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脂質結合オリゴサッカリドがER膜を横切るトランスロケーションには,Rft1タンパク質が必要である
Jonne Helenius1, Davis T W Ng, Cristina L Marolda
1Institute of Microbiology, Swiss Federal Institute of Technology, Zürich, CH-8092 Zürich, Switzerland.
Nature
|January 25, 2002
まとめ
研究者らは酵母中のRFT1タンパク質を,糖質タンパク質前駆体である糖質を,エンドプラズマの網膜膜に転移させるのに欠かせないものとして特定した. この発見は,真核細胞の保存されたN-結合グリコシル化経路に光を当てています.
科学分野:
- バイオケミストリー バイオケミストリー
- 分子生物学は分子生物学である.
- 細胞生物学 細胞生物学
背景:
- N-リンクされたグリコシレーションは,タンパク質の改変のための真核細胞における重要な保存経路である.
- このプロセスは,テトラデカサカライド (Glc3Man9GlcNAc2) を,エンドプラズマ網膜 (ER) の内のドリコール・フォスファートキャリアに組み込むことを含む.
- 脂質結合オリゴサカリド中間物質がER膜を横切るトランスロケーションは不可欠ですが,関与するタンパク質 (フリッパース) は難解のままです.
研究 の 目的:
- Man5GlcNAc2-PP-Dol中間物質のトランスメブラン移動に責任を負うタンパク質を特定する.
- このタンパク質がN-リンクされたグリコシル化経路における役割を調査する.
主な方法:
- 酵母をモデル生物として利用した.
- RFT1遺伝子とその暗号化されたタンパク質の機能を調査した.
主要な成果:
- 酵母RFT1がMan5GlcNAc2-PP-Dol転位に不可欠なタンパク質をコードする証拠を提供した.
- オリゴサッカライド中間物質を細胞プラズマからER膜の光面側に移動するためにRFT1が必要であることを実証しました.
- RFT1が進化的に保存されたタンパク質であることを示した.
結論:
- RFT1は,N結合グリコシライゼーションにおける重要な転位ステップを触媒する難解なフリップフェーズである.
- この発見は,様々な細胞タイプに意味を持つ基本的な細胞プロセスに関する私たちの理解を前進させます.
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