酵母における全身ヒストンのアセチル化およびデセチル化
1Department of Biological Chemistry, UCLA School of Medicine and the Molecular Biology Institute, University of California, Los Angeles 90095, USA.
Nature
|December 2, 2000
まとめ
アセチル化および脱アセチル化を含むヒストンの改変は,酵母ゲノム全体に広く存在しています. 標的型遺伝子調節は,グローバルなヒストンの変化のより広範な文脈の中で発生し,基礎転写に影響を与えます.
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:
- ヒストンアセチルトランスフェラーゼ (HAT) とデサセチラーゼ (HDAC) はヒストンを改変することによって遺伝子発現を調節する.
- 特定のHATs (例えば,GCN5) とHDACs (例えば,RPD3) は,転写因子によってDNAに採用されます.
- PHO5遺伝子の発現は核細胞によって抑制され,GCN5によって調節されるが,UME6.6は抑制されない.
研究 の 目的:
- ヒストンのアセチル化とデアセチル化がPHO5遺伝子でプロモーター特異的かどうかを調査する.
- PHO5遺伝子領域とその周辺の領域のアセチル化状態を検査する.
- ターゲットとグローバルヒストンの改変の相互作用を理解する.
主な方法:
- クロマチン免疫降水 (ChIP) アッセイ.
- アセチルライシン残基に対する抗体.
- PHO5遺伝子と他の染色体領域を取り囲む4.25キロベース領域の分析.
主要な成果:
- PHO5遺伝子領域は,ESA1とGCN5によって広くアセチル化され,HDA1とRPD3.3によって脱アセチル化されます.
- 広範囲にわたるヒストンの改変は,3つの異なる染色体領域で観察され,合計22kbでした.
- 標的ヒストンの改変は,グローバルアセチル化および脱アセチル化の背景に発生します.
結論:
- 全球ヒストンのアセチル化とデセチル化により,基礎転写レベルが低下する.
- この全体的な改変により,ターゲティング因子を除去すると,初期アセチル化状態に迅速に戻ることができます.
- ヒストンの改変はダイナミックなプロセスで,ターゲットとグローバルの両方のメカニズムが関与しています.
関連する概念動画
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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.
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The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
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Compact chromatin makes reprogramming difficult. Enzymes, such as histone demethylases and acetyltransferases, are often added during reprogramming to loosen the chromatin, making the DNA more accessible to transcription factors. Molecules that inhibit histone...