ヒストンアセチル化により,核細胞核粒子の連結番号の変化が減少します
1Department of Biological Chemistry, School of Medicine, University of California, Davis 95616.
Cell
|May 5, 1989
まとめ
ヒストンのアセチル化がDNAのスーパーコイリングに影響を与える. ヌクレオソームのアセチル化が増加すると,ネガティブな結合数が減少し,DNAのスーパーコイルを放出する役割が示唆されます.
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
- バイオケミストリー バイオケミストリー
背景:
- 核細胞は,真核生物のDNA包装の基本的な単位である.
- ヒストンアセチル化は,クロマチンの構造と遺伝子調節に影響を与える重要なエピジェネティック変異です.
- ヒストンアセチル化がDNAトポロジー,特にスーパーコーリングに与える影響は,依然として活発な研究分野です.
研究 の 目的:
- 異なるヒストンアセチル化レベルが,核細胞核粒子の結合数に及ぼす影響を調査する.
- ヒストンアセチル化が,閉じたクロマチンのループ内のスーパーコイルの制約にどのように影響するかを決定する.
主な方法:
- 定義されたDNA配列上の制御されたヒストンアセチル化レベルを持つ核細胞核粒子の形成.
- バイオケミカルアッセイを用いて,ニュクレオソーム粒子あたりのリンク数変化の測定.
主要な成果:
- ヒストンのアセチル化が増加するにつれて,核個体あたりの負のリンク数変化の減少が観察されました.
- コントロール核細胞は -1.04 ± 0.08の結合数変化を示し,高度にアセチル化核細胞は -0.82 ± 0.05の変化を示した.
- これらの発見は,ヒストンアセチル化に関連したトポロジカル変化を定量化します.
結論:
- ヒストンアセチル化は,核細胞によって制約された負のスーパーコイルを積極的に放出します.
- ヒストンアセチル化は,真核生物のギラゼと類似して機能し,DNAトポロジーを調節する.
- このメカニズムは,クロマチンの構造とDNAの緊張のダイナミックな調節に関する洞察を提供します.
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関連する概念動画
02:33The Nucleosome
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DNA is wound twice around a protein complex called histone core, that consist of 8 histone proteins. This complex...
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The paradox
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Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their main responsibility is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. While on the other hand, they must allow polymerase enzymes to access DNA...
02:32Histone Modification
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Acetylation
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Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
02:33The Nucleosome
DNA in a human cell is almost 2m long and it is packed inside a tiny nucleus that is only a few microns in diameter. The level of compaction of DNA inside the nucleus is astonishing. It is organized into several sequentially higher levels of compaction to fit into such a tiny space. The most compact form of DNA is a chromosome that can be seen under a microscope in a dividing cell.
DNA is wound twice around a protein complex called histone core, that consist of 8 histone proteins. This complex...
DNA is wound twice around a protein complex called histone core, that consist of 8 histone proteins. This complex...
01:19The Nucleosome
Human DNA is almost two meters long. However, it is compressed inside a tiny nucleus measuring only a few microns in diameter. To make this degree of compaction possible, DNA is organized into several sequential levels so that it can fit into such a tiny space. The most compact form of DNA is a chromosome that can be seen under a microscope in a dividing cell.
In a chromosome, DNA is wound twice around a protein complex called a histone octamer core, which consists of 8 histone proteins. This...
In a chromosome, DNA is wound twice around a protein complex called a histone octamer core, which consists of 8 histone proteins. This...
01:12The Nucleosome Core Particle
Nucleosomes are the DNA-histone complex, where the DNA strand is wound around the histone core. The histone core is an octamer containing two copies of H2A, H2B, H3, and H4 histone proteins.
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their primary aim is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. On the other hand, they must allow polymerase enzymes to access histone-bound DNA during...
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their primary aim is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. On the other hand, they must allow polymerase enzymes to access histone-bound DNA during...