芜菁花叶病毒（TuMV）是农业生产上危害最重要的病毒之一。前期研究发现TuMV复制酶蛋白NIb与寄主细胞核输出蛋白XPO1互作。单独表达NIb和XPO1都位于细胞核与细胞质中，但是病毒侵染使它们聚集在病毒复制复合物中。本项目将开展以下研究：鉴定NIb与XPO1互作关键结构域，分析NIb细胞核输出对病毒侵染的重要性，分析XPO1及其关键结构域在介导NIb细胞核输出及TuMV复制和侵染中的重要作用，解析SUMO化修饰是否是决定XPO1介导NIb细胞核输出的分子开关。研究结果将会揭示NIb细胞核输出的机理及SUMO化修饰在XPO1介导的NIb细胞核输出及病毒侵染中的作用，为TuMV的防治提供新思路和新靶标。

Turnip mosaic virus (TuMV) is one of the most devastating viruses in agricultural production. Our previous results showed that the TuMV replicase NIb interacted with XPO1, a nuclear exportin, and NIb or XPO1 alone was localized in the nucleus and cytoplasm, while they aggregated in the viral replication complexes (VRCs) in the cytoplasm during viral infection. These following-up work would be done in this project: mapping the interaction motif and the key sub-cellular localization motif of NIb and XPO1; revealing the significance of NIb nuclear export in TuMV infection; analyzing the role of XPO1 and its key domains in mediating the nuclear export of NIb and VRCs in the replication and infection of TuMV; clarifying the scientific significance of the interaction between NIb and XPO1 in TuMV infection; analyzing whether SUMO modification is the molecular switch that determines XPO1-mediated the nuclear export of NIb. These study will reveal the mechanism of NIb nuclear export and the role of SUMO modification in XPO1-mediated NIb nuclear export and TuMV infection, and provide new ideas and targets for the prevention and treatment of TuMV.