ヘテロクロマチンの形成と静止のためのエピジェネティック・コード:通常の容疑者を丸める
Eric J Richards1, Sarah C R Elgin
1Department of Biology, Washington University, One Brookings Drive, St. Louis, MO 63130, USA.
Cell
|March 23, 2002
まとめ
ヒストンの低酸化化,H3-Lys9メチル化,およびサイトシンメチル化の自己強化ネットワークは,ヘテロクロマチンの形成と安定した遺伝を駆動する. これらのエピジェネティックマークは,活発な遺伝子を沈黙させます.
科学分野:
- エピジェネティクスと遺伝子調節
- クロマチンの生物学
- 遺伝の分子メカニズムについて
背景:
- ヘテロクロマチンの形成には,ヒストンとDNAの特定の共性修正が含まれます.
- ヒストンのハイポアセチル化,ヒストンのH3-Lys9メチル化,およびサイトシンメチル化が重要なマークです.
- これらの変更は,クロマチンの静かな状態を維持するために不可欠です.
研究 の 目的:
- 主要なヘテロクロマチン改変の相互関連性を調査する.
- ヘテロクロマチンの拡散と表遺伝子遺伝のメカニズム的根拠を解明する.
- これらのマークが,ヘテロクロマチンとユークロマティック遺伝子サイレンスにおいて同じように機能するかどうかを判断する.
主な方法:
- さまざまなモデル生物からの最近の発見の分析.
- ヒストンのハイポアセチル化,H3-Lys9メチル化,およびサイトシンメチル化の比較研究.
- 自己強化相互作用ネットワークの証拠のレビュー.
主要な成果:
- ヒストン低酸化化,H3-Lys9メチル化,およびサイトシンメチル化の間に自己強化ネットワークが存在する.
- このネットワークは,ヘテロクロマチンが大きなゲノム領域に広がるためのメカニズムを提供します.
- 同様の改変は,ヘテロクロマティックとユークロマティックの両方の遺伝子の安定した静止のために使用されます.
結論:
- 研究された表遺伝子の改変は,ヘテロクロマチン維持のための協力的なシステムを形成します.
- このシステムは,静かな染色体状態の安定した表遺伝子遺伝を基礎としています.
- これらの保存されたメカニズムは,遺伝子調節におけるエピジェネティックマークの基本的な役割を強調しています.
関連する概念動画
Epigenetic Regulation
Epigenetic mechanisms play an essential role in healthy development. Conversely, precisely regulated epigenetic mechanisms are disrupted in diseases like cancer.
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 is an enzyme that can...
Writers
The writer is an enzyme that can...
Epigenetic Regulation
Epigenetic mechanisms play an essential role in healthy development. Conversely, precisely regulated epigenetic mechanisms are disrupted in diseases like cancer.
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 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...
Epigenetic Regulation
Epigenetic changes alter the physical structure of the DNA without changing the genetic sequence and often regulate whether genes are turned on or off. This regulation ensures that each cell produces only proteins necessary for its function. For example, proteins that promote bone growth are not produced in muscle cells. Epigenetic mechanisms play an essential role in healthy development. Conversely, precisely regulated epigenetic mechanisms are disrupted in diseases like cancer.
X-chromosome...
X-chromosome...
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 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...


