ヘテロクロマチンの相分離を促進するために,HP1は核細胞核を再構成する
S Sanulli1, M J Trnka1, V Dharmarajan2
1Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA, USA.
Nature
|October 17, 2019
まとめ
スウィ6のようなHP1タンパク質は,ダイナミックヒストンの曝露によってクロマチンを液体滴に圧縮します. この予期せぬメカニズムは多価相互作用を強化し,ヘテロクロマチン形成と潜在的に他のクロマチン組織を駆動する.
科学分野:
- エピジェネティクスと分子生物学
- クロマチン生物学
- 原子力機関
背景:
- ヘテロクロマチンは遺伝子調節,染色体安定性,核力学において重要な役割を果たします.
- H3K9meに結合するHP1タンパク質はヘテロクロマチンの重要な成分であり,相分離によってクロマチンを圧縮することが提案されています.
- HP1媒介の相分離とクロマチンの圧縮の正確な関係は完全に理解されていません.
研究 の 目的:
- HP1タンパク質,特にS. pombeのSwi6がクロマチンの圧縮と相分離を誘発するメカニズムを調査する.
- HP1媒介の染色体組織における核染色体ダイナミクスの役割を明らかにする.
主な方法:
- S. pombe HP1タンパク質 (Swi6) を利用してクロマチンの圧縮を誘導し,相分離液体凝縮物を見ました.
- 核細胞内のヒストンの残留のアクセシビリティとダイナミクスを評価した.
- スウィ6媒介のクロマチンの圧縮に対するヒストンダイナミクス抑制の影響を調査した.
主要な成果:
- Swi6媒介のクロマチンの圧縮により,相分離液体凝縮物が形成される.
- スイ6は,核細胞内に埋もれたヒストンの残留物のアクセシビリティとダイナミクスを著しく増加させる.
- これらのヒストンのダイナミクスを阻害すると,Swi6誘発のクロマチンの凝縮が液滴に低下する.
結論:
- Swi6は,埋もれたヌクレオソーム領域のダイナミックな曝露によって,そのオリゴメリゼーションをクロマチン相分離と結合する.
- このメカニズムは,核細胞核分裂と相分離の間の多価相互作用を促進し,核細胞核分裂の核を再構成する.
- この発見は,ヘテロクロマチンを超えたクロマチンの組織化のための新しいメカニズムを示唆しています.
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