ジャーナル: Nat Commun / 年: 2021 タイトル: Cryo-EM structural analysis of FADD:Caspase-8 complexes defines the catalytic dimer architecture for co-ordinated control of cell fate. 著者: Joanna L Fox / Michelle A Hughes / Xin Meng / Nikola A Sarnowska / Ian R Powley / Rebekah Jukes-Jones / David Dinsdale / Timothy J Ragan / Louise Fairall / John W R Schwabe / Nobuhiro Morone ...著者: Joanna L Fox / Michelle A Hughes / Xin Meng / Nikola A Sarnowska / Ian R Powley / Rebekah Jukes-Jones / David Dinsdale / Timothy J Ragan / Louise Fairall / John W R Schwabe / Nobuhiro Morone / Kelvin Cain / Marion MacFarlane / 要旨: Regulated cell death is essential in development and cellular homeostasis. Multi-protein platforms, including the Death-Inducing Signaling Complex (DISC), co-ordinate cell fate via a core FADD: ...Regulated cell death is essential in development and cellular homeostasis. Multi-protein platforms, including the Death-Inducing Signaling Complex (DISC), co-ordinate cell fate via a core FADD:Caspase-8 complex and its regulatory partners, such as the cell death inhibitor c-FLIP. Here, using electron microscopy, we visualize full-length procaspase-8 in complex with FADD. Our structural analysis now reveals how the FADD-nucleated tandem death effector domain (tDED) helical filament is required to orientate the procaspase-8 catalytic domains, enabling their activation via anti-parallel dimerization. Strikingly, recruitment of c-FLIP into this complex inhibits Caspase-8 activity by altering tDED triple helix architecture, resulting in steric hindrance of the canonical tDED Type I binding site. This prevents both Caspase-8 catalytic domain assembly and tDED helical filament elongation. Our findings reveal how the plasticity, composition and architecture of the core FADD:Caspase-8 complex critically defines life/death decisions not only via the DISC, but across multiple key signaling platforms including TNF complex II, the ripoptosome, and RIPK1/RIPK3 necrosome.
全体 : Ternary complex of full-length Caspase-8 with FADD
全体
名称: Ternary complex of full-length Caspase-8 with FADD
要素
複合体: Ternary complex of full-length Caspase-8 with FADD
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超分子 #1: Ternary complex of full-length Caspase-8 with FADD
超分子
名称: Ternary complex of full-length Caspase-8 with FADD / タイプ: complex / ID: 1 / 親要素: 0 詳細: Proteins co-expressed and co-purified with FLAG affinity tag
タイプ: NEGATIVE / 材質: Uranyl Acetate 詳細: Negatively stained EM specimens were prepared following incubation of the sample on the grid overnight at 4 degrees
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電子顕微鏡法
顕微鏡
FEI TALOS ARCTICA
撮影
フィルム・検出器のモデル: FEI CETA (4k x 4k) / 撮影したグリッド数: 1 / 実像数: 620 / 平均露光時間: 1.0 sec. / 平均電子線量: 35.0 e/Å2
電子線
加速電圧: 200 kV / 電子線源: FIELD EMISSION GUN
電子光学系
照射モード: FLOOD BEAM / 撮影モード: BRIGHT FIELD / Cs: 2.7 mm / 倍率(公称値): 57000
実験機器
モデル: Talos Arctica / 画像提供: FEI Company
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画像解析
粒子像選択
選択した数: 3200 / 詳細: Complexes were manually picked from the micrographs