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ミトコンドリアに誤った折りたたまれたタンパク質をインポートすることにより,細胞細胞タンパク質静止
Linhao Ruan1,2, Chuankai Zhou3, Erli Jin2
1Center for Cell Dynamics, Department of Cell Biology, Johns Hopkins University School of Medicine, 855 North Wolfe Street, Baltimore, Maryland 21205, USA.
Nature
|February 28, 2017
まとめ
誤った折り畳まれたタンパク質は,分解のためにミトコンドリアに輸入され,その過程はMAGIC (サイトゾールの守護者としてのミトコンドリア) と呼ばれる. このメカニズムは老化と神経変性における タンパク質集積とミトコンドリアの健康管理に役立ちます
科学分野:
- 細胞生物学
- 分子生物学
- 老化に関する研究
背景:
- タンパク質集積とミトコンドリア機能障害によって特徴づけられる プロテオスタシスの喪失は,老化と神経変性において中心的なものです.
- ミトコンドリア機能障害とタンパク質の集積の関係が完全に理解されていません.
- 細胞塩基タンパク質はしばしば母細胞に留まり,ミトコンドリアと結合し,Hsp104がクリアランスを促進する.
研究 の 目的:
- ミトコンドリアが細胞内タンパク質の集積とプロテオスタシスを管理する役割を調査する.
- タンパク質の集積,ミトコンドリアの輸入,分解を結びつけるメカニズムを解明する.
- このミトコンドリア媒介のプロテオスタシスメカニズムがヒト細胞に保存されているかどうかを特定する.
主な方法:
- タンパク質の集積とミトコンドリアの輸入を研究するためのモデルシステムとして芽生える酵母を使用した.
- ミトコンドリアの輸入機構との相互作用を分析した熱ショック状態のタンパク質集積物.
- ミトコンドリアのインポートとプロテアソームの活性を阻害することで,総分解への影響を調査した.
- ミトコンドリアへのタンパク質の輸入における細胞塩基Hsp70sの役割を評価した.
主要な成果:
- 集積傾向にある細胞タンパク質は,分解のためにミトコンドリアに輸入されます.
- 熱ショック誘発のタンパク質集積はミトコンドリアのインポート複合体と相互作用し,集積傾向のタンパク質はミトコンドリアのコンパートメントに入ります.
- ミトコンドリアの輸入機構とプロテアゼは,集合体の適時溶解に不可欠であり,輸入を阻害することで分解を遅らせます.
- 細胞細胞のHsp70sの欠陥はミトコンドリアへの誤ったタンパク質の侵入を増加させ,ミトコンドリアのストレスを増加させます.
結論:
- ミトコンドリアが集積した細胞溶液タンパク質を分解する新しいミトコンドリア媒介のプロテオスタシスメカニズムを MAGIC (ミトコンドリアが細胞溶液における守護者) と名付けました.
- このメカニズムはミトコンドリアの輸入機構とプロテアゼを必要とし,プロテアソームの分解とは異なる.
- 証拠によると,MAGIC経路はヒトの細胞に保存され,高齢化および神経変性疾患の新たな治療標的を提供している.
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