核细胞凝聚物和链接DNA改变染色体折叠路径和速度
Yunrui Qiu1,2,3, Shuming Liu4,3, Lin Xingcheng4
1Department of Chemistry, Theoretical Chemistry Institute, University of Wisconsin-Madison, Madison, WI, USA.
bioRxiv : the preprint server for biology
|November 28, 2024
概括
染色体组织受到DNA链接长度和核细胞群拥挤的影响. 较短的链接器有利于纤维结构,而较长的链接器和拥挤导致动态折叠中间体,揭示了体内染色质结构的洞察力.
科学领域:
- 分子生物学分子生物学
- 生物物理学的生物物理.
- 结构生物学 结构生物学
背景情况:
- 染色体组织对于DNA包装和真核生物中的基因调节至关重要.
- 核细胞的精确原子排列和影响体内染色体结构的因素仍然不完全理解.
- 像冷电子显微镜 (cryo-EM) 这样的实验技术提供了结构洞察力,但在捕捉动态体内条件方面存在局限性.
研究的目的:
- 为了研究链接者DNA长度和核细胞凝聚物拥挤对染色体组织的影响.
- 为了绘制自由能量景观,识别构造,并量化四核核体系统的折叠动力学.
- 通过提出一个统一的模型来协调不同对染色质结构的实验观测.
主要方法:
- 利用校准的残留水平粗粒度模型来模拟核系统.
- 使用先进的非马科夫动力学建模来分析折叠路径和动力学.
- 在不同的链接DNA长度和在模拟的核细胞缩物中描述了染色质结构.
主要成果:
- 具有较短DNA链接长度 (基对) 的染色体有利于稳定的齐格扎格纤维结构.
- 较长的链接长度 () 和核酶体拥挤破坏了纤维结构的稳定性,促进了动态折叠中间体.
- 该研究确定了对染色质折叠通路至关重要的转移稳定构造和中间状态.
结论:
- 活体染色体组织可能源于纤维结构展开的动态相互作用,受核细胞挤压和链接长度变化的影响.
- 这些发现表明,染色质存在于结构的动态组合中,而不是单一的静态构造.
- 这项工作为统一实验数据和开发更准确的染色质原子模型提供了一个框架.
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