Structural Mechanisms of Alphavirus Membrane Fusion

甲病毒膜融合的结构机制

基本信息

批准号：
10444088
负责人：
Wei Zhang
金额：
$ 39.34万
依托单位：
UNIVERSITY OF MINNESOTA
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-04-22 至 2027-03-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10444088
关键词：
Address Affect Alphavirus Antiviral Therapy Area Arthritis Back Biochemical Biochemistry Biological Assay Biological Models Biophysics Capsid Cells Cellular Membrane Centrifugation Chimeric Proteins Complex Cryo-electron tomography Cryoelectron Microscopy Deposition Disease Disease Outbreaks Drops Early Endosome Economic Burden Encephalitis Endosomes Environment Equus caballus Event Flavivirus Glycoproteins Goals Human Human papillomavirus 16 E1 protein Image In Vitro Knowledge Length Lipid Bilayers Liposomes Mediating Membrane Membrane Fusion Membrane Lipids Methods Modeling Molecular Molecular Conformation Molecular Structure Mutagenesis Mutation Orthobunyavirus Play Process Proteins RNA Viruses Reaction Recurrence Research Role Rubella virus Sindbis Virus Site Structural Models Structural Protein Structure System Testing Vaccine Therapy Viral Viral Envelope Proteins Viral Genome Virus Virus Assembly Virus Diseases Work antiviral drug development base insight mutant novel organizational structure prevent protein structure prototype receptor receptor mediated endocytosis recombinant virus uptake virus envelope

项目摘要

Alphaviruses, a group of enveloped RNA viruses, cause persistent arthritis and encephalitis among horses and humans. Currently, no licensed vaccine or antiviral therapy is available to prevent or cure the disease. A critical step in enveloped virus infection is membrane fusion between the viral and the host cellular membranes, a process leading to cytoplasmic delivery of the viral genome. Alphaviruses enter the host cell via receptor- mediated endocytosis. The viral E1 protein mediates membrane fusion through conformational changes upon acidification in the early endosomes. The other viral envelope protein, E2, functions as a molecular chaperon for the E1 protein during virus assembly and plays a role in virus capsid core uptake at the budding site and release after membrane fusion. We have obtained exciting, unprecedented images that captured robust alphavirus membrane fusion events with target liposomes by cryo-electron microscopy. Using coordinated biochemical, biophysical, cryo-electron microscopy, and cryo-electron tomography methods, we will investigate the molecular structures of the E1 and E2 proteins in a prototype alphavirus, Sindbis virus, at specific fusion stages. We will test specific predictions about the alphavirus membrane fusion mechanism based on our structural results by generating and characterizing mutants of the glycoproteins. We will test the fusion function of key mutations in the context of recombinant viruses. Completing this research will advance our understanding about how alphavirus glycoproteins promote membrane fusion.

甲病毒是一组有包膜的 RNA 病毒，可在马和人类中引起持续性关节炎和脑炎。目前，尚无获得许可的疫苗或抗病毒疗法可用于预防或治愈该疾病。有包膜病毒感染的关键步骤是病毒和宿主细胞膜之间的膜融合，这是导致病毒基因组进入细胞质的过程。甲病毒通过受体介导的内吞作用进入宿主细胞。病毒 E1 蛋白通过早期内体酸化时的构象变化介导膜融合。另一种病毒包膜蛋白 E2 在病毒组装过程中充当 E1 蛋白的分子伴侣，并在病毒衣壳核心在出芽位点的摄取和膜融合后的释放中发挥作用。我们获得了令人兴奋的、前所未有的图像，通过冷冻电子显微镜捕获了甲病毒与目标脂质体的膜融合事件。使用协调的生物化学、生物物理、冷冻电子显微镜和冷冻电子断层扫描方法，我们将研究原型甲病毒（辛德比斯病毒）在特定融合阶段的 E1 和 E2 蛋白的分子结构。我们将通过生成和表征糖蛋白突变体，根据我们的结构结果测试有关甲病毒膜融合机制的具体预测。我们将在重组病毒的背景下测试关键突变的融合功能。完成这项研究将加深我们对甲病毒糖蛋白如何促进膜融合的理解。