染色素在转录过程中缓冲扭曲应力
Jin Qian1,2, Lucyna Lubkowska3, Shuming Zhang1,2
1Department of Physics & LASSP, Cornell University, Ithaca, NY 14853, USA.
bioRxiv : the preprint server for biology
|October 28, 2024
概括
通过RNA聚合酶II (Pol II) 的DNA转录会产生扭曲应力. 染色质结构有效缓冲这种压力,使核细胞通过核细胞进行高效的转录,并揭示其作用超出了简单的障碍.
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 遗传学 是一个
背景情况:
- 通过RNA聚合酶II (Pol II) 的转录涉及导航DNA,由于其螺旋结构导致扭曲应力.
- 了解Pol II如何克服核子和在转录期间管理超级卷是至关重要的,但有限的.
- 染色质在减轻转录过程中的扭力应激中的作用在很大程度上仍未被探索.
研究的目的:
- 在转录过程中可视化和量化Pol II的DNA旋转.
- 确定扭力应力如何影响转录速率和Pol II停滞.
- 为了研究染色质结构和相关因素对扭曲下的转录的影响.
主要方法:
- 开发用于可视化转录过程中的Pol II旋转和DNA超级卷的方法.
- 扭矩测量以在各种条件下确定Pol II停滞点.
- 使用单核细胞和染色质基质的实验来评估转录效率.
主要成果:
- 由于广泛的回溯,Pol II在约±9 pN·nm扭矩下停机,接近DNA化的水平.
- 转录因子TFIIS将Pol II的失速扭矩提高到+13 pN·nm,从而提高了其旋转电机的能力.
- 通过染色体的转录比通过单个核体更有效,这表明染色体能够缓冲扭曲应力.
- 拓酶II活性通过放松扭曲应力显著改善了通过多个核细胞体的转录延长.
结论:
- 染色体在转录过程中积极减少扭曲应激,在促进基因表达方面发挥着至关重要的作用.
- 波尔二号作为一个强大的旋转电机,其扭力能力显著增强,由诸如TFIIS等因素.
- 这些发现重新定义了染色质的功能,突出了其在管理扭曲应力的机械特性,以实现高效的转录,而不是仅仅作为物理屏障.
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