L3MBTL1はヒストロンメチル化に依存するクロマチンのロックです
Patrick Trojer1, Guohong Li, Robert J Sims
1Howard Hughes Medical Institute, University of Medicine and Dentistry of New Jersey, 683 Hoes Lane, Piscataway, NJ 08854, USA.
Cell
|June 2, 2007
まとめ
悪性脳腫瘍 (MBT) タンパク質L3MBTL1はメチル化ヒストンと結合し,核細胞を圧縮して転写を抑制する. このタンパク質はヒストンの改変を遺伝子静止とヘテロクロマチン形成と結びつけます.
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
- クロマチン生物学 クロマチン生物学
背景:
- ヒストンのメチル化マークは遺伝子発現とヘテロクロマチン形成を調節する.
- これらのマークが転写抑制を誘発する正確なメカニズムは,完全に理解されていません.
研究 の 目的:
- 転写抑制における悪性脳腫瘍 (MBT) タンパク質L3MBTL1の役割を調査する.
- L3MBTL1がヒストンの改変と相互作用する分子機構を解明する.
主な方法:
- L3MBTL1の相互作用するパートナーを特定するための共免疫プレシピテーション.
- 核粒子の配列圧縮アッセイ. 核粒子の配列圧縮アッセイ.
- L3MBTL1およびE2F活動に関連した遺伝子発現の分析.
主要な成果:
- L3MBTL1は,コアヒストン,ヒストンH1b,HP1gamma,Rb.と複合体を形成する.
- L3MBTL1のMBTドメインは,モノおよび二メチル化ヒストンH4ライシン20およびヒストンH1bライシン26と結合する.
- L3MBTL1は,これらのヒストンマークに依存する核細胞配列の凝縮を媒介する.
- L3MBTL1は,E2F制御遺伝子のサブセットを否定的に調節する.
結論:
- L3MBTL1は,特定のヒストンのメチル化マークの認識を,転写抑制と直接関連づけている.
- L3MBTL1は,選択性ヘテロクロマチンの形成と維持に役割を果たします.
- L3MBTL1の複数の核子を同時に結合する能力は,遺伝子サイレンスメカニズムに寄与する.
関連する概念動画
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...
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...
02:38Heterochromatin
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...
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...
02:32Histone 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,...