RNA-dependent RNA Synthesis by the Hepatitis C Virus

描述（由申请人提供）：丙型肝炎病毒（HCV）感染了大约2%的世界人口，是美国肝脏移植的主要原因。基于从艾滋病等疾病中吸取的经验教训，HCV RNA复制是抗病毒药物开发的一个有希望的靶点。然而，人们对所有带正链RNA基因组的病毒的复制知之甚少，特别是在生化水平上。Kao实验室研究的总体目标是了解RNA病毒复制的机制。

DESCRIPTION (provided by applicant): Hepatitis C virus (HCV) infects approximately 2% of the world's population and is the primary cause of liver transplants in the United States. Based on lessons learned from diseases such as AIDS, HCV RNA replication is a promising target for antiviral development. However, the replication of all viruses with plus-strand RNA genomes is poorly understood, especially at the biochemical level. The overall goal of the research in the Kao lab is to understand mechanism of RNA virus replication. The goal for this project is to build knowledge about the subunits of the HCV replication complex, with emphasis on protein-RNA, and protein-protein interactions. This is an extension of the past six years of research in the Kao lab, where a number of basic properties of the HCV polymerase and the HCV protease-helicase have been examined using biochemical, biophysical, and cell-based methods. The research can be partitioned into several related subaims that will: 1. Identify and validate the biological importance of the residues in the HCV RdRp that interacts with the substrate NTPs, the template RNA, and during different stages of HCV RNA synthesis. 2. Elucidate the interactions between the HCV RdRp and the nascent RNA and identify and characterize the nascent RNA exit channel. 3. Examine the protein-protein and protein-RNA interactions with other replicase- associated subunits of the HCV replicase and examine effects of the interactions on HCV replicase formation in cells. 4. Obtain images of the protein complexes using electron microscopy and reconstruct their structures. Results from this proposal will advance the understanding of the mechanism of viral RNA-dependent RNA synthesis for ALL positive-strand RNA viruses. The knowledge can also be used to compare the mechanisms of action of all template-dependent (both viral and cellular) polymerases.