Elucidation of the mammalian mitochondrial unfolded protein response network

哺乳动物线粒体未折叠蛋白反应网络的阐明

• 批准号: 390339347
• 负责人: Dr. Christian Münch
• 金额: --
• 依托单位: Institut für Biochemie II
• 依托单位国家: 德国
• 项目类别: Independent Junior Research Groups
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/390339347?language=en
• 关键词: Elucidation; mammalian; mitochondrial; unfolded; protein

Mitochondria contain a dedicated protein quality control system to ensure proper folding of the mitochondrial proteome. The enzymatic activity of mitochondrial proteins is central to cellular function and perturbations of the mitochondrial proteome have been implicated in ageing and numerous diseases, such as neurodegenerative diseases. Upon mitochondrial protein misfolding, mitochondria activate the mitochondrial unfolded protein response (UPRmt) to restore mitochondrial proteostasis and function. Despite our extensive knowledge of the C. elegans UPRmt, little is known about the proteins and mechanisms underlying the mammalian UPRmt. Two functional branches form the mammalian UPRmt: a transcriptional response to increase mitochondrial chaperones levels and a translational response, recently discovered by me, that leads to decreased mitochondrial translation. Considering the important role of the UPRmt network for understanding the mitochondrial responses to stresses, ageing, and disease, the mammalian UPRmt has been vastly understudied, mainly due to the lack of experimental paradigms to study the UPRmt under defined, acute conditions.My previous work established highly specific chemical induction of mitochondrial protein misfolding to study the acute mammalian UPRmt and provided with proteins and mechanisms likely playing a role in regulating the UPRmt. Guided by this data, I propose four objectives as part of this proposal, combining mainly biochemical, quantitative mass spectrometry-based, cell biological, and gene editing techniques to elucidate and discover proteins playing a crucial role in the mammalian UPRmt and to decipher the mechanisms underlying sensing and signaling of the mammalian UPRmt: 1) The elucidation of sensing and signaling of UPRmt inside mitochondria, especially in the context of calcium signaling and studying the role of LETM1, which I identified to regulate the UPRmt; 2) Defining the temporal profile controlling progression through the UPRmt and the transition towards a pro-death response upon pro-longed UPRmt activation; 3) The extension of my preliminary and establishment of further genetic screens to identify the proteins essential for the UPRmt and to elucidate the mechanisms of their action; 4) To decipher the signaling pathways transmitting the UPRmt to the nucleus and eliciting the transcriptional response. Together, these objectives will largely extent our knowledge of the proteins forming and the mechanisms guiding the mammalian UPRmt and will form the essential foundation for understanding the processes underlying the mitochondrial response to perturbations in mitochondrial proteostasis upon ageing or disease.

线粒体含有专用的蛋白质质量控制系统，以确保线粒体蛋白质组的正确折叠。线粒体蛋白质的酶活性对细胞功能至关重要，线粒体蛋白质组的扰动与衰老和许多疾病如神经退行性疾病有关。在线粒体蛋白错误折叠时，线粒体激活线粒体未折叠蛋白反应（UPRmt）以恢复线粒体蛋白质稳态和功能。尽管我们对C.尽管哺乳动物的UPRmt与线虫的UPRmt相似，但对哺乳动物UPRmt的蛋白质和机制知之甚少。哺乳动物的UPRmt有两个功能分支：一个是增加线粒体伴侣水平的转录反应，另一个是我最近发现的导致线粒体翻译减少的翻译反应。考虑到UPRmt网络对于理解线粒体对应激、衰老和疾病的反应的重要作用，哺乳动物UPRmt的研究非常不足，主要是由于缺乏实验范式来研究定义的UPRmt，我以前的工作建立了高度特异性的线粒体蛋白质错误折叠的化学诱导来研究急性哺乳动物UPRmt，并提供了可能的蛋白质和机制。在规范UPR方面发挥作用。在这些数据的指导下，我提出了四个目标作为本提案的一部分，主要结合生物化学，定量质谱，细胞生物学和基因编辑技术来阐明和发现在哺乳动物UPRmt中发挥关键作用的蛋白质，并破译哺乳动物UPRmt的传感和信号传导机制：1）阐明线粒体内UPRmt的传感和信号传导，特别是在钙信号传导的背景下，并研究LETM 1的作用，我确定LETM 1调节UPRmt; 2）确定通过UPRmt控制进展的时间分布和在延长的UPRmt激活后向促死亡反应的转变; 3）扩展我的初步和建立进一步的遗传筛选以鉴定UPRmt必需的蛋白质并阐明它们的作用机制; 4）破译UPRmt向细胞核传递并引发转录反应的信号通路。总之，这些目标将在很大程度上扩大我们的知识的蛋白质形成和机制指导哺乳动物UPRmt和将形成的基本基础，了解线粒体响应的过程中的线粒体蛋白质稳态扰动老化或疾病。