Molecular functions of the Ssk1 osmo-regulator in the yeast HOG MAPK pathway

酵母 HOG MAPK 通路中 Ssk1 渗透调节因子的分子功能

• 批准号: 17570105
• 负责人: TATEBAYASHI Kazuo
• 金额: $ 2.24万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2005
• 资助国家: 日本
• 起止时间: 2005 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17570105/
• 关键词: yeast; stress response; high osmolarity; MAP kinase cascade; HOG pathway; signal transduction; 酵母; MAPキナーゼ; リン酸化; Ssk1; Ssk2; Ssk22

Yeast Ste11 MAPKKK takes part in three different MAPK signaling modules that respond to, respectively, mating pheromones, osmostress, and nutritional conditions. Nevertheless, each MAPK pathway is activated only by the cognate stimulus. To investigate how osmostress activates only the Hog1 MAP kinase module (HOG pathway), we isolated and characterized constitutively activated alleles in three key genes involved in the pathway, namely STE11, STE50, and SHO1. We found that Cdc42 not only activates the upstream kinases in the HOG pathway, Ste20 and Cla4, but also binds to Ste11-bound Ste50, thereby bringing activated Ste20/Cla4 and their substrate Ste11 together. Subsequently, activated Ste11 and its HOG pathway-specific substrate, Pbs2 MAPKK, are brought together by binding of the Ste50-Ste11 complex to the cytoplasmic domain of Sho1, to which Pbs2 is also bound. Thus, both Sho1 and Ste50 act as adaptive docking proteins that restrict the flow of the osmostress signal from Ste20/Cla4 to Pbs2, via Ste11.

酵母Ste11 MAPKKK参与了三个不同的MAPK信号模块，分别对交配信息素、渗透胁迫和营养条件做出反应。然而，每个MAPK通路只被同源刺激激活。为了研究渗透胁迫如何仅激活Hog1 MAP激酶模块(HOG途径)，我们分离并鉴定了参与该途径的三个关键基因，即STE11、STE50和SHO1中的结构性激活等位基因。我们发现，CDC42不仅能激活HOG途径上游的蛋白激酶Ste20和Cla4，而且还能与Ste11结合，从而将激活的Ste20/Cla4与其底物Ste11结合在一起。随后，通过将Ste50-Ste11复合体与Sho1的细胞质结构域结合，激活的Ste11与其HOG途径特异性底物PBS2 MAPKK结合在一起，PBS2也与Sho1结合。因此，Sho1和Ste50都作为适应性对接蛋白，通过Ste11限制渗透胁迫信号从Ste20/Cla4到PBS2的流动。

项目成果

Adaptor functions of Cdc42, Ste50, and Shol in the yeast osmoregulatory HOG MARK pathway

Cdc42、Ste50 和 Shol 在酵母渗透调节 HOG MARK 通路中的适配器功能

• 发表时间: 2006
• 期刊: The EMBO Journal 25
• 作者: Tatebayashi K;Yamamoto K;Tanaka K;Tomida T;Maruoka T;Kasukawa E;Saito H;Tatebayashi K
• 通讯作者: Tatebayashi K

Conserved docking site is essential for activation of mammalian MAP kinase kinases by specific MAP kinase kinase kinases

• DOI: 10.1016/j.molcel.2005.04.001
• 发表时间: 2005-04-29
• 期刊: MOLECULAR CELL
• 影响因子: 16
• 作者: Takekawa, M;Tatebayashi, K;Saito, H
• 通讯作者: Saito, H

Adaptor functions of Cdc42, Ste50, and Sho1 in the yeast osmoregulatory HOG MAPK pathway

• DOI: 10.1038/sj.emboj.7601192
• 发表时间: 2006-07
• 期刊: The EMBO Journal
• 作者: K. Tatebayashi;Katsuyoshi Yamamoto;Keiichiro Tanaka;T. Tomida;Takashi Maruoka;Eri Kasukawa;H. Saito