The role of mitochondria-associated RING finger proteins in mitochondrial quality

线粒体相关环指蛋白在线粒体质量中的作用

• 批准号: 7674813
• 负责人: MARIUSZ KARBOWSKI
• 金额: $ 16.91万
• 依托单位: UNIVERSITY OF MD BIOTECHNOLOGY INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-01 至 2010-01-02
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7674813
• 关键词: Address; Affect; Apoptosis; Apoptotic; Area; Biochemical; Biology; Calcium; Cell physiology; Cells; Cellular biology; Characteristics; Data; Defect; Development; Disease; Employee Strikes; Environment; Event; Family; Fingers; Generations; Goals; Homeostasis; Human; Image; Incentives; Investigation; Knowledge; Life; Ligase; Maintenance; Malignant - descriptor; Malignant Neoplasms; Mammalian Cell; Membrane; Methodology; Methods; Mitochondria; Mitochondrial Membrane Protein; Mitochondrial Proteins; Molecular; Molecular Genetics; Nature; Nerve Degeneration; Organelles; Outcome; Outer Mitochondrial Membrane; Pathology; Peripheral; Phase; Prevalence; Prevention approach; Process; Production; Property; Proteins; Quality Control; Regulation; Research; Role; Scientist; Signal Pathway; Signal Transduction; Structure; Substrate Specificity; System; Testing; Ubiquitin; Ubiquitination; Whole Organism; Work; base; design; human RBX1 protein; improved; innovation; instrumentation; lipid biosynthesis; loss of function; mitochondrial dysfunction; mitochondrial membrane; multicatalytic endopeptidase complex; mutant; novel; novel therapeutics; protein complex; protein degradation; public health relevance; response; stem; time use; tool; tumor; ubiquitin-protein ligase

DESCRIPTION (provided by applicant): Mitochondria are essential for a variety of cellular functions, including ATP production, lipid biosynthesis and calcium homeostasis. Moreover, a number of major cell signaling pathways, including apoptosis, require mitochondria. Consistent with a major role of mitochondria in the control of cell function, mitochondrial defects result in a variety of malignant pathologies. Thus, the molecular components that control mitochondrial homeostasis are likely to be major determinants of cell fate and the well being of the whole organism. However, despite their importance, the mechanisms of mitochondrial quality control, as well as the signaling mechanisms between mitochondria and other cell compartments, are largely unknown. We have identified MARCH5 and IBRDC2, two novel mitochondrial E3 ubiquitin ligases, and have determined that these two proteins are essential for the regulation of mitochondrial function in apoptosis and mitochondrial division, respectively. These results implicate a family of novel mitochondrial membrane-associated RING finger E3 ubiquitin ligases in the regulation of mitochondrial homeostasis through ubiquitin-dependent mechanisms. The present proposal seeks to elucidate the functions of IBRDC2 and MARCH5, and their roles in mitochondrial protein regulation and in membrane dynamics, both in healthy cells and during apoptosis. Biochemical and cellular studies, imaging investigations using time-lapse methods, new fluorescent tools developed by the PI (including photoactivable fluorescent proteins), and a variety of molecular genetic methodologies will be utilized to address the following three questions: 1) What are the biochemical properties of IBRDC2 and MARCH5? The sub-mitochondrial localization, membrane topology and substrate specificity of IBRDC2 and MARCH5 will be determined. 2) How do IBRDC2 and MARCH5 work in the mitochondria of living cells? Studies exploiting gain- and loss-of-function approaches will test the roles of IBRDC2 and MARCH5 in proteasome-dependent mitochondrial protein degradation, as well as in the regulation of membrane dynamics and apoptosis-related mitochondrial protein complexes. These studies will also identify mitochondrial proteins that are under regulatory control of IBRDC2 and MARCH5. 3) What is the influence of IBRDC2 and MARCH5 on specific molecular events in the apoptotic cascade? These studies will determine to what degree IBRDC2 and MARCH5 activities are required for progression of distinct steps of apoptosis. Addressing these questions will improve our general understanding of mitochondrial function and, in the long term, are likely to contribute to the development of novel pharmacological approaches to treat diseases stemming from mitochondrial dysfunction. The proposed studies are part of our long- term effort to understand the normal functions of mitochondria and how mitochondrial defects contribute to disease. Public Health Relevance: We have identified MARCH5 and IBRDC2, two novel mitochondrial E3 ubiquitin ligases, and have determined that these two proteins are essential for the regulation of mitochondrial function in apoptosis and mitochondrial division, respectively. These results implicate a family of novel mitochondrial membrane-associated RING finger E3 ubiquitin ligases in the regulation of mitochondrial homeostasis through ubiquitin-dependent mechanisms. The present proposal seeks to elucidate the functions of IBRDC2 and MARCH5, and their roles in mitochondrial protein regulation and in membrane dynamics, both in healthy cells and during apoptosis. The results of these studies, should improve our general understanding of mitochondrial function and, in the long term, are likely to contribute to the development of novel pharmacological approaches to treat diseases stemming from mitochondrial dysfunction.

描述（由申请人提供）：线粒体对于多种细胞功能至关重要，包括ATP产生，脂质生物合成和钙稳态。此外，许多主要的细胞信号通路（包括凋亡）需要线粒体。与线粒体在控制细胞功能中的主要作用一致，线粒体缺陷导致多种恶性病理。因此，控制线粒体稳态的分子成分可能是细胞命运的主要决定因素和整个生物体的健康。然而，尽管它们的重要性，但线粒体质量控制的机制以及线粒体和其他细胞室之间的信号传导机制在很大程度上是未知的。我们已经确定了March5和IBRDC2，这是两个新型的线粒体E3泛素连接酶，并确定这两种蛋白分别对于调节细胞凋亡和线粒体分裂的线粒体功能至关重要。这些结果暗示了通过泛素依赖性机制调节线粒体稳态的新线粒体膜相关环E3泛素连接酶的家族。本提案旨在阐明IBRDC2和March5的功能及其在健康细胞和凋亡过程中的线粒体蛋白质调节以及膜动力学中的作用。生化和细胞研究，使用延时方法的成像研究，由PI开发的新荧光工具（包括可光活化的荧光蛋白）以及各种分子遗传学方法论将用于解决以下三个问题：1）IBRDC2和3月5的生化特性是什么？将确定IBRDC2和MARCH5的膜局部定位，膜拓扑和底物特异性。 2）IBRDC2和March5在活细胞的线粒体中如何工作？利用功能丧失方法的研究将测试IBRDC2和MARCH5在蛋白酶体依赖性的线粒体蛋白降解以及膜动力学和与凋亡相关的线粒体蛋白质复合物的调节中的作用。这些研究还将鉴定在IBRDC2和March5的调节控制下的线粒体蛋白。 3）IBRDC2和March5对凋亡级联反应中特定分子事件的影响是什么？这些研究将确定IBRDC2和MARCH5在多大程度上需要进行凋亡的不同步骤的发展。解决这些问题将改善我们对线粒体功能的一般理解，从长远来看，很可能有助于开发新的药理方法来治疗因线粒体功能障碍而引起的疾病。拟议的研究是我们长期努力的一部分，以了解线粒体的正常功能以及线粒体缺陷如何促进疾病。 公共卫生相关性：我们已经确定了三月5和IBRDC2，这是两个新型的线粒体E3泛素连接酶，并确定这两种蛋白分别对于调节细胞凋亡和线粒体分裂的线粒体功能至关重要。这些结果暗示了通过泛素依赖性机制调节线粒体稳态的新线粒体膜相关环E3泛素连接酶的家族。本提案旨在阐明IBRDC2和March5的功能及其在健康细胞和凋亡过程中的线粒体蛋白质调节以及膜动力学中的作用。这些研究的结果应提高我们对线粒体功能的一般理解，从长远来看，可能有助于发展新型药理方法，以治疗因线粒体功能障碍而导致的疾病。