Putative Phosphorylation Sites On WCA Domain of HA2 Is Essential For Helicoverpa armigera Single Nucleopolyhedrovirus Replication  

作　　者：Yi-pin Lv Qian Wang Chun-chen Wu Rong-juan Pei Yuan Zhou Yun Wang Xin-wen Chen 

机构地区：[1]Key Laboratory of Agricultural and Enviromental Microbiology, Wuhan Institute of I~rology, Chinese Academy of Sciences, Wuhan, 430071, China [2]Graduate University of the Chinese Academy of Sciences, Beijing, 100039, China [3]Department of Biochemistry ＆ Molecular Biology, Nanjing Medical University, Nanjing 210029, China.

出　　处：《Virologica Sinica》2011年第4期245-251,共7页中国病毒学（英文版）

基　　金：National Nature Science Foundations of China (31030027,30770085 and 30800044)

摘　　要：Protein phosphorylation is one of the most common post-translational modification processes that play an essential role in regulating protein functionality.The Helicoverpa armigera single nucleopolyhedrovirus (HearNPV) orf2-encoded nucleocapsid protein HA2 participates in orchestration of virus-induced actin polymerization through its WCA domain,in which phosphorylation status are supposed to be critical in respect to actin polymerization.In the present study,two putative phosphorylation sites (232Thr and 250Ser) and a highly conserved Serine (245Ser) on the WCA domain of HA2 were mutated,and their phenotypes were characterized by reintroducing the mutated HA2 into the HearNPV genome.Viral infectivity assays demonstrated that only the recombinant HearNPV bearing HA2 mutation at 245Ser can produce infectious virions,both 232Thr and 250Ser mutations were lethal to the virus.However,actin polymerization assay demonstrated that all the three viruses bearing HA2 mutations were still capable of initiating actin polymerization in the host nucleus,which indicated the putative phosphorylation sites on HA2 may contribute to HearNPV replication through another unidentified pathway.Protein phosphorylation is one of the most common post-translational modification processes that play an essential role in regulating protein functionality. The Helicoverpa armigera single nucleopolyhedrovirus （HearNPV） orf2-encoded nucleocapsid protein HA2 participates in orchestration of virus-induced actin polymerization through its WCA domain, in which phosphorylation status are supposed to be critical in respect to actin polymerization. In the present study, two putative phosphorylation sites （^232Thr and ^250Ser） and a highly conserved Serine （^245Ser） on the WCA domain of HA2 were mutated, and their phenotypes were characterized by reintroducing the mutated HA2 into the HearNPV genome. Viral infectivity assays demonstrated that only the recombinant HearNPV bearing HA2 mutation at ^245Ser can produce infectious virions, both ^232Thr and ^250Ser mutations were lethal to the virus. However, actin polymerization assay demonstrated that all the three viruses bearing HA2 mutations were still capable of initiating actin polymerization in the host nucleus, which indicated the putative phosphorylation sites on HA2 may contribute to HearNPV replication through another unidentified pathway.

关 键 词：Helicoverpa armigera single nucleopolyhedrovirus （HearNPV） Actin polymerization Protein phosphorylation N-WASP 

分 类 号：S513.01[农业科学—作物学] TQ341.2[化学工程—化纤工业]