Processing Site-Specific DNA Lesions by DNA Repair/Recom

通过 DNA 修复/重组处理位点特异性 DNA 损伤

• 批准号: 6990365
• 负责人: Karen M Vasquez
• 金额: $ 16.16万
• 依托单位: UNIVERSITY OF TX MD ANDERSON CAN CTR
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-04-21 至 2009-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6990365
• 关键词: CHO cells; DNA damage; DNA repair; cell free system; crosslink; genetic recombination; mitomycin C; psoralens; triple helix; ultraviolet radiation

DNA interstrand crosslinks (ICLs) present a formidable block to DNA metabolic processes and must be repaired for cell survival. While much work has been done to define the mechanism(s) of DNA interstrand crosslink repair in bacteria and yeast, very little is known about their repair in mammalian cells. It is has been proposed that both homologous recombination (HR) and nucleotide excision repair pathways are involved in DNA crosslink repair. It is becoming increasingly evident that there is overlap among the DNA repair pathways for certain types of DNA lesions. Our working hypothesis is that a number of proteins already defined as essential in DNA repair mechanisms are also required for efficient HR, or work together with HR in DNA interstrand crosslink processing and removal. The long-term objectives of the proposed research are to elucidate the molecular mechanism(s) involved in the removal of site-specific DNA interstrand crosslinks and complex DNA lesions (psoralen plus UVA radiation and mitomycin C crosslinks directed by triplex formation) from the mammalian genome, to identify interactions among the DNA repair pathways, and to determine the role(s) of homologous recombination, nucleotide excision, and mismatch repair mechanisms in the removal and processing of ICLs and complex DNA lesions. Specifically we propose to: 1) direct sitespecific DNA crosslinks to the genome in normal and recombination-deficient Chinese hamster ovary cells to elucidate the role of recombination in the removal of interstrand crosslinks and complex DNA lesions; 2) determine the mechanism(s) of removal of site-specific DNA interstrand crosslinks and complex DNA lesions directed by triplex-forming oligonucleotides in mammalian cell-free extracts; and 3) identify interactions between proteins involved in DNA repair pathways in the removal of site-specific DNA interstrand crosslinks and complex DNA lesions.

DNA链间交联(ICL)是DNA代谢过程中的一大障碍，必须进行修复才能保证细胞的生存。虽然已经做了很多工作来确定细菌和酵母中DNA链间交联修复的机制(S)，但对它们在哺乳动物细胞中的修复知之甚少。DNA的交联修复涉及同源重组(HR)途径和核苷酸切除修复途径。越来越明显的是，某些类型的DNA损伤的DNA修复途径之间存在重叠。我们的工作假设是，一些已经被定义为DNA修复机制中必不可少的蛋白质也是有效的HR所必需的，或者与HR一起工作 在DNA链间交联的处理和去除中。这项研究的长期目标是阐明从哺乳动物基因组中移除特定位点的DNA链间连接和复杂的DNA损伤(补骨脂素+UVA辐射和三链形成的丝裂霉素C交联)所涉及的分子机制(S)，确定DNA修复途径之间的相互作用，并确定同源重组、核苷酸切除和错配修复机制在ICL和复杂的DNA损伤的移除和处理中的作用(S)。具体来说，我们建议：1)直接针对特定站点 目的：2)确定哺乳动物无细胞提取液中三链形成寡核苷酸的作用机制(S)；3)确定DNA修复通路中参与蛋白质间相互作用的蛋白质之间的相互作用。