Heat Shock Protein 72 Is Associated with the Hepatitis C Virus Replicase Complex and Enhances Viral RNA Replication
Heat Shock Protein 72 Is Associated with the Hepatitis C Virus Replicase Complex and Enhances Viral RNA Replication
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DOI：
10.1074/jbc.m110.118323
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发表时间：
2010-09-03
影响因子：
4.8
通讯作者：
Hwang, Lih-Hwa
中科院分区：
文献类型：
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作者：
Chen, Yin-Ju;Chen, Yu-Hsuan;Hwang, Lih-Hwa
丙型肝炎病毒（HCV）的NS5A蛋白是病毒复制酶的一个组成部分。它还可以调节细胞信号传导并干扰宿主干扰素反应。NS5A的多功能特性主要归因于其与多种细胞蛋白相互作用的能力。本研究旨在鉴定与NS5A相互作用的新细胞因子，并破译这种相互作用在病毒复制中的意义。通过串联亲和纯化（TAP）从表达NS5A的细胞中纯化NS5A相互作用蛋白，并进行质谱鉴定。本文鉴定了伴侣蛋白Hsp72。体内蛋白-蛋白相互作用通过共免疫沉淀和原位接近结扎实验验证。除NS5A外，Hsp72还与复制酶复合体的其他成员NS3和NS5B相关，提示它可能直接参与HCV复制复合体。Hsp72通过增加复制酶复合体的水平，在HCV RNA复制中发挥着积极的调节作用，这可能是由于复制酶复合体中病毒蛋白的稳定性增加，或者是由于HCV内部核糖体进入位点的翻译活性增强。宿主伴侣蛋白Hsp72参与HCV RNA复制的事实可能代表了控制病毒产生的治疗靶点。
The NS5A protein of the hepatitis C virus (HCV) is an integral component of the viral replicase. It also modulates cellular signaling and perturbs host interferon responses. The multifunctional characteristics of NS5A are mostly attributed to its ability to interact with various cellular proteins. This study aimed to identify the novel cellular factors that interact with NS5A and decipher the significance of this interaction in viral replication. The NS5A-interacting proteins were purified by the tandem affinity purification (TAP) procedure from cells expressing NS5A and identified by mass spectrometry. The chaperone protein Hsp72 was identified herein. In vivo protein-protein interaction was verified by co-immunoprecipitation and an in situ proximity ligation assay. In addition to NS5A, Hsp72 was also associated with other members of the replicase complex, NS3 and NS5B, suggesting that it might be directly involved in the HCV replication complex. Hsp72 plays a positive regulatory role in HCV RNA replication by increasing levels of the replicase complex, which was attributed either to the increased stability of the viral proteins in the replicase complex or to the enhanced translational activity of the internal ribosome entry site of HCV. The fact that the host chaperone protein Hsp72 is involved in HCV RNA replication may represent a therapeutic target for controlling virus production.