P-Rex1,a PtdIns(3,4,5) P3-およびRacのガマンヌクレオチド交換因子に対するセベガマ調節によるガミンヌクレオチド交換因子
Heidi C E Welch1, W John Coadwell, Christian D Ellson
1Inositide Laboratory, Cambridge CB2 4AT, United Kingdom.
Cell
|April 17, 2002
まとめ
研究者らは,中性粒子のシグナル伝達に不可欠な新しいRac活性化剤であるP-Rex1を特定しました. このグアニン・ヌクレオチド交換因子 (GEF) は,特定の脂質とGタンパク質サブユニットによって活性化され,細胞応答に影響を与えます.
科学分野:
- 細胞生物学 細胞生物学
- 分子シグナリング
- 免疫学 免疫学とは
背景:
- Rac GTPasesは,細胞プロセスの重要なレギュレーターです.
- 中性粒子のシグナル伝達には,複雑な細胞内経路が含まれています.
- フォスフォノシチドとGタンパク質は,細胞活性化において重要な役割を果たします.
研究 の 目的:
- 中性粒子のRacの新規活性化剤を特定し,特徴づけること.
- Racの活性化の規制メカニズムを解明する.
- 中性粒子の機能におけるRac信号伝達の役割を理解する.
主な方法:
- 中性粒子のサイトゾールからPtdIns ((3,4,5) P3-感受性Rac活性化剤を浄化する.
- 特定されたタンパク質,P-Rex1.1のクローン化および再結合表現.
- P-Rex1のグアニン・ヌクレオチド交換因子 (GEF) 活性を評価するためのインビトロおよびインビボアッセイ.
- 反感覚オリゴヌクレオチドを用いて,中性子のような細胞におけるP-Rex1の機能を評価する.
主要な成果:
- P-Rex1と呼ばれる新しい185 kDaのGEFが浄化し,Rac活性化剤として特定されました.
- P-Rex1の活動は,フォスファディチルノシトール (3,4,5) -トリスホスファート (PtdIns(3,4,5) P3) とセベタガマサブユニットによって直接,実質的に,そして相乗的に活性化されます.
- 反感覚オリゴヌクレオチドを用いたP-Rex1のダウンレギュレーションにより,C5a刺激に反応する反応性酸素種形成が減少した.
- P-Rex1は,PtdIns ((3,4,5) P3とGebetagammaの信号伝達経路のための偶然検出器として機能します.
結論:
- P-Rex1は,中性粒子の新しい,重要な Rac グアニン-ヌクレオチド交換因子です.
- P-Rex1は,PtdIns ((3,4,5) P3とGebetagamma経路からの信号を統合する.
- P-Rex1は中性粒子の活性化において重要な役割を果たし,特にC5a.のような化学吸引剤への反応において重要な役割を果たします.
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