Homology-directed Repair of DNA Breaks in Humans

人类 DNA 断裂的同源定向修复

• 批准号: 6920822
• 负责人: Patrick Sung
• 金额: $ 33.52万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-07-14 至 2009-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6920822
• 关键词: DNA damage; DNA repair; adenosine triphosphate; adenosinetriphosphatase; chemical binding; enzyme activity; enzyme complex; enzyme mechanism; enzyme substrate; genetic recombination; genetic techniques; human genetic material tag; hydrolysis; molecular genetics; mutant; neoplasm /cancer genetics; nuclear proteins; protein protein interaction; protein purification; recombinase

DESCRIPTION (provided by applicant): Cells are continually exposed to endogenous and exogenous elements that induce DNA double-strand breaks (DSB)s, which, if not properly removed, can cause death or gross chromosome aberrations. Homologous recombination (HR) is a major pathway for the elimination of DSBs. There is compelling evidence that homology-directed DNA repair is needed for cancer avoidance in humans. Genetic analyses in yeast have led to the identification of the RAD52 epistasis group of genes needed for HR. Subsequent cloning, biochemical, and genetic studies have shown remarkable conservation of the structure and function of the RAD52 group genes and proteins during eukaryotic evolution. Biochemical analyses of the RAD51-encoded product, a key member of the RAD52 group, have uncovered in it a homologous DNA pairing and strand exchange activity that can serve to link recombining chromosomes. The recombinase activity of Rad51 is subject to multiple layers of control. This research project will utilize a variety of molecular tools to delineate the homologous DNA pairing and strand exchange reaction mediated by human Rad51 protein and define the role of various human recombination factors in regulating the hRad51 recombinase activity. Specifically, we will (1) examine how ATP binding and hydrolysis modulate the affinity of hRad51 for its DNA substrates and hRad51 presynaptic filament dynamics, and (2) define the biochemical properties of the hRad54 and Rad54B proteins, dissect the multifaceted role of these factors in HR, and identify and characterize complexes that contain these factors. The results should shed some light on the mechanistic underpinnings of the homologous recombination machinery in human cells and will have important implications for cancer etiology and prevention.

描述（由申请人提供）：细胞不断暴露于诱导DNA双链断裂（DSB）S的内源性和外源性元素，如果未正确去除，可能会导致死亡或染色体差异。同源重组（HR）是消除DSB的主要途径。有令人信服的证据表明，人类避免癌症需要以同源为导向的DNA修复。 酵母中的遗传分析已导致鉴定HR所需的RAD52上毒基因。随后的克隆，生化和遗传学研究表明，在真核进化过程中，RAD52基因和蛋白质的结构和功能明显保存。 RAD51编码产品的生化分析是RAD52组的关键成员，它在其中发现了一种同源的DNA配对和链交换活性，可以用来连接重组染色体。 RAD51的重组酶活性受到多层对照。该研究项目将利用各种分子工具来描述由人Rad51蛋白介导的同源DNA配对和链交换反应，并定义各种人重组因子在调节HRAD51重组酶活性中的作用。具体而言，我们将（1）研究ATP结合和水解如何调节HRAD51对其DNA底物和HRAD51的亲和力，以及HRAD51突触前细丝动力学，以及（2）定义HRAD54和RAD54B蛋白的生化特性，并识别了这些因子的多面因素，并识别了这些因素和特征，并识别了这些因素和特征，以致并识别了这些因子的作用。结果应阐明人类细胞中同源重组机制的机械基础，并将对癌症的病因和预防具有重要意义。