Determining the mechanism of mitochondrial outer membrane fusion

确定线粒体外膜融合的机制

• 批准号: 10441835
• 负责人: Suzanne C Hoppins
• 金额: $ 33.53万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-02-01 至 2026-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10441835
• 关键词: Address; Aging; Allosteric Regulation; Apoptotic; Ataxia; Automobile Driving; Behavior; Binding; Binding Proteins; Biochemical; Biochemistry; Biological Assay; Biology; Blood Coagulation Factor VII; Cell physiology; Cells; Cellular biology; Collection; Complement; Complex; Cytoplasmic Protein; Cytosol; Data; Defect; Development; Disease; Dynamin; Event; Family; Fluorescence Resonance Energy Transfer; Foundations; GTP Binding; Genes; Goals; Guanosine Triphosphate; Guanosine Triphosphate Phosphohydrolases; Health; Homology Modeling; Hydrolysis; Impairment; Knowledge; Link; Maps; Mediating; Membrane; Membrane Fusion; Metabolic; Microtubules; Mitochondria; Modeling; Molecular; Molecular Conformation; Movement; Muscle; Mutation; Myopathy; Nerve Degeneration; Neurodegenerative Disorders; Neurons; Optic Atrophy; Organelles; Outer Mitochondrial Membrane; Pathway interactions; Patients; Peripheral Nervous System Diseases; Polymers; Positioning Attribute; Production; Property; Protein Dynamics; Proteins; Publishing; Regulation; Research; Shapes; Stimulus; Stress; Structure; Techniques; Testing; Transmembrane Domain; Tubulin; Variant; Work; age related; base; experimental study; flexibility; insight; mitochondrial dysfunction; novel; novel strategies; paralogous gene; pro-apoptotic protein; programs; reconstitution; self assembly; therapeutic development; tool

Project Summary This proposal examines the mitofusin proteins, which catalyze both mitochondrial tethering and outer membrane fusion. Mitochondrial shape is central to mitochondrial function and is closely linked to changes in cellular physiology during development, stress, and aging. Mitochondrial fusion increases metabolic production, protects against excessive degradation of mitochondria, reduces sensitivity of the cell to apoptotic stimuli and allows functional complementation of damaged organelles. Compromised mitochondrial function and decreased organelle connectivity are associated with neurodegeneration and other age-related diseases. Furthermore, mutations in the genes encoding components of the mitochondrial fusion machine cause peripheral neuropathy, optic atrophy, myopathy and ataxia. Both mitochondrial division and mitochondrial fusion are mediated by conserved dynamin superfamily proteins. This diverse family of mechanochemical GTPases couple self-assembly and conformational changes to membrane remodeling events throughout the cell. Mitofusin is the mitochondrial outer membrane fusion machine and must assemble both in cis within a single membrane, and in trans across two mitochondria. The molecular details, including of the composition of these assemblies, the regulation of their formation and how they contribute to membrane tethering and fusion are not known. We address these gaps in knowledge utilizing biochemical analyses of mitofusin function. In Aim 1, we will elucidate mechanisms of allosteric regulation that control assembly of mitofusin into fusion- competent complexes. Our collection of functional variants and novel approaches will provide a powerful tool in dissecting the contribution of each mitofusin functional domain to cis oligomerization and trans complex formation. Our work characterizing CMT2A-associated variants of mitofusin revealed that molecular defects of mitofusin can be compensated for by cytosolic factors in cells. In Aim 2, we use a reductionist approach that combines cell biology, biochemistry, and reconstituted assays developed in my lab to determine how the cytosolic mitofusin effectors Bax and MSTO1 alter mitofusin assembly to regulate mitochondrial fusion. This research program draws on our strengths in cellular and biochemical analysis of mitochondrial biology and will yield fundamental insights not only for mitochondrial dynamics but for the mechanisms through which dynamin superfamily proteins in general operate.

项目摘要 这项提议研究了线粒体融合蛋白，它催化线粒体的束缚和外部的 膜融合线粒体的形状是线粒体功能的核心，并与线粒体功能的变化密切相关。 发育、压力和衰老过程中的细胞生理学。线粒体融合增加了代谢产物， 防止线粒体过度降解，降低细胞对凋亡刺激的敏感性， 允许受损细胞器的功能互补。线粒体功能受损， 细胞器连接性的降低与神经变性和其他与年龄有关的疾病有关。 此外，编码线粒体融合机器组件的基因突变导致 周围神经病变、视神经萎缩、肌病和共济失调。线粒体分裂和线粒体 融合由保守的发动蛋白超家族蛋白介导。这个机械化学的多元化家族 GTP酶将自组装和构象变化偶联到整个细胞的膜重塑事件。 cell.线粒体融合素是线粒体外膜融合机器，并且必须在线粒体内顺式组装两者。 单个膜，并且反式跨越两个线粒体。分子细节，包括 这些组件，其形成的调节以及它们如何有助于膜束缚和融合 不知道。我们利用线粒体融合蛋白功能的生化分析来解决这些知识上的差距。在 目的1，我们将阐明控制丝裂融合蛋白组装成融合蛋白的变构调节机制。 competent complex.我们收集的功能变体和新方法将提供一个强大的工具 在剖析每个丝裂融合蛋白功能结构域对顺式寡聚化和反式复合物的贡献时， 阵我们的研究表明，线粒体融合蛋白的CMT2A相关变体的分子缺陷， 丝裂融合蛋白可以通过细胞中的胞质因子来补偿。在目标2中，我们使用简化方法， 结合了细胞生物学、生物化学和我实验室开发的重组分析， 胞质线粒体融合蛋白效应子Bax和MSTO 1改变线粒体融合蛋白装配以调节线粒体融合。这 研究计划利用我们在线粒体生物学的细胞和生化分析方面的优势， 不仅对线粒体动力学，而且对发动蛋白 超家族蛋白质一般都能运作。