Neddylation inhibition prevents IκB degradation in BMDC without perturbation of the MAPK/ERK pathway. Protein analysis via western blot of phosphorylated IκBα protein (A-B, top panels) and total IκBα (A-B, middle panels) using whole cell lysate of BMDC stimulated with LPS (0.5 µg/mL) for 6 hours in the presence of vehicle (A) or 500 nm MLN4924 (B). Densitometric and statistical analysis of total IκB (C, top) or pIκB (C, bottom) of vehicle or MLN4924-treated cells. α-tubulin protein levels were analyzed as an equal loading control. One representative experiment of 3 is shown. Protein analysis via western blot of phosphorylated ERK protein (D-E, top panels) and total ERK (D-E, middle panels) using whole cell lysate of BMDC stimulated with LPS for 6 hours in the presence of vehicle (D) or 500 nm MLN4924 (E). Densitometric analysis of vehicle-treated cells (D, right) or 500 nm MLN4924-treated cells (E, right) of phosphorylated ERK and total ERK protein. α-tubulin protein levels were analyzed as an equal loading control. One representative experiment of 3 is shown. *P < .05.