MOLECULAR ANALYSIS OF CARCINOGEN-INDUCED DNA REPAIR

致癌物诱导的 DNA 修复的分子分析

基本信息

批准号：
3175105
负责人：
STEVEN L DRESLER
金额：
$ 5.24万
依托单位：
WASHINGTON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
1986
资助国家：
美国
起止时间：
1986-09-30 至 1989-04-30
项目状态：
已结题

项目摘要

Excision repair is generally regarded as the major process by which mammalian cells reduce the cytotoxic, mutagenic, and carcinogenic effects of DNA damage produced by ultraviolet radiation and chemical carcinogens. The long-term objective of this project is to investigate in detail the molecular mechanisms of excision repair of carcinogen damage and the ways in which the repair process is modulated by the chromatin structure of mammalian cells. Understanding the details of the excision repair process is of particular interest in light of recent studies indicating that different regions of mammalian genomes are repaired at different rates. The first goal of the present application is to explore the role of ATP in the early steps of excision repair in cells damaged with several different carcinogens. The possibility that the ATP requirement is related to involvement of a DNA topoisomerase will be specifically examined. This application also proposes studies of damage and repair-associated modifications of chromatin proteins. Such modifications will be identified using appropriate radioactively labeled precursors. In addition, the temporal relation of the chromatin modifications to the pre- and post-incision phases of the repair process will be explored and the physical relation of modified chromatin proteins to sites of excision repair will be examined. These studies will be conducted using a permeable human fibroblasts in which excision repair proceeds in a fashion essentially identical to that seen in intact cells, but is accessible at all stages to biochemical manipulation. The project also involves development of a technique using biotin-modified dUTP and affinity chromatography which for the first time will permit isolation and direct analysis of chromatin undergoing excision repair. The proposed studies should generate biochemical data which will be directly applicable to understanding the process of excision repair in vivo.

切除修复通常被认为是修复的主要过程哺乳动物细胞减少细胞毒性、诱变和致癌作用紫外线辐射和化学致癌物质造成的 DNA 损伤。该项目的长期目标是详细调查致癌物损伤切除修复的分子机制及途径其中修复过程受到染色质结构的调节哺乳动物细胞。了解切除修复过程的细节鉴于最近的研究表明，哺乳动物基因组的不同区域以不同的速度修复。本申请的首要目标是探索 ATP 在几种不同的损伤细胞的切除修复的早期步骤致癌物质。 ATP 需求与以下因素相关的可能性将专门检查 DNA 拓扑异构酶的参与。这该申请还提出了与损坏和修复相关的研究染色质蛋白的修饰。此类修改将被识别使用适当的放射性标记前体。此外，染色质修饰与前体和前体的时间关系将探讨修复过程的切开后阶段，修饰染色质蛋白与切除位点的物理关系将检查修复情况。这些研究将使用渗透性人类成纤维细胞，其中切除修复以某种方式进行与完整细胞中看到的基本相同，但可以在生化操作的所有阶段。该项目还涉及使用生物素修饰的 dUTP 和亲和力开发技术色谱法首次允许分离和直接分析正在进行切除修复的染色质。拟议的研究应生成可直接应用于的生化数据了解体内切除修复的过程。