对虾白斑综合症病毒（WSSV）是危害我国对虾养殖业最主要的病原体。目前人们对WSSV利用宿主细胞达成自身增殖的机制仍缺乏全面的认识。对许多病毒的研究已表明，泛素化是病毒用于控制宿主的一个重要途径，与病毒增殖密切相关。我们在前期工作中发现WSSV极早期基因编码了一类具有Ring结构域的泛素连接酶，说明WSSV在感染早期很可能利用泛素化途径对宿主细胞进行调控。因此，本项目将以其中一个WSSV泛素连接酶WSV249为对象，通过对WSV249的生物学功能及转录调控机制的研究来解析泛素化途径在WSSV感染中所扮演的角色。主要内容包括筛选WSV249的泛素化底物蛋白，分析WSV249介导的底物蛋白泛素化过程对病毒增殖的影响；鉴定wsv249基因启动子中的关键调控元件以及与之结合的转录因子，解析wsv249基因的转录调控机制。本研究将有助于揭示WSSV对 宿主的操控机制，为白斑综合症的防治提共理论依据。

White spot syndrome virus (WSSV) is a major pathogen of aquacultured shrimp, but the detailed mechanism of how this virus manipulates the host cells during infection remains largely unclear. As a post-translational modification important for nearly every aspect of cellular physiology, ubiquitin becomes a attractive target for viruses. WSV249 is a Ring-domain E3 ubiquitin ligase encoded by a WSSV immediate early gene, which indicates the involvement of ubiquitination in the early stage of WSSV infection. The aim of this project is to reveal the biological function and the transcriptional regulation of WSV249. First we will screen for the substrates of WSV249 through yeast-two-hybrid or proteomic approaches. Then we will analyze how the WSV249-mediated ubiquitination affect WSSV replication by RNA interference. The key regulatary elements on wsv249 promoter and the transcription factors binds to them will also be explored to uncover the transcriptional regulation mechanism of wsv249 gene. This work will lead to a better understanding of how WSSV takes advantage of host ubiquitin system to favour their propagation and provide valuable clues for the disease control.