XIAPによるカスパース-3の抑制の構造的基礎
S J Riedl1, M Renatus, R Schwarzenbacher
1The Program in Apoptosis and Cell, Death Research, The Burnham Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA.
Cell
|March 21, 2001
まとめ
X関連アポトーシスタンパク質阻害剤 (XIAP) は,ユニークなステリックブロックメカニズムによってカスパース3の活性を阻害する. この構造的な洞察は,XIAPがどのようにXIAPを明らかにしているかを明らかにします.
科学分野:
- バイオケミストリー バイオケミストリー
- 分子生物学は分子生物学である.
- 構造生物学 構造生物学とは
背景:
- カスパース阻害によるアポトーシスの調節は完全に理解されていません.
- XIAPのようなアポトーシスタンパク質 (IAP) 家族のメンバーの阻害剤は,主要な内生カスパース阻害剤です.
- XIAPは,開始カスパゼ9と実行カスパゼ3と-7を標的とする.
研究 の 目的:
- XIAPによるカスパース抑制の分子メカニズムを解明する.
- XIAPのBIR2ドメインの結晶構造を,カスパース-3との複合体として決定する.
主な方法:
- 構造を決定するために,X線結晶学を用いた.
- 構造は2.7A解像度で解像しました.
主要な成果:
- カスパーゼ-3に結合したXIAP BIR2ドメインの結晶構造が得られた.
- XIAPは,そのBIRドメインからの限られた接触と,そのN端末拡張からの広範な接触を通じて,カスパース-3と相互作用する.
- N端の拡張は,基板結合裂け目を逆方向に占め,ステリック障害を引き起こします.
結論:
- 構造データは,XIAPがステリックブロックを通してカスパース3を阻害し,基板結合を防ぐことを明らかにしています.
- このメカニズムは,合成基板アナログ阻害剤のメカニズムと異なる.
- XIAPの阻害メカニズムを理解することは,アポトーシスの調節に関する洞察を提供します.
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