相关实验视频

Updated: Jun 13, 2025

HOX Loci Focused CRISPR/sgRNA Library Screening Identifying Critical CTCF Boundaries

HOX Loci Focused CRISPR/sgRNA Library Screening Identifying Critical CTCF Boundaries

Published on: March 31, 2019

通过Chd1和FACT解决转录诱导的六体体-核体复合体

Maik Engeholm¹, Johann J Roske², Elisa Oberbeckmann¹

¹Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, Göttingen 37077, Germany.

|September 13, 2024

概括

像Chd1这样的染色体重塑剂在转录过程中解决了六体-核体复合体. 实际上,FACT恢复了基因组二次体,激活了Chd1,以支持RNA聚合酶II的活性.

科学领域:

分子生物学分子生物学
染色体生物学染色体生物学
生物化学生物化学

背景情况:

在基因转录过程中,依赖ATP的染色质重塑剂和基因素陪伴剂保持核细胞组织.
RNA聚合酶II (RNAPII) 活动可以破坏核体结构,需要重塑因素.
六体体,核体中间体缺少一个组素H2A/H2B二元体,在转录的基因区域形成.

研究的目的:

阐明染色体重塑剂Chd1与六体-核体复合体相互作用的机制.
确定FACT复合体在调节这些复合体上的Chd1活性中的作用.
为在转录过程中对染色质重塑的调节提供结构性见解.

主要方法:

低温电子显微镜 (cryo-EM) 用于确定 Chd1 与六体体-核体复合体结合的结构.
生物化学测试以评估在FACT存在或不存在的情况下的Chd1重塑活性.
对Chd1-核酶体相互作用的结构分析.

主要成果:

两个冷EM结构显示了Chd1与六体-核体复合体结合,在FACT的H2A/H2B二元恢复之前和之后.
Chd1 独特地与该复合体相互作用,利用其ATPase 域将六体离核体转移.
在没有H2A/H2B二元体的情况下,Chd1的DNA结合域 (DBD) 与其ATPase域相对应,表明它处于抑制状态.
H2A/H2B二元体的FACT介导的恢复触发了一种构造变化,它取代了DBD并激活了Chd1重塑.

结论:

Chd1重塑活动是由内部H2A/H2B基因组二次体的存在调节的.
实际上,FACT充当了休斯伴侣来恢复二元体,从而刺激了Chd1.1.
这些发现揭示了Chd1和FACT如何合作维持染色质组织并促进RNAPII转录的机制.

关键词:

Chd1 一个小时事实上,这是一个事实.染色体重塑染色体重塑的方法六酶体-核酶体复合体转录转录是一种转录.

更多相关视频

Deciphering High-Resolution 3D Chromatin Organization via Capture Hi-C

Deciphering High-Resolution 3D Chromatin Organization via Capture Hi-C

Published on: October 14, 2022

Author Spotlight: Efficient Nucleosome Reconstitution for Single-Molecule Techniques

Author Spotlight: Efficient Nucleosome Reconstitution for Single-Molecule Techniques

Published on: September 6, 2024

相关概念视频

Heterochromatin

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...

Duplication of Chromatin Structure

Duplication of Chromatin Structure

The process of chromosome duplication during cell division requires genome-wide disruption and re-assembly of chromatin. The chromatin structure must be accurately inherited, reassembled, and maintained in the daughter cells to ensure lineage propagation.
The basic unit of the chromatin is the nucleosome, consisting of DNA wrapped around octameric histone proteins and short stretches of linker DNA separating individual nucleosomes. The histone proteins within the nucleosome have their...

Spreading of Chromatin Modifications

Spreading of Chromatin Modifications

The histone proteins in the nucleosomes are post-translationally modified (PTM) to increase or decrease access to DNA. The commonly observed PTMs are methylation, acetylation, phosphorylation, and ubiquitination of lysine amino acids in the histone H3 tail region. These histone modifications have specific meaning for the cell. Hence, they are called "histone code". The protein complex involved in histone modification is termed as "reader-writer" complex.
Writers
The writer...

Nucleosome Remodeling

Nucleosome Remodeling

Nucleosomes are the basic units of chromatin compaction. Each nucleosome consists of the DNA bound tightly around a histone core, which makes the DNA inaccessible to DNA binding proteins such as DNA polymerase and RNA polymerase. Hence, the fundamental problem is to ensure access to DNA when appropriate, despite the compact and protective chromatin structure.
Nucleosome remodeling complex
Eukaryotic cells have specialized enzymes called ATP-dependent nucleosome remodeling enzymes. These enzymes...

Histone Modification

Histone Modification

The histone proteins have a flexible N-terminal tail extending out from the nucleosome. These histone tails are often subjected to post-translational modifications such as acetylation, methylation, phosphorylation, and ubiquitination. Particular combinations of these modifications form “histone codes” that influence the chromatin folding and tissue-specific gene expression.
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone...

Inheritance of Chromatin Structures

Inheritance of Chromatin Structures

Epigenetics is the study of inherited changes in a cell's phenotype without changing the DNA sequences. It provides a form of memory for the differential gene expression pattern to maintain cell lineage, position-effect variegation, dosage compensation, and maintenance of chromatin structures such as telomeres and centromeres. For example, the structure and location of the centromere on chromosomes are epigenetically inherited. Its functionality is not dictated or ensured by the underlying...