has identified numerous expressed sequence tag (EST) cDNAs (Accession Numbers: H26516, H42839, H59025, H59896, H59897, H72004, H72005, H89857, H90702, R02556, R02674. R07849, R07901, R36543, R38463, R58365, R78883, R78977, R85622) with significant homology (Poisson Sum P(N) values less than or equal to 5.5e-26) to bbk These cDNAs also begin and end within several bases ot the endpoint of bbk suggesting that bbk is a nearly tull length clone Bbk encodes an open reading frame (ORF) ol 249 amino acids beginning with nucleotide number 51 and ending at nucleotide number 799 This ORF is in the same trame as mat predicted by the GAL4 activation domain which is luscd N-terminal to Bbk. The sequence sunounding the predicted initiating methionine codon is consistent with the Kozak consensus sequence (Kozak, M. Nucleic Acids Res. 75:8125 ( 1987)) and there are no additional methionines or in-frame stop codons in the putative untranslated bbk sequence present between the Gal4 activation domain and the Bbk ORF. Thus, it is believed that die true ORF ot the Bbk gene has been identified. It is interesting to nole lhat several ol ihc clones isolated by two-hybrid analysis, as well as several ol the EST clones, have three additional nucleotides (AAG) not lound in Bbk, between nucleotides 157 and 158 ol Bbk These nucleotides may be introduced as the result ol alternate splice site usage The addition ot these mrec nucleotides in the putative coding region maintains the predicted reading Iramc and would serve to introduce an arginme residue at position 36. An analysis ol protein databases using me putative Bbk ORF identified sequences ot only limited homology Thus, novel proteins that interact with the apoptosis-related protein, Bak, can be identified through the use ot the two hybrid system. 3. Expression ot Bbk mRNA in lctal and adult tissues Northern blot analysis was performed lo determine the expression pattern and size ot the Bbk messenger RNA. Northern blots ol fetal and adult tissue probed with Bbk (Figure 3) show that Bbk is a single mRNA species ot approximately 0.8- 1.2 kb This message size is consistent with the notion diat a full length clone has been isolated. The northern blot analysis also shows that Bbk is expressed in many diverse tissues with a distribution roughly similar lo lhat ol Bak (Kieler. M.C., et al. Nature 374:136 (1995)) supporting the behct that Bbk and Bak may be complcxcd together in the cell. 4 Expression ot Bbk m vitro and in transtectcd cells The deduced amino acid sequence ot Bbk predicts a protein ot MW 26 7 kD The Bbk clone was subcloncd lrom the ycasl two-hybrid vector into pcDNA3 (Clontech) tor in vitro expression using the T7 promoter and loi mammalian expression using the human cytomcgalovirus immediate early promoter In order to detect the protein, the Bbk sequence was tused al the amino terminus to a 14 amino acid segment derived trom the influenza hemaglutinin antigen (HA) This short peptide provides a well characterized epilopc that permits immunological detection ot the "tagged" protein by the monoclonal antibody 12CA5 (Boehnngcr Mannheim) In vttio transcription/translation ol the Bbk clone in rabbit rcticulocyte lysates produces a protein with eleetrophorctic mobility on SDS polyacrylamide gels corresponding to a molecular weight ol about 37 kD (Figure 4A), in approximate agreement with the size predicted Irom conceptual translation ot the cDNA sequence plus the HA lag and nonspecific ammo acids introduced by cloning The pcDNA3 vector expressing HA-tagged Bbk was transtectcd into COS7 cells Cell lysates were prepared 48 hours alter transtcction, and analyzed by Western blot with the anu-HA monoclonal antibody The HA tagged Bbk protein, ot the appropriate size , was detected in the COS7 cell extracts (Figure 4B) These results demonstrate lhat the protein encoded by the isolated Bbk cDNA can be expressed both in vitro and in vivo 5. Expression ot Bbk accelerates cell death in Ratl, HeLa, and BT549 cells The HA-tagged Bbk clone expressed irom the pcDNA3 vector was cotranstected with a plasmid expressing β-galactosidase into normal rat fibroblasts (Ratl cells) and into human tumor lines HeLa and BT549, to determine the ettect ot Bbk expression on cellular viability Such a cell death assay has been previously descnbed (Miuia, M , e t al , Cell 75 653 (1993); Boyd. J M . rt fl/ , Oncogene 11 1921 ( 1995), Chittenden, T , et al , EMBO J 74(22):5589 ( 1995); co-pending United States application Seπal Number 08/440.391 , filed 12 May 1995; and consists ol co-translcction ol a gene ol interest into cells with a β-galactosidase gene as a marker tor translectanls The cllcct ol translcctcd gene products upon cellular viability is measured by scoring blue cells ( β-galactosidase positive) relative to vector controls cells 24 hours post-transleclion. Inert or anu-apoptotic gene products are manileslcd as flat (live) blue cells in numbers similar lo those ol the vector controls, while detrimental gene products can be seen as an overall reduction in blue cell numbers or an increase in the lrcqucncy of round (dead) blue cells. The results in Figure 5A clearly show a decrease in the number ol blue cells when Rat l cells arc translcctcd with a plasmid expressing Bbk Thus, it appears thai, like its binding partner Bak. Bbk can induce cell death Both Bak and Bbk can induce apoptosis when expressed individually in Rat I cells. While not intending to be bound by a particular theory, this suggests either that the Bak/Bbk interaction is not necessary for the induction of apoptosis or that there are rat homologs of Bak and Bbk that can functionally interact with the human proteins. Alternatively, the interaction between these two proteins may serve a regulatory function to modulate their apoptotic potential. The data in Figure 5 A demonstrate that the co-expression of Bak and Bbk does not block the induction of apoptosis, suggesting that their ability to bind each other does not inlubit their ability to promote apoptosis However, because Bak and Bbk each is a potent promoter of cell death individually, it was not possible in these assays to determine if their co-expression results in a cooperative induction of apoptosis. The apoptotic function of Bbk can be reversed by the coexpression ol the known survival proteins, Bcl-2, Bcl-x, , and Epstem-Barr virus BHRF1 (Figure 5B). The extent of the cell death promoted by the apoptosis related proteins, Bak and Bik, is similarly reduced in the presence of the survival proteins (not shown). Increasing the ratio ol the apoplosis-promoling protein, Bik, relative to these survival proteins can restore Bik cyloioxicily This observation suggests that in the appropriate setting apoptosis promoting proteins can actually repress the action ol survival proteins The cell death promoting proteins may there tore be used to induce apoptosis in cells where survival is dependent upon the action ol one of the Bcl-2 related cell survival proteins. The ability ol Bbk to induce apoplo.sis is also evident in the tumor cell lines, HeLa and BT549 (Figure 6Λ, B) The extent ol apoptosis induced by Bbk is comparable to that of Bak in the BT549 cells while in HeLa cells Bbk is somewhat less ef fective lhat Bak in Ihe induction of cell death While Bbk can induce cell death, human tumor cells appear to display varying degrees ol sensitivity to the apoptotic tunction of Bbk. Cells thai are less sensitive to Bbk-induccd apoptosis may. however, become more sensitive to conventional anti-cancer therapies subsequent lo treatment with Bbk. Thus, a novel protein that binds Bak and induces apoptosis in a variety ol cell types has now been identified 6. Bbk interacts with Bak. Bax, Bcl-x, in vitro. The reversal oi Bbk induced apoptosis by cell survival members ot ihe Bcl-2 lamily may suggest that diesc proteins can interact widi Bbk. It was desired to determine if Bbk interacts solely with Bak or il it could also bind to other proteins known to be involved in apoptosis. A Glutathione S-translcrase (GST)- Bbk fusion protein was expressed in E. coli and purified over glutathionc-agarose HA-tagged Bak, Bax, and Bik as well as Bcl-x, tagged with the FLAG epitope (Kodak) were radioaclivcly labeled by in vitro translation and subsequcndy incubated with GST-Bbk or GST alone. Complexes were isolated on glulathione-agarosc and analyzed by SDS-PAGE. Figure 7 clearly shows Bbk interaction with Bak, Bcl-x, , and Bax but not with Bik. These intcractons are specific, as the GST alone fails to complex with any of the in vitro translated material. Thus it appears that Bbk can interact with several members of the Bcl-2 lamily. Bbk does not appear to interact exclusively with ihc cell death inducing members ol the Bcl-2 lamily, as demonstrated by it's interaction with Bcl-x, . despite the tact that Bbk was isolated by virtue ol its interaction with the cell death promoter, Bak. Il is interesting to note thai Bbk cannot, however, interact wiih Bik, a novel death inducing protein that shares the BH3 domain with Bcl-2 family members (Boyd, J.M., et al, Oncogene 77:1921 ( 1995)) 7. Bbk shares sequence homology with the Bcl-2 prolcin lamily The observations that Bbk interacts with several members ol the Bcl-2 lamily and that it shares apoptosis related lunclion suggested lhat Bbk might additionally share sequence homology. The database searches performed above did not reveal any sequence homology to Bcl-2 tamily members, however, a caret ui visual inspection identified a motil that is highly homologous to the BH2 domain ol Bcl-2 and related lamily members (Figure 8A). Alignment ot the Bbk ORF with Bcl-2 tamily members using ihc BH2 domain as an anchor did noi reveal any homology to the BH1 domain of Bcl-2 but does show some homology (Figure 8B) to the newly defined BH3 domain (co-pending United States application Serial Number 08/440,391 , filed 12 May 1995 (BH3 is rctcncd to therein as the GD Domain)). Thus, Bbk appears to be a novel death-promoting member ol the Bcl-2 protein tamily. 8. Bbk induced apoptosis is mediated by its BH3-likc domain It has been previously shown that die BH3 domain ol Bak is both necessary and sufficient tor its induction ot cell death (co-pending United Stales application Serial Number 08/440,391, filed 12 May 1995 (BH3 is rctened to therein as the GD Domain)). Because Bbk shares a weak homology to the Bak BH3 domain, il was desired to determine whether this region provides a similar lunction for Bbk. To test this theory a series of deletions that encroach upon the putative BH3 domain were made and tested in the Rat- 1 cell death assay. The results in Figure 9A show lhat two ol these mutants, Δ 1 - 105 (a deletion of the N-tcrminus to amino acid residue 106) and Δ 142-249 (a deletion ot the C-lcrminus beginning at amino acid residue 142), still retain the ability to induce apoptosis. These results suggest thai a large portion ol the Bbk molecule (including Ihc BH2 domain) is dispensiblc lor the cytotoxic activity ol Bbk. Further, these data define the region between amino acids 106 to 141 as necessary tor Bbk to induce cell death Interestingly, this region coincides with the putative Bbk BH3 domain (residues 125- 137). To definitively prove that this region was required for Bbk cyloloxicity, four alanine scanning mutants (Figure 9B) that mutate several conserved residues were made and tested for their ability lo induce apoptosis in Rai l cells The results shown in Figure 9C demonstrate that PM-LVLEE, which contains live alamine substitutions in the BH3 element, has completely lost its apoptosis induction capabilities To prove lhat the abolition ol cytotoxicity in PM-LVLEE is not due lo a lailurc to be synthesized, its expression was verified in COS7 cells where it was produced at levels comparable to those ot wild type Bbk. The data thcrelorc support the conclusion that the BH3 legion ol Bbk is absolutely necessary lor its apoptotic lunction. The remaining mutants, PM-V, PM-L and PM-EE, are single and double alanine mutations that were constructed to more precisely define the BH3 residues required for Bbk-induced apoptosis. The data in Figure 9C demonstrate that each of these substitutions reduces, but does not abolish, the induction of cell death, indicating that all of the mutated residues are required in part for Bbk cytotoxicity. Again, each of these mutants was expressed in COS7 cells at levels comparable to those of wild type Bbk. To determine if the Bbk BH3 domain was also sufficient to induce apoptosis, a plasmid expressing only amino acids 1 17- 166 of Bbk (which includes the Bbk BH3 domain between residues 125-137) was transfected into Rat l cells. The results in Figure 10 show that expression of this 50 amino acid peptide encompassing the Bbk BH3 domain is sufficient to induce apoptosis Thus, it appears that the BH3 domain of Bbk is analogous in function to the Bak BH3 domain, in that it is both necessary and sufficient for the induction ot apoptosis 9 Apoptosis induction by Bbk correlates with its ability to bind Bak Co-pending United States application Serial Number 08/440,391, filed 12 May 1995, demonstrated that the Bak BH3 domain is responsible for its cytotoxic activity as well as its ability to bind the Bcl-x, , an anti-apoptotic member of the Bcl-2 family Since the Bbk BH3 domain appears to share the ability to induce apoptosis function in a manner similar to that ot the Bak BH3 domain, it was of interest to determine whether the Bbk BH3 domain mediates the Bbk/Bak mteraction To test this possibility, the alamne mutations used above to define the apoptosis inducuig domain of Bbk (PM-LVLEE, PM-V, PM-L, PM-EE) were fused to the Gal4 activation domain tor use in the yeast two hybrid system with Bak as bait In this assay, the expression levels of β-galactosidase are a measure oi the affinity and/or stabhty of interaction between the two proteins, with high levels indicating a strong interaction and low levels indicating a weak mteraction Figure 1 1 shows that PM-LVLEE, the Bbk mutant that has lost the ability to mduce apoptosis, has also lost the ability to bind to Bak, as demonstrated by low levels of β-galactosidase (comparable to the negative control) The mutants that have retained intermediate levels of apoptotic potential (PM-V, PM-L, PM-EE) retain intermediate levels of mteraction with Bak Tlus direct coπelation between Bbk cytotoxicity and Bbk binding to Bak further supports the hypothesis that the Bbk/Bak interaction is required for the induction of apoptosis. Alternatively, there remains the possibility that there are additional binding partners for Bbk that also interact with its BH3 domain to effect cell death All publications mentioned in this specification arc herein incorporated by rcterencc, to the same extent as it each individual publication was specifically and individually indicated to be incoφoialcd by rclcrcncc It will be understood that the invenuon is capable ol lurther 7S modifications and this application is intended to cover any vanauons, uses, or adoptions ol the invention including such departures lrom the present disclosure as come within known or customary practice within the ait lo which the invention pertains, and is intended to be limited only by the appended claims SEQUENCE LISTING ( 1 ) GENERAL INFORMATION (i) APPLICANT GALLO Gregory J (n) TITLE OF INVENTION APOPTOSIS ASSOCIATED PROTEIN BBK (in) NUMBER OF SEQUENCES 28 (iv) CORRESPONDENCE ADDRESS (A) ADDRESSEE Hale and Dorr LLP (B ) STREET 1455 Pennsylvania Avenue, N W (C) CITY Washington. D C (E) COUNTRY U S A (F) ZIP 20004 (v) COMPUTER READABLE FORM (A) MEDIUM TYPE Floppy disk (B ) COMPUTER IBM PC compatible (C) OPERATING SYSTEM PC-DOS/MS-DOS (D) SOFTWARE P.ucniln Release # 1 0. Version ff l 25 (vi ) CURRENT APPLICATION DATA (A) APPLICATION NUMBER PCT - TO BE ASSIGNED (B ) FILING DATE HEREWITH (C) CLAS SIFICATION (vn) PRIOR APPLICATION DATA (A) APPLICATION NUMBER US 08/632,514 (B) FILING DATE 29-MAY- 1996 (C) CLASSIFICATION (ix) ATTORNEY/AGENT INFORMATION (A) NAME WIXON, Henry N (B) REGISTRATION NUMBER 12,071 (C) REFERENCE/DOCKET NUMBER 104122 188 (x) TELECOMMUNICATION INFORMATION (A) TELEPHONE (202)942-8459 (B ) TELEFAX (202)942-8484 (2) INFORMATION FOR SEQ ID NO 1 (0 SEQUENCE CHARACTERISTICS (A) LENGTH 11 amino and (C) STRANDEDNESS single (D) TOPOLOGY linear (n) MOLECULE TYPE peplide (xi) SEQUENCE DESCRIPTION SEQ ID NO 1 SO Leu Arg Arg Leu Val Ala Leu Leu Glu Glu Glu Ala Glu 5 10 (2) INFORMATION FOR SEQ ID NO:2 ( i) SEQUENCE CHARACTERISTICS (A ) LENGTH I I amino acid (B ) TYPE, amino acid (C) STRANDEDNESS. .single (D) TOPOLOGY linear (u) MOLECULE TYPE peptide (xi ) SEQUENCE DESCRIPTION. SEQ ID NO.2 Leu Arc Arg Leu Ala Ala Leu Leu Glu Glu Glu Ala Glu 5 10 (2) INFORMATION FOR SEQ ID NO 1 (i) SEQUENCE CHARACTERISTICS (A ) LENGTH 11 amino acids (B ) TYPE amino acid (C) STRANDEDNESS smgle (D) TOPOLOGY linear (u) MOLECULE TYPE pepiide (xi) SEQUENCE DESCRIPTION SEQ ID NO 1 Leu Arg Arg Leu Val Ala Leu Ala Glu Glu Glu Ala Glu 5 10 (2) INFORMATION FOR SEQ ID NO'4 (i) SEQUENCE CHARACTERISTICS (A) LENGTH 13 amino acids (B) TYPE. amino acid (C) STRANDEDNESS. single (D) TOPOLOGY: linear (n) MOLECULE TYPE' peptide (xi) SEQUENCE DESCRIPTION SEQ ID NO 4 Leu Arg Arg Leu Val Ala Leu Leu Glu Ala Ala Ala Glu 5 10 (2) INFORMATION FOR SEQ ID NO:5. (I ) SEQUENCE CHARACTERISTICS (A) LENGTH- 1.1 amino acids ( B) TYPE. amino acid (C) STRANDEDNESS. single ( D) TOPOLOGY linear (π) MOLECULE TYPE peptide (xi ) SEQUENCE DESCRIPTION SEQ ID NO 5 Leu Arg Arg Leu Val Ala Leu Leu Glu Glu Glu Ala Glu 5 10 (2) INFORMATION FOR SEQ ID NO 6 (i) SEQUENCE CHARACTERISTICS (A) LENGTH 11 ammo acids (C) STRANDEDNESS single (D) TOPOLOGY linear (u) MOLECULE TYPE peptide ( xi) SEQUENCE DESCRIPTION SEQ ID NO d Leu Arg Art; Leu Ala Ala Leu Leu Glu Gin Glu Ala Glu 5 10 (2 ) INFORMATION FOR SEQ ID NO 7 (i) SEQUENCE CHARACTERISTICS (A) LENGTH 11 ami no acids (B ) TYPE amino acid (C) STRANDEDNESS sinelc (D) TOPOLOGY linear (n) MOLECULE TYPE peptide (xi) SEQUENCE DESCRIPTION SEQ ID NO 7 Leu Arg Arg Leu Val Ala Leu Ala Glu Glu Glu Ala Glu 5 10 (2) INFORMATION FOR SEQ ID NO 8 (I ) SEQUENCE CHARACTERISTICS (A) LENGTH 11 ammo acids (B) TYPE amino acid (C) STRANDEDNESS single (D) TOPOLOGY linear (n) MOLECULE TYPE peptide (xi) SEQUENCE DESCRIPTION SEQ ID NO 8 Leu Arg Arg Leu Val Ala Leu Leu Glu Ala Ala Ala Glu 5 10 (2) INFORMATION FOR SEQ ID NO 9 X2 (0 SEQUENCE CHARACTERISTICS (A ) LENGTH 958 base pairs (B) TYPE- nucleic acid (C) STRANDEDNESS single (D) TOPOLOGY linear (n ) MOLECULE TYPE DNA (genomic ) (xi ) SEQUENCE DESCRIPTION SEQ ID NO 1 ) CGCAAGTTGA GTGGAGGAGG CGGCGGTGGG GCCCCGGACC AGGTGCCTCC ATGGCAGGCT 60 CTGAAGAGCT GGGGCTCCGG GAAGACACGC TGAGGGTCCT AGCTGCCTTC CTTAGGCGTG 120 GTGAGGCTGC CGGGTCTCCT GTTCCAACTC CACCTAGCCC TGCCCAAGAA GAGCCAACAG 180 ACTTCCTGAG CCGCCTTCGA AGATGTCTTC CCTGCTCCCT GGGGCGAGGA GCAGCCCCCT 240 CTGAGTCCCC TCGGCCTTGC TCTCTGCCCA TCCGCCCCTG CTATGGTTTA GAGCCTGGCC 100 CAGCTACTCC AGACTTCTAT GCTTTGGTGG CCCAGCGGCT GGAACAGCTG GTCCAAGAGC 160 AGCTGAAATC TCCGCCCAGC CCΛGAATTAC AGGGTCCCCC ATCGACAGAG AAGGAAGCCA 420 TACTGCGGAG GCTGGTGGCC CTGCTGGAGG AGGAGGCAGA AGTCATTAAC CAGAAGCTGG 480 CCTCGGACCC CGCCCTGCGC ΛGCAAGCTGG TCCGCCTGTC CTCCGACTCT TTCGCCCGCC 540 TGGTGGAGCT GTTCTGTAGC CGGGATGACA GCTCTCGCCC AAGCCGAGCA TGCCCCGGGC 600 CCCCGCCTCC TTCCCCGGAG CCCCTGGCCC GCCTGGCCCT AGCCATGGAG CTGAGCCGGC 660 GCGTGGCCGG GCTGGGGGGC ACCCTGGCCG GACTCAGCGT GGAGCACGTG CACAGCTTCA 720 CGCCCTGGAT CCAGGCCCAC GGGGGCTGGG AGGGCATCCT GGCTGTTTCA CCCGTGGACT 780 TGAACTTGCC ATTGGACTGΛ GCTCTTTCTC AGAAGCTGCT ACAAGATGAC ΛCCTCATGTC 840 CCTGCCCTCT TCGTGTGCTT TTCCAAGTCT TCCTATTCCA CTCAGGGCTG TGGGGTGGTG 900 GTTGCCCTAC CTGTTTTTGC CAAAAATAAA TTGTTTAAAA CTTTTCTTAT TAAAAACG 958 (2) INFORMATION FOR SEQ ID NO- 10. (l) SEQUENCE CHARACTERISTICS (A) LENGTH: 958 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY linear (u) MOLECULE TYPE DNA (genomic ) ( \ι) SEQUENCE DESCRIPTION SEQ ID NO 10 GCGTTCAACT CACCTCCTCC GCCGCCACCC CGGGGCCTGG TCCACGGAGG TACCGTCCGA 60 GACTTCTCGA CCCCGAGGCC CTTCTGTGCG ACTCCCAGGA TCGACGGAAG GAATCCGCAC 120 CACTCCGACG GCCCAGAGGA CAAGGTTGAG GTGGATCGGG ACGGGTTCTT CTCGGTTGTC 180 TGAAGGACTC GGCGGAAGCT TCTACAGAAG GGACGAGGGA CCCCGCTCCT CGTCGGGGGA 240 GACTCAGGGG AGCCGGAACG AGAGACGGGT AGGCGGGGAC GATACCAAAT CTCGGACCGG 100 GTCGATGAGG TCTGAAGATA CGAAACCACC GGGTCGCCGA CCTTGTCGAC CAGGTTCTCG 160 TCGACTTTAG AGGCGGGTCG GGTCTTAATG TCCCAGGGGG TAGCTGTCTC TTCCTTCGGT 420 ATGACGCCTC CGACCACCGG GACGACCTCC TCCTCCGTCT TCAGTAATTG GTCTTCGACC 480 GGAGCCTGGG GCGGGACGCG TCGTTCGACC AGGCGGACAG GAGGCTGAGA AAGCGGGCGG 540 ACCACCTCGA CAAGACATCG GCCCTACTGT CGAGAGCGGG TTCGGCTCGT ACGGGGCCCG 600 GGGGCGGAGG AAGGGGCCTC GGGGACCGGG CGGACCGGGA TCGGTACCTC GACTCGGCCG 660 CGCACCGGCC CGACCCCCCG TGGGACCGGC CTGAGTCGCA CCTCGTGCAC GTGTCGAAGT 720 GCGGGACCTA GGTCCGGGTG CCCCCGACCC TCCCGTAGGA CCGACAAAGT GGGCACCTGA 780 ACTTGAACGG TAACCTGACT CGAGAAAGAG TCTTCGACGA TGTTCTACTG TGGAGTACAG 840 GGACGGGAGA AGCACACGAA AAGGTTCAGA AGGATAAGGT GAGTCCCGAC ACCCCACCAC 900 CAACGGGATG GACAAAAACG GTTTTTATTT AACAAATTTT GAAAAGAATA ATTTTTGC 958 (2) INFORMATION FOR SEQ ID NO 1 1 (l) SEQUENCE CHARACTERISTICS (A) LENGTH 249 amino acids (B) TYPE amino acid (C) STRANDEDNESS single (D) TOPOLOGY linear (li) MOLECULE TYPE peptide (xi) SEQUENCE DESCRIPTION SEQ ID NO 1 1 Met Ala Gly Ser Glu Glu Leu Gly Leu Arg Glu Asp Thr Leu Arg 5 10 15 Val Leu Ala Ala Ala Gl> Ser Pro Val Pro Thr Pro Pro Ser Pro Ala Gin Glu Glu Pro Thr Asp Phe 15 40 45 Leu Ser Arg Leu Arg Arg Cys Leu Pro Cys Ser Leu Gly Are Gly 50 55 60 Ala Ala Pro Ser Glu Ser Pro Arg Pro Cys Ser Leu Pro lie Arg 65 70 75 Pro Cys Tyr Gly Leu Glu Pro Gly Pro Ala Thr Pro Asp Phe Tyr 80 85 90 Ala Leu Val Ala Gin Arg Leu Glu Gin Leu Val Gin Glu Gin Leu 95 100 105 Lys Ser Pro Pro Ser Pro Glu Leu Gin Gly Pro Pro Ser Thr Glu 1 10 1 15 120 Lys Glu Ala He Leu Arg Arg Leu Val Ala Leu Leu Glu Glu Glu 125 110 115 Ala Glu Val lie Asn Gin Lys Leu Ala Ser Asp Pro Ala Leu Arg 140 145 150 Ser Lys Leu Val Arg Leu Sci Ser Asp Ser Phe Ala Arg Leu Val 155 160 165 Glu Leu Phe Cys Ser Arg Asp Asp Ser Ser Arg Pro Ser Arg Ala 170 175 180 Cys Pro Gly Pro Pro Pro Pro Ser Pro Glu Pro Leu Ala Arg Leu 185 190 195 Ala Leu Ala Met Glu Leu Ser Arg Arg Val Ala Gly Leu Gly Gly 200 205 210 Thr Leu Ala Gly Leu Ser Val Glu His Val His Ser Phe Thr Pro 215 220 225 Trp He Gin Ala His Gly Gly Trp Glu Gly He Leu Ala Val Ser 230 215 240 Pro Val Asp Leu Asn Leu Pro Leu Asp 245 (2) INFORMATION FOR SEQ ID NO 12 (l) SEQUENCE CHARACTERISTICS (A) LENGTH: 14 amino acids (C) STRANDEDNESS single (D) TOPOLOGY: linear (n) MOLECULE TYPE peptide US (xi ) SEQUENCE DESCRIPTION SEQ ID NO 12 Trp He Gin Ala His Gly Gl> Trp Glu Gly lie Leu Ala Val 5 10 (2 ) INFORMATION FOR SEQ ID NO 1 λ (i) SEQUENCE CHARACTERISTICS (A ) LENGTH 14 amino acids ( B ) TYPE amino acid (C) STRANDEDNESS simile (D) TOPOLOGY hncar (u) MOLECULE TYPE peptide (xi) SEQUENCE DESCRIPTION SEQ ID NO 1 1 Trp lie Ala Gin Arg Gly Gly Trp V,ιl Ala Ala Leu Asn Leu 5 10 (2 ) INFORMATION FOR SEQ ID NO 14 ( D SEQUENCE CHARACTERIST ICS (A) LENGTH 14 ammo acids (C) STRANDEDNESS single (D) TOPOLOGY linear (u) MOLECULE TYPE peptide (xi ) SEQUENCE DESCRIPTION SEQ ID NO 14 Trp He Gin Asp Gin Gly Gly Trp Asp Gly Leu Leu Ser Tyr 5 10 (2) INFORMATION FOR SEQ ID NO 15 (l) SEQUENCE CHARACTERISTICS (A) LENGTH 15 amino acids (B ) TYPE amino acid (C) STRANDEDNESS single (D) TOPOLOGY linear (n) MOLECULE TYPE peptide (xi ) SEQUENCE DESCRIPTION SEQ ID NO 15 Trp Arg Ser Pro Asn Pro Gly Ser Trp Val Ser Cys Glu Gin Val 5 10 I S (2) INFORMATION FOR SEQ ID NO 16 (i) SEQUENCE CHARACTERISTICS (A) LENGTH 14 amino acids (B ) TYPE amino acid (C) STRANDEDNESS single (D) TOPOLOGY linear (n) MOLECULE TYPE peptide (xi ) SEQUENCE DESCRIPTION SEQ ID NO 16 Trp He Gin Asp Asn Gly Gl> Trp Asp Ala Phe Val Glu Leu 5 10 ( 2 ) INFORMATION FOR SLQ ID NO 17 (l) SEQUENCE CHARACTER ISTICS (A) LENGTH 14 ammo acids ( B ) TYPE amino acid (C) STRANDEDNESS simile (D) TOPOLOGY lincar ( u) MOLECULE TYPE peptide (xi) SEQUENCE DESCRIPTION SEQ ID NO 17 Trp He Gin Glu Asn Gly Gl> Trp Asp Thr Phe Val Glu Leu 5 10 (2 ) INFORMATION FOR SEQ ID NO 18 (l) SEQUENCE CHARACTERISTICS (A) LENGTH 1 1 amino acids (C) STRANDEDNESS single (D) TOPOLOGY linear (ii ) MOLECULE TYPE peptide (xi) SEQUENCE DESCRIPTION SEQ ID NO 18 Leu Arg Arg Leu Val Ala Leu Leu Glu Glu Glu Ala Glu 5 10 (2) INFORMATION FOR SEQ ID NO 19 (0 SEQUENCE CHARACTERISTICS (A) LENGTH 11 ammo acids (C) STRANDEDNESS single (D) TOPOLOGY linear (ii) MOLECULE TYPE peptide (xi ) SEQUENCE DESCRIPTION SEQ ID NO 19 Val Gly Arg Gin Leu Ala He He Gly Asp Asp lie Asn 5 10 (2) INFORMATION FOR SEQ ID NO 20 (l) SEQUENCE CHARACTERISTICS (A) LENGTH 11 ammo acids (B ) TYPE amino acid (C) STRANDEDNESS single (D) TOPOLOGY linear (ii) MOLECULE TYPE peptide (xi ) SEQUENCE DESCRIPTION SEQ ID NO 20 Leu Ser Glu Cys Leu Lys Arg He Gly Asp Glu Leu Asp 5 10 (2 ) INFORMATION FOR SEQ ID NO 2 I ( l) SEQUENCE CHARACTERISTICS (A) LENGTH 1 1 amino acids (B ) TYPE amino acid (C) STRANDEDNESS single (D) TOPOLOGY linear (n) MOLECULE TYPE peptide (xi ) SEQUENCE DESCRIPTION SEQ ID NO 21 Leu Ala Leu Arg Leu Ala Cys He Gly Asp Glu Met A.sp • i " 10 (2) INFORMATION FOR SEQ ID NO 22 (0 SEQUENCE CHARACTERISTICS (A ) LENGTH 11 amino acids (B ) TYPE amino acid (C) STRANDEDNESS single (D) TOPOLOGY linear (n) MOLECULE TYPE peptide (xi) SEQUENCE DESCRIPTION SEQ ID NO 22 Val His Leu Ala Leu Arg Gin Ala Gly Asp Asp Phe Ser 5 " 10 (2) INFORMATION FOR SEQ ID NO 21 (l) SEQUENCE CHARACTERISTICS (A) LENGTH 11 amino acids (B ) TYPE ammo acid (C) STRANDEDNESS single (D) TOPOLOGY hncar 8S (n ) MOLECULE TYPE peptide ( xi ) SEQUENCE DESCRIPTION SEQ ID NO 21 Val Lys Gin Ala Leu Arg Glu Ala Gly Asp Glu Phe Glu 5 10 (2) INFORMATION FOR SEQ ID NO 24 ( i ) SEQUENCE CHARACTERISTICS (A) LENGTH 11 amino acids (B ) TYPE amino acid (C) STRANDEDNESS sinejc (D) TOPOLOGY linear (n ) MOLECULE TYPE peptide ( xi ) SEQUENCE DESCRIPTION SEQ ID NO 24 Leu Arg Arc Leu Val Ala Leu Leu Glu Glu Ghi Ala Glu 5 10 (2 ) INFORMATION FOR SEQ ID NO 25 (i) SEQUENCE CHARACTERISTICS (A) LENGTH 11 amino acids (B ) TYPE ammo acid (C) STRANDEDNESS single (D) TOPOLOGY linear (n) MOLECULE TYPE peptide (xi ) SEQUENCE DESCRIPTION SEQ ID NO 25 Ala Arc Arc Leu Ala Ala Leu Ala Glu Ala Ala Ala Glu 5 10 (2) INFORMATION FOR SEQ ID NO 26 (D SEQUENCE CHARACTERISTICS (A) LENGTH 11 amino acids (B ) TYPE amino acid (C) STRANDEDNESS single (D) TOPOLOGY linear (u) MOLECULE TYPE peptide (xi) SEQUENCE DESCRIPTION SEQ ID NO 26 Leu Arg Arg Leu Ala Ala Leu Leu Glu Glu Glu Ala Glu 5 10 (2) INFORMATION FOR SEQ ID NO 27 ( i ) SEQUENCE CHARACTERISTICS i A l LENGTH 1 1 amino acids (B ) TYPE amino acid (C) STRANDEDNESS single (D) TOPOLOGY hnear (u) MOLECULE TYPE peptide (xi) SEQUENCE DESCRIPTION SEQ ID NO 27 Leu Arg Arg Leu Val Ala Leu Ala Glu Glu Glu Ala Glu 5 10 (2) INFORMATION FOR SEQ ID NO 28 (0 SEQUENCE CHARACTERISTICS (A) LENGTH 1 1 amino acids (B ) TYPE amino acid (C) STRANDEDNESS single (D) TOPOLOGY linear ( u ) MOLECULE TYPE peptide (xi) SEQUENCE DESCRIPTION SEQ ID NO 28 Leu Arg Arg Leu Val Ala Leu Leu Glu Ala Ala Ala Glu 5 10 9(1

Claims: What is claimed is: 1. An isolated Bbk prolcin. 2. The isolated Bbk prolcin ol claim 1 , wherein said prolcin is a human protein. 3 The isolated Bbk protein ol claim 2. wherein said piotcin consists essentially ol the amino acid sequence as shown in Figure 2 4. The isolated Bbk pi otcin ot claim 2. wherein .said protein is encoded by the nucleotide sequence as shown in Figure 2. 5. An isolated nucleotide sequence coding lor Bbk protein 6 The isolated nucleotide sequence ol claim 5, wherein said sequence is as shown in Figure 2 7 The isolated nucleotide sequence of any one of claims 5 or 6. wherein said sequence comprises genomic DNA 8. The isolated nucleotide sequence ol any one ol claims 5 or 6, wherein said sequence comprises cDNA 9 The isolated nucleotide sequence ot any one ot claims 5 oi 6, wherein said sequence comprise RNA 10. An isolated recombinant DNA molecule consisting essentially ot a nucleotide sequence that codes tor Bbk prolcin. 1 1. The isolated recombinant DNA molecule ol claim 10, wherein said nucleotide sequence is as shown in Figure 2. 12. The isolated recombinant DNA molecule ol claim 1 1 , wherein said molecule is a vector. 13. A vector consisting essentially of a recombinant DNA molecule encoding Bbk protein, wherein said vector expresses a sequence that codes lor Bbk m said recombinant DNA molecule. 14. A vector comprising a recombinant DNA molecule encoding Bbk protein, wherein said vector expresses an antisense RNA ol said recombinant molecule. 15. The vector ol claim 13, wherein said recombinant DNA molecule consists essentially ol a nucleotide sequence as shown in Figure 2. 16. A host cell translormed with the vector ol any one of claims 13 or 15. 17 The host cell ol claim 1 1 , wherein said host cell is a mammalian cell. I S. A method lor producing isolated Bbk polypeptidc. comprising: (a) constructing the vector ol claim 13; (b) transforming a suitable host cell with said vector ol Step (a): (e) cultuπng the host cell of Step (b) under conditions which allow the expression ol " said Bbk polypeptide by said host cell; and (d) isolating said Bbk polypeptide expressed by the host cell of Step (c); wherein isolated substantially pure Bbk polypeptide is produced. 19. The method according to claim 18, wherein said host cell is a mammalian cell. 20. An antibody raised against the Bbk protein of claim 4. 21. The antibody of claim 20, wherein said antibody is selected from the group consisting of a polyclonal antibody, a monoclonal antibody, an anti-idiotypic antibody, and an anti-anti-idiotypie antibody. 22. The antibody ol claim 21 , wherein said antibody is delectably labeled. 23 The antibody ol claim 22, wherein said antibody is detcctably labeled with a detectable label selected from the group consisting ol. a radio label, an cn/yme label, a co-lactor label, a lluore.scent label, a paramagnetic label, a chemiluminescent label, and a metal label 24 A delectably labeled nucleotide probe, comprising a lirsl nucleotide sequence which is substantially complementary lo a second nucleotide sequence that spccilically codes lor the Bbk protein ot claim 4 25 A pharmaceutical composition compnsmg the Bbk piotcin ol claim 4 and a pharmaceutically acceptable carrier 26 A method lor inducing apoptosis in a cell comprising intioducing into a nonapoptotic cell an amount ol the Bbk protein ol claim 4 el lcclivc to induce apoptosis in 27 The method ot claim 26, wherein said Bbk protein is introduced by express¬ ing a nucleotide encoding Bbk in said nonapoptotic cell 28 A peptide comprising the Bbk BH3 domain 29 The peptide ol claim 28 having an amino acid sequence selected lrom the group consisting ol LRRLVALLEEEAE -[SEQ ID NO. 5j- LRRLAALLEEEAE --[SEQ ID NO: 6]~ LRRLVALAEEEAE -[SEQ ID NO. 7)- LRRLVALLEAAAE -{SEQ ID NO: 8]~ wherein said peptide induces apoptosis in transfected Ratl cells. 30 An isolated nucleotide sequence coding tor the peptide ol claims 28 or 29 3 1 A vector comprising the nucleotide sequence ol claim 30 32 A host cell translormed with the vector ol claim 31. 33. The host cell ot claim 32, wherein said host cell is a mammalian cell.

Inventors: GALLO GREGORY J, GALLO, GREGORY, J.
Applicants: APOPTOSIS TECHNOLOGY INC, APOPTOSIS TECHNOLOGY, INC.
Application year: 1997
Main classification: A61K31
IPC codes: A61K31, A61K35, A61K38, A61K48, A61P35, A61P37, C07K7, C07K14, C07K16, C12N5, C12N15, C12P21