RQC装置の故障はタンパク質の集積とタンパク質毒性ストレスを引き起こす
Young-Jun Choe1, Sae-Hun Park1, Timm Hassemer1
1Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany.
Nature
|March 3, 2016
まとめ
リボソームの停滞は ストップコドンが欠けることで タンパク質の集積と神経変性が生じます リボソーム品質管理 (RQC) 機構は通常これを防ぐが,その障害はタンパク質のホメオスタシスを破壊する.
科学分野:
- 分子生物学
- 細胞生物学
- 神経科学
背景:
- 停止コードンなしのメッセンジャーRNAの翻訳は,リボソームの停滞とノンストップタンパク質の生成を引き起こす.
- リボソーム品質管理 (RQC) 機構は,通常,これらの停滞した新生鎖をプロテオソーム分解の標的とする.
- RQC機能の障害は神経変性に関連しているが,その根本的なメカニズムは不明である.
研究 の 目的:
- リボソームが安定したポリペプチドがタンパク質毒性を引き起こすメカニズムを調査する.
- 停止したタンパク質の管理におけるE3ユビキチンリガゼLtn1pおよび他のRQC成分の役割を解明する.
- タンパク質の品質管理の欠陥が 神経変性プロセスにどのように貢献するのかを理解する.
主な方法:
- 主要なRQC成分であるLtn1pの削除の結果を研究するために酵母モデルを使用した.
- Ltn1pが欠けている酵母におけるタンパク質集積とインクルージョンの形成を分析した.
- 聚合物形成におけるC端のアラニン/スレオニン尾とポリライシン経路の役割を調査した.
主要な成果:
- イーストのLtn1pの削除は,スタックしたタンパク質から洗剤耐性アグレガントとインクルージョンの形成につながります.
- アグレガットの形成は,Rqc2pとノンストップタンパク質のポリライシン経路によって追加されたC端のアラニン/スレオニン尾に依存する.
- これらのアグレガートは,タンパク質の品質管理経路を妨害して,細胞細胞を隔離します.
結論:
- リボソームで安定したポリペプチドは,プロテオスタシスを破壊する有毒な集積を形成する.
- Ltn1pとRqc2pを含むRQC機構は,停滞したタンパク質の結合と毒性を防止する上で重要な役割を果たします.
- これらの発見は,RQCの機能障害,タンパク質の集積,および神経変性との間のメカニズム的リンクを提供します.
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