NOVEL PROTEIN TYROSINE KINASES

Abstract: The identification and isolation of novel protein tyrosine kinase genes present on human megakaryocytic and lymphocytic cells, the proteins encoded by these genes, antibodies specific for the encoded proteins, RNA nucleic acid sequences which hybridize to the genes and methods of use therefor.

Description: NOVEL PROTEIN TYROSINE KINASES Description Background of the Invention Transduction of signals that regulate cell growth and differentiation is regulated in part by phosphorylation of various cellular proteins. Protein tyrosine kinases are enzymes that catalyze this process. Moreover, many act as growth factor receptors. Summary of the Invention The present invention relates to novel protein tyrosine kinase genes present in human megakaryocytic and lymphocytic cells, the proteins encoded by these genes, antibodies specific for the encoded proteins, RNA nucleic acid sequences which hybridize to the genes and methods of use therefor. The genes isolated as described herein are referred to, collectively, as protein tyrosine kinase (pTK) genes. The nucleic acid sequences of these genes, isolated as discussed herein, show significant homology with previously identified protein tyrosine kinases containing extracellular domains which function as growth factor receptors. The pTK genes have been shown to be present in both megakaryocytic and lymphocytic cells. The pTK genes of the present invention show significant sequence homology with members of the c-kit subgroup of growth factor receptors with protein tyrosine kinase activity. The c-kit subgroup of receptor tyrosine kinases catalyze the phosphorylation of exogenous substrates, as well as tyrosine residues within their own polypeptide chains. (Ullrich, A. and Schlessinger, J. , Cell. 61:203 (1990)). Members of the c-kit subgroup include FLT/FLK (Fetal Liver Kinase) , FGF (Fibroblast Growth Factor Receptor) and NGF (Nerve Growth Factor Receptor) . In particular, fourteen pTK genes have been identified. Two pTK genes, referred to as SAL-SI and SAL- D4 (also referred to as megakaryocyte derived FGF-like receptor tyrosine kinase) were identified in megakaryocytic cells. Five pTK genes, referred to as LpTKs, were identified in lymphocytic cells and have been shown to be present in megakaryocytes as well. One pTK gene, referred to a HpTKs, was identified in human hepatoma cells. Six pTK genes, referred to as bpTK genes, found in human brain tissue. SAL-SI is related to the FLT/FLK family of pTKs. SAL-D4 is related to the FGF receptor family of pTKs, and one LpTK (LpTK 3) is related to the NGF receptor family of pTKs. The pTK genes, which are the subject of the present invention, were identified using two sets of degenerative oligonucleotide primers: a first set which amplifies all pTK DNA segments (SEQ ID NOS:1-2), and a second set which amplifies highly conserved sequences present in the catalytic domain of the c-kit subgroup of pTKs (SEQ ID NOS:3-4). The pTK genes identified in this manner are described below. SAL-SI is expressed in several megakaryocytic cell lines, but not in erythroid cell lines. The nucleotide sequence of SAL-SI was obtained, revealing a sequence containing 158 base pairs. (SEQ ID NO:5). This isolated DNA fragment encoded an amino acid sequence (SEQ ID NO:6) which exhibited significant sequence homology with known protein tyrosine kinases of the FLT/FLK family. The full length gene sequence (SEQ ID NO: 17) contains 6827 b.p. and the deduced amino acid sequence (SEQ ID NO: 18) contains 349 residues. SAL-D4, also expressed in megakaryocytic cells, is a DNA fragment containing the nucleotide sequence of 141 base pairs. (SEQ ID NO:7) . This isolated DNA fragment encoded an amino acid sequence (SEQ ID NO:8) which exhibited significant sequence homology with known protein tyrosine kinases of the FGF receptor family. The LpTKs, including LpTK 2, LpTK 3, LpTK 4, and LpTK 13 and LpTK 25, are expressed in lymphocytic cells, as well as megakaryocytic cells. The nucleotide sequence (151 base pairs) of the LpTK 3 gene was obtained (SEQ ID NO:11), and exhibited significant homology with known protein tyrosine kinases of the NGF receptor family. The nucleotide sequences of the LpTK 2, LpTK 4, and LpTK 13 genes contained 149 base pairs (SEQ ID NO:9), 137 base pairs (SEQ ID NO:13), and 211 base pairs (SEQ ID NO:15) respectively. LpTK 25 has a nucleotide sequence of 3120 b.p. (SEQ ID NO: 22) . A full length gene sequence has been obtained for LpTK 2 (SEQ ID NO: 19) which contains 7606 b.p. Additional sequencing of LpTK 4 revealed a sequence of 404 b.p. (SEQ ID NO: 21). The HpTK 5 gene, expressed in human hepatoma cells, has a nucleotide sequence of 3120 b.p. (SEQ ID NO: 22) . Nucleotide sequences of the bpTK's, including bpTK 1, bpTK 2, bpTK 3, bpTK 4, bpTK 5 and bpTK 7 are expressed in human brain tissue encode proteins having the amino acid sequences of SEQ ID NOS: 25-30 respectively. Thus the present invention includes DNA isolated from a human megakaryocytic cell line, which hybridizes to a DNA fragment which hybridizes to DNA encoding an amino acid sequence which is highly conserved in the catalytic domain of protein tyrosine kinases of the c-kit subgroup. The present invention also includes the proteins encoded by the pTK genes identified as described herein, which exhibit significant sequence homology with members of the c-kit subgroup of pTks (i.e. FLT/FLK (SAL-SI), FGF receptor (SAL-D4) or NGF receptor (LpTKS) ) as well as the proteins encoded by HpTK 5 and the bpTKs. The present invention also includes SAL-SI, SAL-D4, and LpTK, HpTK and bpTK homologues or equivalents (i.e., proteins which have amino acid sequences substantially similar, but not identical, to that of SAL-SI, SAL-D4, the LpTKs HpTK and the bpTKs, which exhibit tyrosine kinase activity.) This invention further includes peptides (SAL-SI, SAL-D4, LpTK, HpTK and bpTK fragments) which retain tyrosine kinase activity, yet are less than the entire SAL-Sl, SAL-D4, LpTK, HpTK and bpTK sequences) , monoclonal and polyclonal antibodies specific for SAL-SI, SAL-D4, the LpTKs, HpTK and the bpTKs, and uses for the SAL-SI, SAL-D4, the LpTK, HpTK and the bpTK nucleic acid sequences and SAL-SI, SAL- D4, LpTK, ΗpTK and bpTK equivalents. The present invention further includes nucleic acid sequences which hybridize with DNA or RNA encoding the proteins described herein, which exhibit significant sequence homology with the FLT/FLK, FGF receptor or NGF receptor family of protein tyrosine kinases contained within the c-kit subgroup. Such nucleic acid sequences are useful as probes to identify pTK genes in other vertebrates, particularly mammals, and in other cell types. They can also be used as anti-sense oligonucleotides to inhibit protein tyrosine kinase activity, both in vitro and in vivo. The SAL-SI, SAL-D4, LpTK, HpTK and bpTK, tyrosine kinases of the present invention can be used as target proteins in conjunction with the development of drugs and therapeutics to modulate cell growth, differentiation and other metabolic functions. The SAL-SI, SAL-D4, LpTK, HpTK or bpTK proteins can be used as agonists or antagonists to other tyrosine kinases. The SAL-SI, SAL-D4, LpTK, HpTK or bpTK tyrosine kinases can also be instrumental in the modulation of megakaryocyte and/or platelet adhesion interactions. In addition, the SAL-SI, SAL-D4, LpTK, HpTK and bpTK tyrosine kinases can be used in screening assays to detect cellular growth and/or differentiation factors. Using standard laboratory techniques, the ligands of the pTKs of the present invention can be identified. Once identified, assays can be designed to detect these ligands present endogenously, within cells, as well as exogenously, in extra cellular fluids. Assays can also be designed as diagnostic aids to detect these ligands in body fluids such as blood and urine. Brief Description of the Drawings Figure 1 depicts the nucleotide sequence of SAL-SI (SEQ ID NO: 5) and the deduced amino acid sequence (SEQ ID NO:6) . Figure 2 depicts the nucleotide sequence of SAL-D4 (SEQ ID NO:7) and its deduced amino acid sequence (SEQ ID NO:8) . Figure 3A depicts the nucleotide sequence (SEQ ID O:9) and its deduced amino acid sequence (SEQ ID NO:10) for LpTK 2. Figure 3B depicts the nucleotide sequence (SEQ ID O:11) and its deduced amino acid sequence (SEQ ID NO:12) for LpTK 3. Figure 3C depicts the nucleotide sequence (SEQ ID NO:13) and its deduced amino acid sequence (SEQ ID NO:14) for LpTK 4. Figure 3D depicts the nucleotide sequence (SEQ ID NO:15) and its deduced amino acid sequence (SEQ ID NO:16) for the LpTK 13. Figure 4A-4J depicts the full-length nucleotide sequence (SEQ ID NO: 17) and its deduced amino acid sequence (SEQ ID NO: 18) for SAL-SI. Figure 5A-5J depicts the full length nucleotide sequence (SEQ ID NO: 19) and the deduced amino acid sequence (SEQ ID NO: 20) for LpTK2. Figure 6 depicts the partial nucleotide sequence (SEQ ID NO: 21) for LpTK4. Figure 7A-7D depicts the full length nucleotide sequence (SEQ ID NO: 22) for LpTK25. Figure 8A-8F depicts the full length nucleotide sequence (SEQ ID NO: 23) and the deduced amino acid sequence (SEQ ID NO: 24) for HpTK5. Figure 9 depicts the amino acid sequence (SEQ ID NO: 25) of bpTKl. Figure 10 depicts the amino acid sequence (SEQ ID NO: 26) of bpTK2. Figure 11 depicts the amino acid sequence (SEQ ID NO: 27) of bpTK3. Figure 12 depicts the amino acid sequence (SEQ ID NO: 28) of bpTK4. Figure 13 depicts the amino acid sequence (SEQ ID NO: 29) of bpTK5. Figure 14 depicts the amino acid sequence (SEQ ID NO: 30) of bpTK7. Detailed Description of the Invention Novel protein tyrosine kinase genes have been identified, their nucleic acid sequences determined, and the amino acid sequences of the encoded proteins deduced. The genes isolated as described herein are referred to, collectively, as protein tyrosine kinase (pTK) genes. The nucleic acid sequences of these genes, isolated as discussed herein, show significant homology to with previously identified protein tyrosine kinases containing extracellular domains which function as growth factor receptors. These genes have been shown to be present in both megakaryocytic and lymphocytic cells. To facilitate the isolation and identification of these novel pTKs, two sets of DNA probes were used, as described in the Exemplification. The first set consisted of two degenerative oligonucleotide sequences, pTK 1 (SEQ ID N0:l) and pTK 2 (SEQ ID NO:2) (Matthews, W. Cell 65: 1143 (1991; Wilks, A. F. Proc. Natl. Acad. Sci. USA 86:1603 (1989)). These sequences were used as primers in a polymerase chain reaction to amplify tyrosine kinase DNA segments. (Mullis, K. et al.. Cold Spring Harbor Symp. Advan. Biol. 51:263 (1986). The second set consisted of two oligonucleotide sequences, pTK 3 (SEQ ID NO:3) and pTKK (SEQ ID NO:4) designed to amplify the nucleic acid sequence which encodes the highly conserved regions of the catalytic domains of the c-kit family of protein tyrosine kinases. These sequences were used as primers in the polymerase chain reaction in a second round of DNA amplification. Using this two-step amplification procedure, DNA fragments which hybridized to these pTK primers were identified, isolated and subsequently sequenced. In particular, fourteen pTK genes exhibiting significant homology with the c-kit subgroup of protein tyrosine kinases have been identified. Two pTK genes, referred to as SAL-SI and SAL-D4 (also referred to as megakaryocyte derived FGF-like receptor) were identified in several megakaryocytic cell lines, including CMK 11-5, DAMI, UT-7 and UT-7 grown in erythropoietin, but not in the erythroid cell lines HEL, PMA stimulated HEL cells, or K562. Five pTK genes, referred to as LpTKs, were identified in lymphocytic, as well as in megakaryocytic cells. One pTK gene, referred to as HpTK5 was identified in human hepato a cells and six genes, referred to as bpTKs, were identified in human brain tissue. SAL-SI (SEQ ID NO:6 and 18) encoded by the nucleic acid sequence SEQ ID NOS:5 and 17, exhibits significant homology with the FLT/FLK family of pTKs. SAL-D4 (SEQ ID NO:8) encoded by SEQ ID NO:7, is related to the FGF receptor family of pTKs, and one LpTK (LpTK 3 (SEQ ID NO:12) encoded by the SEQ ID NO:11, is related to the NGF receptor family of pTKs. The remaining LpTKs, LpTK2 (SEQ ID NO:10) encoded by SEQ ID NO:9; LpTK4 (SEQ ID NO:14) encoded by SEQ ID NO:13; LpTK13 (SEQ ID NO:16) encoded by SEQ ID NO:15 LpTK25 encoded by SEQ ID NO: 22, also exhibit sequence homology with known protein tyrosine kinases (Data not shown) . HpTK5 (SEQ ID NO: 24) encoded by SEQ ID NO: 23 and the bpTKs 1, 2, 3, 4, 5 and 7 (SEQ ID NOS: 25-30 respectively, also exhibit sequence homology with known protein tyrosine kinases. Thus, as described above, DNA which hybridize with DNA encoding amino acid sequences present in the catalytic domain of a protein tyrosine kinase of the c-kit subgroup of protein kinases have been isolated and sequenced. These isolated DNA sequences, collectively referred to as pTKs genes, (and their deduced amino acid sequences) have been shown to exhibit significant sequence homology with known members of receptor tyrosine kinase families. Once isolated, these DNA fragments can be amplified using known standard techniques such as PCR. These amplified fragments can then be cloned into appropriate cloning vectors and their DNA sequences determined. These DNA sequences can be excised from the cloning vectors, labeled with a radiolabeled nucleotide such as 32 P and used to screen appropriate cDNA libraries to obtain the full-length cDNA clone. The pTk genes as described above have been isolated from the source in which they occur naturally, i.e. megakaryocyte and lymphocytic cells. The present invention is intended to include pTk genes produced using genetic engineering techniques, such as recombinant technology, as well as pTk genes that are synthesized chemically. The deduced amino acid sequences of the pTK genes include amino acid sequences which encode peptides exhibiting significant homology with the catalytic domain of protein tyrosine kinases of the c-kit subgroup of tyrosine kinases. These proteins, encoded by the pTk genes, can include sequences in which functionally equivalent amino acid residues are substituted for residues within the sequence, resulting in a silent change, that is a change not detected phenotypically. For example, one or more amino acid residues within the sequence can be substituted by another amino acid of a similar polarity which acts as a functional equivalent, resulting in a silent substitution. In addition, the protein structure can be modified by deletions, additions, inversion, insertions or substitutions of one or more amino acid residues in the sequence which do not substantially detract from the desired functional tyrosine kinases properties of the peptide. Modified pTKs of the present invention, with receptor tyrosine kinase activity can be made using recombinant DNA techniques, such as excising it from a vector containing a cDNA encoding such a protein, or by synthesizing DNA encoding the desired protein mechanically and/or chemically using known techniques. An alternate approach to producing the pTKs of the present invention is to use peptide synthesis to make a peptide or polypeptide having the amino acid sequence of such a protein. The peptides or modified equivalents thereof, can be synthesized directly by standard solid or liquid phase chemistries for peptide synthesis. Preferably, the pTKs of the present invention will be produced by inserting DNA encoding the proteins into an appropriate vector/host system where it will be expressed. The DNA sequences can be obtained from sources in which they occur naturally, can be chemically synthesized or can be produced using standard recombinant technology. This invention also pertains to an expression vector comprising a pTK gene of the present invention, encoding for a protein which exhibits receptor tyrosine kinase activity. The pTK genes of the present invention can be used for a number of diagnostic and therapeutic purposes. For example, the nucleic acid sequences of the pTK genes can be used as probes to identify other protein tyrosine kinases present in other cell types, including eukaryotic and prokaryotic cell types. The nucleic acid sequences can be used to design drugs that directly inhibit the kinase activity of protein tyrosine kinases, or to design peptides that bind to the catalytic domain of tyrosine kinases, thus inhibiting their activity. These sequences can also be used to design anti-sense nucleotides that can also inhibit, or destroy, tyrosine kinase activity. Such inhibition of tyrosine kinase activity would be desirable in pathological states where decreased cellular proliferation would be beneficial, such as leukemias or other malignancies. The nucleic acid sequences can also be used to design drugs, peptides or anti-sense nucleotides as above, but with enhancing, rather than inhibitory effects, on tyrosine kinases. Such enhanced tyrosine kinase activity would result in increasing the phosphorylation of substrates (exogenous, as < well as endogenous tyrosine residues) . Enhanced effects would be desirable in states where increased cellular proliferation would be beneficial, such as anemias, bleeding disorders and during surgical procedures. The pTK genes of the present invention can also be used to obtain soluble fragments of receptor tyrosine kinases, capable of binding their respective ligands (i.e. fibroblast growth factor) . pTK genes encoding soluble receptor tyrosine kinase fragments can be produced using recombinant DNA techniques or synthetically. In either case, the DNA obtained encodes a soluble pTK fragment which lacks a substantial portion of the hydrophobic transmembrane region to permit solubilization of the fragment. These soluble pTK protein fragments can be introduced exogenously to act as competitors with the endogenous, membrane bound pTK for their respective ligands, thus inhibiting tyrosine kinase activity. Alternately, a modified soluble pTK protein fragment can be introduced which binds the ligand but does not activate kinase activity. These soluble pTK protein fragments can also be used in binding assays to detect ligands such as growth and differentiation factors. Once these ligands are identified, they may be altered or modified to inhibit or enhance kinase activity. For example, the ligands may be modified or attached to substances that are toxic to the cell, such a ricin, thus destroying the target cell. The substance may be a super-activating substance which, after binding to the pTK, may substantially increase the kinase activity, or activate other growth factors. pTk genes of the present invention would also be useful to develop diagnostic tools for in vitro screening assays for ligands such as growth factors or differentiation factors that inhibit or enhance kinase activity. The proteins encoded by the pTK genes can also be used in such assays, or as immunogens to produce monoclonal or polyclonal antibodies to be used in such assays. Such antibodies can also be used in methods of treating conditions in which an individual would benefit therapeutically if protein tyrosine kinase activity could be modified, such as increasing platelet production in bleeding disorders. The present invention will now be illustrated by the following Exemplification, which is not intended to be limiting in any way. Exemplification: The Identification and Isolation of the TK Genes . To facilitate the isolation and identification of these novel pTK genes, two sets of DNA probes were used. (See Table) . The first set consisted of two degenerative oligonucleotide sequences, pTK 1 (SEQ ID N0:1) and pTK 2(SEQ ID NO:2). These sequences were used as polymerase chain reaction (PCR) primers, using standard PCR techniques, to amplify tyrosine kinase DNA segments. The second set consisted of two oligonucleotide sequences, pTK 3 (SEQ ID NO:3) and pTKKW (SEQ ID NO:4) selected from the highly conserved regions of the catalytic domains of the c-kit subgroup of protein tyrosine kinases. These sequences were also used as polymerase chain reaction primers in a second round of DNA amplification. Using this two-step amplification procedure, DNA fragments which hybridized to these pTK primers were identified, isolated and subsequently sequenced using known laboratory techniques. TABLE First Round of Amplification PTK1 CGGATCCACAGNGACCT PTK2 GGAATTCCAAAGGACCAGACGTC Second Round of Amplification PTK3 (kit family specific) CGGATCCATCCACAGAGATGT PTKKW (kit family specific) GGAATTCCTTCAGGAGCCATCCACTT Eguivalents Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the following claims.

Claims: CLAIMS The invention claimed is: 1. Isolated DNA of human megakaryocytic origin which hybridizes to a DNA fragment which hybridizes to DNA encoding an amino acid sequence present in the catalytic domain of a protein tyrosine kinase of the c-kit subgroup of protein tyrosine kinases. 2. Isolated DNA of Claim 1 having a nucleotide sequence selected from the group of nucleotide sequences consisting of: a) SAL-SI (SEQ ID NOS:5 and 7) ; b) SAL-D4 (SEQ ID N0:7); c) LpTK 2 (SEQ ID NOS:9 and 19); d) LpTK 3 (SEQ ID NO:11); e) LpTk 4 (SEQ ID N0S:13 and 21); f) LpTK 13 (SEQ ID N0:15); g) LpTK 25 (SEQ ID NO: 22 and h( HpTK 5 (SEQ ID NO: 23) . 3. Isolated DNA of Claim 1 which encodes an amino acid sequence selected from the group consisting of: a) SAL-SI (SEQ ID NOS:6 and 18); b) SAL-D4 (SEQ ID NO:8); c) LpTK 2 (SEQ ID NOS:10 and 20); d) LpTK 3 (SEQ ID NO: 12); e) LpTK 4 (SEQ ID NO:14); f) LpTK 13 (SEQ ID NO:16); g) HpTK 5 (SEQ ID N0:24); h) bpTK 1 (SEQ ID NO:25) i) bpTK 2 (SEQ ID NO:26) j) bpTK 3 (SEQ ID NO:27) k) bpTK 4 (SEQ ID NO:28) 1) bpTK 5 (SEQ ID NO:29) and m) bpTK 7 (SEQ ID NO:30) Isolated DNA of human megakaryocytic origin which comprises a DNA fragment whose sequence encodes an amino acid sequence present in the catalytic domain of a protein tyrosine kinase of the c-kit subgroup of protein tyrosine kinases. Isolated DNA of Claim 4 which encodes an amino acid sequence selected from the group consisting of: a) SAL-SI (SEQ ID NO:6); b) SAL-D4 (SEQ ID NO:8); c) LpTK 2 (SEQ ID NO:10); d) LpTK 3 (SEQ ID NO:12); e) LpTk 4 (SEQ ID NO:14); and f) LpTK 13 (SEQ ID NO:16). g) HpTK 5 (SEQ ID NO:24) h) bpTK 1 (SEQ ID NO:25) i) bpTK 2 (SEQ ID NO:26) j) bpTK 3 (SEQ ID NO:27) k) bpTK 4 (SEQ ID NO:28) 1) bpTK 5 (SEQ ID NO:29); and m) bpTK 7 (SEQ ID NO:30) A homogeneous protein of human megakaryocytic origin which includes an amino acid sequence exhibiting sequence homology with the catalytic domain of tyrosine kinases of the c-kit family. 7. A homogeneous protein of Claim 6 in which the amino acid sequence is selected from the group consisting of: a) SAL-SI (SEQ ID NO:6); b) SAL-D4 (SEQ ID NO:8); c) LpTK 2 (SEQ ID NO:10); d) LpTK 3 (SEQ ID N0:12); e) LpTk 4 (SEQ ID N0:14); and f) LpTK 13 (SEQ ID NO:16). g) HpTK 5 (SEQ ID NO:24) h) bpTK 1 (SEQ ID NO:25) i) bpTK 2 (SEQ ID NO:26) j) bpTK 3 (SEQ ID NO:27) k) bpTK 4 (SEQ ID NO:28) 1) bpTK 5 (SEQ ID NO:29); and m) bpTK 7 (SEQ ID NO:30) 8. A protein of human megakaryocytic origin which exhibits significant sequence homology with the FLT/FLK family of protein tyrosine kinases. 9. A protein of Claim 8 encoded by the nucleotide sequence (SEQ ID NO:5). 10. A protein of Claim 8 encoded by the amino acid sequence (SEQ ID NO:6). 11. A protein of Claim 8 encoded by the nucleotide sequence (SEQ ID NO:17). 12. A protein of Claim 8 encoded by the amino acid sequence (SEQ ID NO: 18) . 13. A protein of human megakaryocytic origin which exhibits significant sequence homology with the FGF receptor family of protein tyrosine kinases. 14. A protein of Claim 10 encoded by the nucleotide sequence (SEQ ID NO:7) . 15. A protein of Claim 10 encoded by the amino acid sequence (SEQ ID NO:8). 16. A protein of human megakaryocytic origin which exhibits significant sequence homology with the NGF receptor family of protein tyrosine kinases. 17. A protein of Claim 14 encoded by the nucleotide sequence (SEQ ID NO:11). 18. A protein of Claim 14 encoded by the amino acid sequence (SEQ ID NO:12). 19. A DNA expression vector containing a DNA sequence of human megakaryocytic origin which hybridizes to a DNA fragment which hybridizes to DNA encoding an amino acid sequence present in the catalytic domain of a protein tyrosine kinase of the c-kit subgroup of protein kinases. 20. The DNA expression vector of Claim 17 containing a DNA sequence selected from the group consisting of: a) SAL-SI (SEQ ID N0:5); b) SAL-D4 (SEQ ID N0:7); C) LpTK 2 (SEQ ID N0:9); d) LpTK 3 (SEQ ID N0:11); e) LpTk 4 (SEQ ID NO:13); and f) LpTK 13 (SEQ ID NO:15). g) LpTK 25 (SEQ ID NO: 22 and h( HpTK 5 (SEQ ID NO: 23). 21. A cell transformed by the expression vector of Claim 17.

Inventors: AVRAHAM HAVA, COWLEY SALLY, GROOPMAN JEROME, SCADDEN DAVID, AVRAHAM, HAVA, COWLEY, SALLY, GROOPMAN, JEROME, SCADDEN, DAVID
Applicants: NEW ENGLAND DEACONESS HOSPITAL
Application year: 1993
Main classification: C12N9
IPC codes: A61K38, C07K14, C07K16, C07K19, C12N9, C12N15, C12Q1