G1/S cyclin-dependent kinase regulates small GTPase Rho1p through phosphorylation of RhoGEF Tus1p in Saccharomyces cerevisiae
G1/S cyclin-dependent kinase regulates small GTPase Rho1p through phosphorylation of RhoGEF Tus1p in Saccharomyces cerevisiae
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DOI：
10.1091/mbc.e07-09-0950
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发表时间：
2008-04-01
影响因子：
3.3
通讯作者：
Ohya, Yoshikazu
中科院分区：
文献类型：
--
作者：
Kono, Keiko;Nogami, Satoru;Ohya, Yoshikazu
Rho1p是一种必需的小分子GTP酶，在酿酒酵母的形态发生中起着关键作用。我们在这里表明，Rho1p的激活是由细胞周期蛋白依赖性激酶(CDK)调节的。在Rho1p的鸟嘌呤核苷酸交换因子Tus1p的介导下，Rho1p被Cln2p(G1细胞周期蛋白)和CDC28p(CDK)复合体激活，在G1/S的转变中。Tus1p与Cln2p/CDc28p相互作用，并以依赖于Cln2p/CDc28p的方式被磷酸化。Tus1p上的CDK磷酸化共识位点是依赖Cln2p激活Rho1p和极化组织肌动蛋白细胞骨架所必需的。我们认为，在G1/S转变过程中，依赖Cln2p/CDc28p的Tus1p的磷酸化是Rho1p适当的时空激活所必需的。
Rho1p is an essential small GTPase that plays a key role in the morphogenesis of Saccharomyces cerevisiae. We show here that the activation of Rho1p is regulated by a cyclin-dependent kinase (CDK). Rho1p is activated at the G1/S transition at the incipient-bud sites by the Cln2p (G1 cyclin) and Cdc28p (CDK) complex, in a process mediated by Tus1p, a guanine nucleotide exchange factor for Rho1p. Tus1p interacts physically with Cln2p/Cdc28p and is phosphorylated in a Cln2p/ Cdc28p-dependent manner. CDK phosphorylation consensus sites in Tus1p are required for both Cln2p-dependent activation of Rho1p and polarized organization of the actin cytoskeleton. We propose that Cln2p/Cdc28p-dependent phosphorylation of Tus1p is required for appropriate temporal and spatial activation of Rho1p at the G1/S transition.