貯蔵されたカルシウム電流 I ((CRAC): InsP3による非線形活性化と,カルシウム放出からの解離
A B Parekh1, A Fleig, R Penner
1Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany.
Cell
|June 13, 1997
まとめ
カルシウム放出による貯蔵式カルシウム電流 (CRAC) の活性化は極めて非線形である. 細胞は,カルシウムの流出からカルシウムの放出を分離し,正確なカルシウムシグナル伝達のために異なる細胞内貯蔵物を利用することができます.
科学分野:
- 細胞生理学 細胞生理学
- カルシウムシグナル伝達
背景:
- 蓄積されたカルシウムエントリー (SOCE) は,細胞カルシウムホメオスタシスにとって極めて重要です.
- SOCEの活性化と細胞内カルシウム放出を結びつける正確なメカニズムは,まだ完全に理解されていません.
研究 の 目的:
- 細胞内カルシウム放出と,貯蔵庫で運行されるカルシウム電流 (CRAC) の活性化との関係を調査する.
- イノシトール三酸塩 (InsP3) へのカルシウム放出と流入の異なる感受性を決定する.
主な方法:
- I ((CRAC) を測定するために,パッチクランプ電気生理学が採用されました.
- 実験では,カルシウムの放出と流入を刺激するために,アゴニストとInsP3の濃度を変化させました.
主要な成果:
- I ((CRAC) のアゴニストおよびInsP3媒介活性化の両方が,狭い濃度範囲内で発生する高非線形性を示した.
- カルシウムの放出と流入は,InsP3に対する異なる感受性を示し,低濃度が放出を好み,流入に必要なマイクロモラー濃度を示した.
- これらの発見は,機能的に異なる細胞内カルシウム貯蔵が,放出と流入を調節することを示唆しています.
結論:
- 細胞は,カルシウムの流入からカルシウムの放出を分離することができます.
- 機能的に異なる貯蔵庫の存在は,カルシウムシグナル伝達経路に対する正確な細胞制御を可能にします.
- このメカニズムは,特定の生理学的要求を満たすためにカルシウムシグナル伝達を細胞に適応させることができます.
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