Defining the Allosteric Network of Stress-Responsive Mitochondrial Protease OMA1

应激反应线粒体蛋白酶 OMA1 的变构网络的定义

• 批准号: 10327312
• 负责人: Albert Sanghoon Song
• 金额: $ 3.38万
• 依托单位: SCRIPPS RESEARCH INSTITUTE, THE
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-02-01 至 2022-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10327312
• 关键词: Active Sites; Acute; Affect; Age; Aging; Amyotrophic Lateral Sclerosis; Architecture; Biochemical; Bioenergetics; Biological Assay; Cardiomyopathies; Catalytic Domain; Cell physiology; Cellular Stress; Charge; Chronic; Chronic stress; Cryoelectron Microscopy; Development; Disease; Equilibrium; Etiology; Face; Fluorescence-Activated Cell Sorting; Goals; Homo; In Vitro; Inner mitochondrial membrane; Intervention; Longevity; Mediating; Membrane; Membrane Proteins; Metabolic; Metalloproteases; Mitochondria; Mitochondrial Matrix; Modeling; Molecular; Molecular Conformation; Morphology; Mutation; N-terminal; Nerve Degeneration; Neurodegenerative Disorders; OPA1 gene; Pathogenesis; Pathologic; Peptide Hydrolases; Phenotype; Process; Proteolysis; Regulation; Reperfusion Injury; Role; Site; Stress; Structure; Structure-Activity Relationship; System; Therapeutic; Tissues; Zinc; acute stress; biological adaptation to stress; functional genomics; in silico; insight; interest; mitochondrial dysfunction; molecular modeling; multimodality; mutant; mutation screening; protein structure function; proteostasis; response; sensor; small molecule inhibitor; stress management; stress tolerance; structural biology; therapeutic target; transcription factor

PROJECT SUMMARY Systems to identify, endure, and respond to stress are critical for longevity and cellular function. As the hub of bioenergetic processes, mitochondria have an array of stress tolerance systems, one of which is comprised of proteases localized to the inner mitochondrial membrane (IMM). IMM proteases acutely manage stress, but chronic imbalances in the activity of IMM proteases contribute to mitochondrial dysfunction associated with ageing and etiologically-diverse age-associated diseases including many neurodegenerative disorders and cardiomyopathy. Remarkably, interventions to rescue and restore balance to IMM protease activity have demonstrated therapeutic benefit for mitigating pathologic mitochondrial dysfunction implicated in both acute and chronic age-associated diseases as well as lifespan extension. This multimodal therapeutic value has led to significant interest in defining the molecular mechanisms that drive IMM protease function. One central stress responsive IMM protease that remains understudied is the ATP-independent zinc metalloprotease OMA1. Basally inactive, OMA1 is activated in response to mitochondrial insults through a poorly defined mechanism. Active OMA1 site-specifically cleaves select IM substrates to protect mitochondria from acute mitochondrial insults through modulation of morphology and the activation of stress-responsive transcription factors. Despite the central role of OMA1 in mounting a mitochondrial stress response and its high therapeutic value, no structural information of OMA1 activation or proteolytic activity has been defined. Here, we integrate cryo-EM structure determination (Aim 1) and deep mutational scanning (Aim 2) to establish the first structure-function relationship for OMA1 activation and proteolytic activity. Through these efforts, we will define the molecular mechanism of OMA1 activation and proteolysis. This will reveal new insights into OMA1-dependent regulation of mitochondrial proteostasis and function and establish a structural basis to develop new strategies to therapeutically target OMA1 to mitigate pathologic mitochondrial dysfunction associated with ageing and ageing-associated neurodegeneration and cardiomyopathy.

项目摘要 识别、忍受和应对压力的系统对长寿和细胞功能至关重要。作为 在生物能量过程中，线粒体具有一系列应激耐受系统，其中之一包括 位于线粒体内膜（IMM）的蛋白酶。IMM蛋白酶能有效地控制压力， IMM蛋白酶活性的慢性失衡导致线粒体功能障碍， 衰老和病因多样的年龄相关疾病，包括许多神经退行性疾病， 心肌病值得注意的是，拯救和恢复IMM蛋白酶活性平衡的干预措施已经 证明了减轻急性和慢性粒细胞白血病中涉及的病理性线粒体功能障碍的治疗益处， 与年龄有关的慢性疾病以及延长寿命。这种多模式治疗价值导致 在定义驱动IMM蛋白酶功能的分子机制方面具有重大意义。一个中心应力 仍然未充分研究的响应性IMM蛋白酶是ATP非依赖性锌金属蛋白酶OMA 1。 基础失活，OMA 1被激活，通过一个不明确的机制响应线粒体损伤。 活性OMA 1位点特异性切割选择的IM底物以保护线粒体免受急性线粒体损伤 通过调节形态学和激活应激应答转录因子来抑制损伤。尽管 OMA 1在启动线粒体应激反应中的核心作用及其高治疗价值，而非结构性的 已经定义了OMA 1激活或蛋白水解活性的信息。在这里，我们集成了冷冻EM结构， 确定（目标1）和深度突变扫描（目标2），以建立第一个结构-功能关系 用于OMA 1活化和蛋白水解活性。通过这些努力，我们将确定的分子机制， OMA 1激活和蛋白水解。这将揭示OMA 1依赖的线粒体调控的新见解。 蛋白质稳态和功能，并建立结构基础，以开发新的策略，以治疗目标 OMA 1减轻与衰老相关的病理性线粒体功能障碍 神经变性和心肌病。