Early events in double-strand break repair in local, genomic and metabolic contexts

项目总结/摘要 染色体重排对人类健康有多种影响，如癌症、遗传性遗传病、 和正常的组织功能虽然比单核苷酸变化频率低，但结构变异是 不成比例的影响，因为它们改变了基因组的连续性，并立即改变了许多碱基对。 重排主要通过DNA双链断裂（DSB）发生，因为它们破坏了染色体 完整多年来，该项目一直致力于DSB修复分子机制的基础研究 以及主要在酵母中进行的染色体诱变，特别是非同源末端连接（NHEJ）， 它和其他修复途径如同源重组（HR）如何有助于基因组的维持。 我们将继续利用酵母来探索一系列关键的背景影响，这些影响决定了通过 DSB修复朝向可变结果，专注于单细胞真核生物是理想的环境 实验系统该项目将专门调查DSB修复中的一些最早事件， 在识别到断裂后不久发生，并与修复机制的承诺一致。在 最小的规模，我们将利用新的单碱基分辨率切除和蛋白质占有率测定来探索 局部序列对DSB修复的影响，特别是在DSB修复的初始阶段对特定蛋白质功能的影响。 体内DSB切除术。在基因组水平上，我们将跟进我们最近的发现，以了解核 不同DSB位置的功能特性通过DSB影响致突变结果频率 运动在细胞尺度上，我们将扩大我们的重点，以研究代谢的机制， 响应碳源的信号传导与DNA损伤反应和细胞周期相互作用，我们先前的研究表明， 工作确定为一个重要的和未充分探索的方面DSB修复法规。结果将提供新的 深入了解这些细胞过程通常如何保存基因组，以及当 他们受到环境或遗传因素的干扰。

Project Summary / Abstract Chromosomal rearrangements have multiple impacts on human health in cancer, inherited genetic disease, and normal tissue function. While less frequent than single-nucleotide changes, structural variants are disproportionately impactful because they alter genome continuity and change many base pairs at once. Rearrangements mainly arise through DNA double-strand breaks (DSBs) because they disrupt chromosomal integrity. Over many years this project has engaged basic studies of the molecular mechanisms of DSB repair and chromosomal mutagenesis conducted mainly in yeast, specifically nonhomologous end joining (NHEJ) and how it and other repair pathways such as homologous recombination (HR) contribute to genome maintenance. We will continue to exploit yeast to explore a set of critical contextual influences that determine the flux through DSB repair toward variable outcomes, focusing on contexts for which a single-cell eukaryote is an ideal experimental system. This project will specifically investigate some of the earliest events in DSB repair that occur soon after recognition of the break and coincident with the commitment to a repair mechanism. At the smallest scale, we will exploit novel single-base resolution resection and protein occupancy assays to explore the impact of local sequence on DSB repair, in particular on specific protein functions in the initial stages of DSB resection in vivo. At the genomic scale, we will follow up our recent findings to understand how nuclear and functional properties of different DSB locations influence mutagenic outcome frequencies through DSB movement. At the cellular scale, we will expand our focus to investigate the mechanisms by which metabolic signaling in response to carbon source interacts with the DNA damage response and cell cycle, which our prior work identifies as an important and underexplored aspect of DSB repair regulation. Results will provide novel insights into how these cellular processes normally preserve the genome and how rearrangements result when they are perturbed by environmental or genetic factors.