Molecular events regulated by the Ku heterodimer in non-homologous end-joining and DNA damage signaling pathways

非同源末端连接和 DNA 损伤信号通路中 Ku 异二聚体调控的分子事件

• 批准号: RGPIN-2018-05518
• 负责人: SchildPoulter, Caroline
• 金额: $ 3.64万
• 依托单位: University of Western Ontario
• 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=744097
• 关键词: Molecular; events; regulated; Ku; heterodimer

Ku is an abundant, ubiquitous factor that has been remarkably conserved throughout evolution as it has beenidentified in all organisms from bacteria to man. Ku is a complex of two proteins that plays an essential role inthe repair of double-strand DNA breaks, a form of DNA damage in which both strands of the double helixbreak, leading to chromosome rearrangements and, ultimately, genomic instability.While it is understood that Ku is essential for the proper repair of DNA, its mode of action is still unclear. It isknown that Ku interacts with a number of other factors that play roles in the repair of DNA, however, thedetails and the outcome of these interactions are poorly understood.Using the crystal structure of Ku that was recently made available, we can predict regions of the protein that areaccessible to contact other proteins. Thus we have made mutations in several of these accessible regions to testif they alter Ku DNA repair functions. We have identified two Ku mutations that alter its ability to function inresponse to DNA damage. We found that these mutations result in different defects suggesting that the mutatedregions are involved in distinct functions. We propose to identify the proteins that interact with these Ku motifsand elucidate how they function together in the repair of DNA.In the long-term, these analyses will enhance our understanding of the functions of Ku in the mechanisms thatare set in place to deal with double-stranded DNA breaks.

Ku是一种丰富的、普遍存在的因子，在整个进化过程中一直非常保守，因为它在从细菌到人类的所有生物中都被发现。Ku是一种由两种蛋白质组成的复合物，在修复双链DNA断裂中起着重要作用，双链DNA断裂是一种DNA损伤形式，其中双螺旋的两条链断裂，导致染色体重排，最终，虽然理解Ku对于DNA的适当修复是必不可少的，但其作用模式仍不清楚。我们知道Ku与许多其他在DNA修复中发挥作用的因子相互作用，然而，对这些相互作用的细节和结果知之甚少。利用最近获得的Ku的晶体结构，我们可以预测蛋白质中与其他蛋白质接触的区域。因此，我们已经在这些可接近的区域中的几个中进行了突变，以证明它们改变Ku DNA修复功能。我们已经确定了两个Ku突变，改变了它对DNA损伤的反应能力。我们发现这些突变导致不同的缺陷，这表明突变区域参与了不同的功能。我们建议鉴定与这些Ku基序相互作用的蛋白质，并阐明它们如何在DNA修复中共同发挥作用。从长远来看，这些分析将增强我们对Ku在处理双链DNA断裂机制中的功能的理解。