伊诺西六酸盐刺激NHEJ的结构和功能基础通过稳定Ku-XLF相互作用来稳定NHEJ
Antonia Kefala Stavridi1, Amandine Gontier2, Vincent Morin2
1Heartand Lung Research Institute, University of Cambridge, Biomedical Campus, Papworth Road, Trumpington, Cambridge CB2 0BB, UK.
Nucleic acids research
|October 23, 2023
概括
代谢物伊诺西-六酸盐 (IP6) 通过与Ku70-Ku80异构体 (Ku) 结合来增强DNA修复,使其稳定在DNA上,并促进非同类末端结合 (NHEJ) 途径.
科学领域:
- 分子生物学分子生物学
- 结构生物学 结构生物学
- 生物化学 生物化学
背景情况:
- 经典的非同源端结合 (c-NHEJ) 途径对于修复哺乳动物的DNA双链断裂至关重要.
- 这种修复途径受到各种因素的影响,包括像伊诺西-六酸盐 (IP6) 这样的代谢物.
- 已知IP6与Ku70-Ku80异构体 (Ku) 相互作用,这是c-NHEJ的关键组成部分.
研究的目的:
- 阐明IP6刺激c-NHEJ通路的分子机制.
- 确定IP6与Ku异构体之间的相互作用的结构基础.
- 研究这种相互作用对DNA修复效率的功能后果.
主要方法:
- 低温电子显微镜 (cryo-EM) 用于确定带有和没有DNA和IP6的Ku结构.
- 进行X射线晶体学,以获得Ku-DNA-IP6复合物的高分辨率结构.
- 生物物理实验评估IP6对Ku稳定性和相互作用的影响.
- 涉及局部导向突变发生的细胞测试,以评估对DNA修复的影响.
主要成果:
- 确定了Apo-Ku,DNA结合Ku和Ku-IP6复合物的冷EM结构,以及Ku-DNA-IP6.6的X射线晶体结构.
- 发现IP6通过Ku70/Ku80接口的盐桥与Ku结合,远离DNA结合部位,但靠近XLF结合部位.
- 证明IP6结合增加了Ku的热稳定性,使其稳定在DNA上,并增强了XLF亲和力.
- 表明IP6结合口袋中的突变会损害DNA损伤部位的Ku招募和XLF结合,从而降低末端结合效率.
结论:
- 这项研究确定了IP6对c-NHEJ的刺激作用的分子基础.
- IP6通过调节Ku稳定性及其与其他NHEJ因子,特别是XLF的相互作用来增强DNA修复.
- 这为细胞代谢物如何直接影响DNA双链断裂修复提供了机械的理解.
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