セラミド活性化タンパク質キナーゼによるラフのリン酸化
1Laboratory of Signal Transduction, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA.
Nature
|November 16, 1995
まとめ
セラミド活性化タンパク質 (CAP) キナーゼは,細胞シグナル伝達における重要な酵素であるRaf1をリン酸化して活性化します. この発見は,腫瘍死滅因子-アルファ (TNF-alpha) 経路における重要なリンクとして,CAPキナーゼを明らかにしています.
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.
- バイオケミストリー バイオケミストリー
背景:
- スフィンゴミエリン経路は,腫瘍死滅因子-アルファ (TNF-alpha) とインタールイキン-1βシグナル伝達を媒介するために重要である.
- この経路にはセラミド活性化タンパク質 (CAP) キナーゼが関与しているが,Raf1活性化におけるその特定の役割は不明である.
研究 の 目的:
- TNF-α信号伝達経路内のRaf1の活性化におけるCAPキナーゼの役割を調査する.
- CAPキナーゼがRaf1活性に影響を与える特定のメカニズムを特定する.
主な方法:
- CAPキナーゼ基板特異性を決定するインビトロキナーゼアッセイ.
- CAPキナーゼとRaf1のタンパク質相互作用の分析
- Raf1.1のリン酸化部位のマッピング
- TNFとセラミド類似体で刺激された無傷のHL-60細胞での実験.
主要な成果:
- CAPキナーゼはThr269でRaf1をリン酸化し,MEK (MAPキナーゼ/ERKキナーゼ) への活性を増強する.
- CAPキナーゼは,HL-60細胞でRaf1と複合体を形成する.
- TNFとセラミド類は,CAPキナーゼ媒介のリン酸化とRaf1.1の活性化を刺激する.
結論:
- CAPキナーゼはRaf1を直接リン酸化して活性化させ,それを特定のRafキナーゼとして識別する.
- CAPキナーゼは,スフィンゴミエリン経路におけるTNF受容体とRaf1活性化との間の重要なリンクとして作用する.
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