核细胞组织的包装机制在真核细胞基因组中被重建
Zhenhai Zhang1, Christian J Wippo, Megha Wal
1Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA.
Science (New York, N.Y.)
|May 21, 2011
概括
活跃的转基因作用因子,而不是DNA序列,在基因起始点附近建立正规的核细胞组. 这种转录独立的机制创造了基因调节的必不可少的染色体组织中心.
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:
- 细胞基因在其5'端附近表现出正规的核细胞组.
- 以前的假设将这种组织归因于统计定位,DNA序列或转录启动.
研究的目的:
- 研究驱动真核细胞基因5'末端精确核酶定位和间距的机制.
- 确定负责建立染色体组织中心的因素.
主要方法:
- 在酵母菌中核酶组的生物化学重组.
- 评估腺三酸盐依赖转作用因子的作用.
- 评估染色体组织的转录独立机制.
主要成果:
- 腺三酸盐依赖的转化作用因子成功地重建了核细胞的定位,间距和占用.
- 这些因素取代了基于DNA的内在定位.
- 即使在低密度下,核细胞的均间距也保持不变,独立于转录.
结论:
- 一个活跃的,非统计的核细胞包装机制负责5'基因末端的染色质组织.
- 这种机制建立了对调节元件功能至关重要的染色质组织中心.
- 积极的因素,而不是被动的DNA编码定位,决定了最初的染色质结构.
相关概念视频
00:58DNA Packaging
Overview
00:58DNA Packaging
Overview
01:32Chromatin Packaging
Each human somatic cell contains 6 billion base pairs of DNA. Each base pair is 0.34 nm long, meaning each diploid cell contains a staggering 2 meters of DNA. This long DNA strand is packed inside a nucleus measuring only 10-20 microns in diameter with the help of specialized DNA-binding proteins called histones. Together they form a compact DNA-protein complex called chromatin. The chromatin is further compacted into higher-order structures. The highest level of compaction is achieved during...
02:21Chromatin Packaging
Each human somatic cell contains 6 billion base-pairs of DNA. Each base-pair is 0.34 nm long, which means that each diploid cell contains a staggering 2 meters of DNA. How is such a long DNA strand packed inside a nucleus measuring only 10 - 20 microns in diameter?
The chromatin
In combination with specialized DNA binding protein called Histones, the DNA double helix forms a compact DNA: protein complex called chromatin. The chromatin itself is further compacted into higher-order structures.
The chromatin
In combination with specialized DNA binding protein called Histones, the DNA double helix forms a compact DNA: protein complex called chromatin. The chromatin itself is further compacted into higher-order structures.
02:21Chromatin Packaging
Each human somatic cell contains 6 billion base-pairs of DNA. Each base-pair is 0.34 nm long, which means that each diploid cell contains a staggering 2 meters of DNA. How is such a long DNA strand packed inside a nucleus measuring only 10 - 20 microns in diameter?
The chromatin
In combination with specialized DNA binding protein called Histones, the DNA double helix forms a compact DNA: protein complex called chromatin. The chromatin itself is further compacted into higher-order structures.
The chromatin
In combination with specialized DNA binding protein called Histones, the DNA double helix forms a compact DNA: protein complex called chromatin. The chromatin itself is further compacted into higher-order structures.
00:58Genomic DNA in Eukaryotes
Eukaryotes have large genomes compared to prokaryotes. To fit their genomes into a cell, eukaryotic DNA is packaged extraordinarily tightly inside the nucleus. To achieve this, DNA is tightly wound around proteins called histones, which are packaged into nucleosomes that are joined by linker DNA and coil into chromatin fibers. Additional fibrous proteins further compact the chromatin, which is recognizable as chromosomes during certain phases of cell division.