Mechanisms of Membrane Fusion

膜融合机制

• 批准号: 10646379
• 负责人: WILLIAM Tobey WICKNER
• 金额: $ 77.89万
• 依托单位: DARTMOUTH COLLEGE
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-07-01 至 2026-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10646379
• 关键词: Bacteria; Binding Proteins; Biological Assay; Biological Models; Cells; Complex; Cytolysis; Development; Elements; Genes; Goals; Hormone secretion; Human; Humulus; In Vitro; Individual; Infection; Invaded; Lipid Bilayers; Lipids; Lysosomes; Membrane; Membrane Fusion; Molecular Chaperones; Pathway interactions; Process; Protein Array; Proteins; Role; SNAP receptor; Structure; Vacuole; Virus; Yeasts; catalyst; cell growth; drug development; human disease; insight; neurotransmission; novel; pathogen; pathogenic bacteria; pathogenic virus; proteoliposomes; reconstitution; Bacteria; Binding Proteins; Biological Assay; Biological Models; Cells; Complex; Cytolysis; Development; Elements; Genes; Goals; Hormone secretion; Human; Humulus; In Vitro; Individual; Infection; Invaded; Lipid Bilayers; Lipids; Lysosomes; Membrane; Membrane Fusion; Molecular Chaperones; Pathway interactions; Process; Protein Array; Proteins; Role; SNAP receptor; Structure; Vacuole; Virus; Yeasts; catalyst; cell growth; drug development; human disease; insight; neurotransmission; novel; pathogen; pathogenic bacteria; pathogenic virus; proteoliposomes; reconstitution

Project Summary/Abstract Membrane fusion is essential for cell growth, hormone secretion, neurotransmission, and cell invasion by pathogens. Membrane fusion mechanisms are conserved from yeast to humans. We have developed yeast vacuole fusion as a model system, identifying genes for membrane fusion, establishing an in vitro fusion assay with purified vacuoles, and purifying each relevant protein and lipid for reconstitution into proteoliposomes which faithfully reconstitute each aspect of fusion. These studies have revealed novel elements, most recently: 1. A dazzling array of proteins and lipids which cooperate for orderly lipid bilayer strain and rearrangement, giving fusion without lysis. 2. The assembly of complexes among membrane-bound proteins termed "SNAREs" isn't spontaneous, as heretofore believed. Their assembly is actually catalyzed by a large hexameric complex termed HOPS, which recognizes each of the individual SNAREs and assembles them in active intermediates, poised for rapid fusion. 3. Chaperones to the SNAREs, termed NSF/Sec18 and aSNAP/Sec17, which had been believed to only function to disassemble SNARE complexes after fusion, also promote fusion. 4. Lipids have a vital and active role in fusion. Each of these mechanistic insights will be pursued; our goals for the next 5 years are to understand the intermediates of HOPS-catalyzed SNARE assembly, their structures, the roles of chaperones Sec17/Sec18, and how these proteins trigger the lipid rearrangements of fusion. The importance of understanding this pathway is underscored by the central role of HOPS in the invasion of human cells by pathogenic viruses and bacteria.

项目摘要/摘要 膜融合对于细胞生长，激素分泌，神经传递，至关重要， 病原体的细胞侵袭。膜融合机制是由 酵母对人类。我们已经开发了酵母液泡融合作为模型系统， 识别膜融合的基因，建立具有纯化的体外融合测定 液泡，并净化每种相关蛋白质和脂质以重建为 忠实地重建融合的各个方面的蛋白质体。这些研究有 揭示了新颖的元素，最近：1。一系列令人眼花over乱的蛋白质和脂质 合作以使脂质双层菌株和重排有序，无裂解而进行融合。 2。膜结合的蛋白质中复合物的组装称为“贪食” 正如迄今为止所相信的那样，不是自发的。他们的组装实际上是由 大型六聚体复合物称为啤酒花，它识别每个个体 圈圈和组装在活跃的中间体中，并准备快速融合。 3。 被称为NSF/sec18和ASNAP/SEC17的网罗的伴侣 认为仅在融合后才能拆卸圈套复合物，也促进 融合。 4。脂质在融合中具有重要和积极的作用。这些机制中的每一个 洞察力将被追求；我们接下来5年的目标是了解 啤酒花催化的军鼓组件的中间体，它们的结构，角色 伴侣Sec17/sec18，以及这些蛋白质如何触发脂质重排 融合。理解这一途径的重要性是由中心角色强调的 通过致病病毒和细菌侵袭人类细胞的啤酒花。