Fig. 1

Simplified scheme of inflammasome elements, types and formation. Domain organization and basic inflammasome formation. At the molecular level, assembly of inflammasome signaling complexes is mediated through interactions between homotypic protein domains. The domains of AIM2, NALPs, NLRC4, NLRP1, Pyrin, NLRP3, ASC, and CASP1 are shown here. The inflammasome is composed of a sensor, adaptor, and effector protein. Several inflammasomes contain a PYD, responsible for the recruitment of the adaptor protein ASC. After activation, inflammasomes using this adaptor interact with ASC through PYD–PYD interactions, forming large, filamentous oligomers. ASC then recruits CASP1 across CARD–CARD interactions. NLRP1 and NLRC4 may directly interact with CASP1 by CARD–CARD interactions, though these NLRs could also interact with ASC via CARD–CARD interactions. After activation, the sensor oligomerizes and recruits the adaptor and effector proteins to the inflammasome complex. ASC, apoptosis-associated speck-like protein containing a caspase recruitment domain; AIM2, absent in melanoma 2; BIR, baculoviral inhibitor of apoptosis protein repeat; FIIND, function-to-find domain; CARD, caspase recruitment domain; CASP, caspase; LRR, leucine-rich repeat; NALP, Nucleotide-binding oligomerization domain, Leucine-rich Repeat and Pyrin domain containing; NLRC4, NLR family CARD domain-containing protein 4; NLRP1, nucleotide-binding domain (NOD)-like receptor family pyrin domain containing 1; NLRP3, nucleotide-binding domain (NOD)-like receptor family pyrin domain containing 3; PYD, pyrin domain