在核膜上的染色质的DNA序列依赖的分离和沉默
Joseph M Zullo1, Ignacio A Demarco, Roger Piqué-Regi
1Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, IL 60637, USA.
Cell
|June 26, 2012
概括
不活跃的染色体域称为层状相关域 (LADs) 是基因调节的关键. 这项研究确定了建立LADs的特定DNA序列和蛋白质,将基因组组织与基因沉默联系起来.
科学领域:
- 基因组学就是基因组学.
- 表观遗传学 在表观遗传学中,表观遗传学是指表观遗传学.
- 细胞生物学 细胞生物学
背景情况:
- 哺乳动物基因组的很大一部分存在于不活跃的染色体域中,称为膜相关域 (LAD),位于核外围.
- 控制LADs形成和维护的精确机制尚未完全理解.
研究的目的:
- 阐明底层层膜相关域 (LAD) 建立的分子机制.
- 为了确定DNA序列和蛋白质因子,负责染色质与核膜和基因抑制的关联.
主要方法:
- 用基因组重新定位测试来研究IgH和Cyp3a位置上的LAD.
- 精细尺度映射识别了板膜关联序列 (LAS) 和它们的相关图案.
- 进行了蛋白质淘汰实验 (cKrox,HDAC3),以评估它们在LAD形成中的作用.
主要成果:
- 发现LADs内的离散DNA区域将染色质在核膜上,抑制基因活性.
- 拉米纳关联是在线索分裂期间确立的,涉及Lamin B招募在晚期的亚纳相.
- 拉米纳关联序列 (LAS) 对GAGA动机进行了丰富,由cKrox,HDAC3和Lap2β结合.
- 对cKrox或HDAC3的抑制破坏了LAD与核层的关联.
结论:
- 揭示了一种新的机制,将染色质域的核细分与基因活性调节联系起来.
- 在LAS中,由cKrox复合体结合的GAGA动机对于指导板状关联和基因抑制至关重要.
相关概念视频
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Keratin proteins, found at the cell periphery near cell junctions, undergo a cycle of assembly and disassembly. In Type...
Keratin proteins, found at the cell periphery near cell junctions, undergo a cycle of assembly and disassembly. In Type...
DNA Packaging
Overview
Chromatin 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...
Chromatin 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.
Chromatin 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.
Heterochromatin
The extent of chromatin compaction can be studied by staining chromatin using specific DNA binding dyes. Under the microscope, the dense-compacted regions that take up more dye are called heterochromatin. Heterochromatin is further classified into two forms – constitutive heterochromatin and facultative heterochromatin.
Constitutive heterochromatin: It is a highly compact region of chromatin that is mostly concentrated in the centromere and telomere. Unlike euchromatin, the amino acid at 9th...
Constitutive heterochromatin: It is a highly compact region of chromatin that is mostly concentrated in the centromere and telomere. Unlike euchromatin, the amino acid at 9th...


