1つの2つの酵素; 2つの酵母ペロキシレドキシンは,過酸化酵素から分子チャペロン機能への酸化ストレス依存の切り替えを示します
Ho Hee Jang1, Kyun Oh Lee, Yong Hun Chi
1Division of Applied Life Sciences, Gyeonsang National University, Chinju, 660-701, South Korea.
Cell
|May 28, 2004
まとめ
酵母ペロキシレドキシン (Prxs) は,細胞のストレスに基づいて機能を切り替えます. 酸化ストレスや熱ショック下では,これらのタンパク質はペロキシダースから分子チャペロン役割にシフトし,酵母菌の生存を高めます.
科学分野:
- 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
- ストレス反応はストレス反応です.
背景:
- ペロキシレドキシン (Prxs) は,既知の生化学的役割を持つ酵素ですが,その生理学的機能は不明です.
- サイトソリック酵母Prxs,cPrxI,IIは,構造的多様性と異なる分子量 (MW) を表しています.
研究 の 目的:
- サイトゾール酵母ペロキシレドキシン (cPrxIとII) の生理学的機能を調査する.
- タンパク質の構造と分子量が,Prxs.の二重機能にどのように影響するかを決定する.
- 細胞ストレスを感知し,機能スイッチを媒介する活性サイトシステイン残留物の役割を明らかにする.
主な方法:
- 酵母ペロキシレドキシン構造と分子量の分析.
- ペロキシダースと分子チャペロン活動の評価 in vitroとin vivo.
- イーストモデルにおける酸化ストレスと熱ショックの誘導.
- ストレス感知と機能的調節に関与する主要な残留物の特定.
主要な成果:
- イーストのcPrxIとIIは二重ペロキシダゼと分子チャペロン機能を有する.
- Prxsの低MW形態は主に過酸化酵素活性を実行し,高MW複合体はシャペロンとして機能します.
- 酸化ストレスと熱ショックは,低MW複合体から高MW複合体へのシフトを誘導し,ペロキシダースからシャパロン活動への機能的なスイッチを誘発します.
- アクティブ・ペロキシダース・サイト残基であるCys{47}は,過酸化水素 (H2O2) センサーとして作用し,これらの in vivo 構造的および機能的変化を誘導する.
- Prxsのチャペロン機能は,熱ショックに対する酵母耐性を高めます.
結論:
- 酵母ペロキシレドキシンには,ペロキシダースとチャペロン活動との間のダイナミックな機能的なスイッチがあります.
- 細胞のストレス条件は,構造的複合体の形成を通じて,Prxsの主要な機能を決定する.
- Cys(47) は,H2O2を感知し,機能的なスイッチを開始するために不可欠であり,細胞のストレス耐性に貢献します.
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