基礎FGF受容体のシグナル伝達が二次元Grb2によって阻害される
Chi-Chuan Lin1, Fernando A Melo, Ragini Ghosh
1Department of Biochemistry and Molecular Biology and Center for Biomolecular Structure and Function, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
Cell
|June 26, 2012
まとめ
アダプタータンパク質Grb2は,線維細胞成長因子受容体2 (FGFR2) の活性を活性的に調節する. Grb2がFGFR2と結合すると,最初は完全な受容体活性化が妨げられ,これは刺激とGrb2のフォスフォリレーションによってのみ達成される.
科学分野:
- セルラー・シグナリング
- 分子生物学は分子生物学である.
- 受容体チロシンキナーゼは,受容体チロシンキナーゼを
背景:
- 受容体チロシンキナーゼ (RTK) は,外部信号なしで基礎活性を示します.
- この基礎的活動は,下流のシグナル伝達には不十分であり,規制メカニズムを示しています.
- 線維細胞成長因子受容体2 (FGFR2) は,細胞プロセスに関与する重要なRTKである.
研究 の 目的:
- FGFR2の活性化を制御するメカニズムを解明する.
- RTKシグナリングの調節におけるアダプタータンパク質Grb2の役割を調査する.
- 基礎RTKの活性が細胞応答を引き起こすのを防ぐ方法を理解する.
主な方法:
- Grb2とFGFR2.2の相互作用を調査しました.
- 分析された受容体のリン酸化状態は,異なる条件下で異なる.
- Grb2結合がFGFR2の活性化と下流シグナル伝達に与える影響を研究した.
主要な成果:
- ディメリックGrb2は2つのFGFR2分子のC端に結合し,ヘテロテトラメアを形成する.
- この複合体は低レベルのトランスホルリレーションを可能にしますが,C端末のリン酸化とシグナリングタンパク質の徴集をステリックに阻害します.
- FGFR2の刺激はGrb2のリン酸化につながり,Grb2の解離を引き起こし,完全な受容体活性化と下流シグナル伝達を可能にします.
結論:
- Grb2は,FGFR2.2の重要な負の調節体として作用する.
- Grb2とFGFR2のダイナミックな相互作用により,ベース状態と完全活性信号状態の切り替えが制御されます.
- このメカニズムは,RTK信号の値を積極的に調節するアダプタータンパク質の新たな役割を強調しています.
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