Protein tyrosine phosphatase activity modulation by endothelin-1 in rabbit platelets.
FEBS Lett
; 400(3): 280-4, 1997 Jan 06.
Article
in En
| MEDLINE
| ID: mdl-9009214
ABSTRACT
Protein tyrosine phosphorylation, modulated by the rate of both protein tyrosine kinase and protein tyrosine phosphatase activities, is critical for cellular signal transduction cascades. We report that endothelin-1 stimulation of rabbit platelets resulted in a dose- and time-dependent tyrosine phosphorylation of four groups of proteins in the molecular mass ranges of 50, 60, 70-100 and 100-200 kDa and that one of these corresponds to focal adhesion kinase. This effect is also related to the approximately 60% decrease in protein tyrosine phosphatase activity. Moreover, this inhibited activity was less sensitive to orthovanadate. In the presence of forskolin that increases the cAMP level a dose-dependent inhibition of the endothelin-stimulated tyrosine phosphorylation of different protein substrates and a correlation with an increase in the protein tyrosine phosphatase activity (11.6-fold compared to control) have been found. Further studies by immunoblotting of immunoprecipitated soluble fraction with anti-protein tyrosine phosphatase-1C from endothelin-stimulated platelets have demonstrated that the tyrosine phosphorylation of platelet protein tyrosine phosphatase-1C is correlated with the decrease in its phosphatase activity. As a consequence, modulation and regulation by endothelin-1 in rabbit platelets can be proposed through a cAMP-dependent pathway and a tyrosine phosphorylation process that may affect some relevant proteins such as focal adhesion kinase.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Blood Platelets
/
Protein Tyrosine Phosphatases
/
Endothelin-1
Limits:
Animals
Language:
En
Journal:
FEBS Lett
Year:
1997
Document type:
Article
Affiliation country:
Spain