Stimulation of G‐protein coupled receptors in vascular smooth muscle cells induces tyrosine kinase dependent increases in calcium without tyrosine phosphorylation of phospholipase C γ‐1

FEBS Letters

Raatz Nelson, Stephanie¹  Di Salvo, Joseph¹ 

[1] Department of Physiology, University of Minnesota, 6-255 Millard Hall, 435 Delaware St. SE, Minneapolis, MN 55455, USA

关键词: Angiotensin-II;    Cellular Ca2+;    Endothelin;    G-protein coupled receptor;    Fura-2;    Genistein;    Phospholipase C;    Platelet derived growth factor;    Protein tyrosine phosphorylation;    Serotonin;    Vascular smooth muscle cell;    Vasopressin;   

DOI  :  10.1016/S0014-5793(97)01606-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

It is often believed that increases in intracellular Ca²⁺ ([Ca²⁺]_i) resulting from stimulation of G-protein coupled receptors in vascular smooth muscle cells (VSMC) require activation of the β1 isoform of phospholipase C (PLC). However, recent studies showed that rat aortic VSMC do not express PLC β-1 and that stimulation with angiotensin-II induces tyrosine kinase dependent increases in [Ca²⁺]_i and tyrosine phosphorylation of PLC γ-1. Whether this pathway is activated by other vasoactive agents that stimulate G-protein coupled receptors is unknown. Here, we show that A10 VSMC express PLC β-2, PLC β-3, PLC δ-1, and PLC γ-1. The cells also expressed Gα_q/11. However, neither PLC β-1 nor PLC β-4 was detected. Stimulation with angiotensin-II, vasopressin, serotonin, or endothelin induced tyrosine kinase dependent increases in [Ca²⁺]_i. However, tyrosine phosphorylation of PLC γ-1 did not occur. In contrast, stimulation with platelet derived growth factor increased [Ca²⁺]_i and tyrosine phosphorylation of PLC γ-1. The results show that tyrosine phosphorylation of PLC γ-1 is not required for tyrosine kinase dependent increases in [Ca²⁺]_i resulting from stimulation of diverse G-protein coupled receptors in VSMC.

【 授权许可】

Unknown