Fig. 5

USP13 binds to and stabilizes IκBα. a Analysis by IP/MS indicated IκBα interacts with USP13. b Detection of endogenous protein interactions between USP13 and IκBα in BV2 microglia by Co-IP. c, d Detection of exogenous protein interactions between USP13 and IκBα in HEK 293T cells by Co-IP. Flag-tagged USP13 and Myc-tagged IκBα plasmids were transfected in HEK 239T cells. e IκBα mRNA level in indicated groups. f, g Detection and quantification of IκBα and USP13 protein level in indicated groups with or without proteasome inhibitor MG132 treatment by western blot analysis. ***P < 0.001. h Increasing amounts of Flag-tagged USP13 (WT or C345A mutant) were transfected and the expression levels of IκBα and Flag-tagged USP13 were detected by western blot analysis. i, j Measurement and quantification of IκBα protein expression in indicated groups with cycloheximide (CHX, 10 µg/ml) treatment by western blot analysis. **P = 0.0021, ***P < 0.001