Association of the protein tyrosine phosphatase PTP1C with the protein tyrosine kinase c-Src in human platelets.
Protein tyrosine phosphatase 1C (PTP1C), highly expressed in hematopoietic cells, is a soluble protein tyrosine phosphatase containing two Src homology 2 (SH2) domains at the N-terminus and two putative sites of tyrosine phosphorylation at the C-terminus. This paper reports that PTP1C and c-Src could be coimmunoprecipitated during thrombin-induced platelet activation. Moreover, association between the two signalling proteins occurred only after PTP1C had been tyrosine phosphorylated. In in vitro experiments, PTP1C bound to the SH2 domain of c-Src, suggesting that association between tyrosine phosphorylated PTP1C and c-Src was mediated by the SH2 domain of c-Src. Finally, in resting platelets, PTP1C was mainly found in the Nonidet P-40 soluble fraction whereas following thrombin-induced activation, around 17% of PTP1C was associated with the insoluble fraction.
Falet
H
H
INSERM U 428, UFR des Sciences Pharmaceutiques et Biologiques, Université René Descartes, Paris, France.
Ramos-Morales
F
F
Bachelot
C
C
Fischer
S
S
Rendu
F
F
D001792:Blood Platelets / Q000201:enzymology*; D003902:Detergents; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D005982:Glutathione Transferase / Q000302:isolation & purification; D006801:Humans; D007700:Kinetics; D017027:Protein Tyrosine Phosphatases / Q000097:blood* / Q000302:isolation & purification; D011505:Protein-Tyrosine Kinases / Q000097:blood* / Q000302:isolation & purification; D016392:Proto-Oncogene Proteins pp60(c-src) / Q000097:blood* / Q000302:isolation & purification; D011993:Recombinant Fusion Proteins / Q000302:isolation & purification / Q000378:metabolism; D013347:Subcellular Fractions / Q000201:enzymology; D013917:Thrombin / Q000494:pharmacology
D003902:Detergents; D011993:Recombinant Fusion Proteins; D005982:Glutathione Transferase; D011505:Protein-Tyrosine Kinases; D016392:Proto-Oncogene Proteins pp60(c-src); D017027:Protein Tyrosine Phosphatases; D013917:Thrombin