H3K27デメチラゼは,ついに長期間存在した
1Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.
Cell
|October 10, 2007
まとめ
ポリコンブ抑制複合体2 (PRC2) タンパク質はヒストンH3をリシン27 (H3K27me) でメチレートし,遺伝子を静止させます. UTXとJMJD3デメチラゼは,このマークを取り除き,発達と免疫のための遺伝子を活性化します.
科学分野:
- エピジェネティクス エピジェネティクス
- 分子生物学は分子生物学である.
- 発達生物学 発達生物学とは
背景:
- ヒストンのメチル化,特にH3K27meは,ポリコンブ抑制複合体2 (PRC2) によって調節される重要な表遺伝子マーカーです.
- H3K27meは一般的に遺伝子静止と関連しており,発達過程において重要な役割を果たしています.
- H3K27meの除去と,その後の遺伝子活性化の正確なメカニズムは,完全に解明されていません.
研究 の 目的:
- H3K27me.me.の脱メチル化に責任を負う酵素を特定し,特徴づけること.
- H3K27meの除去が,発達と炎症の文脈における遺伝子発現にどのように影響するかを理解する.
主な方法:
- H3K27meに対するデメチラゼの活性をテストするための生化学分析.
- 特定されたデメチラゼの機能を評価するために,モデル生物における遺伝子研究.
- デメチラーゼの活動に伴う遺伝子発現の変化の分析.
主要な成果:
- JmjCドメインのタンパク質UTXとJMJD3は,特定のH3K27デメチラゼとして特定されました.
- UTXとJMJD3は,H3K27meマークの除去を触媒として作用する.
- UTXとJMJD3による脱メチル化は,動物の体パターニングと炎症反応に不可欠な遺伝子の活性化につながります.
結論:
- UTXとJMJD3は,H3K27に特異的な重要なデメチラゼである.
- これらのデメチラゼによるH3K27meの動的調節は,重要な発達および免疫遺伝子の活性化に不可欠である.
- これらの発見は,発達と免疫における遺伝子発現の表遺伝子制御のための新しいメカニズムを明らかにしています.
関連する概念動画
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
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Writers
The writer is an enzyme that can...
02:32Histone Modification
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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,...
02:32Histone 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,...
02:30Histone Variants at the Centromere
Histone variants are the histone proteins with structural and sequence variations. These variants may be regarded as “mutant” forms that replace their canonical histone counterparts in the nucleosomes. Specific post-translational modifications on the histone variants enable further chromatin complexity and regulate tissue-specific gene expression. The most common histone variants are from histone H2A, H2B, and linker histone H1 families. However, several variants of histone H3 variants are also...
02:32Position-effect Variegation
In 1928, a German botanist Emil Heitz observed the moss nuclei with a DNA binding dye. He observed that while some chromatin regions decondense and spread out in the interphase nucleus, others do not. He termed them euchromatin and heterochromatin, respectively. He proposed that the heterochromatin regions reflect a functionally inactive state of the genome. It was later confirmed that heterochromatin is transcriptionally repressed, and euchromatin is transcriptionally active chromatin.
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...