...
首页> 外文期刊>Molecular and Cellular Biology >RhoA Phosphorylation Induces Rac1 Release from Guanine Dissociation Inhibitor α and Stimulation of Vascular Smooth Muscle Cell Migration
【24h】

RhoA Phosphorylation Induces Rac1 Release from Guanine Dissociation Inhibitor α and Stimulation of Vascular Smooth Muscle Cell Migration

机译:RhoA磷酸化诱导从鸟嘌呤解离抑制剂α释放Rac1,并刺激血管平滑肌细胞迁移。

获取原文
           

摘要

Although overactivation of RhoA is recognized as a common component of vascular disorders, the molecular mechanisms regulating RhoA activity in vascular smooth muscle cells (VSMC) are still unclear. We have previously shown that in VSMC, RhoA is phosphorylated on Ser188 by nitric oxide (NO)-stimulated cGMP-dependent kinase (PKG), which leads to RhoA-Rho kinase pathway inhibition. In this study, we showed that expression of phosphoresistant RhoA mutants prevented the stimulation of VSMC migration and adhesion induced by NO-PKG pathway activation. In contrast, under basal conditions, phosphomimetic RhoA mutants stimulated VSMC adhesion and migration through a signaling pathway requiring Rac1 and the Rho exchange factor Vav3. RhoA phosphorylation or phosphomimetic RhoA mutants induced Rac1 activation but did not activate Vav3. Indeed, phosphorylated RhoA or phosphomimetic mutants trapped guanine dissociation inhibitor α (GDIα), leading to the release of Rac1 and its translocation to the membrane, where it was then activated by the basal Vav3 nucleotide exchange activity. In vivo, RhoA phosphorylation induced by PKG activation in the aortas of rats treated with sildenafil induced dissociation of Rac1 from GDIα and activation of the Rac1 signaling pathway. These results suggest that the phosphorylation of RhoA represents a novel potent and physiological GDIα displacement factor that leads to Rac1 activation and regulation of Rac1-dependent VSMC functions.
机译:尽管RhoA的过度激活被认为是血管疾病的常见原因,但尚不清楚调节血管平滑肌细胞(VSMC)中RhoA活性的分子机制。先前我们已经表明,在VSMC中,一氧化氮(NO)刺激的cGMP依赖性激酶(PKG)会在Ser188上磷酸化RhoA,从而导致RhoA-Rho激酶途径抑制。在这项研究中,我们表明抗磷酸RhoA突变体的表达阻止了由NO-PKG途径激活诱导的VSMC迁移和粘附的刺激。相反,在基础条件下,拟磷酸化的RhoA突变体通过要求Rac1和Rho交换因子Vav3的信号传导途径刺激VSMC粘附和迁移。 RhoA磷酸化或模拟RhoA突变体诱导Rac1激活,但不激活Vav3。确实,磷酸化的RhoA或拟磷酸化突变体捕获了鸟嘌呤解离抑制剂α(GDIα),导致Rac1的释放及其向膜的转运,然后被基础Vav3核苷酸交换活性激活。 体内,西地那非处理的大鼠主动脉中PKG激活引起的RhoA磷酸化诱导Rac1从GDIα分离,并激活Rac1信号通路。这些结果表明,RhoA的磷酸化代表了一种新颖的强效生理GDIα置换因子,可导致Rac1激活和Rac1依赖性VSMC功能的调节。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号