Cellular responses to DNA replication stress

项目摘要 基因组的不稳定性驱动癌症、衰老和其他人类疾病的进展。的完整性 基因组在复制时尤其危险，因为复制叉经常遇到障碍， 进展，包括DNA损伤、难以复制的序列、转录中间体或蛋白质-DNA 配合物这些接触通常会导致DNA断裂，染色体重排， 非整倍体，这是癌症发生的关键事件。正确修复停滞或崩溃的复制分叉 通过同源重组（HR）为基础的机制发挥了重要作用，在防止复制 应激诱导的基因组不稳定性和HR机制组分中的许多突变已经被 与癌症易感性有关。在没有一个完整的人力资源机制，容易出错的机制 例如非同源末端连接（NHEJ）趋向于被过度利用，导致广泛基因组 不稳定因此，HR和NHEJ因子向DNA损伤募集的调节基础是 基因组生物学和癌症研究的核心兴趣，不仅是为了解释 肿瘤发生，但也为癌症治疗提供了有前途的途径，最近证明， PARP抑制剂现已被批准用于治疗BRCA 1突变的卵巢癌患者 欧洲和美国。这一建议将探讨一种新的机制，调控重组DNA 修复和修复途径的选择。核心假设是进化上保守的脚手架 蛋白TopBP 1在HR介导的修复和DNA调控中起着重要的作用，但在很大程度上尚未探索。 修复路径选择利用生物化学、蛋白质组学和遗传学方法在酵母、人类细胞系和 基因组编辑的小鼠，我们将定义TopBP 1及其酵母直系同源物Dpb 11 控制DNA修复。我们的研究将提供无与伦比的分子理解如何行动的关键HR 和NHEJ因子是协调的，并将揭示信号网络如何整合DNA的控制 复制、检查点信号传导和DNA修复。拟议的实验将揭示新的修复机制 途径选择和重组修复对抑制基因组不稳定性和癌症至关重要。 产生的结果将对研究HR修复功能障碍引起的肿瘤发生产生影响 并且应该为治疗提供新的理论基础。

PROJECT SUMMARY Genomic instabilities drive the progression of cancer, aging, and other human diseases. The integrity of our genome is especially at risk while it is being replicated, as replication forks often encounter obstacles to their progression, including DNA lesions, hard-to-replicate sequences, transcription intermediates, or protein-DNA complexes. These encounters often result in DNA breaks, gross chromosomal rearrangements and aneuploidy, which are key events in cancer initiation. The proper repair of stalled or collapsed replication forks through homologous recombination (HR)-based mechanisms plays a major role in preventing replication stress-induced genomic instabilities and many mutations in components of the HR machinery have been associated with cancer predisposition. In the absence of an intact HR-machinery, error-prone mechanisms such as non-homologous end joining (NHEJ) tend to become hyper-utilized, leading to extensive genomic instability. The regulatory basis of the recruitment of HR and NHEJ factors to DNA lesions is therefore of central interest to genome biology and cancer research, not only for explaining the mechanisms of tumorigenesis, but also for providing promising avenues for cancer therapy, as recently demonstrated for PARP inhibitors that are now approved for treatment of ovarian cancer patients with BRCA1 mutations in Europe and the US. This proposal will investigate a new mechanism for regulation of recombinational DNA repair and repair pathway choice. The central hypothesis is that the evolutionarily conserved scaffolding protein TopBP1 plays a central, yet largely unexplored, role in the control of HR-mediated repair and DNA repair pathway choice. Utilizing biochemical, proteomic and genetic approaches in yeast, human cell lines and genome-edited mice, we will define the molecular mechanism by which TopBP1 and its yeast ortholog Dpb11 control DNA repair. Our studies will provide unparalleled molecular understanding of how the action of key HR and NHEJ factors are coordinated and will reveal how signaling networks integrate the control of DNA replication, checkpoint signaling and DNA repair. Proposed experiments will reveal novel mechanisms of repair pathway choice and recombinational repair that are crucial to suppress genomic instability and cancer. Generated outcomes will have implications in the study of tumorigenesis caused by dysfunctions in HR repair and should provide new rationale for therapy.