Role of RhoGAP Rgd1 in Pkc1 signaling-related actin repolarization under heat shock stress in Saccharomyces cerevisiae
Role of RhoGAP Rgd1 in Pkc1 signaling-related actin repolarization under heat shock stress in Saccharomyces cerevisiae
复制标题
RhoGAP Rgd1 在酿酒酵母热休克应激下 Pkc1 信号相关肌动蛋白复极化中的作用
DOI：
10.1016/j.bbagen.2021.129853
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Inoue Yoshiharu
中科院分区：
文献类型：
--
作者：
Nomura Wataru;Futamata Ryota;Inoue Yoshiharu
背景丝氨酸/苏氨酸激酶Pkc 1是芽殖酵母中唯一的蛋白激酶C，在极性生长和热激等应激反应的调节中起重要作用。细胞暴露于高温会短暂地阻止极化生长，导致肌动蛋白细胞骨架去极化，随后在适应热休克应激期间发生肌动蛋白复极化。肌动蛋白复极化通过激活Pkc 1信号传导来保证;然而，这一现象背后的分子机制仍然知之甚少。方法使用组成型活性突变体Pkc 1的过表达构建（Pkc1R398P），结果PKC 1 R398过表达和热休克应激均增加了Rho GTP酶激活蛋白的磷酸化水平，RhoGAP）Rgd1。Rgd 1被发现有助于Pkc 1信号相关的肌动蛋白复极化过程中适应热休克应激的GAP活性独立的方式，与Ser 148在Rgd 1起着至关重要的作用。结论Rgd 1是Pkc 1信号转导的靶点，在热休克应激条件下，Rgd 1参与维持Pkc 1下游效应子--丝裂原活化蛋白激酶Mpk 1的磷酸化状态。本研究结果为深入了解热休克应激下肌动蛋白的复极化过程提供了分子基础潜在的PKC 1介导的调节肌动蛋白复极化下热休克应激。
BackgroundA serine/threonine kinase Pkc1 is the sole protein kinase C in the budding yeastSaccharomyces cerevisiae, and plays an important role in the regulation of polarized growth and stress responses such as those due to heat shock. Exposure of cells to high temperature transiently arrests polarized growth and leads to depolarization of the actin cytoskeleton, followed by actin repolarization during adaptation to heat shock stress. Actin repolarization is ensured by the activation of Pkc1 signaling; however, the molecular mechanisms underlying this phenomenon remain poorly understood.MethodsUsing an overexpression construct of a constitutively active mutant of Pkc1 (Pkc1R398P), we explored the Pkc1 target molecules involved in actin repolarization.ResultsPKC1R398Poverexpression as well as heat shock stress increased the phosphorylation levels of Rho GTPase-activating protein (RhoGAP) Rgd1. Rgd1 was found to contribute to Pkc1-signaling-related actin repolarization during adaptation to heat shock stress in a GAP activity-independent manner, with Ser148 in Rgd1 playing a crucial role. Furthermore, Rgd1 was involved in the maintenance of phosphorylation status of the mitogen-activated protein (MAP) kinase Mpk1, a downstream effector of Pkc1, under heat shock stress.ConclusionsRgd1 is a target of Pkc1 signaling under conditions of heat shock stress, and required for the normal process of actin repolarization during adaptation to heat shock stress.General significanceOur results provide insights into the molecular mechanism underlying Pkc1-mediated modulation of actin repolarization under heat shock stress.