Cyclic GMP-dependent protein kinase signaling pathway inhibits RhoA-induced Ca2+ sensitization of contraction in vascular smooth muscle
Cyclic GMP-dependent protein kinase signaling pathway inhibits RhoA-induced Ca2+ sensitization of contraction in vascular smooth muscle
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DOI：
10.1074/jbc.m000753200
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发表时间：
2000-07-14
影响因子：
4.8
通讯作者：
Loirand, G
中科院分区：
文献类型：
--
作者：
Sauzeau, V;Le Jeune, H;Loirand, G
环GMP依赖性蛋白激酶（cGK）的有效的血管扩张作用涉及通过未知的机制经由肌球蛋白轻链磷酸酶的刺激降低平滑肌收缩的Ca 2+敏感性（Wu，X.，Somlyo，A.五、和Somlyo，A. P.（1996）Biochem. Biophys. Res. Commun. 220，658-663）。肌球蛋白轻链磷酸酶活性由小G蛋白RhoA及其靶点Rho激酶控制。在这里，我们证明cGMP的影响，抑制RhoA依赖的Ca 2+敏化的收缩血管和肌动蛋白细胞骨架组织在培养的血管肌细胞cGK介导的。8-溴-cGMP和硝普钠（SNP）均抑制Ca 2+敏化和肌动蛋白组织化。SNP还引起活化的RhoA从膜移位到胞质溶胶，SNP诱导的肌动蛋白分解在培养的血管肌细胞中在连续传代后丢失，但用cGK I转染细胞后恢复。此外，cGK磷酸化RhoA在体外，并添加cGK I抑制RhoA诱导的Ca 2+敏化透化平滑肌。在表达RhoA（Ala-188）（一种不能被磷酸化的突变体）的血管肌细胞中，8-溴-cGMP诱导的肌动蛋白分解被抑制。总的来说，这些结果表明cGK磷酸化并抑制RhoA，并表明随后对RhoA诱导的Ca 2+敏化和肌动蛋白细胞骨架组织的抑制有助于一氧化氮的血管舒张作用。
The potent vasodilator action of cyclic GMP-dependent protein kinase (cGK) involves decreasing the Ca2+ sensitivity of contraction of smooth muscle via stimulation of myosin light chain phosphatase through unknown mechanisms (Wu, X., Somlyo, A. V., and Somlyo, A. P. (1996) Biochem. Biophys. Res. Commun. 220, 658-663). Myosin light chain phosphatase activity is controlled by the small GTPase RhoA and its target Rho kinase. Here we demonstrate cGMP effects mediated by cGK that inhibit RhoA-dependent Ca2+ sensitization of contraction of blood vessels and actin cytoskeleton organization in cultured vascular myocytes. Ca2+ sensitization and actin organization were inhibited by both 8-bromo-cGMP and sodium nitroprusside (SNP). SNP also caused translocation of activated RhoA from the membrane to the cytosol, SNP-induced actin disassembly was lost in vascular myocytes in culture after successive passages but was restored by transfection of cells with cGK I. Furthermore, cGK phosphorylated RhoA in vitro, and addition of cGK I inhibited RhoA-induced Ca2+ sensitization in permeabilized smooth muscle. 8-Bromo-cGMP-induced actin disassembly was inhibited in vascular myocytes expressing RhoA(Ala-188), a mutant that could not be phosphorylated, Collectively, these results indicate that cGK phosphorylates and inhibits RhoA and suggest that the consequent inhibition of RhoA-induced Ca2+ sensitization and actin cytoskeleton organization contributes to the vasodilator action of nitric oxide.