Elucidating the molecular mechanisms of structure-selective endonucleases in DNA repair and genome stability

阐明结构选择性核酸内切酶在 DNA 修复和基因组稳定性中的分子机制

• 批准号: RGPIN-2017-06670
• 负责人: Wyatt, Haley
• 金额: $ 4.81万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=744147
• 关键词: Elucidating; molecular; mechanisms; structure; selective

An essential component of every living organism is DNA, which provides the blueprint for life and is required for the biological processes in each and every cell. During normal cell growth, this genetic information must be accurately replicated and propagated to two daughter cells. Paradoxically, DNA is highly susceptible to damage by agents that occur naturally (e.g. metabolic by-products) and in the environment (e.g. ultraviolet radiation, carcinogenic chemicals). If left unrepaired, damaged DNA can trigger mutations, chromosomal rearrangements and genome instability. To counteract the deleterious effects of genotoxic agents, cells contain sophisticated DNA repair networks that safeguard genome integrity and ensure proper cell function. Understanding the intricate mechanisms that underpin these essential cellular pathways is a major goal of scientists that study the basic biological processes of DNA repair and genome stability. Most DNA repair pathways require the actions of structure-selective endonucleases (SSEs), which are molecular scissors that remove potentially toxic DNA structures that form during DNA repair (and normal cell growth). The failure to remove these structures compromises chromosome stability. Nevertheless, DNA cleavage opens the door for indiscriminate repair that can fuel genetic rearrangements, emphasizing the importance of regulatory mechanisms to control the activity of SSEs and prevent uncontrolled DNA cleavage.The conserved SSEs SLX1-SLX4, MUS81-EME1 and XPF-ERCC1 are required for DNA recombination and repair in most eukaryotes. The SLX4 protein provides a scaffold for the SMX tri-nuclease complex, formed by interactions with SLX1, MUS81-EME1 and XPF-ERCC1. SLX4 interacts with several other genome stability proteins, leading to the prevailing model that SLX4 provides a hub for the assembly of versatile macromolecular complexes that orchestrate diverse protein-DNA transactions. Key questions about the structure, function and regulation of these complexes remain to be addressed. My research will elucidate the cellular roles, regulation and biochemical mechanisms of macromolecular SLX4 complexes. This information will provide a mechanistic framework for understanding how these complexes function and mediate genome stability. My studies will also provide fundamental new insights into DNA recombination and repair, both of which are essential cellular processes. My research has numerous tangible benefits for Canadians, including the training of high quality personnel, development of research capacity, and knowledge advancement. My studies will elevate Canada's recognition as a hub for research innovation and excellence in the fields of DNA repair and genome stability, thereby stimulating economic and societal growth through the recruitment and training of world-class scientists.

DNA是每个活着的有机体的一个重要组成部分，它提供了生命的蓝图，是每个细胞中生物过程所必需的。在正常的细胞生长过程中，这种遗传信息必须被准确地复制并传播到两个子细胞。自相矛盾的是，DNA极易受到自然(如代谢副产物)和环境中(如紫外线辐射、致癌化学品)的损害。如果不加以修复，受损的DNA可能会引发突变、染色体重排和基因组不稳定。为了抵消遗传毒性物质的有害影响，细胞包含复杂的DNA修复网络，以保护基因组的完整性，并确保细胞的正常功能。了解支撑这些基本细胞通路的复杂机制是研究DNA修复和基因组稳定性的基本生物学过程的科学家的主要目标。大多数DNA修复途径都需要结构选择内切酶(SSE)的作用，SSE是一种分子剪刀，可以去除DNA修复(和正常细胞生长)过程中形成的潜在有毒DNA结构。如果不能移除这些结构，就会损害染色体的稳定性。然而，DNA切割为促进基因重排的不分青红皂白的修复打开了大门，强调了调控机制的重要性，以控制SSE的活性和防止不受控制的DNA切割。大多数真核生物中保守的SSE SLX1-SLX4、MUS81-EME1和XPF-ERCC1是DNA重组和修复所必需的。SLX4蛋白为SMX三核酸酶复合体提供了支架，该复合体由SLX1、MUS81-EME1和XPF-ERCC1相互作用形成。SLX4与其他几种基因组稳定蛋白相互作用，导致流行的模型，即SLX4为协调不同蛋白质-DNA交易的多功能大分子复合体的组装提供了一个枢纽。关于这些复合体的结构、功能和调控的关键问题仍有待解决。我的研究将阐明大分子SLX4复合体的细胞作用、调节和生化机制。这些信息将为理解这些复合体如何发挥作用和调节基因组稳定性提供一个机械框架。我的研究还将为DNA重组和修复提供基本的新见解，这两个过程都是基本的细胞过程。我的研究对加拿大人有许多实实在在的好处，包括培训高素质的人才，发展研究能力，以及知识进步。我的研究将提升加拿大作为DNA修复和基因组稳定领域研究创新和卓越中心的认可度，从而通过招募和培训世界级科学家来刺激经济和社会增长。