Fig. 4: Cryo-EM structure of the dimeric NLRP1 CARD filament.
From: Mechanism of filament formation in UPA-promoted CARD8 and NLRP1 inflammasomes
a Overall structure of the NLRP1-CT inflammasome. Each subunit of the inner helical CARD filament (purple) dimerizes with an outer CARD (blue). b Dimeric interface between an inner (purple) and outer (blue) CARD pair. c Zoom-ins of type I, II, and III helical interfaces between inner CARD molecules. d Structure-guided mutations of helical interfaces and the CARD–CARD dimer interface on UPA-CARD inflammasome signaling. LDH release (top) and western blot (bottom) are shown. P-values are compared to empty vector (EV) by two-sided Student’s t-test. Exact P-values are provided in the Source Data File. Data are means ± SEM of n = 3 biological replicates. In c, d residues and mutations are labeled in the colors of the interface types as defined in Fig. 2c. e Alignment between Inner-outer CARD (purple and blue) and a dimer within the crystallographic symmetry unit of the NLRP1 CARD crystal structure (gray).
