Heat Shock Protein 70 Modulates Influenza A Virus Polymerase Activity
Heat Shock Protein 70 Modulates Influenza A Virus Polymerase Activity
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DOI：
10.1074/jbc.m113.507798
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发表时间：
2014-03-14
影响因子：
4.8
通讯作者：
Takada, Ayato
中科院分区：
文献类型：
--
作者：
Manzoor, Rashid;Kuroda, Kazumichi;Takada, Ayato
研究背景：热休克蛋白70（Hsp 70）在甲型流感病毒复制过程中起重要作用。结果：Hsp 70的核质穿梭与病毒复制/转录活性相关。结论：Hsp 70可调节甲型流感病毒聚合酶活性。重要性：这项研究首次表明，热休克蛋白70（Hsp 70）实际上可能有助于甲型流感病毒的复制。已知Hsp 70在流感病毒复制中的抑制作用是基于在具有不同Hsp 70表达水平的细胞中进行的研究。在这项研究中，我们确定了Hsp 70在HeLa和HEK 293 T细胞中流感病毒复制中的作用，这些细胞组成型表达Hsp 70。免疫共沉淀和免疫荧光研究表明，Hsp 70与PB 2或PB 1单体以及PB 2/PB 1异二聚体相互作用，但不与PB 1/PA异二聚体或PB 2/PB 1/PA异三聚体相互作用，并与PB 2单体或PB 2/PB 1异二聚体一起进入细胞核。敲低Hsp 70导致病毒转录和复制活性降低。来自感染细胞的核和胞质部分的报告基因测定、免疫荧光测定和蛋白质印迹分析表明，在热休克期期间病毒聚合酶活性的增加伴随着核中Hsp 70和病毒聚合酶水平的增加，其中流感病毒复制发生，而病毒聚合酶活性的降低伴随着Hsp 70沿着病毒聚合酶的胞质再定位的增加。此外，在热休克期观察到的病毒基因组RNA（vRNA）水平显著高于恢复期。总的来说，第一次，这些研究结果表明，热休克蛋白70可能作为一个伴侣的流感病毒聚合酶，和热休克蛋白70的调节作用似乎是一个续集之间的穿梭热休克蛋白70的核和细胞质的隔间。
Background: It has been shown that heat shock protein 70 (Hsp70) plays a role in influenza A virus replication. Results: A correlation between viral replication/transcription activities and nuclear/cytoplasmic shuttling of Hsp70 was observed. Conclusion: Hsp70 modulates the influenza A virus polymerase activity. Significance: This study, for the first time, suggests that Hsp70 may actually assist in influenza A virus replication.The role of heat shock protein 70 (Hsp70) in virus replication has been discussed for many viruses. The known suppressive role of Hsp70 in influenza virus replication is based on studies conducted in cells with various Hsp70 expression levels. In this study, we determined the role of Hsp70 in influenza virus replication in HeLa and HEK293T cells, which express Hsp70 constitutively. Co-immunoprecipitation and immunofluorescence studies revealed that Hsp70 interacted with PB2 or PB1 monomers and PB2/PB1 heterodimer but not with the PB1/PA heterodimer or PB2/PB1/PA heterotrimer and translocated into the nucleus with PB2 monomers or PB2/PB1 heterodimers. Knocking down Hsp70 resulted in reduced virus transcription and replication activities. Reporter gene assay, immunofluorescence assay, and Western blot analysis of nuclear and cytoplasmic fractions from infected cells demonstrated that the increase in viral polymerase activity during the heat shock phase was accompanied with an increase in Hsp70 and viral polymerases levels in the nuclei, where influenza virus replication takes place, whereas a reduction in viral polymerase activity was accompanied with an increase in cytoplasmic relocation of Hsp70 along with viral polymerases. Moreover, significantly higher levels of viral genomic RNA (vRNA) were observed during the heat shock phase than during the recovery phase. Overall, for the first time, these findings suggest that Hsp70 may act as a chaperone for influenza virus polymerase, and the modulatory effect of Hsp70 appears to be a sequel of shuttling of Hsp70 between nuclear and cytoplasmic compartments.