ヒストンH2A.Zは転写を調節し,核細胞再構成複合体と部分的に冗長である
M S Santisteban1, T Kalashnikova, M M Smith
1Department of Microbiology and Cancer Center, University of Virginia, Charlottesville 22908, USA.
Cell
|November 18, 2000
まとめ
変異ヒストンH2A.Zは,染色体構造を調節することによって遺伝子転写を調節する. この欠落により,転写因子SNF/SWIとSAGAの必要性が高まり,新たな規制経路が明らかになる.
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:
- 核細胞は,SNF/SWIのような再構成複合体やSAGAのようなヒストン修飾物質によって克服される転写ブロックとして作用します.
- コアヒストンの変異は,転写抑制を緩和し,SNF/SWIとSAGAの必要性を回避することができます.
研究 の 目的:
- 遺伝子転写調節における変異ヒストンH2A.Zの役割を調査する.
- H2A.ZとSNF/SWIおよびSAGA複合体との関係を理解する.
主な方法:
- H2A.Z遺伝子の削除です.
- 単一の遺伝子レベルで合成遺伝子の相互作用の分析.
- PH05とGAL1ロケーションでのインビボクロスリンク研究.
主要な成果:
- H2A.Zを削除すると,SNF/SWIとSAGAの要件が大幅に増加します.
- この効果は,プロモーター核細胞の再編成の下流で発生する.
- H2A.Zは,好ましくは,インタージェニックDNAと関連付けられ,その関連は,転写活性化によって変化します.
結論:
- 変異ヒストンH2A.Zは,遺伝子転写の調節に重要な役割を果たしています.
- H2A.Zはクロマチンの構造を調節することによって機能します.
- 変異ヒストンを含む転写調節のための新しい経路が特定されました.
関連する概念動画
02:10The 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.
The paradox
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...
The paradox
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...
02:54Nucleosome Remodeling
Nucleosomes are the basic units of chromatin compaction. Each nucleosome consists of the DNA bound tightly around a histone core, which makes the DNA inaccessible to DNA binding proteins such as DNA polymerase and RNA polymerase. Hence, the fundamental problem is to ensure access to DNA when appropriate, despite the compact and protective chromatin structure.
Nucleosome remodeling complex
Eukaryotic cells have specialized enzymes called ATP-dependent nucleosome remodeling enzymes. These enzymes...
Nucleosome remodeling complex
Eukaryotic cells have specialized enzymes called ATP-dependent nucleosome remodeling enzymes. These enzymes...
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,...
02:38Heterochromatin
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...
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,...
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...