4月8日,国际学术期刊《Emerg Microbes Infect》在线发表了病毒学国家重点实验室陈新文研究组的最新研究成果。论文题为Genetic and biochemicalcharacterizations of Zika virus NS2A protein(寨卡病毒NS2A蛋白的遗传和生化特征),该工作揭示了寨卡病毒非结构蛋白2A(Nonstructural protein 2A,NS2A)的膜拓扑结构并鉴定了其在病毒RNA复制以及病毒粒子装配中发挥的功能。
ABSTRACT:Zika virus (ZIKV) can cause devastating congenital Zika syndromes in pregnant women and Guillain-Barre syndrome in adults. Understanding the molecular mechanism of ZIKV replication is essential for antiviral and vaccine development. Here we report the structural and functional characterization of ZIKV NS2A protein. Biochemical structural probing suggests that ZIKV NS2A has a single segment that traverses the ER membrane and six segments that peripherally associate with the ER membrane. Functional analysis has defined distinct NS2A residues essential for viral RNA synthesis or virion assembly. Only the virion assembly-defective mutants, but not the RNA synthesis-defective mutants, could be rescued through trans complementation with a wide-type NS2A protein. These results suggest that the NS2A molecules in virion assembly complex could be recruited in trans, whereas the NS2A molecules in viral replication complex must be recruited in cis. Together with previous results, we propose a flavivirus assembly model where NS2A plays a central role in modulating viral structural and nonstructural proteins as well as genomic RNA during virion assembly.