関連する実験動画
Updated: May 7, 2026

07:34
A Method to Study de novo Formation of Chromatin Domains
Published on: August 23, 2019
ヒラに依存するヒストンH3.3の堆積は,ES細胞の発達部位でPRC2の募集を容易にする
Laura A Banaszynski1, Duancheng Wen2, Scott Dewell3
1Laboratory of Chromatin Biology & Epigenetics, The Rockefeller University, New York, New York, 10065 USA.
Cell
|October 1, 2013
まとめ
ヒストン変種H3.3は,ポリコンブ抑制複合体2 (PRC2) がマウスの胚性幹細胞 (ESC) に遺伝子サイレンシングマーク (H3K27me3) を確立するために不可欠です. H3.3の減少はPRC2結合とHiraチャペロン相互作用を減少させ,差異化に影響を与える.
科学分野:
- エピジェネティクスと遺伝子調節
- クロマチン生物学 クロマチン生物学
- 発達生物学 発達生物学とは
背景:
- ポリコンブ抑制複合体2 (PRC2) は,ヒストンH3ライシン27トリメチル化 (H3K27me3) 経由で遺伝子発現を調節するために重要である.
- ドロソフィラのポリコンブ結合部位はダイナミックで,ヒストンの変異種H3.3.3で充実しています.
- 哺乳類の胚性幹細胞 (ESCs) のPRC2媒介による遺伝子静止におけるH3.3の役割は,まだ完全に理解されていません.
研究 の 目的:
- ネズミのESCにおける発達遺伝子プロモーターにおけるPRC2によるH3K27me3マークの確立におけるヒストン変異H3.3の役割を調査する.
- 微分化に不可欠な染色体の状態を維持する際のH3.3,PRC2,ヒストンチャペロンHiraの機能的関係を解明する.
主な方法:
- マウスのESCでH3.3の枯渇.
- デノボ合成ヒストンの堆積を用いた核細胞の周回量の測定.
- ターゲット遺伝子プロモーターにおけるPRC2占有率とHiraとの相互作用の評価.
- ヒラ染色体の局所化の分析.
主要な成果:
- H3.3の枯渇は,発達の遺伝子プロモーターにおけるH3K27me3の確立を減少させた.
- H3.3 枯渇時に核細胞の周回率とPRC2 の占有率の減少が観察されました.
- H3.3は,PRC2とヒストンのチャペロンであるHiraとの相互作用のために必要である.
- ヒラの染色体への局所化は,H3.3.3. に依存しています.
結論:
- H3.3は,マウスのESCでPRC2によるH3K27me3の適切な確立に不可欠です.
- H3.3は,ヒラヒストンチャペロンと相互作用することによって,PRC2の採用と機能を促進します.
- これらの発見は,H3.3が"活性"クロマチンの状態から独立して,微分化中の遺伝子調節に必要なクロマチンの風景を維持する上で果たす重要な役割を強調しています.
関連する概念動画
Chromatin Modification in iPS Cells
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...
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...
Inheritance of Chromatin Structures
Epigenetics is the study of inherited changes in a cell's phenotype without changing the DNA sequences. It provides a form of memory for the differential gene expression pattern to maintain cell lineage, position-effect variegation, dosage compensation, and maintenance of chromatin structures such as telomeres and centromeres. For example, the structure and location of the centromere on chromosomes are epigenetically inherited. Its functionality is not dictated or ensured by the underlying DNA...
Position-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.
Histone 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...
Euchromatin
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...

