在细菌中的转录调节器-DNA相互作用的记忆效应
Won Jung1,2, Tai-Yen Chen1,3, Ace George Santiago1,4
1Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853.
概括
在活生生的细菌细胞中,金属调节器在DNA结合中表现出记忆效应,在不同的调节器类型和状态中持续存在. 这些效应与空间微域相关,增强基因调节效率.
科学领域:
- 分子生物学分子生物学
- 生物物理学的生物物理.
- 遗传学 是一个遗传学.
背景情况:
- 记忆效应描述了过去事件如何影响系统行为,通常通过时间相关性在生物系统中看到.
- 实验室研究表明,酶和DNA结合蛋白具有记忆效应,但细胞实例以前是未知的.
- 金属调节剂是控制基因表达的关键蛋白质,以响应金属离子.
研究的目的:
- 研究活体细菌细胞内的金属调节器-DNA相互作用中记忆效应的存在和特征.
- 探索这些细胞记忆效应背后的时空动态和潜在机制.
- 了解微域在促进这些相互作用和基因调节中的作用.
主要方法:
- 使用单分子追踪 (SMT) 来实时观察蛋白质动态.
- 采用单细胞蛋白质量测量来测量单个细菌中的蛋白质水平.
- 在活体大肠杆菌细胞中结合了这些技术,分析了DNA上的金属调节器结合事件.
主要成果:
- 鉴定了MerR和Fur家族金属调节器的DNA结合/解结合事件的明显时间相关性,表明具有~1秒时间尺度的记忆效应.
- 观察到这些记忆效应独立于金属调节器类型或金属化状态.
- 发现了金属调节器在DNA结合点附近的时间相关性和空间限制之间的关联,表明存在~100nm微域.
结论:
- 在活体细菌细胞内的蛋白质-DNA相互作用中展示了第一个对记忆效应的证据.
- 提出了微域,可能来自染色体组织,通过增强调节器-DNA接触频率,有助于记忆效应.
- 突出了时空动态和微域在细菌高效,记忆驱动的基因调节中的重要性.
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