New regulatory mechanisms for the intracellular localization and trafficking of influenza A virus NS1 protein revealed by comparative analysis of A/PR/8/34 and A/Sydney/5/97
New regulatory mechanisms for the intracellular localization and trafficking of influenza A virus NS1 protein revealed by comparative analysis of A/PR/8/34 and A/Sydney/5/97
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DOI：
10.1099/vir.0.024943-0
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发表时间：
2010-12-01
影响因子：
3.8
通讯作者：
Zhang, Xian-En
中科院分区：
文献类型：
--
作者：
Han, Han;Cui, Zong-Qiang;Zhang, Xian-En
在甲型流感病毒感染过程中，NS1蛋白在不同的细胞内发挥不同的功能，在Madin-Darby犬肾细胞中瞬时表达时，A/PR/8/34的NS1基因定位于与A/悉尼/5/97不同的位置。NS1的221个残基被鉴定为参与A/悉尼/5/97嵌合NS1的C末端核定位信号(NLS)和核仁定位信号(NOLS)的一个新的关键残基。进一步的突变体分析表明，负责NS1与裂解结合的残基和多聚腺苷化特异性因子(CPSF)与光漂白成像中瞬时表达的NS1蛋白的细胞内定位丢失相关药物抑制实验和荧光共振能量转移分析表明，NS1蛋白是通过CRM1不依赖的途径输出到细胞核外的。这些发现为甲型流感病毒NS1蛋白的胞内定位和转运机制提供了新的见解，这对理解其功能具有重要意义。
During influenza A virus infection, the NS1 protein is engaged in different functions in different intracellular compartments In this study, we showed that the NS1 of A/PR/8/34 localized in different positions from that of A/Sydney/5/97 when transiently expressed in Madin-Darby canine kidney cells Residue 221 of NS1 was identified to be a new key residue involved in the C-terminal nuclear localization signal (NLS) and nucleolar localization signal (NoLS) of NS1 from A/Sydney/5/97 Analysis of chimeric NS1 and further mutants showed that residues responsible for the binding between NS1 and the cleavage and polyadenylation specificity factor (CPSF) are correlated with the intracellular localization of transiently expressed NS1 proteins Fluorescence loss in photobleaching imaging revealed that the NS1 protein with both functional NLSs and nuclear export signal (NES) was able to shuttle between the nucleus and cytoplasm Drug inhibition experiments and fluorescence resonance energy transfer analysis suggested that NS1 was exported out of the cell nuclei via a Crm1-independent pathway Moreover, it is likely that another cytoplasmic localization-related sequence exists in the NS1 protein other than the leucine-rich NES These findings provide new insights into the mechanism of intracellular localization and trafficking of influenza A virus NS1 protein, which is important for understanding its function