Function and mechanism of the HCV p7 channel and its therapeutic potential

HCV p7通道的功能、机制及其治疗潜力

• 批准号: 9198039
• 负责人: JAMES Jeiwen CHOU
• 金额: $ 46.4万
• 依托单位: HARVARD MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9198039
• 关键词: Address; Adopted; Antiviral Agents; Architecture; Binding; Binding Sites; Biological Assay; Biology; Calcium; Calcium Channel; Capsid; Cations; Chronic; Complex; Consensus; Data; Drug Interactions; Elements; Environment; Hepatitis C; Integral Membrane Protein; Investigation; Ions; Knowledge; Life Cycle Stages; Link; Liver diseases; Measurement; Mediating; Membrane; Methods; Molecular; Molecular Conformation; Molecular Virology; Mutagenesis; Mutation; Names; Nature; Pathogenicity; Pharmaceutical Chemistry; Pharmaceutical Preparations; Production; Proteins; Protons; RNA; RNA Viruses; Reading; Reporting; Research; Resistance; Role; Site; Structure; System; Therapeutic; Titrations; Viral; Viral Genome; Viral Proteins; Virion; Virus; Virus Assembly; Virus Diseases; Work; base; drug development; experimental study; extracellular; inhibitor/antagonist; insight; interdisciplinary approach; molecular dynamics; mutant; novel; protein protein interaction; public health relevance; small molecule; structural biology; synergism; virology

 DESCRIPTION (provided by applicant): Many viral genomes encode small integral membrane proteins that form channels in membrane, and they conduct protons, cations, and other molecules across the membrane barrier to aid various steps of viral entry and maturation. These viral proteins, collectively named viroporins, are crucial for viral pathogenicity and have been pursued as antiviral targets. The viroporin p7 encoded by the Hepatitis C virus (HCV) genome is one of the more important viral channels that has been validated as a target for developing drugs for treating HCV infections. p7 is an integral membrane protein that oligomerizes to form channels with cation selectivity, for Ca2+ over other cations; it has been shown to facilitate assembly and egress of infectious virions. The name "viroporin" assigned to p7 suggests a simple pore until our lab showed in Ouyang et al Nature 2013 that p7 adopts a rather sophisticated mode of hexameric assembly. The novel architecture implies a new channel mechanism developed by the HCV, but at present, the structural bases for Ca2+ selectivity and ion conduction are unknown. It has been shown that blocking p7 channel activity reduces production of infectious viral progeny, and several compounds have already been identified. These drug interactions should provide useful information for rational drug development, but there is no information on how and where these compounds act in the p7 channel. Furthermore, despite the consensus that p7 channel activity is important for virus production, it remains unclear in which of the steps of assembly and release is the role of channel activity required. We will capitalize on the recent p7 channel structure and utilize a multidisciplinary approach involving structural biology, channel recording, molecular virology, and medicinal chemistry to address these key questions. In Aim 1, we will determine the structure of the p7 channel in bicelles, identify key residues important for cation binding and conduction, and investigate conformational exchange relevant to the conduction mechanism. In Aim 2, we will separate the channel activity of p7 from its role in protein-protein interaction through mutagenesis to understand the role of p7 channel activity during virus infection. Finally in Aim 3, we will identiy the inhibitor binding sites, delineate mechanism of inhibition, and explore strategies to develop new inhibitors. The knowledge to be gained from the proposed research may give rise to new opportunities for developing compounds for treating HCV infections.

 描述（由适用提供）：许多病毒基因组编码在膜上形成通道的小型整合膜蛋白，并在整个膜屏障中进行蛋白质，阳离子和其他分子进行蛋白质，阳离子和其他分子，以帮助病毒进入和成熟的各个步骤。这些病毒蛋白统称为病毒蛋白，对病毒致病性至关重要，并已被作为抗病毒药靶标。由丙型肝炎病毒（HCV）基因组编码的Viropolin P7是最重要的病毒通道之一，已被验证为开发用于治疗HCV感染的药物的靶标。 P7是一种积分的膜蛋白，对于其他阳离子而言，Ca2+以阳离子的选择性形成通道。已显示它可以促进传染病的组装和出口。分配给P7的“ Viroporin”这个名称表明了一个简单的孔，直到我们在Ouyang等人自然2013中展示的P7采用相当软化的六聚体组装模式为止。新型结构意味着HCV开发的新通道机制，但目前，Ca2+选择性和离子传导的结构碱基尚不清楚。已经表明，阻断P7通道活性降低了传染性病毒进展的产生，并且已经鉴定出几种化合物。这些药物相互作用应为合理的药物开发提供有用的信息，但是没有关于这些化合物在P7通道中如何和何处的信息。此外，努力共识，即P7通道活性对病毒的产生很重要，尚不清楚组装和释放的步骤是所需的通道活动的作用。我们将利用最近的P7通道结构，并利用涉及结构生物学，通道记录，分子病毒学和药物化学的多学科方法来解决这些关键问题。在AIM 1中，我们将确定Bicelles中P7通道的结构，确定密钥对阳离子结合和传导保持重要，并研究与传导机制相关的会议交换。在AIM 2中，我们将通过诱变将P7的通道活性与其在蛋白质蛋白质相互作用中的作用分开，以了解P7通道活性在病毒感染中的作用。最后，在AIM 3中，我们将确定抑制剂结合位点，描述抑制作用机制，并探索开发新抑制剂的策略。从拟议的研究中获得的知识可能会带来开发用于治疗HCV感染的化合物的新机会。