FADDDEDフィラメントは,TNF誘発のアポトーシス中に複合IIa集合を調整する
Ying Chen1, Vinh Thang Huynh1, Lihua Lai1
1Laboratory of NF-κB Signalling, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore 138673, Singapore.
まとめ
この研究では,FADD死亡エフェクタドメイン (DED) のフィラメントは,RIPK1とカスパース-8の採用を促進することによって,外来アポトーシスを開始するために重要であることが明らかになった. このフィラメント形成は,TNF誘発の細胞死亡に不可欠であり,cFLIPに関する新しい洞察を明らかにします.
科学分野:
- 細胞生物学
- 分子生物学
- 生物化学
背景:
- 外部アポトーシスはRIPK1,FADD,カスパース-8を組み立てる死亡受容体によって誘発される.
- カスパース-8の活性化には,そのタンデム死亡エフェクタドメイン (tDED) によるフィラメント形成が含まれます.
- アポトーシスにおけるFADDのDED (FADDDED) の小分子構造と機能はよく理解されていません.
研究 の 目的:
- FADD/DEDフィラメント形成の構造的基礎を解明する.
- 外的アポトーシスの開始におけるFADD/DEDフィラメントの役割を調査する.
- cFLIPがアポトーシスを調節する新しいメカニズムを明らかにする.
主な方法:
- 冷凍電子顕微鏡 (cryogenic-electron microscopy,cryo-EM) で,FADD/DEDフィラメントの構造を決定する.
- フィラメントの機能的影響の評価のためのサイト指向型変異.
- タンパク質とタンパク質の相互作用と熱力学的好みを分析するための分子動力学シミュレーション.
主要な成果:
- FADD DEDフィラメントは,繰り返し相互作用によって安定した3つの螺旋状の鎖を形成します.
- FADDDEDフィラメントの破壊は,RIPK1/カスパース-8の徴募を阻害し,TNF誘発のアポトーシスを廃止する.
- RIPK1-FADDの相互作用にはFADDのフィラメンテーションが必要であり,cFLIPによって反作用する.
結論:
- FADDDEDフィラメント形成は,TNF誘発の外部アポトーシスの重要なメカニズム的なステップである.
- このプロセスは死亡誘発信号複合体 (DISC) の組み立てに不可欠です.
- cFLIPは,FADD/DEDフィラメントを不安定化することによって,追加の抗アポプトシスメカニズムを使用します.
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