SRPは,制限されたERターゲティングサイトにマッチするように翻訳を遅らせることで,ポリペプチドの転位能力を維持します
Asvin K K Lakkaraju1, Camille Mary, Anne Scherrer
1Département de biologie cellulaire, Université de Genève, Sciences III, 1211 Geneva, Switzerland.
Cell
|May 6, 2008
まとめ
信号認識粒子の (SRP) 遅延は,タンパク質をエンドプラズマ網膜 (ER) に効率的に標的化するために極めて重要です. このメカニズムは,タンパク質転位と翻訳を調整し,適切なタンパク質の折りたたみと機能を確保することで,細胞の欠陥を防ぐ.
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
- バイオケミストリー バイオケミストリー
背景:
- 信号認識粒子 (SRP) 経路は,タンパク質をエンドプラズマ網膜 (ER) にターゲットにします.
- 新生ポリペプチド鎖の延長を遅らせるSRPの役割は知られているが,そのインビボの重要性については不明である.
- 細胞翻訳速度は,SRP受容体 (SR) の利用可能性が限られているため,効率的なタンパク質転位と相容れない可能性があります.
研究 の 目的:
- 哺乳類の細胞におけるSRP媒介の延長停止の機能的意義を調査する.
- SRPの遅延機能が効率的なタンパク質ターゲティングと細胞ホメオスタシスに不可欠であるかどうかを判断する.
- 翻訳率,SRP機能,およびタンパク質転位の間の関係を明らかにする.
主な方法:
- 哺乳類の細胞におけるSRP14の枯渇に続いて,延伸停止機能が欠けている野生型および変異性SRP14との補充が行われます.
- タンパク質転位効率,分泌欠陥,膜タンパク質レベル,細胞成長率の分析.
- 細胞タンパク質合成速度とSRP受容体 (SR) 発現レベルを操作する.
主要な成果:
- SRP14が枯渇した哺乳類の細胞と,非拘束型変異体を発現する細胞は,ERへの非効率的なタンパク質ターゲティングを示した.
- これらの細胞は,タンパク質分泌の有意な欠陥,内生性膜タンパク質の枯渇,細胞成長の減少を示した.
- タンパク質合成速度を低下させたり,SR発現を増加させたりすることで,有害な効果を救出し,翻訳と転位を調整する重要性を強調した.
- SRP媒介の遅延により,新生チェーンがSR依存の時間枠内で転位する能力を保ちます.
結論:
- SRP媒介の延長停止は,タンパク質の効率的な ERへの転位に不可欠です.
- この遅延メカニズムは,細胞ホメオスタシスの維持,適切なタンパク質の分泌,細胞の成長に不可欠です.
- SRPの遅延機能は,タンパク質合成とER転位能力の調整のための規制メカニズムとして機能し,SRP信号配列の親和性に基づいて特定のタンパク質のターゲティングに影響を与える可能性があります.
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