Molecular and physiological analysis of mitochondrial calcium uptake

线粒体钙摄取的分子和生理分析

• 批准号: 9036744
• 负责人: Julia Chang Liu
• 金额: --
• 依托单位: U.S. NATIONAL HEART LUNG AND BLOOD INST
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-10-01 至 2018-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9036744
• 关键词: Affect; Animal Model; Animals; Ataxia; Autophagocytosis; Behavior; Binding Proteins; Biochemical; Bioenergetics; Biological; Biological Assay; Biological Models; Body Composition; Body Weight; CRISPR/Cas technology; Calcium; Cell Death; Cell Line; Cell physiology; Cells; Co-Immunoprecipitations; Complex; Confocal Microscopy; Cultured Cells; Disease; EF Hand Motifs; Embryo; Energy Metabolism; Exhibits; Fibroblasts; Functional disorder; Gatekeeping; Generations; Genetic; Genus Hippocampus; Health; Homeostasis; Human; Innovative Therapy; Knock-out; Knockout Mice; Lead; Learning Disorders; Link; Measurement; Measures; Membrane Proteins; Metabolism; Mitochondria; Mitochondrial Diseases; Mitochondrial Matrix; Modeling; Molecular; Molecular Weight; Mus; Myopathy; Names; Necrosis; Patients; Permeability; Phenocopy; Phenotype; Physiological; Physiology; Play; Production; Property; Proteins; Regulation; Resources; Respiration; Role; Signaling Molecule; Site; Stimulus; Structure; Swelling; Testing; Tissues; Tremor; VDAC1 gene; Wild Type Mouse; calcium uniporter; clinically relevant; extracellular; human disease; loss of function mutation; mitochondrial permeability transition pore; motor disorder; mouse model; mutant; paralogous gene; protein complex; public health relevance; response; uptake

 DESCRIPTION (provided by applicant): Popularly known as "the powerhouse of the cell," mitochondria are not only the site of metabolism and energy generation but also a hub for other cellular processes, including the initiation of cell death. Mitochondrial uptake of the signaling molecule calcium plays a role in the stimulation of ATP production, but too much calcium can lead to opening of the mitochondrial permeability transition pore (mPTP), triggering necrosis. The recent identification of the molecule forming the pore through which calcium can rapidly enter the mitochondria, the mitochondrial calcium uniporter (MCU), has provided a genetic means to directly test the functional importance of calcium uptake. In particular, MCU is part of a large multi-protein complex including other protein components. EMRE and MICU1 are two of these proteins that in cell lines have been shown to play critical roles in regulation of calcium uptake. EMRE was found to be necessary for MCU activity, and its deletion blocked calcium from entering mitochondria. Though its mechanism is controversial, MICU1 has been characterized as a gatekeeper of MCU, inhibiting MCU activity at low levels of extramitochondrial calcium and stimulating MCU when calcium levels rise. This project began with the generation of the first animal models of EMRE and MICU1 deletion. The aims of this project are to determine the impact of EMRE and MICU1 deletion on isolated mitochondria, on primary cells, and on the physiology of the whole animal. The new EMRE and MICU1 knockout mice also make it possible to determine the topology of the calcium uniporter complex, measure effects on basal bioenergetics, and elucidate the role of EMRE and MICU1 respectively in the regulation of mitochondrial calcium uptake and homeostasis. Furthermore, mouse models will reveal the consequences of mitochondrial calcium deregulation on cell death responses, physiological phenotypes including body weight and composition, and disease pathophysiology. Interestingly, human patients with loss-of-function mutations in MICU1 present with conditions such as proximal myopathy and extrapyramidal motor disorder. MICU1 knockout mice are preliminarily observed to exhibit ataxia and tremors, suggesting that this model may mirror human disease features and thus potentially motivate innovative therapies to treat mitochondrial disorder. Altogether, EMRE and MICU1 knockout mice are valuable resources for answering biological questions with both basic and clinical relevance.

 描述（由适用提供）：俗称“细胞的动力室”，线粒体不仅是代谢和能量产生的位置，而且还是其他细胞过程的枢纽，包括细胞死亡的倡议。信号分子钙的线粒体摄取在ATP产生的刺激中起作用，但是过多的钙会导致线粒体通透性过渡孔（MPTP）的打开，从而触发坏死。最近鉴定出钙可以快速进入线粒体的分子，即线粒体钙统一（MCU）提供了一种遗传平均值，可以直接测试钙吸收的功能重要性。特别是，MCU是 大型多蛋白质复合物，包括其他蛋白质成分。 EMRE和MICU1是这些蛋白质中的两种，在细胞系中已显示出在钙摄取调节中起关键作用。发现EMRE对于MCU活性是必需的，其缺失阻止了钙进入线粒体。尽管它的机制是有争议的，但MICU1已被描述为MCU的守门人，在钙水平升高时抑制低水平的MCU活性并刺激MCU。 该项目始于EMRE和MICU1缺失的第一个动物模型的产生。该项目的目的是确定EMRE和MICU1缺失对分离的线粒体，原代细胞以及整个动物生理学的影响。新的EMRE和MICU1敲除小鼠还可以确定钙通用复合物的拓扑，测量对基本生物能力的影响，并阐明EMRE和MICU1的作用，有趣的是，MICU1中具有功能丧失突变的人类患者具有近端肌病和外肌肉外运动障碍等条件。初步观察到MICU1敲除小鼠会杀死共济失调和震颤，这表明该模型可以反映人类疾病的特征，从而有可能激励创新疗法治疗线粒体疾病。总体而言，EMRE和MICU1敲除小鼠是回答具有基本和临床相关性的生物学问题的宝贵资源。