在Polycomb抑制二维基因酶的H2AK119特异性的基础上
Weiran Ge1,2, Cong Yu1,2, Jingjing Li1,2
1National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.
Nature
|March 29, 2023
概括
聚合物抑制二维基因酶 (PR-DUB) 复合物精确地准了核细胞中的H2AK119ub1. 结构洞察力揭示了ASXL1和BAP1与DNA和基因组结合如何确保这种特定的基因调节机制.
科学领域:
- 表观遗传学和基因调控
- 结构生物学
- 发育生物学
背景情况:
- 多组蛋白对胚胎发育和通过基因表达抑制的细胞类型规范至关重要.
- 通过去除H2AK119ub1,保证适当的基因沉默和保护活跃基因,Polycomb抑制二维基因酶 (PR-DUB) 复合物抵消Polycomb抑制复合物1 (PRC1).
- 由于PR-DUB无差别地分离自由基因素和,与其在特定核细胞向中的重要作用形成鲜明对比,其基质特异性机制尚不清楚.
研究的目的:
- 阐明Polycomb抑制二维基因酶 (PR-DUB) 复合物的核体依赖基质特异性的结构基础.
- 了解PR-DUB如何准确地准核素上的单基因基因子H2A K119 (H2AK119ub1).
主要方法:
- 使用冷电子显微镜 (cryo-EM) 来确定人体PR-DUB复合物的结构.
- 该结构与染色体一起复合,为相互作用提供了详细的视图.
主要成果:
- 低温-EM结构显示ASXL1引导BAP1的C端延伸结合核细胞DNA和H3-H4基因组.
- 在BAP1的催化域中,一个保存的循环与H2A-H2B酸性补丁相互作用,将H2A C-终端尾部移动.
- 这种独特的结合方式赋予了PR-DUB对核细胞的H2AK119ub1的特异性.
结论:
- 这项研究揭示了PR-DUB核细胞识别和基质特异性的新机制.
- 这些结构发现解释了PR-DUB如何精确地准H2AK119ub1,这对于其在基因调节中的作用至关重要.
- 这项工作提供了关于PR-DUB如何在发育过程中确保精确的表观遗传沉默的分子理解.
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