人类SRCAP复合体对组织激素交换的结构洞察力
Jiali Yu1,2, Fengrui Sui1, Feng Gu1
1Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, New Cornerstone Science Laboratory, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai, China.
Cell discovery
|February 8, 2024
概括
该SRCAP复合体 (SRCAP-C) 在促进器处用H2A.Z取代组合素H2A,以调节转录. 结构研究揭示了SRCAP-C如何破坏稳定并去除H2A-H2B二元体,从而促进H2A.Z的结合.
科学领域:
- 染色体生物学 染色体生物学
- 转录调节的分子机制
- 结构生物学是结构生物学.
背景情况:
- 基因组突变H2A.Z对于基因转录调节至关重要.
- 该SRCAP复合体 (SRCAP-C) 促进了正规H2A-H2B二元体与H2A.Z-H2B二元体的交换.
- 了解这种交换的结构基础是破译转录控制的关键.
研究的目的:
- 确定人体SRCAP-C与含有H2A的核细胞结合的近原子分辨率结构.
- 阐明SRCAP-C调解H2A-H2A.Z交换的分子机制.
主要方法:
- 接近原子分辨率的冷电子显微镜 (cryo-EM) 人类SRCAP-C结合于核体.
- 生物化学试验用于研究ATPase活性和核酶结合模式.
- 结构指导的染色体免疫沉测序 (ChIP-seq) 来评估基因组H2A.Z占用率.
主要成果:
- 该SRCAP子单元包括一个与乙烯相关蛋白 (ARP) 模块和一个ATPase电机模块.
- 该ARP模块围绕着核细胞DNA,可能抑制DNA转位.
- 运动模块在不同核酸结合状态中的不同结合模式显示出一种由ATPase驱动的机制,该机制通过ZNHIT1子单元破坏稳定并提取H2A-H2B.
- 结构引导的CHIP-seq证实了ZNHIT1在维持H2A.Z基因组占用中的作用.
结论:
- 这项研究为通过SRCAP-C.介导的H2A-H2A.Z交换机制提供了前所未有的结构洞察力.
- 这些发现揭示了SRCAP-C如何利用ATPase活动来重塑核细胞和调节转录.
- ZNHIT1被确定为基因组中H2A.Z维护的关键组成部分.
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