Figure 2.

Caspase-1 cleaves HOIP following UVB irradiation. A, HaCaT cells were pretreated with increasing doses of YVAD (2.5, 5, 10, and 20 μm) or DMSO for 45 min before stimulation with 50 mJ/cm² UVB. Cells were lysed at the indicated time points post-irradiation and subjected to immunoblot analysis. Data are representative of two independent experiments. B, skin homogenates from WT, cpdm, or cpdm;Ice^−/− mice were subjected to immunoblot analysis for murine HOIP. Asterisks denote putative cleavage fragments. n = 3–4 mice/genotype. C, in vitro transcribed and translated pro-IL-1β and HOIP were incubated with increasing amounts of recombinant caspase-1 for 1 h at 37 °C and subjected to immunoblot analysis following reaction termination with Laemmli buffer. The asterisk denotes cleaved HOIP. Data are representative of two independent experiments. D, HEK293T cells were transfected with Myc-HOIP and increasing amounts of FLAG-caspase-1. 24 h post-transfection, cells were lysed and subjected to immunoblot analysis. Data are representative of three independent experiments.