Influenza Hemagglutinin: Structure, Dynamics, and Cooperativity During Fusion

流感血凝素：融合过程中的结构、动力学和协同性

• 批准号: 7404454
• 负责人: Kelly Keisen Lee
• 金额: $ 9万
• 依托单位: SCRIPPS RESEARCH INSTITUTE, THE
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-04-15 至 2009-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7404454
• 关键词: 3-Dimensional; Area; Bacteriophages; Binding; Biological; Capsid; Cell membrane; Cell-Matrix Junction; Cells; Cellular Membrane; Cessation of life; Chimeric Proteins; Cleaved cell; Complex; Data; Detergents; Docking; Ebola virus; Elements; Event; Exhibits; FUS-1 Protein; Fluorescence Microscopy; Genome; Glycoproteins; Goals; HIV; Hemagglutinin; Hospitalization; Human; Human Parainfluenza Virus 1; Individual; Infection; Influenza; Influenza A virus; Influenza Hemagglutinin; Invaded; Length; Lipid Bilayers; Lipids; Macromolecular Complexes; Mass Spectrum Analysis; Measurement; Measures; Mediating; Membrane; Membrane Fusion; Methods; Modeling; Molecular Conformation; Monitor; Movement; Neutrons; Pathway interactions; Peptides; Population; Process; Proteins; Range; Refractory; Relative (related person); Research; Research Personnel; Resolution; Roentgen Rays; Shapes; Solutions; Solvents; Structure; Surface; Testing; Time; Transmembrane Domain; United States; Variant; Viral; Virion; Virus; Virus Diseases; base; density; influenzavirus; insight; monomer; particle; pathogen; receptor mediated endocytosis; reconstitution; reconstruction; research study

DESCRIPTION (provided by applicant) Project Summary: Influenza A virus is a paradigm for understanding viral entry of host cells via receptor-mediated endocytosis. We seek to deepen our understanding of viral membrane fusion in order to identify possible strategies for interfering with the process and arresting the infection cycle. The hemagglutinin (HA) protein mediates fusion of the virus and host cell membranes. HA shares core elements with other type-1 fusion proteins such as those found in Ebola virus and HIV. While certain facets of HA-mediated fusion have been characterized, significant gaps remain in the characterization of the molecular conformations that actually drive membrane fusion, in our understanding of how HA changes conformation, and in our understanding of the interplay between fusion protein and membrane deformation. We propose to use solution X-ray and neutron scattering with ab initio shape reconstruction to determine the structure and dynamics of the hemagglutinin assembly both for isolated HA and HA that is interacting with lipid bilayers. By docking known high resolution structures of components into the solution scattering-derived shape envelopes, pseudoatomic models will be composed. This type of integrative approach is necessary for characterization of complex macromolecular machines. The experiments will provide unique insight into the conformational trajectory traversed by HA as it converts from metastable to fusion-active form, determine whether membrane-bound HA exhibits a propensity to assemble into pore complexes, and elucidate resultant changes in membrane structure. In addition, single-particle fluorescence microscopy will be used to reveal the functional context of HA when it is arrayed on the viral membrane. This approach will identify whether the hundreds of HA spikes on the virus surface become fusion-active in a cooperative fashion. Relevance: Influenza virus is a major human pathogen that in a typical year infects 5-20% of the population of the United States and results in more than 200,000 hospitalizations and approximately 36,000 deaths. The proposed research seeks to gain a detailed understanding of the function of the hemagglutinin machinery that influenza uses to invade new host cells. Such an understanding is necessary in order to identify how best to interfere with the mechanism and to arrest the cycle of viral infection.

描述（由申请人提供） 项目摘要：甲型流感病毒是了解病毒通过受体介导的内吞作用进入宿主细胞的范例。我们寻求加深对病毒膜融合的理解，以确定干扰该过程和阻止感染周期的可能策略。血凝素（HA）蛋白介导病毒和宿主细胞膜的融合。 HA 与其他 1 型融合蛋白（例如埃博拉病毒和 HIV 中发现的融合蛋白）共享核心元件。虽然HA介导的融合的某些方面已经得到表征，但在实际驱动膜融合的分子构象的表征、我们对HA如何改变构象的理解以及我们对融合蛋白和膜变形之间相互作用的理解方面仍然存在显着差距。我们建议使用溶液 X 射线和中子散射从头开始形状重建来确定分离的 HA 和与脂质双层相互作用的 HA 的血凝素组装的结构和动力学。通过将组件的已知高分辨率结构对接到解散射衍生的形状包络中，将组成伪原子模型。这种类型的综合方法对于复杂大分子机器的表征是必要的。这些实验将为 HA 从亚稳态转变为融合活性形式时所经历的构象轨迹提供独特的见解，确定膜结合的 HA 是否表现出组装成孔复合物的倾向，并阐明由此产生的膜结构变化。此外，单颗粒荧光显微镜将用于揭示HA排列在病毒膜上时的功能背景。这种方法将确定病毒表面的数百个 HA 尖峰是否以协作方式变得融合活跃。 相关性：流感病毒是一种主要的人类病原体，每年会感染 5-20% 的美国人口，导致超过 200,000 人住院治疗，约 36,000 人死亡。拟议的研究旨在详细了解流感用来侵入新宿主细胞的血凝素机制的功能。为了确定如何最好地干扰该机制并阻止病毒感染的周期，这种理解是必要的。