PTP-S31: a novel protein tyrosine phosphatase

Abstract

A novel protein tyrosine phosphatase designated PTP-S31 and its subfamily are identified, as are nucleic acid molecule coding therefor. Included in this family are PTP-S31 proteins or glycoproteins having one, two, or three identified amino acid changes in previously defined consensus sequences in the catalytic phosphatase domains of known protein tyrosine phosphatases. The PTP-S31 proteins or glycoproteins may be produced by recombinant means. Antibodies to PTP-S31 proteins or glycoproteins and nucleic acid constructs coding therefor, and methods for screening molecules which can bind to PTP-S31 proteins or glycoproteins and inhibit or stimulate their enzymatic activity, are provided.

What is claimed is:  
     
         1 . A molecule comprising a human protein tyrosine phosphatase PTP-S31 protein or glycoprotein, a functional derivative thereof, or a homologue thereof in a non-human mammal, wherein, when said molecule is one which naturally occurs, said molecule is substantially free of other proteins or glycoproteins with which it is natively associated.  
     
     
         2 . A molecule according to  claim 1  which does not occur in nature.  
     
     
         3 . A molecule according to  claim 1  which occurs in nature and is substantially free of other proteins or glycoproteins with which it is associated in natively associated.  
     
     
         4 . A molecule according to  claim 1  which comprises the amino acid sequence SEQ ID NO:4  
     
     
         5 . A molecule according to  claim 1  which is a variant of PTP-S31.  
     
     
         6 . A molecule according to  claim 5  selected from the group consisting of PTP-S31D (SEQ ID NO:11), PTPS31-14 (SEQ ID NO:16), PTPS31-2 (SEQ ID NO:17); PTPS31-5 (SEQ ID NO:18), PTPS31-63 (SEQ ID NO:19), PTPS31-III (SEQ ID NO:20) and PTPS31-RD#2 (SEQ ID NO:22).  
     
     
         7 . A nucleic acid molecule comprising a nucleotide sequence encoding a PTP-S31 protein according to  claim 1 , or a functional derivative or a homologue thereof, wherein, when said protein, functional derivative or homologue is one which naturally occurs, said DNA molecule is substantially free of nucleotide sequences encoding proteins with which said protein or said functional derivative are natively associated.  
     
     
         8 . A nucleic acid molecule according to  claim 7  which is a cDNA sequence.  
     
     
         9 . A nucleic acid molecule according to  claim 7  which is a genomic DNA sequence.  
     
     
         10 . A nucleic acid molecule according to  claim 7  which is a DNA molecule comprising the nucleotide sequence SEQ ID NO:3  
     
     
         11 . A nucleic acid molecule according to  claim 7  wherein said functional derivative is selected from the group consisting of PTP-S31D (SEQ ID NO:11), PTPS31-14 (SEQ ID NO:16), PTPS31-2 (SEQ ID NO:17); PTPS31-5 (SEQ ID NO:18), PTPS31-63 (SEQ ID NO:19), PTPS31-III (SEQ ID NO:20) and PTPS31-RD#2 (SEQ ID NO:22).  
     
     
         12 . A nucleic acid molecule according to  claim 7  which is an expression vehicle.  
     
     
         13 . A nucleic acid molecule according to  claim 12 , wherein said expression vehicle is a plasmid.  
     
     
         14 . A host cell transformed or transfected with a nucleic acid molecule according to  claim 12 .  
     
     
         15 . A host cell according to  claim 14  which is a prokaryotic cell.  
     
     
         16 . A host call according to  claim 14  which is a eukaryotic cell.  
     
     
         17 . A process for preparing a PTP-S31 protein or glycoprotein molecule according to  claim 1 , comprising: 
 (a) culturing a host capable of expressing a PTP-S31 protein or glycoprotein molecule under culturing conditions;    (b) expressing the PTP-S31 protein or glycoprotein molecule; and (c) recovering the PTP-S31 protein or glycoprotein molecule from the culture.    
     
     
         18 . An antibody specific for the PTP-S31 protein or glycoprotein molecule of  claim 1 .  
     
     
         19 . An antibody according to  claim 18  which is monoclonal.