Caspase-14 recognizes and processes IL-1β in epithelial cells to drive anti-bacterial IgG production-Analysis of caspase-1 phosphorylation sites

The resulting MS/MS data were processed using Proteome Discoverer 1.4 (ThermoFisher). Tandem mass spectra were searched against human caspase-1 protein sequence. Trypsin/P was specified as cleavage enzyme allowing up to 2 missing cleavages. Mass error was set to 20 ppm for precursor ions and 0.05 Da for fragments ions. Carbamidomethyl on Cys were specified as fixed modification, oxidation on Met and phosphorylation on Ser and Thr were specified as variable modification. Peptide confidence was set at high, and peptide ion score was set >20. The mass spectrometry analysis was performed by Jingjie PTM Biolabs (Hangzhou, China).