小さなGTP結合タンパク質であるRac1とCdc42は,JNK/SAPKシグナル伝達経路の活動を調節する
O A Coso1, M Chiariello, J C Yu
1Molecular Signaling Unit, National Institute of Dental Research, National Institutes of Health, Bethesda, Maryland 20892, USA.
Cell
|June 30, 1995
まとめ
Rac1とCdc42のGTPアゼは,c-Junアミノ端末キナーゼ (JNK) 信号伝達の主要な調節体である. これらのRho関連タンパク質は,Rasとは異なり,JNKを活性化し,JNKがサイトカインや成長因子に対する反応に不可欠です.
科学分野:
- 細胞の信号伝達経路は,
- 分子生物学は分子生物学である.
- シグナルトランスデュークション.
背景:
- c-Junアミノ末端キナーゼ (JNKs) とミトゲン活性化タンパク質キナーゼ (MAPKs) は関連しているが,独立した調節信号経路である.
- 成長因子とMAPKを結びつける経路は知られているが,JNK活性化の調節はあまり理解されていない.
研究 の 目的:
- JNKとMAPKの活性化を調節するRasとRho関連GTPase (Rac1,Cdc42) の役割を調査する.
- JNK活動を選択的に制御するシグナル伝達分子を特定する.
主な方法:
- COS-7細胞における活性化されたRas,Rac1,Cdc42 GTPasesの発現.COS-7細胞における活性化されたRas,Rac1,Cdc42 GTPasesの発現.COS-7細胞における活性化されたRas,Rac1,Cdc42 GTPasesの発現.COS-7細胞における活性化されたRas,Rac1,Cdc42 GTPasesの発現.
- 腫瘍性グアニン核酸代謝因子 (GEFs) をRho関連タンパク質に利用した.
- Rho関連GTPasesの阻害分子と支配的陰性変異体を使用しています.
主要な成果:
- アクティベーションされたRasはMAPKを刺激するが,JNKの活動は起こさない.
- 活性化されたRac1およびCdc42GTPaseは,MAPKに影響を与えることなくJNKを強力に活性化しました.
- Rac1/Cdc42の腫瘍性GEFは,選択的にJNK活動を刺激した.
- Rac1/Cdc42の阻害剤と支配的陰性変異体は,GEF,サイトカイン,成長因子によるJNK活性化を阻害した.
結論:
- Rac1とCdc42のGTPアゼは,JNKの信号伝達経路を制御する上で重要な役割を果たします.
- これらの発見は,JNK経路とMAPK経路の異なる規制メカニズムを強調しています.
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