膜ターゲティング中のコトランスレーション信号独立 SRP プレロード
Nature
|August 4, 2016
まとめ
信号認識粒子 (SRP) は,mRNA要素の助けを借りて,標的信号が完全に翻訳される前に,分泌タンパク質と結合する. このメカニズムは,限られたポリペプチド情報であっても,正確なコトランスレーション膜標的を保証します.
科学分野:
- 分子生物学
- 細胞生物学
- 生物化学
背景:
- リボソーム関連因子は,正常に細胞の運命を決定する新生ポリペプチドを解読する.
- リボソームの脱出部位近くの競合する因子による新生鎖の正確な認識は不明である.
- 信号認識粒子 (SRP) はタンパク質をエンドプラズマの網膜に標的にしますが,その選択メカニズムは完全に理解されていません.
研究 の 目的:
- コトランスレーション性膜標的化サイクルを in vivoで調べる
- 信号認識粒子 (SRP) がその基板を選択する方法を理解する.
- SRP基質の選択における新生鎖情報とmRNA要素の役割を明確にします.
主な方法:
- 酵母細胞におけるリボソームのプロファイリング
- リボソーム集団の生化学的分化
- コトランスレーションによる新生鎖認識の分析
主要な成果:
- SRPは信号翻訳前に分泌リボソーム新生鎖複合体 (RNC) を優先的に結合する.
- 非コーディング mRNA 要素は,信号独立の SRP 予備募集を促進する.
- SRP選択における伸縮,ポリペプチド決定因子,およびmRNAの運動相互作用を定義した.
結論:
- SRP媒介によるコトランスレーションターゲティングは,完全な信号シーケンストランスレーションとは独立して,事前のリクルートを含みます.
- mRNA要素はSRPの選択を調節する役割を果たします.
- この研究は,タンパク質を膜に正確に標的にするための重要なメカニズムを明らかにしています.
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