Molecular Mechanism of Mitochondrial Membrane Transport

线粒体膜运输的分子机制

基本信息

批准号：
10396663
负责人：
Liang Feng
金额：
$ 41.96万
依托单位：
STANFORD UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-07-01 至 2024-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10396663
关键词：
Address Adopted Affinity Allosteric Regulation Apoptosis Architecture Binding Binding Sites Biophysics Calcium Calorimetry Cations Cell Death Cell Survival Cells Complex Cryoelectron Microscopy Crystallization Disease Epilepsy Future Gatekeeping Heart failure Homeostasis Homologous Gene Human Ion Channel Ions Link Mediating Metabolic Methods Mitochondria Molecular Molecular Probes Muscular Dystrophies Mutation N-terminal Neurodegenerative Disorders Neurons Pathology Physiological Physiological Processes Physiology Play Post-Translational Protein Processing Process Production Property Protein Isoforms Proteins Regulation Reperfusion Injury Resolution Rest Role Route Ruthenium Red Shapes Signal Transduction Structure Therapeutic Time Tissues Titrations Transmembrane Transport Work base calcium uniporter cell growth design excitotoxicity experimental study improved inhibitor insight mitochondrial membrane novel novel therapeutics prevent response therapeutic target uptake

项目摘要

PROJECT SUMMARY Mitochondrial calcium (Ca2+) uptake is central to many fundamental physiological processes. It stimulates ATP production during times of increased metabolic need and provides a Ca2+ sink to modulate Ca2+-mediated signaling locally within a cell. Mitochondrial Ca2+ concentrations also regulate apoptosis and dysregulation–– specifically, Ca2+ overload––is a hallmark of pathologies ranging from neuronal excitotoxicity to heart failure and some epilepsies to muscular dystrophies. Yet despite the importance of mitochondrial Ca2+ uptake in normal physiology and disease, the molecular machinery mediating this process is relatively recently identified and many fundamental questions remain to be answered. The main route of Ca2+ influx to mitochondria is a channel called mitochondrial calcium uniporter, which includes the ubiquitous pore-forming subunit MCU and, depending on the species, several regulatory subunits (termed “uniplex” when in complex). This novel channel is highly selective for Ca2+, and its activity is tightly regulated by cytosolic Ca2+ concentration. My group recently determined a high-resolution crystal structure for a fungal MCU that defined a novel channel architecture and revealed a high-affinity Ca2+-binding site. Moreover, our cryo-EM structure of the human uniplex holocomplex revealed its architecture and hints at the mechanisms by which it is regulated. With these structures and the methods we developed, my lab is uniquely poised to embark on the mechanistic understanding of the mitochondrial calcium uniporter. Here, we propose to: 1) elucidate the structural and biophysical basis of ion selectivity, conduction and inhibition; 2) understand mechanisms of the channel gating and the long-range modulation; and 3) probe the molecular basis of Ca2+-dependent regulation of the uniplex. These results will give us much needed mechanistic insights into the activity and regulation of mitochondrial calcium uniporter, expanding our understanding of general principles of Ca2+ channels. In addition, they should provide a strong framework to aid the design of MCU inhibitors, which may represent promising treatments for diseases and pathologies marked by MCU dysregulation and mitochondrial Ca2+ overload. !

项目摘要线粒体钙（CA2+）的摄取对于许多基本生理过程都是核心。它刺激ATP 在代谢需求增加的时候生产，并提供CA2+接收器以调节Ca2+介导在单元格内局部发出信号。线粒体Ca2+浓度还调节凋亡和失调 - 具体而言，CA2+超载 - 是病理学的标志，从神经元兴奋性到心力衰竭和一些癫痫发作对肌肉营养不良。尽管线粒体Ca2+在正常中的摄取很重要生理学和疾病，介导该过程的分子机械被相对确定，许多基本问题仍有待回答。 Ca2+影响线粒体的主要途径是一个称为线粒体钙Uniter的通道，包括无处不在的孔隙亚基MCU，并取决于物种，几个调节亚基（在复杂时称为“单流”）。这个新颖的频道对Ca2+具有很高的选择性，其活性紧密由胞质Ca2+浓度调节。我的小组最近确定了真菌MCU的高分辨率晶体结构，该结构定义了新颖通道体系结构并揭示了一个高亲和力CA2+结合位点。而且，我们人类的冷冻EM结构 Uniplex全真菌揭示了其结构，并暗示了其调节的机制。与这些结构和我们开发的方法，我的实验室被唯一中毒以启动机械了解线粒体钙统一。在这里，我们建议：1）阐明离子选择性，传导和的结构和生物物理基础抑制; 2）了解通道门控的机制和远程调制； 3）探测 Ca2+依赖性调节的分子基础。这些结果将使我们对线粒体的活动和调节急需的机械洞察力钙Uniter，扩展我们对CA2+通道的一般原理的理解。此外，他们应该提供一个强大的框架来帮助设计MCU抑制剂，这可能代表 MCU失调和线粒体Ca2+超负荷标志的疾病和病理。呢