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巨大な核孔タンパク質で,Ran/TC4に結合する
N Yokoyama1, N Hayashi, T Seki
1Department of Molecular Biology, Graduate School of Medical Science, Kyushu-University, Fukuoka, Japan.
Nature
|July 13, 1995
まとめ
研究者は,Ran/TC4 Gタンパク質と結合する新しい巨大タンパク質であるRanBP2を特定しました. RanBP2は核タンパク質の輸入に関与する核毛孔複合体の成分です.
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.
- タンパク質の相互作用
背景:
- Ran/TC4は,細胞サイクル進行,RNAの輸出,核タンパク質の輸入に不可欠な小さな核Gタンパク質です.
- RCC1は,Ran/TC4.と複合体を形成するグアニンヌクレオチド放出因子です.
- Ran/TC4は,RCC1の機能喪失障害を抑制する能力によって示唆されるように,RCC1のダウンストリームで機能します.
研究 の 目的:
- Ran/TC4.に結合する新しいタンパク質を特定する.
- 新しく特定されたRan/TC4結合タンパク質の構造と機能を特徴付けるため.
主な方法:
- Ran/TC4と相互作用するタンパク質を特定するための酵母2ハイブリッドスクリーニング.
- タンパク質ドメイン解析とシーケンスのホモロジー検索.
- 細胞内のタンパク質の局所化を決定するための免疫局所化研究.
- 核輸入における役割を評価するために抗体を用いた機能分析.
主要な成果:
- 3,224個の残基からなる新しいタンパク質であるRanBP2が,Ran/TC4結合パートナーとして特定されました.
- RanBP2は,レウシンに富んだリピート,RanBP1同型ドメイン,亜鉛指モチーフ,およびサイクロフィリン同型を含むユニークなドメイン構造を有しています.
- RanBP2は核毛孔複合体 (NPC) タンパク質に特徴的なXFXFGモチーフを含み,NPCに局所する.
- RanBP2に対する抗体は,NLS媒介による核インポートを阻害し,このプロセスにおける役割を示唆しています.
結論:
- RanBP2は,Ran/TC4と相互作用する新しい大型NPCタンパク質です.
- RanBP2は,NPC経由のNLS媒介核タンパク質の輸入に機能的な役割を果たしています.
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