家蚕杆状病毒蛋白Bm65的核酸内切酶活性分析及在病毒与宿主抗紫外线辐射中的作用

Bombyx mori nucleopolyhedrovirus (BmNPV) orf65 (Bm65) is an essential gene for viral propagation, and predicted to be an endonuclease involved with the repair of DNA damage by UV light. Our recent evidences indicate that Bm65 is important for BmNPV and BmNPV-infected cells to resist UV irradiation. To test whether Bm65 is able to repair this damage and what other components are implicated in this repair pathway, we will perform the following experiments in the project: (1) Determination of the endonuclease activity of Bm65 in vitro; (2) Analysis of the roles of Bm65 in the UV irradiation; (3) Analysis of Bm65 expression and identification of the interaction proteins with the BmNPV-infected BmN cells under UV-irradiating and normal conditions. This study is helpful for understanding the molecular mechanism of BmNPV to resist UV irradiation and the interactions between virus and host, which is important for controlling the spread of viral infection and application of BmNPV-based anti-pest drug.

申请者前期研究表明BmNPV orf65为病毒增殖的必需基因，预测为与紫外线损伤修复有关的核酸内切酶。过表达Bm65的重组病毒经过相同剂量的紫外线（UV）处理后，较野生型病毒增殖更快。过表达Bm65重组病毒感染的家蚕细胞较未感染及被野生型病毒感染的细胞，表现出对紫外线更强的耐受性。鉴于以上前期基础，本项目拟开展(1) 体外鉴定Bm65的核酸内切酶活性；(2)Bm65的核酸内切酶活性对病毒及宿主细胞抗紫外线辐射的作用研究；(3) 紫外线辐射下，Bm65的表达情况及其互作蛋白的鉴定。该研究有助于了解杆状病毒抗紫外线途径及理解紫外线辐射下病毒与宿主的关系，从而为防控与改造杆状病毒、创建新型杆状病毒生物杀虫剂及优化杆状病毒表达系统提供理论依据。