ヒストンH1の脱アミデーションはDNA修復のためのクロマチンのリラックスを促進する
Yuan Tian1, Tingting Feng1, Jun Zhang1
1International Cancer Center, Guangdong Key Laboratory of Genome Instability and Human Disease Prevention, Marshall Laboratory of Biomedical Engineering, Department of Biochemistry and Molecular Biology, Shenzhen University Medical School, Shenzhen, China.
Nature
|April 16, 2025
まとめ
DNAの修復には クロマチンが必要です 脱アミデーションとアセチル化を含むヒストンH1の改変は,DNA損傷後のこの開口を促進し,癌の放射線治療に対する耐性を高めます.
科学分野:
- 分子生物学
- エピジェネティクス
- 癌 研究
背景:
- アクセシブルクロマチンは DNAの二重鎖の断裂修復に不可欠です
- リンカーヒストンH1がDNA損傷反応中のクロマチンの放緩を調節する役割は不明である.
研究 の 目的:
- ヒストンH1の改変がDNA損傷後のクロマチンのアクセシビリティを調節するメカニズムを解明する.
- H1 変異における CTP 合成酵素1 (CTPS1) の役割と,DNA 修復と放射線治療への反応との関連を調査する.
主な方法:
- DNA損傷への反応としてヒストンH1の脱アミデーションとアセチル化を調査した.
- 改変されたH1に対するp300の基質偏好を評価するために生化学的測定を用いた.
- ネズミの異種移植モデルと臨床コホートにおけるCTPS1発現を分析した.
主要な成果:
- Asn76/77におけるH1のCTP合成酵素1 (CTPS1) 誘導による脱アミデーションは,Lys75におけるアセチル化に先行し,クロマチンの開きにつながる.
- ヒストンアセチルトランスフェラーゼp300は,好ましくアセチラ化H1を脱酸化する.
- 高いCTPS1発現は,臨床前および臨床でのがん放射線治療に対する耐性と相関する.
結論:
- CTPS1によるH1脱アミデーションは,p300媒介アセチル化の前提条件であり,DNA修復のためのクロマチンの開口を促進します.
- この二重 H1 改変経路は,がんの放射線治療に対する抵抗性の強化と関連しており,CTPS1を潜在的な治療標的として強調しています.
関連する概念動画
Spreading of Chromatin Modifications
8.1K
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...
Writers
The writer...
8.1K
Histone Modification
12.9K
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...
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone...
12.9K
Nucleosome Remodeling
8.9K
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...
8.9K
Heterochromatin
9.1K
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...
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...
9.1K
Chromatin Modification in iPS Cells
1.6K
Chromatin modification alters gene expression; therefore, scientists can add histone-modifying enzymes, histone variants, and chromatin remodeling complexes to somatic cells to aid reprogramming into pluripotent stem (iPS) cells.
Compact chromatin makes reprogramming difficult. Enzymes, such as histone demethylases and acetyltransferases, are often added during reprogramming to loosen the chromatin, making the DNA more accessible to transcription factors. Molecules that inhibit histone...
Compact chromatin makes reprogramming difficult. Enzymes, such as histone demethylases and acetyltransferases, are often added during reprogramming to loosen the chromatin, making the DNA more accessible to transcription factors. Molecules that inhibit histone...
1.6K
The Nucleosome Core Particle
811
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...
811


