ミトコンドリアタンパク質のターゲティングと可塑性は,近接特異のリボソームプロファイリングによって明らかになりました

Christopher C Williams¹, Calvin H Jan¹, Jonathan S Weissman²

¹These authors contributed equally to this work.

Science (New York, N.Y.)

|November 8, 2014

まとめ

研究者は,タンパク質が細胞の目的地にどのように到達するかを研究した. ほとんどのタンパク質はミトコンドリアまたはエンドプラズマ網膜 (ER) に行き,しかし1つのタンパク質,Osm1は両方に行ける.

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.
タンパク質の密輸タンパク質の密輸

背景:

ミトコンドリアに割り当てられたほとんどのタンパク質は,サイトゾールで合成され,その後輸入されます.
特定の臓器細胞を標的とするタンパク質の正確なメカニズムを理解することは,細胞機能にとって極めて重要です.

研究の目的:

酵母におけるミトコンドリア表面で発生するタンパク質翻訳を包括的にマッピングする.
タンパク質を標的とする経路の臓器特異性を調査する.
二重オーガネルの局所性を有するタンパク質を識別する.

主な方法:

ミトコンドリア表面での翻訳を分析するために,近接特異のリボソームプロファイリングが使用されました.
ミトコンドリアとエンドプラズマ網膜 (ER) の間のタンパク質局所化の比較分析.

主要な成果:

この研究では,ほとんどの内膜タンパク質は,ERタンパク質ターゲティングに類似して,ミトコンドリアをコトランスレーション的に標的としていることがわかりました.
重要な発見は,ミトコンドリアとERの両方にフーマレート還元酵素Osm1の二重局所化でした.
Osm1のこの二重ターゲティングは,異なるターゲティング信号を生成する代替翻訳開始サイトによって仲介されます.

結論:

臓器細胞の標的化メカニズムは,in vivoにおいて高い特異性を示す.
二重局所化されたOsm1の発見は,タンパク質が複数の細胞区画で機能するための新しいメカニズムを明らかにしています.
代替翻訳開始は,差異的なタンパク質の局所化と機能を達成するための重要な戦略です.

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