微小管の核を形成するガンマ-TuSCは,13倍の微小管のような対称性を持つ構造を組み立てる
Justin M Kollman1, Jessica K Polka, Alex Zelter
1Department of Biochemistry and Biophysics, Howard Hughes Medical Institute, and Keck Advanced Microscopy Center, University of California, San Francisco, San Francisco, California 94158, USA.
Nature
|July 16, 2010
まとめ
核のガンマチューブリン小複合体 (ガンマ-TuSC) は,追加のタンパク質がなくても,マイクロチューブルのテンプレートとして機能するリングを形成します. 酵母 Spc110はこれらのリングをフィラメントに安定させ,マイクロチューブルの対称性に対応する13のガンマチューブリン構造を明らかにします.
科学分野:
- 細胞生物学 細胞生物学
- 構造生物学 構造生物学とは
- バイオケミストリー バイオケミストリー
背景:
- 微小管は細胞の構造と分裂に不可欠です.
- ガンマチューブリン複合体は,微小管の形成を vivo で核化する.
- ガンマチューブリン小複合体 (gamma-TuSC) は,マイクロチューブルの核形成機構の核構成要素である.
研究 の 目的:
- ガンマ-チューブリン小複合体 (ガンマ-TuSC) の自己組み立て能力を調査する.
- ガンマ-TuSCのリングとフィラメントの構造を決定する.
- マイクロチューブル核形成における補助タンパク質の役割を理解する.
主な方法:
- クリオ電子顕微鏡 (8-Å解像度).
- ガンマ-TuSCフィラメントの生化学的再構成.
- サッカロミセス・セレヴィセア・ガンマ-TuSCとSpc110の相互作用の分析.
主要な成果:
- サッカロミセス・セレヴィセア・ガンマ-TuSCは,他のガンマ-TuRC成分なしでリングに自己組み立てられます.
- 酵母アダプタータンパク質 Spc110 は,これらのリングを安定させ,延長された繊維にします.
- Cryo-EMは,回転ごとに13のガンマチューブリンを持つ光線構造を明らかにし,マイクロチューブルの対称性に対応し,プラスエンドを露出しました.
結論:
- ガンマ-TuSC自体はマイクロチューブルテンプレートを形成することができます.
- Spc110は,ガンマ-TuSCを機能的な核状フィラメントに安定させるのに不可欠です.
- この構造は,微小管の核形成の調節と,ガンマ-TuRC特異タンパク質の機能に関する洞察を提供します.
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