ASC依存性炎症ソームの組み立てのための統一ポリメリゼーションメカニズム
Alvin Lu1, Venkat Giri Magupalli1, Jianbin Ruan1
1Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115, USA.
Cell
|March 18, 2014
まとめ
インフラマソームは,2つのポリメリゼーションステップを含む統一されたメカニズムによって組み立てられます. このプロセスは,アダプターASCフィラメントによって駆動され,宿主防御のためのカスパース-1の活性化につながります.
科学分野:
- 免疫学 免疫学とは
- 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:
- インフラマソームは,宿主の防御に不可欠な細胞内先天性免疫センサーです.
- 重要な構成要素には,センサータンパク質 (例えば,AIM2,NLRP3) と,センサーをカスパース-1とリンクするASCアダプタータンパク質が含まれています.
- ASCは,ピリン (PYD) とカスパース活性化およびリクルートドメイン (CARD) を介して相互作用を媒介する.
研究 の 目的:
- ASC依存性炎症体の組み立てメカニズムを解明する.
- ASCフィラメント形成の構造的基礎と,カスパース-1活性化におけるその役割を決定する.
- 異なる炎症体ファミリーに統一されたアセンブリメカニズムが存在するかどうかを調査する.
主な方法:
- クリオ電子顕微鏡 (cryo-EM) で,ASC PYDフィラメントの構造を決定する.
- PYD/PYDの相互作用を確認するための構造誘導型変異性.
- 炎症性細胞複合体の形成と活性化を研究するための生化学的分析.
主要な成果:
- ASC の PYD ドメインと CARD ドメインの両方がフィラメントを形成します.
- 活性化されたAIM2およびNLRP3センサーはASC PYDフィラメントを核化し,ASC CARDをクラスタ化します.
- ASCは,CASPASE-1のCARDフィラメントを核化し,近接誘発のCASPASE-1活性化を促進する.
- ASC PYD ファイラメントの冷凍-EM 構造は,ホモ-およびヘテロ-PYD アソシエーションの詳細を明らかにします.
結論:
- ASC依存性炎症体は,連続的な核形成誘発ポリメリゼーションを含む統一された組み立てメカニズムを共有しています.
- このメカニズムはASC PYDフィラメントを使用して,caspase-1 CARDフィラメントを核化し,活性化につながります.
- 研究結果は,炎症ゾームの組成と潜在的な治療標的を理解するための構造的なテンプレートを提供します.
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