Mitochondrial DNA Replisome: Mechanism, Structure and Physiology

摘要：本研究的长期目标是阐明动物线粒体中DNA复制的机制及其与线粒体突变和人类疾病的关系。结合生物化学、结构生物学和分子遗传学的现有方法，重点研究线粒体复制体的机制、结构和生理，重点研究线粒体复制DNA解旋酶和线粒体单链DNA结合蛋白。结合我们等人对线粒体中关键的复制酶DNA聚合酶3的广泛研究，我们扩大了先前的研究范围，研究线粒体DNA复制叉上蛋白质的组装和功能，探索线粒体DNA在体内和体外的复制模式。线粒体是动物体内产生能量的细胞器，线粒体的功能几乎影响细胞功能的各个方面。因此，线粒体在人类健康中起着重要作用，同样，线粒体功能障碍与人类疾病有着复杂的联系。线粒体功能障碍涉及广泛的神经系统疾病、代谢疾病、肌肉营养不良症和肾病，以及广泛的已命名疾病。线粒体生物发生缺陷导致线粒体DNA突变、耗竭和缺失综合征，导致线粒体和随后的细胞功能丧失。线粒体遗传疾病的流行和最近认识到抗病毒和抗菌药物的线粒体毒性，迫切需要深入了解线粒体DNA复制装置的结构和功能。

DESCRIPTION (provided by applicant): Abstract: The long-term objective of the proposed work is the elucidation of the mechanism of DNA replication in animal mitochondria, and its relationship to mitochondrial mutagenesis and human disease. A combined approach of current methods in biochemistry, structural biology and molecular genetics will be pursued to study the mechanism, structure and physiology of the mitochondrial replisome, with a focus on the replicative DNA helicase and the mitochondrial single-stranded DNA-binding protein. In combination with the extensive studies by us and others on the key replicative enzyme in mitochondria, DNA polymerase 3, we expand the scope of prior research to study the assembly and function of proteins at the mitochondrial DNA replication fork, and to probe the modes of mitochondrial DNA replication in vivo and in vitro. Mitochondria are the energy-producing organelle in animals and mitochondrial function impacts nearly every aspect of cellular function. Thus, mitochondria play a major role in human health and likewise, mitochondrial dysfunction is intricately associated with human disease. Mitochondrial dysfunction is implicated in a wide range of neurological diseases, in metabolic diseases, in muscular dystrophies and nephropathies, and in a broad spectrum of named disorders. Defects in mitochondrial biogenesis lead to mitochondrial DNA mutation, depletion and deletion syndromes that result in loss of mitochondrial and subsequent cellular function. The prevalence of mitochondrial genetic disease and recent recognition of the mitochondrial toxicity of antiviral and antimicrobial drugs the critical need for an in-depth understanding of the structure and functions of the mitochondrial DNA replication apparatus. PUBLIC HEALTH RELEVANCE: Narrative: A common feature in diverse chronic, age-related diseases is a breakdown or disturbance in the cell's ability to produce energy. Central to the cellular energy production is the mitochondrion, an organelle that plays a crucial role in multiple metabolic processes, and whose dysfunction is linked directly to many pathologies, including those most represented in an aging population. Therefore, a clear understanding of mitochondrial biogenesis and energy production and how these processes are deregulated in common disease states, is essential to treating them effectively (and economically).