Characteristics of Nucleocytoplasmic Transport of H1N1 Influenza A Virus Nuclear Export Protein
Characteristics of Nucleocytoplasmic Transport of H1N1 Influenza A Virus Nuclear Export Protein
复制标题
H1N1甲型流感病毒核输出蛋白的核质转运特征。
DOI：
10.1128/jvi.00257-14
复制
发表时间：
2014-07-01
影响因子：
5.4
通讯作者：
Liu, Wenjun
中科院分区：
文献类型：
--
作者：
Gao, Shengyan;Wang, Shanshan;Liu, Wenjun
甲型流感病毒核输出蛋白(NEP)通过染色体区域维护1(CRM1)介导的细胞蛋白转运系统，在病毒核糖核蛋白复合体的核输出中发挥重要作用。然而，NEP核质转运的详细机制仍不完全清楚。在这里，我们研究了两株H1N1甲型流感病毒NEP的亚细胞定位，发现2009年猪源H1N1甲型流感病毒A/California/04/2009(CA04)NEP与A/WSN/33(H1N1)(WSN)NEP相比，表现出不同的细胞分布模式，形成独特的核聚集体。对这两种NNP的核质转运途径的研究表明，它们都是以被动扩散的方式进入细胞核，但通过核输出受体CRM1介导的途径输出的效率不同。这两个非核糖核酸上的核输出信号(NESS)功能相似，尽管它们的氨基酸序列不同。使用双杂交分析，我们证实了CA04NEP与CRM1的相互作用效率较低，并且第48位的苏氨酸残基负责核聚集。本研究揭示了2009年大流行(H1N1)甲型流感病毒CA04与实验室适应的H1N1病毒WSN在亚细胞内NEP转运过程的不同，并揭示了导致这种差异的机制。
The influenza A virus nuclear export protein (NEP) plays crucial roles in the nuclear export of the viral ribonucleoprotein complex through the chromosome region maintenance 1 (CRM1)-mediated cellular protein transport system. However, the detailed mechanism of NEP nucleocytoplasmic trafficking remains incompletely understood. Here, we investigated the subcellular localization of NEP from two strains of H1N1 influenza A virus and found that 2009 swine-origin H1N1 influenza A virus A/California/ 04/2009 (CA04) NEP displayed a distinct cellular distribution pattern, forming unique nuclear aggregates, compared to A/WSN/33 (H1N1) (WSN) NEP. Characterization of the nucleocytoplasmic transport pathways of these two NEPs showed that they both enter the nucleus by passive diffusion but are exported through the nuclear export receptor CRM1-mediated pathway with different efficiencies. The two identified nuclear export signals (NESs) on the two NEPs functioned similarly despite differences in their amino acid sequences. Using a two-hybrid assay, we confirmed that the CA04 NEP interacts less efficiently with CRM1 and that a threonine residue at position 48 is responsible for the nuclear aggregation. The present study revealed the dissimilarity in subcellular NEP transport processes between the 2009 pandemic (H1N1) influenza A virus CA04 and the laboratory- adapted H1N1 virus WSN and uncovered the mechanism responsible for this difference.