Repair of Oxidatively Damaged Guanines in Human

人体氧化损伤鸟嘌呤的修复

• 批准号: 6679407
• 负责人: A-Lien L Lu-Chang
• 金额: $ 27.92万
• 依托单位: UNIVERSITY OF MARYLAND BALTIMORE
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-08-14 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6679407
• 关键词: DNA damage; DNA repair; HeLa cells; SDS polyacrylamide gel electrophoresis; Schizosaccharomyces pombe; aging; chemical carcinogen; chemical carcinogenesis; endonuclease; enzyme activity; flow cytometry; guanine; immunoprecipitation; molecular oncology; mutagens; oxidative stress; phosphorylation; proliferating cell nuclear antigen; protein protein interaction; tissue /cell culture; western blottings

DESCRIPTION (provided by applicant): Defects in DNA repair can lead to genome instability, a hallmark of cancer. Oxidative DNA damage is a major source of mutation load in living organisms and plays a role in carcinogenesis and aging. The 8-oxo-7,8-dihydrodeoxyguanine (8-oxoG) lesion is a major stable product of oxidative damage and has the most deleterious effects because it can mispair with adenine during DNA replication. Thus, repair ol A/8-oxoG and C/8-oxoG by hMYH (MutY adenine glycosylase homolog), hOGG1 (an 8-oxoG glycosylase), and hMSH2/hMSH6 dependent mismatch repair pathways provide levels of defense against oxidative stress The overall goals of this project is to understand the role of hMYH pathway in controlling carcinogenesis and its interplay with other repair pathways in response to oxidative stress such as treatments by hydrogen peroxide and ionizing radiation. The interactions of hMYH with replication proteins hPCNA and hRPA, with repai] enzymes hAPE1 and hMSH6, as well as cell cycle checkpoint proteins hHusl/hRadl/hRad9 will be investigated. (I) Alterations in the interactions of hMYH with hPCNA and hHusl under oxidative stress will be investigated. The interacting domains on hMYH and hHusl will be mapped and the significance of their functional interaction will be tested in vivo. Working models that a molecular switch of hMYH-hPCNA tc hMYH-hRad9/hRadl/hHusl occurs to induce DNA damage response and that hMYH may recruit_ hRad9/hRadl/hHusl to the lesion sites will be tested. (II) Interaction between hMYH and hMSH6 will be elucidated both in vitro and in vivo. Fission yeast S. pombe will be used as a model system to test the in viw function of hMYH mutants. (III) Co-localization of hMYH with hAPE 1, hPCNA, hHus 1, hRPA, and hMSH6 ir repair and replication loci will be examined. (IV) The phosphorylation state of hMYH after DNA damage, the kinase responsible for the hMYH phosphorylation, and the phosphorylation site(s) of hMYH will be determined. The correlation of hMYH activities with protein phosphorylation or certain protein-protein interaction(s) after DNA damage will be examined. This study will advance our understanding of the role of DNA repair in tumor susceptibility.

描述（由申请人提供）：DNA修复中的缺陷会导致基因组不稳定性，这是癌症的标志。氧化DNA损伤是活生物体突变负荷的主要来源，并在癌变和衰老中起作用。 8-oxo-7,8-二氢脱氧瓜氨酸（8-oxog）病变是氧化损伤的主要稳定产物，并且具有最有害的作用，因为在DNA复制过程中，它可能会与腺嘌呤失误。因此，通过HMYH（muty腺嘌呤糖基化酶同源物），HOGG1（HOGG1（一种8-氧基糖基化酶）和HMSH2/HMSH6依赖性不配对的不匹配的不匹配修复途径提供了反对氧化途径的水平，可以与HMY HMY相互作用相互作用，因此，修复了HMSH2/HMSH6，修复了HMSH2/HMSH6，修复hMSH2/HMSH6依赖不匹配的维修途径可与HMY的总体相互作用，这是HMSH6的维修水平，可与HMY互动相互作用，它与HMY的相互作用相互作用，对氧化应激的反应，例如过氧化氢和电离辐射的处理。 HMYH与复制蛋白HPCNA和HRPA的相互作用将研究研究，将研究HAPE1和HMSH6，以及细胞周期检查点蛋白HHUSL/HHRADL/HRAD9。 （i）将研究HMYH与HPCNA和HHUSL在氧化应激下的相互作用的改变。 HMYH和HHUSL上的相互作用域将被映射，其功能相互作用的重要性将在体内测试。 HMYH-HPCNA TC HMYH-HRAD9/HRADL/HHUSL的分子转换发生的工作模型会诱导DNA损伤响应，并且HMYH可能会募集到病变位点的HMYH hrad9/hradl/hhusl。 （ii）HMYH和HMSH6之间的相互作用将在体外和体内阐明。裂变酵母菌S. POMBE将用作模型系统，以测试HMYH突变体的VIW功能。 （iii）将检查HMYH与HAPE 1，HPCNA，HHUS 1，HRPA和HMSH6 IR修复和复制基因座共定位。 （iv）DNA损伤后HMYH的磷酸化状态，负责HMYH磷酸化的激酶和HMYH的磷酸化位点将确定。将检查HMYH活性与蛋白质磷酸化或DNA损伤后某些蛋白质蛋白质相互作用的相关性。这项研究将促进我们对DNA修复在肿瘤敏感性中的作用的理解。