Mitochondrial Calcium Uniporter in Signaling and Dynamics

线粒体钙单向转运蛋白在信号传导和动力学中的作用

基本信息

批准号：
10720242
负责人：
Gyorgy Hajnoczky
金额：
$ 42.18万
依托单位：
THOMAS JEFFERSON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-09-15 至 2027-06-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10720242
关键词：
Acute Biological Assay Calcium Calcium Signaling Cell Death Cell Line Cell physiology Cells Chronic Complex Crista ampullaris Cytoplasm Data Dependence Disease Endoplasmic Reticulum Energy Metabolism Environment Fingerprint Functional Imaging Gatekeeping Genetic Genetic Diseases Genetic Models Glutathione Disulfide Heterogeneity Homeostasis Human Genetics Hydrogen Peroxide Individual Inner mitochondrial membrane Ischemia Link Liver Malignant Neoplasms Mediating Membrane Potentials Metabolism Mitochondria Mitochondrial Matrix Modification Morphology Mus Muscle Mutation Organ Organelles Oxidation-Reduction Pathogenesis Pathway interactions Patients Pattern Perinatal mortality demographics Permeability Proteins Reactive Oxygen Species Reperfusion Therapy Resolution Rest Role Shapes Signal Transduction Structure Testing Tissues calcium uniporter cell injury dimer driving force extracellular human disease imaging approach mitochondrial membrane mouse genetics novel scaffold spatiotemporal structural imaging uptake

项目摘要

Mitochondrial Ca2+ uptake controls many cell functions, including energy metabolism, signaling and dynamics. Mitochondrial Ca2+ accumulation is supported by the robust driving force of the highly negative, inner mitochondrial membrane potential, but is activated only during Ca2+ signals, when cytoplasmic [Ca2+] is elevated. Ca2+ signals are propagated to the mitochondrial matrix through a channel, the calcium uniporter (mtCU), comprised of pore-forming MCU, scaffold EMRE, and Ca2+-sensing regulatory dimers of MICU1 with itself, MICU2 or MICU3. MICU1 deletion results in a permanently open mtCU, whereas MICU2 loss increases and MICU3 loss decreases the Ca2+ sensitivity of the mtCU gating. MICU1 deletion has been shown by us and others to cause perinatal death in mouse and both MICU1 and MICU2 mutations have been linked to human diseases. Evidence has also started to accumulate in support of MICU1 decrease in common disorders like ischemia-reperfusion and cancer. However, despite the MICUs broad disease relevance, their contribution to the organization of calcium signaling and organelle, cell and tissue structure and functions remains undetermined. Here we present preliminary data indicating cell-to-cell and intracellular heterogeneity in the MICUs, which might be relevant for specialization of cells in complex organs. MICU1 loss was shown to be followed by secondary mtCU composition changes, which might be either adaptive or maladaptive, however the temporal ordering of these changes and others beyond the mtCU itself are not known. Whereas MICU1 loss-induced cell injury has been attributed to mitochondrial Ca2+ overload, our preliminary findings point to the importance of other contributors, namely mitochondrial reactive oxygen species and structural alterations. Thus, delineating the mechanisms by which MICUs contribute to the inter-and intracellular organization of Ca2+ signaling and the stability of mitochondrial structure and function are of vast significance. Here we pose the hypothesis that MICUs are important for individual cells’ Ca2+ signal fingerprints, for redox homeostasis and for fusion-fission and cristae dynamics of the mitochondria. To test these ideas, we have developed novel assays and assembled an array of cell and mouse genetic models. Our specific aims are to determine (1) if MICU1 gating of the mtCU creates intracellular heterogeneity in Ca2+ signaling; (2) if the control of mtCU gating by MICUs is relevant for mitochondrial redox homeostasis; (3) if MICU1, MICU2 and MICU3 contribute to the control of mitochondrial fusion-fission dynamics and cristae shaping and these contributions depend on the gating of the mtCU. Completion of these aims will provide clues to the mechanisms by which MICUs support mitochondrial membrane dynamics and signaling and to the pathogenesis initiated by perturbing mtCU structure and function.

线粒体Ca2+摄取控制许多细胞功能，包括能量代谢，信号传导和动力学。线粒体Ca2+积累受到高度负，内部线粒体膜电位的稳健驱动力的支持，但仅在胞质[Ca2+]升高时仅在Ca2+信号期间激活。 Ca2+信号通过通道传播到线粒体基质，钙统一（MTCU），由孔形成MCU，脚手架EMRE和Ca2+ sensing-sensing调节二聚体，其本身，MICU2或MICU3。 MICU1删除会导致永久开放的mTCU，而MICU2损耗增加，MICU3损耗降低了mTCU门控的Ca2+灵敏度。我们和其他人已经证明了MICU1缺失在小鼠中导致围产期死亡，MICU1和MICU2突变都与人类疾病有关。证据也开始积累以支持MICU1降低常见疾病，例如缺血 - 再灌注和癌症。然而，尽管米克斯疾病具有广泛的相关性，但它们对钙信号传导和细胞器，细胞和组织结构以及功能的贡献仍未确定。在这里，我们介绍了指示MICUS中细胞到细胞和细胞内异质性的初步数据，这可能与复杂器官中细胞的专业化有关。 MICU1丢失被证明是次级MTCU组成的变化，可能是适应性或适应不良的，但是这些变化的临时排序以及MTCU本身以外的其他变化的临时排序。尽管MICU1损耗诱导的细胞损伤已归因于线粒体Ca2+过载，但我们的初步发现表明其他贡献者的重要性，即线粒体反应性氧和结构改变。这是描述MICUS对CA2+信号传导的细胞间和细胞内组织以及线粒体结构和功能的稳定性的机制的重要意义。在这里，我们提出了一个假设，即MICUS对于单个细胞的Ca2+信号指纹，氧化还原稳态以及线粒体的融合膜和CRISTAE动力学很重要。为了测试这些想法，我们开发了新颖的测定法，并组装了一系列细胞和小鼠遗传模型。我们的具体目的是确定（1）MTCU的MICU1门控在Ca2+信号传导中产生细胞内异质性；（2）如果MICUS对MTCU进行控制与线粒体氧化还原稳态有关；（3）如果MICU1，MICU2和MICU3有助于控制线粒体融合 - 裂变动力学和CRISTAE成型，并且这些贡献取决于MTCU的门控。这些目标的完成将为MICUS支持线粒体膜动力学和信号传导以及通过扰动mTCU结构和功能引发的发病机理提供线索。