Repair of Oxidatively Damaged Guanines

氧化损伤鸟嘌呤的修复

• 批准号: 8109911
• 负责人: A-Lien L Lu-Chang
• 金额: $ 26.71万
• 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 2014-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8109911
• 关键词: 8-hydroxyguanosine; Acetylation; Address; Adenine; Affinity; Aging; Aging-Related Process; Antineoplastic Agents; Apoptosis; Base Excision Repairs; Binding; Binding Proteins; Biological; Biological Assay; Cell Aging; Cell Cycle; Cell Cycle Arrest; Cell Cycle Checkpoint; Cell Cycle Progression; Cell Cycle Regulation; Cells; Chromatin; Co-Immunoprecipitations; Colon Carcinoma; Complex; DNA; DNA Damage; DNA Repair; DNA Repair Enzymes; DNA biosynthesis; DNA damage checkpoint; DNA glycosylase; DNA lesion; DNA repair protein; DNA strand break; Deacetylase; Defect; Development; Drug Delivery Systems; Excision; Fluorescence; Frequencies; Gene Activation; Genes; Genome Stability; Genomic Instability; Genomics; Goals; Guanine; Hereditary Nonpolyposis Colorectal Neoplasms; Histone Deacetylase; Homologous Gene; Human; Human Activities; Hydrogen Peroxide; Immunoprecipitation; In Vitro; Individual; Interruption; Knock-out; Lead; Lesion; MSH2 gene; MSH6 gene; Malignant Neoplasms; Measures; Mediating; Mismatch Repair; Modeling; Molecular; Monitor; Mus; Mutagenesis; Mutation; OGG1 gene; Oxidative Stress; Pathway interactions; Peptides; Phosphorylation; Plasma; Process; Proteins; Reactive Oxygen Species; Recruitment Activity; Regulation; Repair Complex; Resistance; Role; Signal Transduction; Site; Stress; Surface; System; Tertiary Protein Structure; Testing; Work; Yeasts; base; cancer prevention; carcinogenesis; cell age; crosslink; design; human H2AX protein; human disease; in vivo; insight; interest; mutant; neoplastic cell; novel; oxidative DNA damage; polyposis; prevent; protein complex; protein protein interaction; public health relevance; rad9 protein; repair enzyme; repaired; response; sensor; theories; tool; transversion mutation

DESCRIPTION (provided by applicant): Oxidative DNA damage presents a serious challenge to genomic integrity and can accelerate carcinogenesis and aging. Reactive oxygen species-dependent DNA damage are repaired by base excision repair (BER), initiated with removal of base lesions by DNA glycosylases. The overall goal of this project is to study the role of selected DNA glycosylases and mismatch repair enzymes in response to cellular oxidative stress. We focus on the role of human MutY homolog (hMYH) glycosylase and its interactions with cell cycle and aging regulators. hMYH reduces stress-induced mutagenesis by removing misincorporated adenines paired with 8-oxoG (the most abundant form of DNA damage), therefore reduces G:C to T:A mutations. hMYH deficiency predispose individuals to colon cancer. hMYH interacts with the DNA replication machinery, other repair enzymes, the 9-1-1 cell cycle checkpoint complex (Rad9/Rad1/Hus1), and the aging regulator SIRT6. In this context, the 9-1-1 proteins interact with and increase the activities DNA glycosylases and hMSH2/hMSH6 mismatch recognition complex. We hypothesize that MYH and other DNA repair enzymes serve as molecular adaptors to recruit checkpoint proteins to DNA lesion sites and coordinate DNA repair and increase repair efficiency and fidelity. To examine this hypothesis, we propose three specific aims: (1) The dynamic interaction of MYH with MSH2/MSH6 both in vitro and in vivo will be delineated. We will test whether these interactions are altered following oxidative stress and during the progression of the cell cycle. (2) The physical and functional Interactions of MYH (and Neil1, hOGG1 and hMSH2/hMSH6) with the 9-1-1 complex will be elucidated. We will investigate how different proteins compete for the 9-1-1 complex and why different glycosylases select different subunits of the 9-1-1 complex. The biological significance of Hus1-MYH interaction will be investigated by interruption of the interaction by mutagenesis and by using a Hus1 binding competitor peptide. We will test a model that DNA glycosylases act as adaptors to recruit the 9-1-1 complex to the lesion sites. (3) The novel role of an aging regulator SIRT6 in DNA repair, cell cycle control, and aging will be studied. SIRT6 interacts with the 9-1-1 complex and has a role in BER by stimulating MYH, but inhibiting NEIL1 activity. We will test whether expression of DNA glycosylase can influence the sensitivity of Sirt6 deficient cells to DNA damage agents and whether SIRT6 can deacetylate hNEIL1. Because SIRT6 is required to regulate genomic integrity and impacts the aging process, revealing the mechanism of SIRT6 interaction in BER and cell cycle checkpoints is important. Successful completion of these studies will reveal important new information regarding the interactions among DNA repair proteins, cell cycle checkpoints, and an aging regulating protein. These studies will advance our understanding of carcinogenesis process and form the background work for the development of new anti-cancer drugs. PUBLIC HEALTH RELEVANCE: The overall goal of this project is to address the roles of several DNA glycosylases and mismatch repair enzymes in cancer prevention. Defects in DNA repair, cell cycle checkpoint activation, and gene silencer SIRT6 are associated with cancer and aging. The findings from our studies will have implications for treating human disease and cancer.

描述（由申请人提供）： 氧化DNA损伤对基因组完整性提出了严重的挑战，并可以加速癌变和衰老。通过碱切除修复（BER）修复活性氧依赖性DNA损伤，该损伤是通过DNA糖基化酶去除碱病变而引发的。该项目的总体目标是研究选定的DNA糖基酶和不匹配修复酶对细胞氧化应激的作用。我们专注于人类强型同源物（HMYH）糖基酶的作用及其与细胞周期和衰老调节剂的相互作用。 HMYH通过去除与8-oxog（最丰富的DNA损伤形式）配对的衰弱的腺丝来减少应力诱导的诱变，从而减少G：C至T：A突变。 HMYH缺乏症患者易于结肠癌。 HMYH与DNA复制机械，其他修复酶，9-1-1细胞周期检查点复合物（RAD9/RAD1/HUS1）和老化调节剂SIRT6相互作用。在这种情况下，9-1-1蛋白与活性DNA糖基酶和HMSH2/HMSH6不匹配识别复合物相互作用并增加了活性。我们假设MYH和其他DNA修复酶是分子适配器，可募集检查点蛋白到DNA病变位点并坐标DNA修复并提高修复效率和保真度。为了审查这一假设，我们提出了三个特定的目的：（1）将描述MYH与MSH2/MSH6的动态相互作用，包括体外和体内。我们将测试在氧化应激和细胞周期进展过程中是否改变了这些相互作用。 （2）将阐明MYH（以及Neil1，HogG1和HMSH2/HMSH6）与9-1-1复合物的物理和功能相互作用。我们将研究不同的蛋白质如何争夺9-1-1复合物，以及为什么不同的糖基酶选择9-1-1复合物的不同亚基。 HUS1-MYH相互作用的生物学意义将通过诱变并使用HUS1结合竞争者肽来研究这种相互作用。我们将测试一个模型，即DNA糖基酶是将9-1-1复合物募集到病变位点的衔接子。 （3）将研究衰老调节剂SIRT6在DNA修复，细胞周期控制和衰老中的新作用。 SIRT6与9-1-1复合物相互作用，并通过刺激MYH但抑制Neil1活性在BER中发挥作用。我们将测试DNA糖基酶的表达是否会影响SIRT6缺陷细胞对DNA损伤剂的敏感性以及SIRT6是否可以脱乙酰酸HNEIL1。由于需要SIRT6来调节基因组完整性并影响衰老过程，因此揭示SIRT6相互作用在BER和细胞周期检查点中的机制很重要。这些研究的成功完成将揭示有关DNA修复蛋白，细胞周期检查点和调节蛋白质衰老的重要新信息。这些研究将提高我们对癌变过程的理解，并构成开发新抗癌药物的背景工作。 公共卫生相关性： 该项目的总体目标是解决几种DNA糖基酶和错配修复酶在预防癌症中的作用。 DNA修复，细胞周期检查点激活中的缺陷和基因消音SIRT6与癌症和衰老有关。我们研究的发现将对治疗人类疾病和癌症有影响。