鸭TRIM25 介导RIG-I信号通路泛素化的调控机制

研究表明，鸭的RIG-I基因（鸡基因组缺失）是鸡和鸭对流感病毒敏感性差异的重要原因，但鸭RIG-I在体内是如何发挥作用，其机制不清楚。大量研究证实，泛素化修饰广泛参与了免疫通路调节，本课题组前期研究也发现鸭泛素连接酶TRIM25直接参与RIG-I信号通路的激活。因此推测TRIM25可能介导RIG-I信号通路的靶分子泛素化，活化信号通路，发挥抗病毒效应。基于此，本项目拟采用5'ppp-dsRNA体外模拟病毒感染（RIG-I能优先识别禽流感等病毒的5'ppp RNA序列），确定TRIM25在RIG-I信号通路中的作用位置（靶分子），进一步揭示 TRIM25介导的靶分子泛素化水平的影响，重点探索TRIM25介导的靶分子泛素化作用位点及其对IFN-β产生的影响。研究将全面阐明鸭TRIM25 介导的RIG-I信号通路泛素化调控机制，也为进一步探明鸡和鸭对禽流感敏感性差异提供一定的科学依据。

Studies have proposed that the RIG-I gene (present in ducks and absent in chickens) might underlie the differences in avian influenza virus immunity between chickens and ducks. However, it remains unclear how the RIG-I gene works in antiviral innate immunity. It is known that ubiquitination has important roles in regulation of the immune pathway extensively. Our previous work found that the duck ubiquitin ligase TRIM25 involved in the activation of RIG-I signaling pathway. We speculate that TRIM25-mediated regulation of RIG-I signaling by ubiquitination in duck. In this study, the 5'ppp-dsRNA is used to mimic virus infection in vitro. Firstly, the TRIM25-mediated ubiquitination of target genes is confirmed on basis of identification of the position in RIG-I signaling. Furthermore, the ubiquitination sites of the target gene are explored and the ubiquitination sites of TRIM25-mediated are verified by detecting IFN-β production. These studies will understand further the molecular mechanism of TRIM25-mediated regulation of RIG-I signaling by ubiquitination, and provide a scientific basis of different sensitivity of the influenza virusbetween chickens and ducks.