RECOGNITION AND REPAIR OF UV DAMAGE TO HUMAN DNA

人类 DNA 紫外线损伤的识别和修复

• 批准号: 6377972
• 负责人: Yue Zou
• 金额: $ 24.9万
• 依托单位: EAST TENNESSEE STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-07-01 至 2005-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6377972
• 关键词: DNA damage; DNA footprinting; DNA repair; adduct; benzopyrenediol epoxide; chemical carcinogenesis; chemical kinetics; deoxyribonuclease I; enzyme activity; fluorescence resonance energy transfer; fluorescence spectrometry; gel mobility shift assay; gene mutation; human genetic material tag; neoplasm /cancer genetics; radiation carcinogenesis; site directed mutagenesis; thermodynamics; ultraviolet radiation

Individuals who suffer from the genetic disease xeroderma pigmentosum (XP) lack nucleotide excision repair (NER) of DNA, and thus have much higher carcinogenic probability than the average population after exposure to UV irradiation. NER is a major cellular biological defense system to remove DNA damage due to the formation of bulky lesions induced by UV irradiation and environmental genotoxic chemicals and carcinogens. Although, it has been generally accepted that DNA damage recognition plays a central role in NER, the molecular and thermodynamic details of DNA damage processing remain largely unclear, and have not been systematically studied using biochemically rigorous approaches. In addition, the roles of the damage recognition proteins XPA, RPA, and XPC-HR23B have been controversial. The long-term objective of this study is to understand the molecular and biochemical details of UV-induced or related DNA damage recognition and repair by human NER proteins, and the potential effects of these relationships on damage-induced mutagenesis and carcinogenesis. To gain a systematic and more precise view of DNA damage recognition and repair by human NER, the following questions will be addressed: What is the hierarchy of damage recognition and how is damage dynamically processed in a stepwise recognition mechanism? What structural and chemical alterations in the DNA helix are identified by repair proteins at specific recognition steps? What is the molecular architecture of recognition intermediates? And what protein domains are important for protein-DNA and protein-protein contacts in the recognition. Specifically, this project aims to determine the thermodynamics and kinetics of the interaction of XPC-HR23B, XPA, and RPA with DNA substrates containing site-specific UV photolesions and benzo[a]pyrene diol epoxide (BPDE) DNA adducts using rigorous biochemical approaches: identify and analyze the important protein motifs involved in damage recognition: characterize the repair intermediates for damage recognition of UV-induced photolesions and BPDE-DNA adducts; and determine the mechanism in which the structural and chemical modifications of damage are recognized and repaired.

患有遗传疾病的个体心胚层色素色素 （XP）缺乏DNA的核苷酸切除修复（NER），因此具有很多 暴露后平均人群的致癌概率高 紫外线照射。 NER是去除的主要蜂窝生物防御系统 紫外线照射引起的笨重病变引起的DNA损伤 环境遗传毒性化学物质和致癌物。虽然是 普遍认为，DNA损伤识别在NER中起着核心作用 DNA损伤处理的分子和热力学细节在很大程度上保持 不清楚，尚未使用生化严格的系统研究 方法。另外，损伤识别蛋白XPA的作用，RPA， XPC-HR23B一直存在争议。这项研究的长期目标是 了解紫外线诱导或相关的分子和生化细节 人类NER蛋白的DNA损伤识别和修复，潜力 这些关系对损伤引起的诱变和 致癌作用。获得DNA损伤的系统，更精确的视图 人类的认可和维修，将解决以下问题： 损害识别的层次结构是什么？如何动态损害 以逐步识别机制进行处理？什么结构和化学 DNA螺旋中的改变是通过特定的修复蛋白来鉴定的 识别步骤？什么是识别的分子结构 中间人？哪些蛋白质结构域对于蛋白质-DNA和 识别中的蛋白质蛋白接触。具体而言，该项目的目的是 确定XPC-HR23B，XPA的相互作用的热力学和动力学 和RPA，带有含有特定位点特异性紫外光子的DNA底物和 苯并[A] pyrene Diol环氧（BPDE）DNA加合物使用严格的生化 方法：识别和分析与 损害识别：描述维修中间体损坏 识别紫外线诱导的光子和BPDE-DNA加合物；并确定 损害的结构和化学修饰的机制是 认可并修复。