酵母ER膜を横断する翻訳後のタンパク質輸送における信号配列認識
K Plath1, W Mothes, B M Wilkinson
1Howard Hughes Medical Institute and Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA.
Cell
|September 30, 1998
まとめ
研究者らは,プレプロアルファ因子信号配列が酵母内プラズマ網膜のSec61pに結合することを発見しました. この相互作用は,Kar2pとATPとは無関係で,超膜領域へのインターキャレーションを含み,タンパク質輸送チャネルを開くための一般的なメカニズムを示唆しています.
科学分野:
- 分子生物学は分子生物学である.
- 細胞生物学 細胞生物学
- タンパク質の輸送
背景:
- エンドプラズマ網膜 (ER) への翻訳後のタンパク質輸送は,細胞機能にとって極めて重要です.
- 前駆タンパク質の信号配列は,それらをER膜に誘導する.
- 信号配列認識の理解は,タンパク質転位機構の解明の鍵です.
研究 の 目的:
- 酵母 ER.にタンパク質を輸送する過程における信号配列認識の分子機構を調査する.
- この最初のステップに含まれる特定のタンパク質の相互作用を特定するために.
- シグナルシーケンスを媒介するチャネルオープニングの一般的なモデルを提案する.
主な方法:
- 相互リンクの研究は,タンパク質とタンパク質の相互作用をマッピングするために使用されました.
- 分析は,プレプロアルファ因子信号配列とタンパク質伝導チャネルの構成要素の相互作用に焦点を当てた.
- バイオケミカルアッセイでは,Kar2pとATPの役割を評価した.
主要な成果:
- プレプロアルファファクターの信号配列は,タンパク質伝導チャネルのコアコンポーネントであるSec61pと直接相互作用する.
- この相互作用は,Sec61pのトランスメブラン領域2と7へのインターキャレーションを経由して発生します.
- 結合された信号配列は,チャネル-脂質二重層インターフェイスでSec62pとSec71pが接触するヘリックスを形成します.
- この相互作用は,Kar2pとATPから独立しています.
結論:
- Sec61pによるシグナルシーケンスの認識は,ATPとKar2pから独立したプロセスです.
- チャネル-膜インターフェースの結合部位は,信号配列の挿入を容易にする.
- このメカニズムは,ポリペプチドがER膜を横断して転位し,潜在的にチャンネルを開くための一般的な経路を表している可能性が高い.
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