The Mechanistic Role of BRCA1-BARD1 DNA and RAD51 Binding in DNA Double-Strand Break Repair

摘要 基因组的不稳定性是癌症的一个标志，它使突变和总染色体畸变的产生成为可能。 重排来驱动肿瘤细胞转化和肿瘤发生。多种保守的DNA修复 机制消除DNA损伤，这些DNA修复途径中的缺陷导致基因组不稳定， 癌同源重组（homopolymerase recombination，HR）是一种DNA修复途径，介导了DNA的精确修复 高毒性的双链DNA断裂（DSB）和受损的DNA复制叉。BRCA 1及其特异性 结合伴侣BARD 1是乳腺癌、卵巢癌和其他癌症的抑制因子，在HR中发挥多方面的作用。 具体地说，BRCA 1-BARD 1复合物影响DSB修复途径的选择，并增强DSB修复的效率。 几个HR步骤，包括DNA损伤的溶核加工，DSB修复核蛋白的组装 携带重组酶RAD 51的复合物和DNA链侵入。我们证明DNA和RAD 51 BRCA 1-BARD 1的绑定属性与DSB修复和复制分叉维护功能密切相关 肿瘤抑制复合体的一部分为了帮助填补主要的知识空白，本研究金提案力求描述 RAD 51与BRCA 1-BARD 1中DNA相互作用的界面，并阐明这些界面的机制作用 HR介导的DNA修复和保护应激和受损DNA复制的生物化学属性 叉子我们的目标将通过两个具体目标下的生物化学和基于细胞的研究来实现。 我们努力的结果将阐明BRCA 1-BARD 1中临床突变的功能相关性。 并为开发针对DNA缺陷肿瘤的新型治疗方法创造了新的途径 修复.

ABSTRACT Genomic instability is a hallmark of cancer, enabling the generation of mutations and gross chromosomal rearrangements to drive neoplastic cell transformation and oncogenesis. A variety of conserved DNA repair mechanisms eliminate DNA damage, and defects in these DNA repair pathways lead to genomic instability and cancer. Homologous recombination (HR) is one such DNA repair pathway, which mediates the accurate repair of highly toxic double-strand DNA breaks (DSBs) and damaged DNA replication forks. BRCA1 and its obligate binding partner BARD1, both suppressors of breast, ovarian, and other cancers, fulfill multifaceted roles in HR. Specifically, the BRCA1-BARD1 complex influences DSB repair pathway choice and enhances the efficiency of several HR steps, including the nucleolytic processing of DNA lesions, the assembly of DSB repair nucleoprotein complexes that harbor the recombinase RAD51, and DNA strand invasion. We posit that the DNA and RAD51 binding attributes of BRCA1-BARD1 are germane for the DSB repair and replication fork maintenance functions of this tumor suppressor complex. To help fill major knowledge gaps, this fellowship proposal strives to delineate RAD51 and DNA interaction interfaces in BRCA1-BARD1 and to elucidate the mechanistic roles of these biochemical attributes in HR-mediated DNA repair and the protection of stressed and damaged DNA replication forks. Our objectives will be accomplished through biochemical and cell-based studies under two specific aims. The results of our endeavors will clarify the functional relevance of clinical mutations within BRCA1-BARD1 domains and create new avenues for the development of novel therapeutics to target tumors deficient in DNA repair.