Figure 2.

Efficient TNF‐induced dissociation of the NF‐κB/RelA‐IκBα complex requires Ub‐dependent proteasomal degradation of IκBα. (A and B) Inhibition of IκBα ubiquitination with MLN4924 stabilizes the association between (phosphorylated) IκBα and (phosphorylated) RelA after TNF stimulation. RelA (A) or IκBα (B) was immunoprecipitated from cytosolic fractions of cells treated with MLN4924 (3 μM), as indicated, 10 min. prior to TNF (10 ng/ml) stimulation. Samples, as indicated, were analysed by IB. Detection of Tubulin in the cytosol was performed for control of equal protein load.