| First Author | Klages B | Year | 1999 |
| Journal | J Cell Biol | Volume | 144 |
| Issue | 4 | Pages | 745-54 |
| PubMed ID | 10037795 | Mgi Jnum | J:53243 |
| Mgi Id | MGI:1331557 | Doi | 10.1083/jcb.144.4.745 |
| Citation | Klages B, et al. (1999) Activation of G12/G13 results in shape change and Rho/Rho-kinase-mediated myosin light chain phosphorylation in mouse platelets. J Cell Biol 144(4):745-54 |
| abstractText | Platelets respond to various stimuli with rapid changes in shape followed by aggregation and secretion of their granule contents. Platelets lacking the alpha-subunit of the heterotrimeric G protein Gq do not aggregate and degranulate but still undergo shape change after activation through thromboxane-A2 (TXA2) or thrombin receptors. In contrast to thrombin, the TXA2 mimetic U46619 led to the selective activation of G12 and G13 in Galphaq-deficient platelets indicating that these G proteins mediate TXA2 receptor-induced shape change. TXA2 receptor-mediated activation of G12/G13 resulted in tyrosine phosphorylation of pp72(syk) and stimulation of pp60(c-src) as well as in phosphorylation of myosin light chain (MLC) in Galphaq-deficient platelets. Both MLC phosphorylation and shape change induced through G12/G13 in the absence of Galphaq were inhibited by the C3 exoenzyme from Clostridium botulinum, by the Rho-kinase inhibitor Y-27632 and by cAMP-analogue Sp-5,6-DCl-cBIMPS. These data indicate that G12/G13 couple receptors to tyrosine kinases as well as to the Rho/Rho-kinase-mediated regulation of MLC phosphorylation. We provide evidence that G12/G13-mediated Rho/Rho-kinase-dependent regulation of MLC phosphorylation participates in receptor-induced platelet shape change. |
