TRAPPの膜結合複合体によるRab Ypt1pの活性化のための構造的基礎
Yiying Cai1, Harvey F Chin, Darina Lazarova
1Department of Cell Biology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA.
Cell
|July 1, 2008
まとめ
TRAPPI複合体はYpt1pを活性化させ,その核酸結合ポケットを安定させ,膜融合の前に重要なステップとなります. Rab GTPaseの活性化に関するこの構造的洞察は,膜結合を理解するための分子枠組みを提供します.
科学分野:
- 分子細胞生物学 分子細胞生物学
- メンブラン取引 メンブラン取引
- 構造生物学 構造生物学とは
背景:
- 多重膜結合複合体であるTRAPPIとTRAPPIIは,細胞膜融合イベントにおいて極めて重要です.
- これらの複合体はサブユニットを共有し,Ypt1pなどのRab GTPasesの活性化に関与し,膜動態を調節します.
研究 の 目的:
- TRAPPI複合体がRab GTPase Ypt1p.を活性化する分子メカニズムを解明する.
- 膜融合に先立つ TRAPPI-Ypt1p 相互作用の構造的基礎を提示する.
主な方法:
- Ypt1p.と複合したヘテロペンタミカのTRAPPI集合体の構造を決定した.
- Ypt1pの活性化における特定のサブユニット相互作用とその機能的役割を特定するために,構造分析を使用した.
主要な成果:
- TRAPPIはYpt1pを活性化させ,その核酸結合ポケットをオープンな形状に安定させ,核酸交換を容易にする.
- Bet3p,Bet5p,Trs23pはYpt1pと直接相互作用し,Bet3pのC端末がポケットを改造する.
- Trs31pは,直接の相互作用なしに,TRAPPI-Ypt1pインターフェイスをアロステリックに調節する.
結論:
- この発見は,膜結合におけるRab GTPase活性化を理解するための分子的枠組みを提供する.
- TRAPPIによるYpt1p活性化の提案されたメカニズムは,関連するTRAPPII複合体で保存されている可能性が高い.
- TRAPPI-Ypt1p複合体の形成に関する構造的な洞察は,膜融合に先立つ重要な出来事を明らかにします.
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