タンパク質キナーゼCはヒト血小板のイノシトールトリソリンホスファート5'-フォスフォモノエステラーゼをリン酸化し,フォスファターゼの活性を増大させます
Cell
|September 12, 1986
まとめ
タンパク質キナーゼCは,イノシトール1,4,5-トリフォスファート5'-フォスフォモノエステラーゼをリン酸化することによって,ヒト血小板におけるカルシウム動員を調節する. この酵素は,
科学分野:
- バイオケミストリー バイオケミストリー
- 細胞シグナリング 細胞シグナリング
- 血液学 ヘマトロジ
背景:
- 人間の血小板のトロンビン刺激は,フォスホイノシチドの分解を誘発し,カルシウムを動員するメッセンジャーを生成します.
- 主なメッセンジャーには,イノシトール1,4,5-トリスホスファートと,タンパク質キナーゼCを活性化するディグリセリドが含まれます.
研究 の 目的:
- ヒトの血小板におけるフォスホイノシチドシグナル伝達を調節するタンパク質キナーゼCの役割を調査する.
- タンパク質キナーゼCがカルシウム動員に影響を与えるメカニズムを解明する.
主な方法:
- 酵素活性を研究するために[ガンマ-32P]ATPを用いた酸化試験.
- SDS-ポリアクリラミドゲル電泳により,タンパク質の移動を分析する.
- 酸化タンパク質を特定するために,タンパク質分解のペプチドマッピング.
主要な成果:
- タンパク質キナーゼCは,イノシトール1,4,5-トリスホスファート5 (phosphomonoesterase) の活性をリン酸化し,強化する.
- リン酸化酵素は,トロンビン刺激により素早くリン酸化される40kDaのタンパク質と結合する.
- ペプチドマッピングは,リン酸化酵素とトロンビン刺激タンパク質の同一性を確認しました.
結論:
- 血小板カルシウム (Ca2+) 運動は,インソシトール1,4,5-トリスフォスファート5のタンパク質キナーゼC媒介型リン酸化によって調節される.
- このリン酸化メカニズムは,イノシトール三酸塩濃度の低下と,ホルボールエステル処理後のCa2+の動員を説明する.
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