染色体改造器ACFは,核細胞を空間化する二次元モーターとして機能する
Lisa R Racki1, Janet G Yang, Nariman Naber
1Department of Biochemistry and Biophysics, University of California, San Francisco, California 94158, USA.
Nature
|December 25, 2009
まとめ
ATP依存染色体組立因子 (ACF) は,核細胞を双方向に動かすダイマーとして機能する. この新しい二次運動メカニズムは,遺伝子サイレンシングとクロマチンの凝縮に不可欠な,調整された動きを可能にします.
科学分野:
- クロマチンの生物学
- 分子モーターは分子モーターです.
- 遺伝子調節 遺伝子調節
背景:
- 均等に配置された核細胞は,凝縮クロマチンと遺伝子サイレンシングに関連しています.
- ATP依存性染色体組立因子 (ACF) は,核細胞間隔を in vitro で生成し,in vivo 静音化に不可欠である.
- ACFは,より長いDNAの隣接する領域に向かってより速く,より短い領域に向かって核細胞を移動させるが,双方向の移動のメカニズムは不明である.
研究 の 目的:
- ACFが二方向的な核細胞体の動きを達成するメカニズムを解明する.
- 核細胞転位中のACFの機能単位とアーキテクチャを決定する.
主な方法:
- 単粒子電子顕微鏡で,ATPase-ヌクレオソーム複合体の3D再構築.
- ACF濃度と核酸状態に依存する核細胞体の動きを研究するための生化学的分析.
主要な成果:
- ACFによる核細胞体の動きは,ACFの2つの分子に協力的に依存しており,ACFが二重体として機能することを示しています.
- ヌクレオチドの状態は,ACFジメルが核細胞の片側または両側を巻き込むかどうかを決定する.
- 3D再構築では,活性化されたATP状態で互いに向き合うATPアゼを持つ二元構造が明らかになった.
結論:
- ACFは二次元モーターとして機能し,2つのATPaseが連携して核細胞を双方向に動かす.
- このメカニズムは,キネシンやヘリコースなどの片方向二次元モーターとは異なる.
- この発見は,染色体組織と遺伝子サイレンシングに不可欠な核細胞転位のための新しいモデルを提供します.
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