Rasは,MAPキナーゼの神経成長因子およびホルボールエステル誘発型チロシンリン酸化に不可欠です
S M Thomas1, M DeMarco, G D'Arcangelo
1Howard Hughes Medical Institute, Department of Microbiology, University of Pennsylvania, Philadelphia 19104.
Cell
|March 20, 1992
まとめ
Rasシグナリングは,PC12細胞におけるミトゲン活性化タンパク質キナーゼ (MAPK) の神経成長因子 (NGF) 誘発型チロシンリン酸化に極めて重要です. この経路のアクティベーションは,Rasの作用の前と後の両方で起こります.
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.
- 神経科学は神経科学である.
背景:
- PC12細胞の神経成長因子 (NGF) 処理は,タンパク質チロシンリン酸化を迅速に誘発する.
- NGF誘発の細胞反応を媒介するRas信号の役割については,さらなる解明が必要である.
研究 の 目的:
- NGFおよびTPA誘発型チロシンリン酸化におけるRasの役割を調査する.
- NGFとTPAの刺激に反応してRasによって調節される特定のタンパク質を特定する.
主な方法:
- PC12細胞は,支配的な阻害性または腫瘍性Ras変異体で感染した.
- 細胞タンパク質のチロシンリン酸化レベルが評価されました.
- 免疫プレシピテーションとウエスタン・ブロッティングは,フォスフォタンパク質を特定するために使用されました.
- ミトゲン活性化タンパク質キナーゼ (MAPK) アクティビティは,インビトロキナーゼアッセイで測定されました.
主要な成果:
- Rasシグナリングは,NGFおよびTPA誘発による42kDaおよび44kDaのタンパク質のチロシンリン酸化を特異的に阻害しました.
- これらの同じタンパク質の腫瘍性Ras誘発型チロシンリン酸化の発現.
- 44 kDaのタンパク質は細胞外信号調節キナーゼ1/MAPKと特定され,42 kDaのタンパク質はMAPKと併合された.
- Rasによって調節されるMAPKの活性化だが,NGFによって誘発されるTrkの活性化やPLC-ガンマ1のリン酸化は認められない.
結論:
- Rasは,NGFとTPAによって誘発されるMAPKのチロシンリン酸化において重要な役割を果たします.
- NGF誘発のチロシンリン酸化は,Ras信号伝達の上流と下流の両方で起こります.
- MAPKは,PC12細胞におけるNGFとTPAへの反応におけるRasの主要な下流エフェクターである.
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