β5i/LMP7 deficiency as well as proteasome inhibition enhances AP-1 activation in stimulated macrophages.

(A-B) Immuno-blot on phosphorylated and non-phosphorylated members of AP-1 and the NF-κB activating pathway in WT and β5i/LMP7^-/- BMM, stimulated in vitro for 0 min, 30 min, and 240 min with (A) LPS (1 μg/ml) or (B) D39Δcps (MOI 10) (each group with n = 3). (C) Immuno-blot on phosphorylated and non-phosphorylated cJun in RAW 264.7 cells, pretreated with DMSO or epoxomicin (250 nM) for 2 h, and subsequently stimulated with LPS (1 μg/ml) or D39Δcps (MOI 10) for 0 h, 2 h, 4 h, and 6 h. (D) Immuno-blot on catalytic β-subunits of the proteasome in RAW 264.7 cells incubated for 2 h with DMSO or epoxomicin (250 nM). Molecular shift indicates inhibitor binding.