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 这项建议研究了丝裂原蛋白，它同时催化线粒体拴系和外链。 膜融合。线粒体的形状是线粒体功能的核心，并与 发育、应激和衰老过程中的细胞生理学。线粒体融合增加了新陈代谢产物， 防止线粒体过度降解，降低细胞对凋亡刺激的敏感性，并 允许受损细胞器的功能互补。线粒体功能受损和 细胞器连接性降低与神经退行性变和其他年龄相关疾病有关。 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、视神经萎缩、肌病和共济失调。线粒体分裂和线粒体 融合是由保守的Dynamin超家族蛋白介导的。这个不同的机械力化学家族 GTP酶将自组装和构象变化与整个细胞膜重塑事件联系在一起。 手机。Mitofusin是线粒体外膜融合机，必须在 单细胞膜，跨两个线粒体。分子细节，包括组成的分子 这些组件，它们的形成的调节，以及它们如何有助于膜系留和融合 都是未知的。我们利用丝裂原功能的生化分析来解决这些知识上的差距。在……里面 目的1，我们将阐明控制丝裂原装配成融合的变构调节机制。 有能力的复合体。我们收集的功能变体和新颖方法将提供一个强大的工具 在解剖每个丝裂原蛋白功能域对顺式齐聚和反式复合体的贡献时 队形。我们的工作揭示了CMT2A相关的丝裂原变异体的分子缺陷 丝裂霉素可被细胞内的胞浆因子所补偿。在目标2中，我们使用了一种简化论的方法 结合细胞生物学、生物化学和我实验室开发的重组分析来确定 胞内丝裂原蛋白效应物BAX和MSTO1改变丝裂蛋白组装以调节线粒体融合。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，并将 不仅为线粒体动力学提供基本见解，也为动力机制提供基础见解 一般情况下，超家族蛋白质起作用。