大麦条纹花叶病毒γb蛋白促进病毒运动和病毒粒子装配的分子机制研究

大麦条纹花叶病毒（BSMV）是一种重要的模式病毒，属于正义单链RNA病毒，它编码的γb蛋白在寄主的防御与病毒的反防御博弈中有多重功能。最近，我们又报道了γb的几个新功能：γb通过抑制寄主ROS的迸发而促进病毒的侵染；γb磷酸化既抑制RNA沉默又抑制寄主的细胞死亡反应；γb蛋白还与病毒复制酶αa直接互作促进病毒的复制。但是，作为重要的病毒学问题，我们既不清楚γb是否还与其他BSMV蛋白互作并调控病毒的运动和粒子装配，也不清楚γb蛋白是否还存在其他翻译后修饰。根据γb还分别与运动蛋白TGB1和外壳蛋白CP直接互作、γb存在棕榈酰化修饰的最新结果，本项目拟对γb通过γb-TGB1互作及γb棕榈酰化修饰促进病毒的运动，和γb-CP互作促进病毒粒子装配及稳定性等科学问题开展系统的研究。本研究将有助于揭示γb蛋白在病毒运动和粒子装配以及病毒-寄主植物互作中的更多未知功能及其分子机理。

The model Barley stripe mosaic virus (BSMV) is a positive single-stranded RNA virus. The γb protein encoded by BSMV has multiple functions in the arm race of host defense and viral counter-defense. Recently, we have reported several novel functions of γb protein: (1) γb inhibits peroxisomal ROS production by interacting with glycolate oxidase to facilitate virus infection; (2) PKA-mediated phosphorylation of γb suppresses both RNA silencing and host cell death response; (3) γb protein is recruited to viral replication sites through interactions with the αa replicase protein where it enhances αa helicase activity to increase the levels of BSMV replication. However, it is unclear whether γb protein interacts with other BSMV proteins to regulate viral movement and virion assembly, and whether γb protein has other post-translational modifications. The latest results from my laboratory found that γb protein also directly interacted with viral movement protein (TGB1) and coat protein (CP), while the palmitoylation modification of the γb protein has been identified in vivo and in vitro. In this proposal, further research on how γb protein promotes virus cell-to-cell movement by interaction with TGB1 and palmitoylation modification of the γb protein, and how γb protein promotes virion assembly and stability though interacting with CP will be carried out. The results will shed more light on our understanding of more novel functions of γb protein in virus movement and virion assembly, and the molecular mechanism of virus-host interactions.