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In Vitro Ubiquitination and Deubiquitination Assays of Nucleosomal Histones
Published on: July 25, 2019
A20のデウビキチン化およびウビキチンリガゼドメインは,NF-kappaBシグナル伝達をダウンレギュレーションする
Ingrid E Wertz1, Karen M O'Rourke, Honglin Zhou
1Department of Molecular Oncology, School of Medicine, University of California, Davis, Davis, California 95616, USA.
Nature
|July 20, 2004
まとめ
A20タンパク質は,重要なシグナル伝達分子であるRIPにユビキチン鎖を取り除き追加することで,慢性炎症を抑制する. この二重アクションは,RIPを分解,NF-kappaBのシグナル伝達をダウンレギュレーションし,細胞死を防止することをターゲットとしています.
科学分野:
- 分子生物学は分子生物学である.
- 免疫学 免疫学とは
- バイオケミストリー バイオケミストリー
背景:
- NF-kappaB転写因子は,腫瘍死滅因子-αとインタールイキン-1βを含む,プロ炎症性サイトカインの重要な媒介者である.
- 調節不良のNF-kappaB活動は,A20欠乏マウスで実証されたように,慢性的な炎症と細胞死につながる.
- A20はNF-kappaBシグナル伝達の強力な阻害剤として認識されていますが,その正確な作用機構は不明のままです.
研究 の 目的:
- A20がNF-kappaBシグナリングをダウンレギュレーションするメカニズムを解明する.
- 炎症経路の調節におけるA20のユビキチン編集ドメインの明確な役割を特徴づける.
- 新規のユビキチンリガゼドメインとシーケンスレギュレーションメカニズムを特定する.
主な方法:
- A20のN端デユビキチン化 (DUB) とC端ユビキチンリガゼドメインの酵素活性を調べました.
- TNF受容体1 (TNFR1) 信号伝達に反応する受容体相互作用タンパク質 (RIP) のユビキチン化状態を分析した.
- RIPの運命を評価するために,プロテアソマル分解測定法を使用しました.
主要な成果:
- A20のN端のOTUドメインは,RIPからK63結合のユビキチン鎖を取り除く.
- A20のC端の亜鉛指領域は,K48結合鎖を持つRIPをポリユビキキチナートし,タンパク質分解を標的とする.
- RIPの連続的なユビキチン編集を通じて,NF-kappaBのダウンレギュレーションの新しいメカニズムを示した.
結論:
- A20は,RIPのデユビキチン化と,その後のポリユビキチン化を含む二重のユビキチン編集戦略を採用しています.
- この協調的な行動は,NF-kappaBのシグナル伝達を効果的に終了させ,慢性炎症を予防します.
- 特定の規制機能を媒介する独特のDUBとユビキチンリガゼドメインを持つタンパク質の重要な例としてA20を強調しました.
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