IP-1:Fos/Junの支配的阻害体であり,その活動はリン酸化によって調節される
1Laboratoire de Génétique Moléculaire, Eucaryotes du CNRS, Faculté de Médecine, Strasbourg, France.
Cell
|March 8, 1991
まとめ
新しい抑制タンパク質 (IP-1) は,DNA結合を防ぐことによって,転写因子AP-1の活性を阻害する. PKAによるリン酸化はIP-1を無活性化させ,遺伝子転写を調節するクロストークメカニズムを示唆する.
科学分野:
- 分子生物学は分子生物学である.
- 細胞シグナル伝達 細胞信号伝達
背景:
- 転写因子AP-1は,FosおよびJunタンパク質のダイマーであり,TPA反応性元素 (TREs) に結合し,タンパク質キナーゼCシグナル伝達における重要な標的である.
- AP-1の活動は,様々な刺激に反応する遺伝子発現の調節に不可欠です.
研究 の 目的:
- AP-1のDNA結合活性に関する新しいレギュレータを特定し,特徴づけること.
- 細胞の異なる部位でAP-1の活性が調節されるメカニズムを調査する.
主な方法:
- 様々な種類の細胞からの核および細胞質抽出物は,AP-1調節器のために分析されました.
- 合成されたFos/Junタンパク質と核抽出物を用いたin vitroアッセイが行われました.
- プロテインキナーゼA (PKA) と合成ペプチドによるコンペティションアッセイを含むリン酸化研究が行われました.
主要な成果:
- 30-40 kDaの抑制性タンパク質 (IP-1) が特定され,核分と細胞プラズマ分の両方に存在しました.
- IP-1は特に,核抽出物と in vitro で合成された Fos/Jun タンパク質からの AP-1 のDNA結合活動を阻害する.
- IP-1の抑制機能には,その非リン酸化状態が必要であり,PKA媒介のリン酸化は,その活性を阻害し,潜在的クロストークを示す.
- 競争実験では,IP-1がFosおよび/またはJunのルシンのジッパー領域と相互作用することを示唆しています.
結論:
- IP-1はAP-1のDNA結合の負の調節体として作用し,その転写活動を調節する.
- PKA媒介によるIP-1のリン酸化は,AP-1依存転写を調節する潜在的なメカニズムを提供します.
- IP-1は,細胞増殖と分化を制御する役割を果たすトランスクリプションアンチオンコゲンとして機能する可能性があります.
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