Fig. 4.
Model for P2X7-mediated ICE/caspase-1 activation and IL-1β maturation.
Stimulation with LPS triggers IL-1β gene transcription and pro–IL-1β accumulation. Opening of the P2X7 pore by extracellular ATP causes a large K+ efflux that triggers proteolytic activation of ICE and cleavage of pro–IL-1β. Mature IL-1β is then secreted through an unknown pathway.