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MAMMALIAN DOUBLE-STRAND BREAK AND RECOMBINATIONAL REPAIR

哺乳动物双链断裂和重组修复

基本信息

批准号：
7334757
负责人：
Mary Ann Osley
金额：
$ 25.6万
依托单位：
UNIVERSITY OF NEW MEXICO
依托单位国家：
美国
项目类别：
财政年份：
1999
资助国家：
美国
起止时间：
1999-01-01 至 2009-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7334757
关键词：
ATP phosphohydrolase ATPase Domain BRCA1 gene BRCA2 gene Biological Models Cell Survival Cells Chemicals Chromosomes Complex Computer Systems Development DNA DNA Damage DNA Double Strand Break DNA biosynthesis Defect Development Disease regression Dominant-Negative Mutation Double Strand Break Repair Exhibits Frequencies Gene Conversion Gene Targeting Genetic Transcription Genome Stability Genomic Instability Goals Human Investigation Length Lesion Maintenance Malignant Neoplasms Mammalian Cell Mammalian Chromosomes Measures Mediating Mutagenesis Outcome Phenotype Positioning Attribute Predisposition Process Proteins RAD51C gene Radiation Radiation Induced DNA Damage Rate Regulation Relative (related person)Research Role SHFM1 gene Staging System Thinking Tumor Suppression XRCC2 gene XRCC3 gene cell killing ds-DNA embryo cell endodeoxyribonuclease SceI filamin gene therapy genetic regulatory protein homologous recombination insight metaplastic cell transformation mutant neoplastic cell nuclease paralogous gene protein function recombinational repair repaired tumor

项目摘要

DESCRIPTION (provided by applicant): The goal of the proposed research is to determine the structural and enzymatic roles of several mammalian proteins in homologous recombinational repair (HR) of DNA double-strand breaks (DSBs), and to determine how these proteins regulate spontaneous HR. DSBs are induced by chemicals and radiation and they arise spontaneously during DNA replication. DSBs are repaired by HR and by nonhomologous end-joining (NHEJ). Proteins with direct roles in HR include RAD51, five RAD51 paralogs (XRCC2, XRCC3, RAD51B, RAD51C, and RAD51D), BRCA1, and BRCA2. RAD51 catalyzes DNA strand transfer and is therefore central to HR processes. However, RAD51 is difficult to study in mammalian cells because null mutants are cell- and embryo-lethal. The RAD51 paralogs form several complexes, and these complexes physically interact with RAD51 and/or DNA, and are thought to augment RAD51 activity. BRCA2 interacts with RAD51 and other proteins, as well as single- and double-stranded DNA. The RAD51 paralogs and BRCA2 are thus uniquely positioned to regulate HR efficiency and outcome. Defects and/ or altered expression of any of these proteins result in genome instability and cancer predisposition. We recently demonstrated that XRCC3 influences early and late stages of HR, and that several BRCA2 functional domains have dominant negative effects on DSB-induced HR in human cells. Two specific aims are proposed to investigate (1) the structural and enzymatic roles of XRCC2, XRCC3, and RAD51C in DSB-induced and spontaneous HR; and (2) the roles of several functional domains of BRCA2 in DSB-induced and spontaneous HR, including BRCA2 domains that interact with single- and double-stranded DNA, RAD51, and other proteins. These projects will help establish roles for specific structural or enzymatic domains of XRCC2, XRCC3, RAD51C, and BRCA2 in early and/or late stages of HR, and thereby provide new insight into the regulation of HR, maintenance of genome stability, and tumor suppression. Because DSB repair is a key determinant of cell survival following DNA damage, the information gained from these studies will also facilitate the development of more effective agents to sensitize tumor cells to DNA damage by radiation and genotoxic chemicals. Studies of HR mechanisms and HR regulatory proteins will also facilitate the development of more effective gene targeting and gene therapy systems.

描述（由申请人提供）：拟议研究的目标是确定几种哺乳动物蛋白质在DNA双链断裂（DSBs）同源重组修复（HR）中的结构和酶作用，并确定这些蛋白质如何调节自发的HR。dsb是由化学物质和辐射诱导的，它们在DNA复制过程中自发产生。dsb由HR和非同源末端连接（NHEJ）修复。在HR中起直接作用的蛋白包括RAD51、RAD51的5个类似蛋白（XRCC2、XRCC3、RAD51B、RAD51C和RAD51D）、BRCA1和BRCA2。RAD51催化DNA链转移，因此是HR过程的中心。然而，RAD51很难在哺乳动物细胞中进行研究，因为零突变体对细胞和胚胎都是致命的。RAD51类似物形成了几种复合物，这些复合物与RAD51和/或DNA发生物理相互作用，并被认为增强了RAD51的活性。BRCA2与RAD51和其他蛋白质以及单链和双链DNA相互作用。因此，RAD51类似物和BRCA2在调节HR效率和结果方面具有独特的定位。这些蛋白的缺陷和/或表达改变会导致基因组不稳定和癌症易感性。我们最近证明XRCC3影响HR的早期和晚期，并且几个BRCA2功能域对人细胞中dsb诱导的HR有主要的负面影响。我们提出了两个具体的研究目标：(1)XRCC2、XRCC3和RAD51C在dsb诱导和自发HR中的结构和酶促作用；(2) BRCA2的几个功能域在dsb诱导和自发HR中的作用，包括与单链和双链DNA、RAD51和其他蛋白质相互作用的BRCA2结构域。这些项目将有助于确定XRCC2、XRCC3、RAD51C和BRCA2的特定结构域或酶结构域在HR早期和/或晚期的作用，从而为HR的调控、基因组稳定性的维持和肿瘤抑制提供新的见解。由于DSB修复是DNA损伤后细胞存活的关键决定因素，从这些研究中获得的信息也将有助于开发更有效的药物，使肿瘤细胞对辐射和遗传毒性化学物质的DNA损伤敏感。对HR机制和HR调节蛋白的研究也将促进更有效的基因靶向和基因治疗系统的发展。