Li Xiao-Dan, Ye Han-Qing, Deng Cheng-Lin, Liu Si-Qing, Zhang Hong-Lei, Shang Bao-Di, Shi Pei-Yong, Yuan Zhi-Ming, Zhang Bo
Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China.
Key Laboratory of Agricultural and Environmental Microbiology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China.
J Gen Virol. 2015 Jun;96(Pt 6):1264-1275. doi: 10.1099/vir.0.000044. Epub 2015 Jan 9.
Flavivirus NS4A and NS4B are important membrane proteins for viral replication that are assumed to serve as the scaffold for the formation of replication complexes. We previously demonstrated that a single Lys-to-Arg mutation at position 79 in NS4A (NS4A-K79R) significantly impaired Japanese encephalitis virus (JEV) replication. In this study, the mutant virus was subject to genetic selection to search for the potential interaction between NS4A and other viral components. Sequencing of the recovered viruses revealed that, in addition to an A97E change in NS4A itself, a Y3N compensatory mutation located in NS4B had emerged from independent selections. Mutagenesis analysis, using a genome-length RNA and a replicon of JEV, demonstrated that both adaptive mutations greatly restored the replication defect caused by NS4A-K79R. Our results, for the first time to our knowledge, clearly showed the genetic interaction between NS4A and NS4B, although the mechanism underlying their interaction is unknown.
黄病毒NS4A和NS4B是病毒复制的重要膜蛋白，被认为是复制复合体形成的支架。我们之前证明，NS4A第79位的单个赖氨酸到精氨酸突变（NS4A-K79R）显著损害了日本脑炎病毒（JEV）的复制。在本研究中，对突变病毒进行遗传筛选以寻找NS4A与其他病毒成分之间的潜在相互作用。对回收病毒的测序显示，除了NS4A自身的A97E变化外，位于NS4B的Y3N补偿性突变也从独立筛选中出现。使用JEV的基因组长度RNA和复制子进行的诱变分析表明，这两个适应性突变都极大地恢复了由NS4A-K79R引起的复制缺陷。据我们所知，我们的结果首次清楚地表明了NS4A和NS4B之间的遗传相互作用，尽管它们相互作用的机制尚不清楚。
