Role of RTEL1 in Microhomology-Mediated End Joining

RTEL1 在微同源介导的末端连接中的作用

基本信息

批准号：
10304187
负责人：
JAMES MATTHEW DALEY
金额：
$ 23.25万
依托单位：
UNIVERSITY OF TEXAS HLTH SCIENCE CENTER
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-11-18 至 2023-10-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10304187
关键词：
20q13 BRCA deficient Biochemical Biochemistry Biological Assay Breast Cancer cell line Cells Chromosomal Rearrangement DNA DNA Damage DNA Double Strand Break DNA Repair DNA Sequence DNA Structure DNA-Directed DNA Polymerase Disease Double Strand Break Repair Environment Environmental Health Enzymes Equilibrium Event Excision Exposure to Frequencies Genetic Genetic Epistasis Genetic Recombination Genome Glioma Goals Immunodeficiency and Cancer In Vitro Intellectual functioning disability Knowledge Lead Malignant Neoplasms Malignant neoplasm of ovary Mediating Modeling Molecular Genetics Mutagenesis Mutagens Mutation Nerve Degeneration Nonhomologous DNA End Joining Ovarian Pathologic Mutagenesis Pathology Pathway interactions Pharmaceutical Preparations Pharmacology Proteins Pulmonary Fibrosis Radiation Reaction Regulation Reporter Research Resected Role Site Structure Tail Testing Therapeutic Work anti-cancer cancer cell drug sensitivity druggable target genotoxicity helicase homologous recombination inhibitor innovation malignant breast neoplasm neoplastic cell nervous system disorder novel pollutant predictive modeling reconstitution repaired

项目摘要

PROJECT SUMMARY/ABSTRACT Double-strand breaks (DSBs) can arise in DNA from exposure to radiation and pollutants prevalent in our environment. Inaccurate repair of DSBs can lead to genome rearrangements, which can cause intellectual disability, neurodegeneration, immunodeficiency, and cancer. DSBs are removed by two major pathways: nonhomologous end joining (NHEJ) and homologous recombination (HR), which are dependent on different factors and are mechanistically very distinct. Importantly, DNA breaks can also undergo microhomology- mediated end joining (MMEJ), in which limited homology in the ssDNA tails exposed by end resection triggers DNA strand annealing to initiate end joining repair. MMEJ leads to deletion of the DNA sequence situated between the regions of microhomology. As such, MMEJ is highly mutagenic, and is a hallmark of cancer cells. The discoveries that MMEJ possesses a dedicated DNA polymerase, POLq, and that it is employed frequently even when NHEJ and HR are intact support the premise that MMEJ is an evolutionarily conserved DSB repair pathway. Tumor cells deficient in NHEJ and HR rely heavily on MMEJ for viability upon treatment with chemotherapeutic DNA damaging agents. Inactivation of MMEJ would thus sensitize tumor cells to such treatments. A major goal of current MMEJ research is to identify novel factors that regulate or directly catalyze MMEJ, to define the genetic and biochemical underpinnings by which they function, and to test their value as potential druggable targets. We have identified RTEL1 as a novel factor that is required for efficient MMEJ. RTEL1 encodes an essential DEAH helicase that disassembles various DNA structures including a key recombination intermediate, the displacement loop (D-loop). We hypothesize that RTEL1 promotes MMEJ by dissociating D-loop structures that otherwise compete with MMEJ. Our model explains several enigmatic observations regarding the inhibitory roles of HR factors in MMEJ and provides a mechanistic framework for understanding the pathology of RTEL1-associated diseases. We will test this innovative idea using a combination of molecular genetics and in vitro biochemistry. This project will better define the mechanism of MMEJ and its regulation, and may reveal factors that can be targeted to treat environmentally induced diseases such as cancer and neurological disorders. As such, our work will exert a strong impact on environmental health research.

项目概要/摘要由于暴露于我们生活中普遍存在的辐射和污染物，DNA 中可能会出现双链断裂 (DSB)。环境。 DSB 的不准确修复会导致基因组重排，从而导致智力下降残疾、神经退行性疾病、免疫缺陷和癌症。 DSB 通过两种主要途径被去除：非同源末端连接（NHEJ）和同源重组（HR），这取决于不同的因素和机制上非常不同。重要的是，DNA 断裂也可以发生微同源性—— 介导末端连接（MMEJ），其中通过末端切除触发暴露的单链DNA尾部的有限同源性 DNA 链退火以启动末端连接修复。 MMEJ 导致位于的 DNA 序列的删除微同源区域之间。因此，MMEJ 具有高度诱变性，是癌细胞的标志。发现 MMEJ 拥有专用 DNA 聚合酶 POLq，并且经常使用它即使 NHEJ 和 HR 完好无损，也支持 MMEJ 是进化上保守的 DSB 修复这一前提途径。缺乏 NHEJ 和 HR 的肿瘤细胞在化疗后的生存能力严重依赖 MMEJ DNA 损伤剂。因此，MMEJ 失活会使肿瘤细胞对此类治疗敏感。一个主要目标当前 MMEJ 研究的重点是确定调节或直接催化 MMEJ 的新因子，以定义遗传机制以及它们发挥作用的生化基础，并测试它们作为潜在药物靶点的价值。我们已确定 RTEL1 是有效 MMEJ 所需的新因子。 RTEL1 编码重要的 DEAH 解旋酶，可分解各种 DNA 结构，包括关键的重组中间体、置换循环（D 循环）。我们假设 RTEL1 通过解离 D 环结构来促进 MMEJ 与 MMEJ 竞争。我们的模型解释了有关 HR 抑制作用的几个神秘观察结果 MMEJ 中的因素，并为理解 RTEL1 相关病理学提供了一个机制框架疾病。我们将结合分子遗传学和体外生物化学来测试这一创新想法。该项目将更好地定义 MMEJ 的机制及其监管，并可能揭示可旨在治疗环境引起的疾病，例如癌症和神经系统疾病。因此，我们的工作将对环境健康研究产生重大影响。