RT Journal Article SR Electronic T1 Caspase-1 interdomain linker cleavage is required for pyroptosis JF Life Science Alliance JO Life Sci. Alliance FD Life Science Alliance LLC SP e202000664 DO 10.26508/lsa.202000664 VO 3 IS 3 A1 Daniel P Ball A1 Cornelius Y Taabazuing A1 Andrew R Griswold A1 Elizabeth L Orth A1 Sahana D Rao A1 Ilana B Kotliar A1 Lauren E Vostal A1 Darren C Johnson A1 Daniel A Bachovchin YR 2020 UL https://www.life-science-alliance.org/content/3/3/e202000664.abstract AB Pathogen-related signals induce a number of cytosolic pattern-recognition receptors (PRRs) to form canonical inflammasomes, which activate pro-caspase-1 and trigger pyroptotic cell death. All well-studied inflammasome-forming PRRs oligomerize with the adapter protein ASC (apoptosis-associated speck-like protein containing a CARD) to generate a large structure in the cytosol, which induces the dimerization, autoproteolysis, and activation of the pro-caspase-1 zymogen. However, several PRRs can also directly interact with pro-caspase-1 without ASC, forming smaller “ASC-independent” inflammasomes. It is currently thought that little, if any, pro-caspase-1 autoproteolysis occurs during, and is not required for, ASC-independent inflammasome signaling. Here, we show that the related human PRRs NLRP1 and CARD8 exclusively form ASC-dependent and ASC-independent inflammasomes, respectively, identifying CARD8 as the first canonical inflammasome-forming PRR that does not form an ASC-containing signaling platform. Despite their different structures, we discovered that both the NLRP1 and CARD8 inflammasomes require pro-caspase-1 autoproteolysis between the small and large catalytic subunits to induce pyroptosis. Thus, pro-caspase-1 self-cleavage is a required regulatory step for pyroptosis induced by human canonical inflammasomes.