リボソーム-Sec61トランスロコン複合体のタイプII信号アンカー配列の段階的な挿入と逆転
Prasanna K Devaraneni1, Brian Conti, Yoshihiro Matsumura
1Department of Biochemistry and Molecular Biology, Oregon Health and Sciences University, Portland, OR 97239, USA.
Cell
|July 7, 2011
まとめ
リボソーム-Sec61トランスロコン複合体 (RTC) は,膜タンパク質のトポロジーを正確に制御する. それは,タイプIIトポロジーのためのユニークな反転機構を含む,4つの異なるステップを通して信号アンカーをガイドします.
科学分野:
- 細胞生物学 細胞生物学
- 分子生物学は分子生物学である.
- 膜タンパク質バイオゲネシス
背景:
- リボソーム-Sec61トランスロコン複合体 (RTC) は,真核細胞における膜タンパク質の挿入とトポロジーに不可欠である.
- 信号アンカーが正しい方向性を達成する方法を理解することは,タンパク質の生体生成に不可欠です.
研究 の 目的:
- タイプII信号アンカー (SA) がその膜トポロジーを取得する段階的なメカニズムを解明する.
- SAトポゲネシスの調整におけるRTCの役割を調査する.
主な方法:
- Photocrosslinking, Collisional quenching,システインアクセシビリティ,プロテアゼ保護アッセイを活用しました.
- RTCとの相互作用中にカノニカル型IISAのトポロジーを分析しました.
主要な成果:
- タイプIISAトポゲネシスにおける4つの異なる,緊密に結合したステップを特定した:頭先挿入,チェーン蓄積,トポロジー逆転,C端の転位.
- 鎖の長さの進行が分子環境の変化とエネルギー移行を誘導することを実証した.
- II型SA逆転は,リボソーム-トランスロコン相互作用によって調節される不安定な中間体で発生することを明らかにした.
結論:
- RTCは,シグナルアンカー・トポゲネシスを,保護された環境内の連続的な,エネルギー的に制御されたプロセスを通じてオーケストラ化します.
- ダイナミックなリボソーム-トランスロコン相互作用は,II型SAトポロジー取得における逆転ステップの調節に極めて重要です.
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