Functional implications of tyrosine protein phosphorylation in platelets. Simultaneous studies with different agonists and inhibitors
| Autor: | F Grelac, Francine Rendu, Sylviane Levy-Toledano, Christilla Bachelot, B J Druker, Siegmund Fischer, S Saleun, E Cano |
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| Rok vydání: | 1992 |
| Předmět: |
Blood Platelets
Platelet Aggregation Platelet Membrane Glycoproteins Protein tyrosine phosphatase In Vitro Techniques Models Biological Biochemistry chemistry.chemical_compound medicine Humans Staurosporine Protein phosphorylation Disulfides Platelet activation Phosphorylation Tyrosine Molecular Biology Protein Kinase C Protein kinase C Plant Extracts Thrombin Tyrosine phosphorylation Blood Proteins Cell Biology Phosphoproteins Platelet Activation Molecular biology chemistry Sulfoxides Tetradecanoylphorbol Acetate Collagen Oligopeptides Platelet Aggregation Inhibitors Research Article medicine.drug |
| Zdroj: | Scopus-Elsevier |
| ISSN: | 1470-8728 0264-6021 |
| DOI: | 10.1042/bj2840923 |
| Popis: | During activation of platelets by agonists, a number of proteins become phosphorylated at tyrosine residues. Using immunoblotting with a monoclonal anti-phosphotyrosine antibody, we have compared the different phosphotyrosine-protein (PTP) profiles of platelets stimulated with thrombin, collagen, ADP, arachidonic acid, phorbol myristate acetate and P256, an anti-glycoprotein-IIb-IIIa (GPIIb-IIIa) monoclonal antibody (mAb). Only a few PTPs were observed in resting platelets, of molecular masses 130, 64, 56-60 and 36 kDa. After stimulation by different agonists these proteins were more intensely phosphorylated and additional PTPs appeared with molecular masses of 170, 150, 140, 120, 105/97 (doublet), 85, 80, 75 and 45 kDa. The kinetics of phosphorylation differed from one agonist to another, but no significant differences in the overall patterns were detected, except in presence of ADP and P256-F(ab')2, which induced only the additional tyrosine phosphorylation of the 64 kDa protein and to a lesser extent that of a 75 kDa protein. The use of various agonists and the inhibitors (staurosporine, ajoene and RGDS) permitted a better characterization of the relationship between the different steps of activation and phosphorylation on tyrosine residues. The studies suggest the following conclusions: (i) stimulation of tyrosine phosphorylation occurs after activation of protein kinase C; (ii) there is a relationship between ligand binding to GPIIb-IIIa and the tyrosine phosphorylation of the 64 kDa protein; and (iii) there is a close relationship between PTP formation and the intensity of platelet activation and aggregation. |
| Databáze: | OpenAIRE |
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