title: Spleen protein tyrosine kinases TPK-IIB and CSK display different immunoreactivity and opposite specificities toward c-src-derived peptides.
abstract: Polyclonal antibodies have been raised against two synthetic peptides reproducing the 48-64 and 353-369 sequences of CSK, a protein tyrosine kinase implicated in the down-regulation of src-related protein kinases. Both antibodies specifically recognize recombinant CSK and a CSK-related 49 kDa protein tyrosine kinase present in spleen but they do not cross-react with purified TPK-IIB, a spleen protein tyrosine kinase sharing with CSK catalytic activity toward src kinases and incapability to autophosphorylate. CSK and TPK-IIB once resolved from each other by heparin-Sepharose affinity chromatography, display opposite specificities toward synthetic peptides reproducing the sequences around the main phosphoacceptor residues of pp60c-src, namely Tyr-416 and Tyr-527. These data support the view that TPK-IIB and CSK may exert opposite effects on the activity of src-related protein tyrosine kinases.
mesh_terms: D000595:Amino Acid Sequence; D000081247:CSK Tyrosine-Protein Kinase; D002147:Calmodulin / Q000378:metabolism; D066246:ErbB Receptors / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D010455:Peptides / Q000276:immunology / Q000378:metabolism; D019000:Phosphotyrosine; D011505:Protein-Tyrosine Kinases / Q000276:immunology* / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D016315:Proto-Oncogene Proteins c-abl / Q000378:metabolism; D016392:Proto-Oncogene Proteins pp60(c-src) / Q000378:metabolism*; D013154:Spleen / Q000201:enzymology*; D013379:Substrate Specificity; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism; D019061:src-Family Kinases
chemical_list: D002147:Calmodulin; D010455:Peptides; D011518:Proto-Oncogene Proteins; D019000:Phosphotyrosine; D014443:Tyrosine; D066246:ErbB Receptors; D011505:Protein-Tyrosine Kinases; D000081247:CSK Tyrosine-Protein Kinase; D016315:Proto-Oncogene Proteins c-abl; D016392:Proto-Oncogene Proteins pp60(c-src); C053102:proto-oncogene proteins c-fgr; D019061:src-Family Kinases; C000631346:CSK protein, human