转录激活的单分子分析:SAGA联合激活剂招募的动态
bioRxiv : the preprint server for biology
|August 23, 2023
概括
转录激活剂将Spt-Ada-Gcn5乙转移酶 (SAGA) 复合体等联合激活剂招募到DNA中. 这项研究揭示了激活剂显著增加SAGAGA.
科学领域:
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
- 生物化学 生物化学
背景情况:
- 转录激活剂通过招募协同激活剂来增强基因表达.
- 这些激活剂-协同激活剂相互作用的精确动态尚不清楚.
- 该Spt-Ada-Gcn5乙转移酶 (SAGA) 复合体是基因调节中的一个关键协活性剂.
研究的目的:
- 在单个分子水平上直接调查转录激活剂-协同激活剂相互作用的动态.
- 区分各种联合激活剂招募的动力模型.
- 阐明激活剂的交换激活域在调节协激活剂结合中的作用.
主要方法:
- 使用单分子显微镜可视化促进体DNA,转录激活剂和核提取物中的SAGA复合物.
- 实时成像允许分析关联和解离率,以及停留时间.
- 实验使用了不同的DNA模板 (无核体与染色体) 和特定的激活器域 (VP16,Rap1).
主要成果:
- 在SAGA的表现中,它与核细胞自由DNA发生了暂时的结合,而不依赖于激活剂.
- 激活剂的存在大大增加了SAGA结合率 (高达10倍) 和促进者DNA的停留时间.
- 素乙化对激活剂的停留时间有更明显的影响,而不是对SAGA结合本身.
- 不同的激活器域 (VP16,Rap1) 导致不同的SAGA动态,表明直接相互作用.
结论:
- 揭示了SAGA基因组相互作用的两种不同的模式:短暂的,与DNA结合的和长期的,与激活器结合的.
- 证明了转录激活剂在促进体中直接控制SAGA动态.
- 提供了对转录激活的动力机制的新见解.
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