特定のライシンにおけるヒストンH3およびH4のGcn5pによる転写関連アセチル化
M H Kuo1, J E Brownell, R E Sobel
1Department of Biology, University of Rochester, New York 14627, USA.
Nature
|September 19, 1996
まとめ
イーストの転写アダプタGcn5p (Gcn5p) は,特定のライシン部位でヒストンH3とH4を特異的にアセチル化する. これらの部位は,染色体組み立ての際に使用された部位と異なるもので,Gcn5ppを強調しています.
科学分野:
- 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
- 遺伝子規制 遺伝子規制
背景:
- Gcn5pは,核ヒストンアセチルトランスフェラーゼの触媒サブユニットとして機能する.
- ヒストンのアセチル化は,遺伝子活性化に関連しています.
- ヒストンアセチルトランスフェラーゼはA型とB型に分類される.
研究 の 目的:
- ヒストンH3とH4のGcn5pがターゲットとする特定のアセチル化部位を特定する.
- Gcn5pアセチル化部位と,B型ヒストンアセチルトランスフェラーゼで使われる部位を比較する.
- ヒストンの改変と遺伝子調節におけるGcn5pの役割を理解する.
主な方法:
- 純化されたGcn5p.を使用したインビトロアセチル化アッセイ.
- ヒストンアセチル化パターンの分析 in vivo.
- 質量スペクトロメトリーは,Gcn5pによってアセチル化された特定のライシン残基を特定するために行われます.
主要な成果:
- Gcn5pは,ヒストンH3およびH4のアミノ端末領域の特定のライシンを非ランダムにアセチル化する.
- H3のライシン14およびH4のライシン8および16は,Gcn5pにとって非常に好ましいアセチル化部位である.
- H3のライシン9は,新たに合成された酵母H3の好ましいアセチル化部位である.
- Gcn5pは,B型ヒストンアセチルトランスフェラーゼと比較して,異なる一連のライシンをアセチル化する.
結論:
- Gcn5pは,ヒストーンH3とH4の特定のライシン残基を標的とし,クロマチンの組立に関与するヒストーンとは異なる.
- この特異性は,標的ヒストンアセチル化を介して遺伝子発現を調節するGcn5pのユニークな役割を示唆しています.
- この発見は,表遺伝的調節におけるヒストンアセチル化の多様なメカニズムの理解に貢献する.
関連する概念動画
02:04Covalently Linked Protein Regulators
Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein.
These groups modify specific amino acids in a protein.
02:32Histone 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 deacetylase,...
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
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...
02:38Heterochromatin
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...
02:38Heterochromatin
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...
02:32Histone 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 deacetylase,...
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...