磷酸酶Cdc25A抑制RIG-I介导的抗病毒天然免疫信号通路的机制

项目名称： 磷酸酶Cdc25A抑制RIG-I介导的抗病毒天然免疫信号通路的机制

项目编号： No.31470774

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 生物科学

项目作者： 王烨涛

作者单位： 中国科学院微生物研究所

项目金额： 85万元

中文摘要： RIG-I介导的天然免疫反应是宿主抗病毒的重要防御机制。我们发现磷酸酶Cdc25A能显著下调RIG-I介导的信号通路的激活；进一步的研究表明，Cdc25A能够干扰RIG-I下游MAVS信号复合体的形成。为了揭示Cdc25A负调控RIG-I信号通路的机制，我们拟开展以下研究：（1）利用过表达和RNA干扰等方法结合实时定量PCR，进一步验证Cdc25A对RIG-I信号通路的抑制作用；（2）构建Cdc25A点突变或缺失突变体，分析Cdc25A磷酸酶活性对RIG-I信号通路的影响，定位其发挥抑制功能的结构域；（3）研究Cdc25A在RIG-I信号通路中的作用节点及影响MAVS信号复合体形成的机制；（4）分析病毒感染对Cdc25A表达水平、定位以及磷酸酶活性的影响，探究Cdc25A与病毒激活的天然免疫之间的相关性。拟通过上述研究阐明Cdc25A负调控RIG-I信号通路的机制及其在抗病毒免疫中的作用。

中文关键词： 磷酸酶Cdc25A；去磷酸化；RIG-I信号通路；天然免疫；蛋白质相互作用

英文摘要： RIG-I (Retinoic acid-inducible gene-I) mediated innate immune signaling plays a critical role in activating host response to RNA virus infections. RIG-I pathway is controlled by both positive and negative regulators. We identified that phosphatase Cdc25A (cell division cycle 25 A) can inhibit the activation of IFN? promoter induced by Sendai virus infection. Further analysis indicated that Cdc25A can interact with RIG-I, MAVS and TRAF6. We also found that over-expression of Cdc25A interferes with the interaction between MAVS and TBK1. To further investigate the molecular mechanisms of how Cdc25A regulates RIG-I pathway, we propose to address the following issues:（1）To confirm the inhibitory effect of Cdc25A on RIG-I signaling pathway by luciferase reporter assay and real-time PCR.（2）To examine whether Cdc25A phosphartase activity is required for regulating the RIG-I pathway and to analyze which domain of Cdc25A is critical for its function; (3) To investigate the molecular mechanism of how Cdc25A affects the formation of MAVS signalsome. (4) To analyze the dynamic correlation between the protein level, localization and the activity of phosphatase of Cdc25A and RNA virus infection or the activation of RIG-I pathway. We expect to reveal the molecular mechanisms of Cdc25A in negatively regulating the RIG-I mediated innate immune signaling during RNA virus infection.

英文关键词： phosphatase Cdc25A;dephosphorylation;RIG-I signal pathway;innate immunity;protein interaction