hnRNP A1における核輸出シグナル:信号媒介型,温度に依存する核タンパク質輸出経路

W M Michael¹, M Choi, G Dreyfuss

¹Howard Hughes Medical Institute, University of Pennsylvania School of Medicine, Philadelphia 19104-6148, USA.

Cell

|November 3, 1995

まとめ

hnRNP A1のM9ドメインは,核の輸出信号として作用し,核から細胞質へのタンパク質の輸送を促進します. この発見は,原子力輸出のための新しい温度に敏感な経路を明らかにしています.

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:

異質な核リボヌクレオプロテイン (hnRNP) は,mRNA生物生成に不可欠である.
hnRNP A1は,核細胞プラズマ輸送に関与する重要なシャトルタンパク質です.
hnRNP A1のM9ドメインは核の輸入を媒介するが,その輸出機能は不明であった.

研究の目的:

核輸出におけるM9ドメインの役割を調査する.
M9が核輸出信号 (NES) として機能するかどうかを判断する.
M9媒介輸送のメカニズムを特徴付けるために.

主な方法:

M9ドメインの核限定タンパク質への融合 (核プラズミンの核ドメイン,NPc).
細胞内のタンパク質の局所化の観察.
温度感度を評価するための温度変化実験.

主要な成果:

M9ドメインはNPcを効率的に核から細胞質に輸出した.
この輸出はM9信号に依存しており,温度に敏感な方法で発生しました.
古典的な核定位信号 (NLS) は,輸出を媒介しなかった.

結論:

M9は,従来のNLSとは異なる核輸出信号として機能します.
信号に依存し,温度に敏感な核輸出経路が存在する.
hnRNP A1および他のシャットリング hnRNPは,細胞質のエクスポート中にRNAキャリアとして作用する可能性があります.

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