Şenbaş Akyazi Burçak, Pirinçal Ayşegül, Kawaguchi Atsushi, Nagata Kyosuke, Turan Kadir
Department of Basic Pharmaceutical Sciences, Faculty of Pharmacy, Marmara University, İstanbul Turkey.
Department of Infection Biology, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba Japan.
Turk J Biol. 2020 Apr 2;44(2):82-92. doi: 10.3906/biy-1909-49. eCollection 2020.
Influenza A viruses have a single-stranded RNA genome consisting of 8 segments. Each RNA segment associates with the nucleoprotein (NP) and viral RNA polymerase to and from a viral ribonucleoprotein (vRNP) particle. The viral mRNA synthesis is dependent on a capped primer derived from nascent host RNA transcripts. For these processes to take place, vRNPs must pass through the cell nuclear pore complex (NPC) to the nucleus. The influenza A virus NS2 protein, also called the nuclear export protein (NES), has an important role in the nucleocytoplasmic transport of vRNPs. This protein interacts with the host cellular nucleoporins during the nuclear export of vRNPs. In this study, the human nucleoporin 214 (Nup214) was identified as an NS2-binding protein by using a yeast two-hybrid assay. The interaction between NS2 and human Nup214 was confirmed in both yeast and mammalian cells. It has been shown that the NS2 protein interacts with the amino terminal FG domain of the Nup214 protein. The influenza viral replication was suppressed in knockdown cells for the Nup214 protein. It was concluded that the FG domains of nucleoporins have an important role in the interaction of the influenza NS2 protein with host NPC for vRNA export.
甲型流感病毒具有由8个节段组成的单链RNA基因组。每个RNA节段与核蛋白（NP）和病毒RNA聚合酶结合形成病毒核糖核蛋白（vRNP）颗粒。病毒mRNA的合成依赖于源自新生宿主RNA转录本的带帽引物。为了使这些过程发生，vRNP必须通过细胞核孔复合体（NPC）进入细胞核。甲型流感病毒NS2蛋白，也称为核输出蛋白（NES），在vRNP的核质运输中起重要作用。该蛋白在vRNP的核输出过程中与宿主细胞的核孔蛋白相互作用。在本研究中，通过酵母双杂交试验鉴定出人核孔蛋白214（Nup214）为NS2结合蛋白。NS2与人Nup214之间的相互作用在酵母和哺乳动物细胞中均得到证实。已表明NS2蛋白与Nup214蛋白的氨基末端FG结构域相互作用。在敲低Nup214蛋白的细胞中，流感病毒复制受到抑制。得出的结论是，核孔蛋白的FG结构域在流感NS2蛋白与宿主NPC相互作用以进行vRNA输出中起重要作用。
