Human cellular protein nucleoporin hNup98 interacts with influenza A virus NS2/nuclear export protein and overexpression of its GLFG repeat domain can inhibit virus propagation
Human cellular protein nucleoporin hNup98 interacts with influenza A virus NS2/nuclear export protein and overexpression of its GLFG repeat domain can inhibit virus propagation
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DOI：
10.1099/vir.0.022681-0
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发表时间：
2010-10-01
影响因子：
3.8
通讯作者：
Chen, Ze
中科院分区：
文献类型：
--
作者：
Chen, Jingjing;Huang, Shengping;Chen, Ze
A型流感病毒的非结构蛋白NS 2（nuclear export protein），又称核输出蛋白NS 2，含有一个富含亮氨酸的核输出信号，可以引导病毒核糖核蛋白穿过核孔复合体（nuclear pore complex，NPC），完成定向的核质运输。在本研究中，通过使用酵母双杂交筛选人cDNA文库，将NPC蛋白质人核孔蛋白98（hNup 98）鉴定为NS 2结合蛋白，并在酵母和哺乳动物细胞中证实了NS 2和hNup 98之间的相互作用。进一步的作图实验表明，NS 2 N端22-53位氨基酸和甘氨酸-亮氨酸-苯丙氨酸-甘氨酸（GLGG）重复结构域的氨基酸序列与NS 2的氨基酸序列一致。共聚焦显微镜显示hNup 98可以特异性地将NS 2募集到核仁中，并且该过程被来普霉素B抑制，一种人染色体区域维持1蛋白的特异性抑制剂。NS 2通过hNup 98的N-末端GLFG重复结构域募集到核仁，但不通过C-末端结构域。此外，流感病毒感染显著下调293 T和Madin-Darby犬肾细胞中的Nup 98水平。hNup 98的GLFG重复结构域的过表达明显抑制病毒繁殖。hNup 98的GLFG重复结构域可能竞争性地抑制NS 2与内源性hNup 98的相互作用，从而抑制病毒的增殖
The non-structural protein NS2, also called nuclear export protein, of influenza A virus contains a leucine-rich nuclear-export signal that could guide viral ribonucleoproteins to cross the nuclear pore complex (NPC) and complete directional nucleocytoplasmic trafficking. In this study, human nucleoporin 98 (hNup98), an NPC protein, was identified as an NS2-binding protein by using yeast two-hybrid screening of a human cDNA library Interaction between NS2 and hNup98 was confirmed in yeast and mammalian cells. Mapping tests further demonstrated that aa 22-53 in the N-terminal region of NS2 and the glycine-leucine-phenylalanine-glycine (GLFG) repeat domain (aa 1-511) of hNup98 are crucial for the interaction of these two proteins Confocal microscopy showed that hNup98 could specifically recruit NS2 to the nucleoli and that this process was inhibited by leptomycin B, a specific inhibitor of human chromosomal region maintenance 1 protein. NS2 recruitment to the nucleoli was through the N-terminal GLFG repeat domain of hNup98, but not through the C-terminal domain Moreover, influenza virus infection downregulated Nup98 levels significantly in 293T and Madin-Darby canine kidney cells Overexpression of the GLFG repeat domain of hNup98 apparently inhibited virus propagation Together, these findings reveal the interaction between hNup98 and NS2 The GLFG repeat domain of hNup98 might competitively inhibit the interaction between NS2 and endogenous hNup98, consequently inhibiting virus propagation