许多单正链RNA病毒如寨卡病毒 (Zika virus)、肠道病毒（Enterovirus）及丙型肝炎病毒（HCV）等对人类健康产生重大威胁。其复制策略高度保守即在特定的宿主膜表面组装病毒的复制复合体，是有效的抗病毒靶点。前期研究我们发现VCP作为HCV复制复合体结合蛋白可能参与病毒复制复合体组装。近期有报道VCP可能调控肠道病毒及黄病毒属病毒成员复制，但机制未知。VCP属于一种AAA＋ATPase，通过水解ATP催化底物构想变化。本研究拟解析VCP调控HCV复制复合体组装的分子机制，鉴定其作用的病毒底物及参与其作用的宿主辅助因子；在此基础上进一步探讨VCP是否以相似机制调控脊髓灰质炎病毒（PV）及黄热病病毒（YFV）复制，并鉴定其作用于PV及YFV的病毒靶点。本研究以期找到VCP作用于一类单正链RNA病毒复制调控的可能的共同机制，为靶向VCP及其作用底物作为广谱抗病毒策略提供理论依据。

The positive-strand RNA viruses are the largest class of viruses and include many medical and economically important pathogens, including hepatitis C virus (HCV); Picornavirueses, which cause hand-foot and mouth disease; and Flaviviruses, such as the west nile virus (WNV) and the zika virus (ZIKV). Positive-strand RNA viruses share a conserved replication mechanism, in which viral proteins induce host membrane modification to assemble membrane-associated viral replication complexes (RCs). Viruses hijack host factors to facilitate this energy unfavorable process. The formation of the RC represents a load-and-choke point of the viral life cycle and may serves as an attractive anti-viral target. In a previous study, using HCV as a model, by affinity purification of the viral replicase, we identified the viral replicase associated host factors and uncovered an ATPases associated with diverse cellular activities (AAA+ATPase) family member, Valosin-containing protein (VCP) as a pivotal host factor that is required for viral replication, depending on its ATPase activity. VCP is recruited to and co-localizes with HCV nonstructural protein clustering sites and inhibition of VCP alters HCV NS5A distribution as judged by fluorescence microscopy in an HCV replicase assembly surrogate system, suggesting a role of VCP in HCV replicase assembly. Very recently, it has been reported that VCP plays a role in west nile virus (WNV) replication and a human genome-wide RNAi screening also identifies VCP to be involved in enterovirus 71 (EV71) replication. While the molecular mechanisms of VCP in these virus replication remains elusive. The AAA+ proteins use their ATPase activity to catalyze conformational changes in diverse substrate proteins. While VCP barely exhibits substrate specificity, it employs a large number of cofactors for temporal and spatial regulation. In this study, we will use VCP pharmacological inhibitors and shRNA-mediated knockdown to inhibit VCP function and then dissect the molecular mechanisms of VCP in HCV viral replicase assembly, to identify the VCP viral substrate and the involving host cofactors for VCP. Meanwhile, we will take polio virus (PV) and yellow fever virus (YFV) as examples, to investigate the roles of VCP in these viruses replication. Understanding the molecular mechanism of VCP regulating viral replication complex may facilitate developing a pan-antiviral strategy by targeting the most conserved viral replication steps.