ジャーナル: Proc Natl Acad Sci U S A / 年: 2018 タイトル: Cryo-EM structures of ASC and NLRC4 CARD filaments reveal a unified mechanism of nucleation and activation of caspase-1. 著者: Yang Li / Tian-Min Fu / Alvin Lu / Kristen Witt / Jianbin Ruan / Chen Shen / Hao Wu / 要旨: Canonical inflammasomes are cytosolic supramolecular complexes that activate caspase-1 upon sensing extrinsic microbial invasions and intrinsic sterile stress signals. During inflammasome assembly, ...Canonical inflammasomes are cytosolic supramolecular complexes that activate caspase-1 upon sensing extrinsic microbial invasions and intrinsic sterile stress signals. During inflammasome assembly, adaptor proteins ASC and NLRC4 recruit caspase-1 through homotypic caspase recruitment domain (CARD) interactions, leading to caspase-1 dimerization and activation. Activated caspase-1 processes proinflammatory cytokines and Gasdermin D to induce cytokine maturation and pyroptotic cell death. Here, we present cryo-electron microscopy (cryo-EM) structures of NLRC4 CARD and ASC CARD filaments mediated by conserved three types of asymmetric interactions (types I, II, and III). We find that the CARDs of these two adaptor proteins share a similar assembly pattern, which matches that of the caspase-1 CARD filament whose structure we defined previously. These data indicate a unified mechanism for downstream caspase-1 recruitment through CARD-CARD interactions by both adaptors. Using structure modeling, we further show that full-length NLRC4 assembles via two separate symmetries at its CARD and its nucleotide-binding domain (NBD), respectively.
A: Apoptosis-associated speck-like protein containing a CARD B: Apoptosis-associated speck-like protein containing a CARD C: Apoptosis-associated speck-like protein containing a CARD D: Apoptosis-associated speck-like protein containing a CARD E: Apoptosis-associated speck-like protein containing a CARD F: Apoptosis-associated speck-like protein containing a CARD G: Apoptosis-associated speck-like protein containing a CARD H: Apoptosis-associated speck-like protein containing a CARD I: Apoptosis-associated speck-like protein containing a CARD J: Apoptosis-associated speck-like protein containing a CARD K: Apoptosis-associated speck-like protein containing a CARD L: Apoptosis-associated speck-like protein containing a CARD M: Apoptosis-associated speck-like protein containing a CARD N: Apoptosis-associated speck-like protein containing a CARD O: Apoptosis-associated speck-like protein containing a CARD P: Apoptosis-associated speck-like protein containing a CARD
らせん対称: (回転対称性: 1 / Dyad axis: no / N subunits divisor: 1 / Num. of operations: 16 / Rise per n subunits: 5 Å / Rotation per n subunits: -100.58 °)
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要素
#1: タンパク質
Apoptosis-associatedspeck-likeproteincontainingaCARD / hASC / Caspase recruitment domain-containing protein 5 / PYD and CARD domain-containing protein / ...hASC / Caspase recruitment domain-containing protein 5 / PYD and CARD domain-containing protein / Target of methylation-induced silencing 1