Novel Interactions of DNA Repair Processes in Replication Fork Maintenance

复制叉维护中 DNA 修复过程的新相互作用

• 批准号: 8404020
• 负责人: Priscilla K. Cooper
• 金额: $ 39.94万
• 依托单位: UNIVERSITY OF CALIF-LAWRENC BERKELEY LAB
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-01-01 至 2016-10-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8404020
• 关键词: Adult; Affect; Aging; Base Excision Repairs; Biochemical; Biological; Cancer Etiology; Cell Cycle; Cell Cycle Checkpoint; Cell Cycle Progression; Cell Survival; Cells; Cockayne Syndrome; Collaborations; Coupled; Cytogenetics; DNA Damage; DNA Double Strand Break; DNA Repair; DNA annealing; DNA biosynthesis; DNA repair protein; Defect; Development; Disease; Environment; Environmental Exposure; Exposure to; Face; Family; Filament; Genetic; Genetic Transcription; Genome; Genome Stability; Genomic Instability; Genomics; Goals; Human; Inherited; Laboratories; Lead; Lesion; Maintenance; Malignant Neoplasms; Maps; Mediating; Mediator of activation protein; Modeling; Molecular; Mutation; Nerve Degeneration; Nucleotide Excision Repair; Organism; Outcome; Pathway interactions; Phenotype; Predisposition; Premature aging syndrome; Process; Proteins; Regulation; Risk; Role; S Phase; Site; Source; Structure; System; Testing; Transcription-Coupled Repair; Werner Syndrome; Xeroderma Pigmentosum; age related; base; cancer cell; cancer therapy; developmental disease; disease phenotype; endonuclease; exodeoxyribonuclease; helicase; homologous recombination; human disease; insight; mutant; nervous system disorder; novel; novel strategies; oxidative DNA damage; postnatal; presynaptic; prevent; recombinase; recombinational repair; repaired; response

DESCRIPTION (provided by applicant): Cells must maintain the integrity of their genomes in order to propagate and survive. However, genomes are constantly challenged by damage from endogenous metabolites and environmental sources that pose impediments to replication and transcription. Special risks arise during replication. If the replication fork is not protected, replisome stalling at lesions can ultimately lead to strand breakage, loss of genetic information, and genomic instability. To face these challenges, organisms evolved multiple DNA repair and checkpoint pathways that must be coordinated with each other, as well as with DNA replication. Breakdown either in any of these processes or their coordination can corrupt genome integrity and cause human disease phenotypes ranging from aging to cancer. This proposal aims to understand the biochemical basis and biological significance of two unexpected findings. First, the DNA repair protein XPG is up-regulated in S-phase and localizes to foci containing proteins that repair damaged replication forks. Second, XPG interacts physically and functionally with WRN, which is known to be important for maintaining genomic integrity during S-phase, and also interacts directly with the RAD51 recombinase. The central hypothesis to be tested is that XPG has novel roles in replication fork maintenance both cooperatively with WRN and through facilitation of RAD51-mediated homologous recombination. The proposed approaches harness the complementary biochemical and cell biological expertise of two established laboratories and their collaborators. Aim 1 will define the role of XPG at replication forks and characterize the biological consequences of its loss. Aim 2 will test the hypothesis that during S-phase XPG functions with WRN at a subset of stalled replication forks and determine the conditions under which they interact in cells. Aim 3 will investigate a proposed role for XPG as a mediator of homologous recombinational repair of replication-associated DNA double-strand breaks. The proposed studies will define the molecular basis for interactions among the DNA repair processes mediated by XPG and WRN and their novel role in preventing loss of genomic integrity during S phase, with implications both for informed regulation of environmental exposures and rational development of novel cancer therapies.

描述（由申请人提供）：细胞必须保持其基因组的完整性才能繁殖和生存。然而，基因组不断受到内源代谢物和环境来源损害的挑战，这些损害对复制和转录构成障碍。复制过程中会出现特殊风险。如果复制叉不受保护，复制体在损伤处停滞最终会导致链断裂、遗传信息丢失和基因组不稳定。为了应对这些挑战，生物体进化出了多种 DNA 修复和检查点途径，这些途径必须相互协调，并与 DNA 复制协调。这些过程中的任何一个或其协调的破坏都会破坏基因组的完整性，并导致从衰老到癌症等人类疾病表型。 该提案旨在了解两个意外发现的生化基础和生物学意义。 首先，DNA 修复蛋白 XPG 在 S 期上调，并定位于含有修复受损复制叉的蛋白质的病灶。其次，XPG 在物理和功能上与 WRN 相互作用，已知 WRN 对于维持 S 期基因组完整性非常重要，并且还直接与 RAD51 重组酶相互作用。要测试的中心假设是 XPG 与 WRN 合作并通过促进 RAD51 介导的同源重组在复制叉维护中具有新的作用。拟议的方法利用了两个已建立的实验室及其合作者的互补生化和细胞生物学专业知识。目标 1 将定义 XPG 在复制叉中的作用并描述其丢失的生物学后果。目标 2 将测试以下假设：在 S 期 XPG 与 WRN 在停滞复制叉子集上发挥作用，并确定它们在细胞中相互作用的条件。 目标 3 将研究 XPG 作为复制相关 DNA 双链断裂同源重组修复介质的作用。拟议的研究将确定 XPG 和 WRN 介导的 DNA 修复过程之间相互作用的分子基础，及其在防止 S 期基因组完整性丧失方面的新作用，对环境暴露的知情调节和新型癌症疗法的合理开发都有影响。