Chemical and Molecular Mechanisms of Mitochondrial DNA Degradation

线粒体 DNA 降解的化学和分子机制

• 批准号: 10212125
• 负责人: Linlin Zhao
• 金额: $ 4.59万
• 依托单位: UNIVERSITY OF CALIFORNIA RIVERSIDE
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2023-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10212125
• 关键词: Address; Aging; Area; Biochemical; Biology; Cardiovascular Diseases; Cells; Chemicals; DNA; DNA Biochemistry; DNA Damage; DNA Maintenance; DNA Packaging; DNA Repair; DNA lesion; Data; Degradation Pathway; Development; Diabetes Mellitus; Disease; Enzymatic Biochemistry; Etiology; Eukaryotic Cell; Funding Opportunities; Genome; Genomics; Goals; Human; Innate Immune System; Knowledge; Lesion; Maintenance; Measures; Mediating; Mitochondria; Mitochondrial DNA; Mitochondrial DNA depletion syndromes; Mitochondrial Diseases; Molecular; Names; Nerve Degeneration; Outcome; Oxidative Phosphorylation; Pathology; Process; Production; Protein Biochemistry; Protein Biosynthesis; Protein Subunits; Proteins; Quality Control; Research; Ribosomal RNA; Role; Signal Transduction; Site; Source; System; Transfer RNA; chemical kinetics; cofactor; environmental chemical; insight; mitochondrial dysfunction; mtTF1 transcription factor; novel; novel therapeutics; programs; public health relevance; repaired; transcription factor

PROJECT SUMMARY/ABSTRACT Mitochondria are subcellular compartments that are critical for energy production, cell signaling, and the biosynthesis of protein cofactors in higher eukaryotic cells. The mitochondrial DNA (mtDNA) genome is indispensable for mitochondrial function because it encodes protein subunits of the oxidative phosphorylation system and a full set of transfer and ribosomal RNAs. mtDNA degradation is an essential mechanism in mitochondrial genomic maintenance and a quality control measure to cope with mitochondrial DNA damage sourced from endogenous and environmental chemicals. The mechanism of mtDNA degradation and factors involved are poorly understood, which represents a significant knowledge gap. Such knowledge is fundamental to the understanding of mitochondrial genomic maintenance and pathology, because mtDNA degradation may contribute to the etiology of mtDNA depletion syndromes and to the activation of the innate immune system by circulating mtDNA. The objective of this project is to define the chemical and molecular basis of damaged mtDNA degradation and to clarify the role of a major transcription factor and DNA packaging protein TFAM (mitochondrial transcription factor A) in DNA degradation and repair. Addressing this critical knowledge gap will facilitate the PI’s long-term goal of unraveling the basis of mitochondrial DNA turnover and its role in mitochondrial pathobiology. This project focuses on a ubiquitous DNA lesion and central DNA repair intermediate, i.e. abasic (AP) sites. The central hypothesis is that TFAM modulates the stability of AP lesions and mediates AP-DNA degradation. This hypothesis is grounded in both strong preliminary data and empirical evidence. Preliminary results will be further evaluated by using a combination of quantitative biochemical, computational, and cellular approaches. Specifically, this research program will delineate the chemical and kinetic basis of TFAM-mediated AP-DNA destabilization, describe the involvement of TFAM in AP-DNA degradation in human cells, and clarify the regulatory role of TFAM in mtDNA repair. The expected outcome is that the project will fill a critical knowledge gap concerning the chemical and molecular mechanisms of mtDNA degradation and novel protein factors involved in the process. This application builds on the PI’s strong background in DNA and protein biochemistry, mechanistic enzymology, and quantitative analysis, and accelerates the progress in an exciting area of research into mitochondrial biology. The significance of this project is that it will define the chemical and molecular basis of an mtDNA-degradation pathway and the role of TFAM in mtDNA degradation and repair. Considering that AP sites are key intermediates in mtDNA repair, insights into AP-DNA degradation will have broad implications for understanding mitochondrial genomic maintenance and instability. New knowledge from this research will profoundly advance the field of mtDNA maintenance and potentially inform the development novel therapeutics for mitochondrial diseases.

项目概要/摘要 线粒体是亚细胞区室，对于能量产生、细胞信号传导和 高等真核细胞中蛋白质辅因子的生物合成线粒体 DNA (mtDNA) 基因组。 对于线粒体功能不可或缺，因为它编码氧化磷酸化的蛋白质亚基 系统和全套转移和核糖体 RNA 降解是一个重要机制。 线粒体基因组维护和应对线粒体 DNA 损伤的质量控制措施 源自内源性和环境化学物质 mtDNA 降解的机制和因素。 所涉及的知识知之甚少，这代表着重大的知识差距。 有助于了解线粒体基因组维护和病理学，因为 mtDNA 降解可能 有助于 mtDNA 耗竭综合征的病因学和先天免疫系统的激活 该项目的目标是确定受损线粒体DNA的化学和分子基础。 降解并阐明主要转录因子和 DNA 包装蛋白 TFAM（线粒体）的作用 转录因子 A）在 DNA 降解和修复中的作用 解决这一关键的知识空白将促进 PI 的长期目标是揭示线粒体 DNA 周转的基础及其在线粒体中的作用 该项目重点关注普遍存在的 DNA 损伤和中心 DNA 修复中间体，即脱碱基。 (AP) 位点的中心假设是 TFAM 调节 AP 病变的稳定性并介导 AP-DNA。 该假设基于强有力的初步数据和初步经验证据。 将通过结合定量生化、计算和细胞来进一步评估结果 具体来说，该研究计划将描述 TFAM 介导的化学和动力学基础。 AP-DNA 不稳定，描述 TFAM 参与人体细胞中 AP-DNA 降解的过程，并阐明 TFAM 在 mtDNA 修复中的调节作用 预期结果是该项目将填补关键知识。 关于 mtDNA 降解的化学和分子机制以及新型蛋白质因子的差距 该应用程序建立在 PI 强大的 DNA 和蛋白质生物化学背景之上， 机械酶学和定量分析，并加速了令人兴奋的研究领域的进展 该项目的意义在于它将定义化学和分子基础。 考虑到 AP 的 mtDNA 降解途径以及 TFAM 在 mtDNA 降解和修复中的作用。 位点是 mtDNA 修复的关键中间体，对 AP-DNA 降解的深入了解将对 了解线粒体基因组的维护和不稳定性将来自这项研究。 极大地推进了 mtDNA 维护领域的发展，并有可能为新疗法的开发提供信息 用于线粒体疾病。