An OsCEBiP/OsCERK1-OsRacGEF1-OsRac1 Module Is an Essential Early Component of Chitin-Induced Rice Immunity
An OsCEBiP/OsCERK1-OsRacGEF1-OsRac1 Module Is an Essential Early Component of Chitin-Induced Rice Immunity
复制标题
DOI：
10.1016/j.chom.2013.03.007
复制
发表时间：
2013-04-17
影响因子：
30.3
通讯作者：
Shimamoto, Ko
中科院分区：
文献类型：
--
作者：
Akamatsu, Akira;Wong, Hann Lin;Shimamoto, Ko
OsCEBiP是几丁质结合蛋白，OsCERK 1是受体样激酶，是质膜（PM）蛋白，它们形成了水稻中真菌几丁质驱动的免疫反应所必需的受体复合物。几丁质感知后立即发生的信号传导事件尚不清楚。研究了水稻小GTbaseOsRac 1的时空调控，发现几丁质诱导OsRac 1在PM快速激活。寻找OsRac 1相互作用，我们确定OsRacGEF 1作为一个鸟嘌呤核苷酸交换因子OsRac 1。OsRacGEF 1与OsCERK 1相互作用，并在其C-末端S549被OsCERK 1的胞质结构域磷酸化时被激活，以响应几丁质。活化的OsRacGEF 1是几丁质驱动的免疫应答和抗稻瘟病真菌感染所必需的。此外，包括OsCERK 1和OsRacGEF 1的蛋白质复合物从内质网转运到PM。总的来说，我们的研究结果表明，OsCEBiP，OsCERK 1，OsRacGEF 1和OsRac 1的功能作为一个“防御体”的关键组成部分，在几丁质诱导的免疫早期关键参与。
OsCEBiP, a chitin-binding protein, and OsCERK1, a receptor-like kinase, are plasma membrane (PM) proteins that form a receptor complex essential for fungal chitin-driven immune responses in rice. The signaling events immediately following chitin perception are unclear. Investigating the spatiotemporal regulation of the rice small GTPase OsRac1, we find that chitin induces rapid activation of OsRac1 at the PM. Searching for OsRac1 interactors, we identified OsRacGEF1 as a guanine nucleotide exchange factor for OsRac1. OsRacGEF1 interacts with OsCERK1 and is activated when its C-terminal S549 is phosphorylated by the cytoplasmic domain of OsCERK1 in response to chitin. Activated OsRacGEF1 is required for chitin-driven immune responses and resistance to rice blast fungus infection. Further, a protein complex including OsCERK1 and OsRacGEF1 is transported from the endoplasmic reticulum to the PM. Collectively, our results suggest that OsCEBiP, OsCERK1, OsRacGEF1, and OsRac1 function as key components of a "defensome" critically engaged early during chitin-induced immunity.