人类MRE11-RAD50-NBS1对DNA断裂传感的结构基础及其通过端粒因子TRF2的调节
Yilan Fan1, Filiz Kuybu1, Hengjun Cui1
1Gene Center, Department of Biochemistry, Ludwig-Maximilians-Universität München, Feodor Lynen Straße 25, 81377, Munich, Germany.
Nature communications
|September 18, 2025
概括
该MRE11-RAD50-NBS1 (MRN) 复合体检测DNA双链断裂 (DSBs) 使用类似的结构. 在端粒上结合TRF2调节MRN.
科学领域:
- 分子生物学分子生物学
- 结构生物学 结构生物学
- 遗传学 遗传学 是一个
背景情况:
- MRE11-RAD50-NBS1 (MRN) 复合体对于检测和处理DNA双链断裂 (DSB) 是至关重要的.
- 了解MRN如何与不同DNA末端相互作用并将感知与核酶活动分开,对于理解DNA修复途径至关重要.
研究的目的:
- 阐明人类MRN与基因和端粒DNA结合的结构机制.
- 研究MRN复合体内的DNA末端传感是如何与核酶活动分离的.
- 通过端粒保护因子TRF2.2确定MRN调节的结构基础.
主要方法:
- 使用冷电子显微镜 (cryo-EM) 来确定与DNA结合的人类MRN的结构.
- 还确定了与TRF2复合的MRN与DNA结合的结构.
- 结构分析的重点是MRN组件与DNA之间的相互作用,以及TRF2.2的作用.
主要成果:
- 对于具有自抑制MRE11核酶活性的DSB,MRN采用了类似的传感状态.
- NBS1隔离了ATM招募模式,需要一个配置交换机来激活ATM.
- 在端粒DNA结合TRF2通过其iDDR基因阻断MRN核酶和ATM激活.
结论:
- 已经建立了一个通过门机制通过MRN感知DNA的结构框架.
- 这项研究揭示了哺乳动物MRN的感知,信号和处理活动是如何分离的.
- 这些发现为DNA修复和端粒维护的调节提供了洞察力.
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