核マトリックス結合領域によるクロマチンのアクセシビリティの拡張
T Jenuwein1, W C Forrester, L A Fernández-Herrero
1Howard Hughes Medical Institute, University of California, San Francisco 94143-0414, USA.
Nature
|January 16, 1997
まとめ
マトリックス結合領域 (MAR) は,免疫グロブリンムイ遺伝子増強剤と連携してクロマチンのアクセシビリティを拡大します. この相互作用は,遺伝子転写を活性化し,アクセス可能なクロマチン領域を確立するために重要である.
科学分野:
- 免疫学 免疫学とは
- 分子生物学は分子生物学である.
- エピジェネティクス エピジェネティクス
背景:
- 免疫グロブリン遺伝子の転写は,強化要素に依存しています.
- マトリックス結合領域 (MARs) は,遺伝子調節に関与することが知られている.
- 強化剤でクロマチンのアクセシビリティを拡張するMARの役割は完全に理解されていません.
研究 の 目的:
- MARsが染色体のアクセシビリティを強化剤のすぐ近くを超えて拡張できるかどうかを調査する.
- 遺伝子アクセシビリティの規制におけるMARsと強化剤の協力的役割を決定する.
主な方法:
- トランスジェニックマウスモデルを使用した.
- バクテリオファージのRNAポリメラーゼ結合部位に結合した免疫グロブリンミュ遺伝子増強剤/MAR断片.
- プロキシマルおよびディスタルプロモーター領域でのクロマチンのアクセシビリティを評価した.
主要な成果:
- 強化剤だけで,近接部位でのクロマチンのアクセシビリティが認められた.
- 遠隔のプロモーターにアクセシビリティを付与するために,エンハンサーに側面のMARが必要でした.
- 長距離アクセシビリティは,拡張された脱メチル化と相関しているが,アクティブトランスクリプションではない.
結論:
- MARsは,mu遺伝子増強剤と連携して,アクセス可能なクロマチンの拡張ドメインを作成します.
- MARsは,遺伝子調節に必要な長距離クロマチンのアクセシビリティを確立する上で重要な役割を果たします.
関連する概念動画
02:54Nucleosome 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...
Nucleosome remodeling complex
Eukaryotic cells have specialized enzymes called ATP-dependent nucleosome remodeling enzymes. These enzymes...
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.
02:25Spreading 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 is an enzyme that can...
Writers
The writer is an enzyme that can...
01:01Euchromatin
The extent of chromatin compaction can be studied by staining chromatin using specific DNA binding dyes. Under the microscope, the dense-compacted regions take up more dye, appearing darker, while the less-compact areas take up less dye and appear lighter. Based on the compaction level, chromatins are classified into two primary forms – euchromatin and heterochromatin.
Euchromatin is the less dense region of the chromatin and stains lighter. Euchromatin contains histone H3 extensively...
Euchromatin is the less dense region of the chromatin and stains lighter. Euchromatin contains histone H3 extensively...
02:35Chromatin Position Affects Gene Expression
Chromatin is the massive complex of DNA and proteins packaged inside the nucleus. The complexity of chromatin folding and how it is packaged inside the nucleus greatly influences access to genetic information. Generally, the nucleus' periphery is considered transcriptionally repressive, while the cell's interior is considered a transcriptionally active area.
Topologically Associated Domains (TADs)
The 3-dimensional positioning of chromatin in the nucleus influences the timing and level of...
Topologically Associated Domains (TADs)
The 3-dimensional positioning of chromatin in the nucleus influences the timing and level of...
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...