ラバプチン-5に複合された新しいRab5 GDP/GTP交換因子は,核酸交換をエフェクター募集と機能に結びつける
H Horiuchi1, R Lippé, H M McBride
1European Molecular Biology Laboratory, Heidelberg, Germany.
Cell
|October 10, 1997
まとめ
研究者らは,内細胞膜融合に不可欠な新しいタンパク質であるRabex-5を発見した. Rabex-5はRabaptin-5と複合体を形成し,Rab5 GTPaseのためのグアニンヌクレオチド交換因子として作用する.
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.
- バイオケミストリー バイオケミストリー
背景:
- Rab5GTPアゼは,内細胞輸送経路の調節に不可欠である.
- Rab GDP解離阻害剤は,Rab5の膜集約を促進する.
- ラバプチン-5は,Rab5.5のエフェクタータンパク質として作用する.
研究 の 目的:
- Rab5媒介の内分細胞分裂に関与する新種のタンパク質を特定し,特徴づけること.
- Rab5の活性化とエフェクター募集の分子メカニズムを解明する.
主な方法:
- タンパク質複合体の分離と特徴付け.
- タンパク質の識別のためのナノエレクトロスプレー質量スペクトロメトリ.
- 遺伝子クローニングとシーケンスホモロジー分析.
- グアニンヌクレオチド交換活性に対するインビトロ測定法.
主要な成果:
- 新しい60 kDaのRab5結合タンパク質であるRabex-5が特定されました.
- Rabex-5は,Rab5エフェクターであるRabaptin-5と安定した複合体を形成する.
- Rabex-5は,Rab5.5に対するグアニンヌクレオチド交換因子の活性を示しています.
- Rabex-5は酵母内細胞タンパク質Vps9pとの同質性を共有しています.
結論:
- Rabex-5は,Rab5の規制機構の重要な構成要素である.
- Rabex-5/Rabaptin-5複合体は,溶性グアニンヌクレオチド交換因子として作用し,膜に転移する.
- この複合体は,Rab5を活性GTP結合状態で安定させ,内細胞膜融合を促進します.
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