在活细胞中诱导凝聚环挤出轨迹的表征
Ruiqi Han1,2, Yike Huang3, Michelle J Robers3
1Oncode Institute, Hubrecht Institute-KNAW and University Medical Center Utrecht, Utrecht, the Netherlands. r.han@nju.edu.cn.
Nature genetics
|October 16, 2025
概括
凝聚素 (SMC1-SMC3-RAD21) 挤出DNA环来组织染色体. 一个新的工具,TArgeted Cohesin Loader (TACL),可以控制循环挤出的激活,揭示复杂的网络及其对基因转录和染色质结构的影响.
科学领域:
- 分子生物学分子生物学
- 基因组学就是基因组学.
- 染色体生物学 染色体生物学
背景情况:
- 凝聚素复合体 (SMC1-SMC3-RAD21) 通过DNA循环挤出对染色体组织至关重要.
- 在CTCF位点的凝聚蛋白结合和暂停定义了染色体内的结构域.
- 了解循环挤出的动态和后果对于理解基因组架构至关重要.
研究的目的:
- 开发一种用于在活细胞中控制,局部激活凝聚素介导循环挤出的新型工具.
- 研究由凝聚力产生的复杂网络形成和DNA循环的动态.
- 阐明诱导循环挤出对基因转录,染色质可访问性和表观遗传修饰的功能影响.
主要方法:
- 针对可诱导色氨酸循环形成的TARGETED Cohesin Loader (TACL) 的开发和应用.
- 在CTCF站点分析复杂的循环网络,凝聚性队列和循环定.
- 在TACL激活后评估基因转录,染色质可访问性和H3K27ac分布.
- 研究STAG2,PDS5A和WAPL在调节循环挤出动态中的作用.
- 追踪NIPBL-MAU2和凝聚素组件的运输到基因组位点.
主要成果:
- 在定义的基因组位置上,TACL可实现受控的,全细胞激活染色质循环形成.
- 证明了复杂的循环网络的存在,在大多数CTCF站点上有凝聚力排队和定.
- 证明激活环挤出阻碍了局部基因转录,并改变了染色质的可访问性和H3K27ac.
- 观察到TACL诱导的循环在STAG2,PDS5A或WAPL耗尽后会扩展.
- 揭示了NIPBL-MAU2和SMC1的RAD21独立传输到增强剂.
结论:
- TACL是一种强大的工具,用于研究有针对性的凝聚环挤出的功能后果.
- 凝聚环挤出建立了复杂的基因组架构,影响基因表达和染色质状态.
- 装载/挤出机器表现出独特的运输机制到CTCF站点和增强器.
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