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通过活跃转录组织素的翻译后修改来抑制PRC2的结构基础
Trinity Cookis1, Alexandria Lydecker1, Paul Sauer2,3
1Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA.
Nature structural & molecular biology
|January 8, 2025
概括
聚合体抑制复合体2 (PRC2) 的活性被基因素修饰H3K4me3和H3K36me3.3所抑制. 这些修改阻止了PRC2.
科学领域:
- 表观遗传学和基因调控
- 染色体生物学 染色体生物学
- 基因沉默的分子机制
背景情况:
- 多胞体抑制复合体2 (PRC2) 通过基因素H3氨酸27三甲基化 (H3K27me3) 建立基因沉默.
- PRC2的功能是由辅助因子调节的,并且与其他基因组修饰物交叉交互.
- 基因组H3氨酸4三甲基化 (H3K4me3) 和氨酸36三甲基化 (H3K36me3) 通常标志着活性转录,但通过未知的机制抑制PRC2.
研究的目的:
- 阐明H3K4me3和H3K36me3抑制PRC2活性的分子机制.
- 了解JARID2辅因子在PRC2调控中对这些抑制标记的作用.
主要方法:
- 低温电子显微镜 (cryo-EM) 用于可视化PRC2与基因组尾巴修饰的相互作用.
- 生物化学试验评估PRC2活性在不同基因组修饰和辅因子的存在下.
主要成果:
- H3K36me3修饰的素H3尾巴表现出与PRC2的不良接触,阻碍了染色体相互作用.
- H3K4me3与EED亚单元的全位结合,对抗PRC2活动并与基本激活剂竞争.
- 在H3K4me3和H3K36me3修饰的背景下,JARID2辅因子会影响PRC2的活动.
结论:
- 基因组H3尾巴上的H3K4me3和H3K36me3的空间定位直接干扰了关键的PRC2功能.
- 这些修改作为关键调节剂,防止异常H3K27me3沉积在活性部位.
- PRC2 调节涉及组织蛋白标记,JARID2 等辅因子和染色质可访问性之间的复杂相互作用.
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