Involvement of Pertussis toxin-sensitive and -insensitive G proteins in α-thrombin signalling on cultured human vascular smooth muscle cells
| Autor: | Omar Benzakour, Chryso Kanthou, Sandip M. Kanse, Vijay V. Kakkar |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
medicine.medical_specialty
Vascular smooth muscle G protein Biology Phosphatidylinositols Pertussis toxin Muscle Smooth Vascular GTP Phosphohydrolases Thrombin GTP-Binding Proteins 1-Methyl-3-isobutylxanthine Internal medicine Cyclic AMP medicine Pi Humans Virulence Factors Bordetella Alprostadil Cells Cultured chemistry.chemical_classification Adenosine Diphosphate Ribose Colforsin Cell Biology Saponins Cell biology Endocrinology Enzyme Pertussis Toxin chemistry Mitogen-activated protein kinase biology.protein Guanosine Triphosphate Poly(ADP-ribose) Polymerases Cell Division Intracellular Signal Transduction circulatory and respiratory physiology medicine.drug |
| Zdroj: | Cellular Signalling. 8:59-66 |
| ISSN: | 0898-6568 |
| Popis: | Alpha-thrombin, a key enzyme of the coagulation cascade, is also a potent mitogen for human vascular smooth muscle cells (HVSMC). Here it is demonstrated that the alpha-thrombin-mediated reduction of intracellular cAMP levels is sensitive to pertussis toxin (PTX). cAMP-elevating agents inhibited alpha-thrombin- and serum-induced mitogenesis, thus cAMP confers an anti-mitogenic signal on HVSMC. The PTX-dependent ADP-ribosylation of a 41 kDa Gi alpha protein(s) was significantly inhibited (up to 55%) by thrombin. HVSMC membranes had an intrinsic GTP'ase activity which was significantly increased (up to 36%) by thrombin. PTX treatment did not alter thrombin-induced elevation of GTP'ase activity. Thrombin stimulated phosphatidyl inositol (PI) turnover in a PTX-insensitive manner. This suggested that PTX insensitive G proteins such as Gq are also activated by thrombin. This study on HVSMC provides additional evidence for the involvement of different families of G proteins in thrombin signalling. |
| Databáze: | OpenAIRE |
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