Mechanisms and Crosstalk of DNA Break Resection Pathways

DNA断裂切除途径的机制和串扰

• 批准号: 8278904
• 负责人: HENGYAO NIU
• 金额: $ 9万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-05-10 至 2014-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8278904
• 关键词: Atomic Force Microscopy; Binding; Binding Proteins; Biochemical; Biochemical Genetics; Biochemistry; Cell Cycle; Chemicals; Chromosomal Breaks; Chromosomes; Complex; DNA; DNA Binding; DNA Damage; DNA Double Strand Break; DNA Repair; DNA Sequence Rearrangement; DNA damage checkpoint; Defect; Deposition; Disease; Double Strand Break Repair; Eukaryota; Excision; Exposure to; G1 Phase; Gene Mutation; Genetic; Genome; Health; Human; Ionizing radiation; Lead; Ligation; Malignant Neoplasms; Maps; Mediating; Mentors; Modeling; Molecular; Motor; Nonhomologous DNA End Joining; Pathway interactions; Phase; Process; Proteins; Rad51 recombinase; Radiation; Reaction; Regulation; Research; Research Design; Research Project Grants; Resected; Role; Saccharomyces cerevisiae; Surgical incisions; System; Tail; Testing; Training; Yeasts; attenuation; base; chromatin immunoprecipitation; cohort; homologous recombination; irradiation; mutant; nuclease; polypeptide; public health relevance; reconstitution; repaired; yeast two hybrid system

DESCRIPTION (provided by applicant) Homologous recombination (HR) and non-homologous end joining (NHEJ) are conserved pathways for the repair of DNA double stranded breaks (DSBs) induced by ionizing radiation and genotoxic chemicals. HR utilizes a homologous template strand to repair damaged DNA in an error-free manner. NHEJ, which entails processing of the broken chromosome ends and their ligation, is often error-prone. HR is initiated by nucleolytic processing of the DNA break to yield 3' ssDNA tails for the recruitment of the repair machinery. Studies in the model eukaryote Saccharomyces cerevisiae have revealed multiple pathways of DNA break resection, two of which are responsible for long-range resection. DNA break processing is regulated during the cell cycle. Specifically, NHEJ proteins suppress it in G1, but this suppression is relieved during S and G2. In the K99 phase of this project, the candidate will determine the mechanisms of polarity control and DNA end engagement during the end resection process. In the R00 phase, the candidate will elucidate the functional crosstalk between the long-range resection paths that are dependent on Sgs1/Dna2 and Exo1 and will also examine how the restriction imposed by NHEJ proteins is overcome by DNA motor proteins in conjunction with the Mre11 complex. Given the remarkable degree of conservation of the DNA end resection mechanisms, the results from this project should provide a valuable experimental framework to guide similar endeavors in other eukaryotes, including humans. Public Health Relevance: DNA damaging agents induce genetic mutations and genome rearrangements. The proposed studies will delineate the mechanism by which DNA breaks resulting from exposure to radiation and genotoxic chemicals are nucleolytically processed in order to activate the DNA damage checkpoint and to prepare for damage repair by homologous recombination. The results from the research endeavors have direct relevance to understanding the relevance of DNA repair in health and disease.

描述（由申请人提供） 同源重组（HR）和非同源末端连接（NHEJ）是通过电离辐射和遗传毒性化学物质诱导的DNA双链断裂（DSB）的保守途径。 HR利用同源模板链以无错误的方式修复受损的DNA。 NHEJ需要处理破裂的染色体末端及其连接的处理，通常容易出错。 HR是通过DNA断裂的核酸化处理引发的 产生3'ssDNA尾巴，用于募集维修机械。 在酿酒酵母的真核生糖含量的模型中，DNA断裂切除术的多种途径，其中两种是造成远距离切除的原因。 在细胞周期中调节DNA断裂处理。 具体而言，NHEJ蛋白在G1中抑制它，但是在 S和G2。 在该项目的K99阶段，候选人将在结束切除过程中确定极性控制和DNA终端参与的机制。 在R00阶段，候选人将阐明依赖于SGS1/DNA2和EXO1的远程切除路径之间的功能性串扰，还将研究如何通过与MRE11复合物结合DNA运动蛋白来克服NHEJ蛋白施加的限制。 鉴于DNA末端切除机制的显着保存程度，该项目的结果应提供一个有价值的实验框架，以指导包括人类在内的其他真核生物中的类似努力。 公共卫生相关性：DNA破坏药物会引起基因突变和基因组重排。拟议的研究将描述暴露于辐射和遗传毒性化学物质导致的DNA断裂的机制，以激活DNA损伤检查点并准备通过同源重组进行损伤修复。研究努力的结果与理解DNA修复在健康和疾病中的相关性有直接相关。