Role of homologous recombination in the replication stress response

项目总结/摘要 DNA的精确复制是维持基因组稳定性所必需的。复制分叉面临许多障碍， 内源性和外源性来源导致叉停滞或断裂，威胁基因组完整性。 双链断裂修复途径，同源重组，在停滞的复制叉中具有关键作用 不依赖于双链断裂修复。这一途径的重要性被以下患者强调： 遗传性染色体不稳定顺序和癌症易感综合征。虽然一个激烈的地区， 尽管在这项研究中，重组蛋白在复制叉中的机制作用仍然知之甚少。一 对复制反应的全面理解对于理解分子生物学中的 人类疾病的机制，并导致开发新的治疗方法，为病人窝藏缺陷 在复制反应基因中。PI的长期目标是阐明重组蛋白在 复制应激反应在这里，我们将阐明重组蛋白在羟基脲停滞中的作用。 复制在两个不同的项目中分叉。在项目1中，我们使用了一个强大的分离功能等位基因的中央 重组酶，RAD 51，以确定RAD 51如何保护复制叉的完整性， 使用遗传学、分子生物学和蛋白质组学的组合， 接近。在项目2中，我们提出了一系列的实验来研究额外的重组的作用 复制反应中的辅助因子。我们实验室的初步数据揭示了 重组蛋白在保护停滞的复制叉的完整性中的作用。我们将测试我们现有的模型 通过使用遗传和分子生物学技术对复制应激反应途径进行机械解剖， 接近。本文的工作将为今后的研究奠定基础， 参与复制应激反应的重组蛋白的分子机制。完成 这项工作不仅有助于更好地理解重组蛋白在失速中的作用， 复制叉，但也将提供分子洞察如何破坏这一途径导致人类 疾病对这一途径的全面了解对于开发治疗患有 遗传性基因组不稳定性疾病和靶向细胞复制反应的癌症。

PROJECT SUMMARY/ABSTRACT Precise replication of DNA is required to maintain genome stability. Replication forks face many obstacles from both endogenous and exogenous sources that result in fork stalling or breakage threatening genome integrity. The double strand break repair pathway, homologous recombination, has critical roles at stalled replication forks independent of double strand break repair. The importance of this pathway is highlighted by patients with inherited chromosomal instability orders and cancer predisposition syndromes. Although an intense area of study, the mechanistic role of recombination proteins at replication forks is still poorly understood. A comprehensive understanding of the replication response is critical for the understanding the molecular mechanisms of human disease and to lead to development of novel therapeutics for patients harboring defects in replication response genes. The long-term goal of the PI to elucidate the roles of recombination proteins in the replication stress response. Here we will elucidate the role of recombination proteins at hydroxyurea-stalled replication forks in two distinct projects. In Project 1, we use a powerful separation-of-function allele of the central recombination enzyme, RAD51, to determine how RAD51 protects the integrity of the replication fork during unchallenged and stressed conditions using a combination of genetic, molecular biology and proteomic approaches. In Project 2, we propose a series of experiments to investigate the role of additional recombination accessory factors in the replication response. Preliminary data from our lab has uncovered a novel role for recombination proteins in protecting the integrity of stalled replication forks. We will test our current models through mechanistic dissection of the replication stress response pathway using genetic and molecular approaches. The work presented here will lay the foundation for future studies involving the elucidation of molecular mechanisms of recombination proteins involved in the replication stress response. The completion of this work will lead to not only a better of understanding of the role recombination proteins play at stalled replication forks, but will also provide molecular insight into how disruption of this pathway results in human disease. A complete understanding of this pathway is essential for development of therapeutics for patients with inherited genome instability disorders and cancer that target the cellular replication response.