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）：细胞必须维持其基因组的完整性，以便传播和生存。但是，基因组不断受到内源性代谢产物和环境来源的损害，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。如果不受保护的复制叉，则在病变处停滞的重新组合可能会导致链断裂，遗传信息的丢失和基因组不稳定性。为了面对这些挑战，生物体进化了多个DNA修复和必须彼此协调的检查点途径以及与DNA复制。这些过程中的任何一个或其协调都可以破坏基因组完整性，并引起从衰老到癌症等等的人类疾病表型。 该建议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期间被上调，并将其定位于含有修复损坏复制叉的蛋白质的焦点。其次，XPG与WRN在物理和功能上相互作用，这对于在S期间维持基因组完整性很重要，并且与RAD51重组酶直接相互作用。要测试的中心假设是，XPG在复制方面具有与WRN合作以及通过促进RAD51介导的同源重组的新作用。拟议的方法利用了两个知名实验室及其合作者的互补生化和细胞生物学专业知识。 AIM 1将定义XPG在复制叉中的作用，并表征其损失的生物学后果。 AIM 2将检验以下假设：在S期XPG期间，在停滞的复制叉子子集中使用WRN函数，并确定它们在细胞中相互作用的条件。 AIM 3将研究XPG作为复制相关DNA双链断裂的同源重组修复的介体提出的作用。拟议的研究将定义由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阶段基因组完整性丧失方面的新作用，这对环境暴露和新型癌症疗法的合理性发展也有意义。