Subversion of hepatocyte phosphoinositide metabolism by hepatitis C virus

丙型肝炎病毒破坏肝细胞磷酸肌醇代谢

• 批准号: 8417277
• 负责人: Andrew W. Tai
• 金额: $ 33.82万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-03-13 至 2018-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8417277
• 关键词: 1-Phosphatidylinositol 4-Kinase; Accounting; Adverse drug effect; Affect; Antiviral Agents; Area; Binding; Binding Proteins; Biochemical; Cells; Cellular Membrane; Cholesterol; Chronic Hepatitis C; Clinical; DNA Sequence Rearrangement; Drug Targeting; Family Picornaviridae; Generations; Goals; Health Benefit; Hepatitis C; Hepatitis C virus; Hepatitis C-Like Viruses; Hepatocyte; Human; Imaging Techniques; Individual; Integration Host Factors; Internet; Lead; Life; Life Cycle Stages; Lipids; Liver Failure; Liver diseases; Membrane; Membrane Proteins; Metabolism; Modeling; Molecular; Names; PIK4CB gene; Peripheral; Pharmaceutical Preparations; Phosphatidylinositols; Phosphotransferases; Physiological; Population; Primary carcinoma of the liver cells; Proteins; Public Health; RNA Interference; RNA Viruses; RNA replication; Recruitment Activity; Regulation; Research; Role; Serine Protease; Structure; Testing; Therapeutic Agents; United States National Institutes of Health; Viral; Viral Proteins; Virus; Virus Replication; base; cofactor; design; innovation; inorganic phosphate; insight; liver transplantation; membrane activity; novel; novel strategies; novel therapeutics; oxysterol binding protein; particle; phosphatidylinositol 4-phosphate; public health relevance; therapeutic development; treatment response; viral resistance

DESCRIPTION (provided by applicant): Chronic hepatitis C virus (HCV) infection develops in 70-80% of all exposed individuals and affects 3% of the world's population. While new drugs that directly target the viral NS3-4A serine protease have been approved for clinical use this year, there remains a need for more effective and better-tolerated HCV therapies. Our long- term goals are to define host-HCV molecular interactions and in so doing, to identify novel therapeutic agents for HCV therapy. HCV, like all other positive-sense single-stranded RNA viruses studied to date, induces the formation of specific membranous structures (called membranous webs) within infected cells for its own replication. Multiple RNAi screens have identified a critical role for a host protein phosphatidylinositol 4-kinase (PI 4-kinase) named PI4KA in HCV replication, most likely at the level of membranous web formation. Intriguingly, three other positive-sense single-stranded RNA viruses subvert the related PI 4-kinase PI4KB for their own replication. The objective of this proposal is to understand how the host hepatocyte protein PI4KA and its product PI 4-phosphate (PI(4)P) support HCV replication. Our central hypothesis is that HCV replication requires the local generation of PI(4)P, which in turn is necessary for the recruitment of effector proteins to the nascent membranous web. The specific aims of the project are to (1) Define the functional domains of PI4KA and its regulation; (2) Identify the phosphoinositide-dependent steps in the HCV life cycle; (3) Identify and characterize downstream effectors of PI4KA and PI(4)P in the HCV life cycle. We will use a variety of biochemical, cell-based, and imaging techniques to accomplish the proposed research. The proposed research is innovative as (1) the model of web assembly presented in this proposal is novel; (2) the mechanisms by which PI4KA is regulated in the host cell and in the context of HCV replication have not been studied (Aim 1); (3) The mechanisms by which PI(4)P and other phosphoinositides support HCV replication has not been previously pursued (Aims 2 and 3); (4) The use of inducible and selective depletion of phosphoinositides (Aim 2) has not been previously used to study viral replication. We expect that the proposed research may have direct public health benefits, as a better understanding of the mechanisms by which PI4KA and host phosphoinositides support viral replication may lead to novel approaches to the treatment of chronic HCV infection. A better understanding of the HCV-host relationship is a stated goal of the NIH Action Plan for Liver Disease Research (Goal B2a). Moreover, completion of the proposed aims will also lead to new insights into the physiological functions and regulation of PI4KA, areas that are currently poorly understood.

描述（由申请人提供）：慢性丙型肝炎病毒（HCV）感染在70-80％的暴露个人中发展，并影响全球3％的人口。虽然今年已批准了直接针对病毒NS3-4A丝氨酸蛋白酶的新药物用于临床使用，但仍需要更有效且耐受性更好的HCV疗法。我们的长期目标是定义宿主 - HCV分子相互作用，并在这样做时确定新型的HCV治疗剂。与迄今为止研究的所有其他阳性单链RNA病毒一样，HCV诱导感染细胞中特定膜结构（称为膜网）的形成，以进行自身的复制。多个RNAi筛选已经确定了宿主蛋白磷脂酰肌醇4-激酶（PI 4-激酶）在HCV复制中称为PI4KA的关键作用，最有可能在膜的Web形成水平上。有趣的是，其他三个阳性单链RNA病毒颠覆了相关的PI 4-激酶PI4KB，以进行自身的复制。该建议的目的是了解宿主肝细胞蛋白PI4KA及其产物PI 4-磷酸（PI（4）P）如何支持HCV复制。我们的核心假设是HCV复制需要局部生成PI（4）P，而PI（4）P又需要将效应蛋白募集到新生的膜膜中所必需。该项目的具体目的是（1）定义PI4KA的功能域及其调节； （2）在HCV生命周期中确定磷酸肌醇依赖性步骤； （3）在HCV生命周期中识别并表征PI4KA和PI（4）P的下游效应子。我们将使用各种生化，基于细胞的成像技术来完成拟议的研究。拟议的研究具有创新性，因为（1）本提案中提出的Web组装模型是新颖的； （2）尚未研究在宿主细胞和HCV复制中调节PI4KA的机制（AIM 1）； （3）以前没有追求PI（4）P和其他磷酸肌醇支持HCV复制的机制（AIMS 2和3）； （4）以前尚未使用诱导和选择性耗竭的磷酸肌醇（AIM 2）来研究病毒复制。我们预计拟议的研究可能具有直接的公共卫生益处，因为对PI4KA和宿主磷酸肌醇支持病毒复制的机制有了更好的理解，可能会导致治疗慢性HCV感染的新方法。对HCV-host关系的更好理解是NIH肝病研究计划的明确目标（目标B2A）。此外，拟议的目标的完成还将导致对PI4KA的生理功能和调节的新见解，PI4KA是目前知之甚少的地区。