ウイルスRNAによる先天性免疫パターン認識受容体RIG-Iの活性化のための構造的基礎
Eva Kowalinski1, Thomas Lunardi, Andrew A McCarthy
1European Molecular Biology Laboratory, Grenoble Outstation, France.
Cell
|October 18, 2011
まとめ
生まれつきの免疫に不可欠なRIG-I受容体は,インターフェロン信号伝達を活性化します. 結晶構造は,RNAとATPの結合がRIG-Iを再編成し,免疫反応のためのCARDを解放する方法を明らかにします.
科学分野:
- 免疫学 免疫学とは
- 構造生物学 構造生物学とは
- 分子生物学は分子生物学である.
背景:
- RIG-Iは,先天的免疫に不可欠なパターン認識受容体です.
- ウイルスの5'三リン酸二鎖RNA (5'ppp-dsRNA) を検知して,インターフェロン発現を誘発する.
- RIG-Iには,N端のCARD,DECHヘリケースコア,C端のドメイン (CTD) がある.
研究 の 目的:
- RIG-Iの活性化の分子メカニズムを解明する.
- RIG-I.のリガンドフリー,自己抑制,RNA結合状態に関する構造的洞察を提示する.
主な方法:
- 異なる状態のRIG-Iの構造を決定するために,X線結晶学を用いた.
- 構造分析は,リガンド結合時の構造変化に焦点を当てました.
主要な成果:
- 非アクティブのRIG-Iは,隔離されたCARDでオープンコンフォームを採用します.
- ATPとdsRNAの結合により,閉じた形状が誘発され,ヘリケーズとCTDが再編成される.
- ヘリカーゼとCTDは5'ppp-dsRNAを突端で結合し,CARD結合とは相容れない.
結論:
- 初期5'ppp-dsRNAがCTDに結合し,その後ATPとRNAがヘリケーズに結合し,CARDsを解放するモデルが提案されています.
- このメカニズムは,先天的な免疫反応における下流信号伝達を促進する.
- これらの発見は,先天的な免疫シグナル伝達ヘリカーゼ活性化に関する分子理解を強化します.
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