Coordination of PAR and Ub signaling in mitochondria

项目摘要/摘要 在过去的10年里，我们的研究计划旨在发现控制 代谢适应对营养供应、细胞分化和氧化应激的反应 基因组重编程。在NIGMS的支持下，我们在识别 负责协调调节基因转录和翻译的机制 线粒体应激反应(MSR)。我们的工作已经确定了非降解性泛素化在 这两个过程都表明，K63泛素化的内源性抑制物GPS2的调节穿梭- 线粒体与细胞核之间的相互作用是维持线粒体动态平衡的基本策略。作为一名 作为对这些机制研究的补充，我们还调查了由NIDDK和 国防部-GPS2介导的生理相关性和翻译潜能调节 泛素信号在乳腺癌和肥胖相关疾病中的作用。总之，这些研究揭示了 GPS2介导的抑制K63Ub信号通路在促进代谢适应中的重要性 应激和细胞分化过程中线粒体的重塑。这一大堆工作突出了我们的 在该领域的专业知识和我们的独特地位，以进一步调查之间的串扰新发现 途径和其他参与调节线粒体功能的PTM。特别是，我们将把我们的未来放在 泛素化和adp-核糖化之间的串扰研究。这些PTM在 核基因组稳定性的调节、先天免疫和应激诱导的翻译调节。然而， 它们在调节线粒体功能方面的关系尚未得到研究。事实上，尽管出现了 线粒体中ADP核糖化活性的研究几十年来一直是已知的，这是线粒体ART的相同之处 酶/S一直难以捉摸，阻碍了对线粒体蛋白的作用和调控的更详细研究 通过ADP-核糖化。因为我们最近鉴定出NEURL4是线粒体专属的ADP-核糖基 在应激诱导和GPS2介导的重编程的调节下，我们现在处于 承担这些研究的职位。我们提出了一个涵盖两个主要领域的研究计划：1)调查 线粒体应激反应中线粒体逆行信号的空间和功能调节 探讨泛素化和ADP核糖化在调节线粒体动态平衡中的相互作用。 我们的研究计划解决了三个关键问题：i)线粒体逆行信号的空间调控； Ii)线粒体逆行信号对ADP-核糖化调节的功能贡献和 跨亚细胞隔间的泛素化；iii)协调的 ADP-核糖化/泛素化的调节。成功完成拟议的研究将带来更好的 翻译后修饰调控线粒体动态平衡的机制 并可能揭示针对治疗目的的调控策略。

Project Summary/Abstract Over the past 10 years, our research program has aimed at discovering molecular mechanisms that control metabolic adaptation in response to nutrient availability, cellular differentiation, and oxidative stress through genomic reprogramming. With NIGMS support, we have made significant contributions to identifying mechanisms responsible for the coordinated regulation of gene transcription and translation during the Mitochondrial Stress Response (MSR). Our work has identified a key role for non-degradative ubiquitination in both processes, showing that the regulated shuttling of GPS2 – an endogenous inhibitor of K63 ubiquitination – between mitochondria and nucleus is an essential strategy for maintaining mitochondrial homeostasis. As a complement to these mechanistic studies, we also investigated – in projects supported by NIDDK and the Department of Defense – the physiological relevance and translational potential GPS2-mediated regulation of ubiquitin signaling in breast cancer and obesity-associated disorders. Together, these studies have revealed the importance of GPS2-mediated restriction of K63Ub signaling in promoting metabolic adaptation and mitochondria remodeling during stress and cellular differentiation. This large body of work highlights our expertise in the field and our unique position to further investigate the crosstalk between this newly identified pathway and other PTMs involved in regulating mitochondrial function. In particular, we will focus our future studies on the crosstalk between ubiquitination and ADP-ribosylation. These PTMs work in tandem in the regulation of nuclear genome stability, innate immunity and stress-induced translational regulation. However, their relationship in regulating mitochondrial function has not yet been investigated. In fact, although the presence of ADP-ribosylation activity in mitochondria was known for decades, the identity of the mitochondrial ART enzyme/s has been elusive, hindering more detailed studies on the role and regulation of mitochondrial proteins through ADP-ribosylation. As we recently identified NEURL4 as a mitochondria-dedicated ADP-ribosyl transferase under the regulation of stress-induced and GPS2-mediated reprogramming, we are now in the position of carrying those studies. We propose a research plan spanning two major areas:1) Investigating the spatial and functional regulation of mitochondria retrograde signaling in response to mitochondrial stress and 2) Exploring the crosstalk between ubiquitination and ADP-ribosylation in regulating mitochondrial homeostasis. Our research plan addresses three key problems: i) the spatial regulation of mitochondria retrograde signaling; ii) the functional contribution of mitochondria retrograde signaling to the regulation of ADP-ribosylation and ubiquitination across subcellular compartments; iii) the molecular mechanisms underlying the coordinated regulation of ADP-ribosylation/ ubiquitination. Successful completion of the proposed studies will lead to a better understanding of the mechanisms regulating mitochondria homeostasis through post-translational modifications and possibly reveal regulatory strategies to be targeted for therapeutic purposes.