カルシウム-ミリストイルスイッチの分子力学

J B Ames¹, R Ishima, T Tanaka

¹Department of Neurobiology, Stanford University School of Medicine, California 94305, USA.

Nature

|September 20, 1997

まとめ

カルシウムの結合により,リカバリンタンパク質のミリスチル基が外転し,細胞膜との相互作用を可能にします. このカルシウム-ミリスチールスイッチメカニズムは古くから存在し,種を超えて保存されています.

科学分野:

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
細胞生物学細胞生物学

背景:

多くの真核およびウイルスのタンパク質は,そのアミノ末端にミリスタイル群で改変されています.
網膜の棒細胞のカルシウムセンサーであるリカベリンは,ロドプシンキナーゼを阻害することによって,光刺激されたロドプシンを調節する.
Recoverinには,アミノ末端のミリストイル群と4つのEFハンドがあり,分子量は23Kです.

研究の目的:

カルシウム結合後のリカバリーンの構造変化を調査する.
ミリストイル群の挤出と膜相互作用のメカニズムを解明する.
カルシウム-ミリストイルスイッチの進化的保存を理解するために.

主な方法:

核磁共振 (NMR) スペクトロスコピーは,復元構造とダイナミクスを研究するために使用されました.
カルシウムイオン (Ca2+) 結合に反応するタンパク質構造の変化の分析.

主要な成果:

カルシウム結合は,水性ポケットからミリスチル基の解き放出と挤出を誘導する.
ミリスチル基は,脂質双層膜との相互作用のために利用可能になります.
アミノ端末とカルボキシ端末のドメインの間に45度の回転が起こり,水害性残留物を露出します.

結論:

カルシウム-ミリストイルスイッチは,カルシウムに敏感な細胞プロセスを制御するための古代のメカニズムです.
構造的移行により,ディスク膜へのリコーベリンの転位が可能になります.
リカバリーンの同類体における構造的特徴の保存は,基本的な生物学的役割を示唆する.

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