Fig. 2

14–3-3ζ stabilizes HO-1 protein expression by protecting HO-1 from ubiquitin-mediated degradation (a, b) Western blot analysis of 14–3-3ζ and HO-1 protein levels in Bel7402 and HLF cell lines transfected with the sh14–3-3ζ plasmids. c, d qRT-PCR analysis of 14–3-3ζ and HO-1 mRNA levels after 14–3-3ζ knockdown. e, f 14–3-3ζ knockdown cells were treated with cycloheximide (CHX) for the indicated times and the expression of endogenous HO-1 protein was analyzed by western blotting (left panel). Three independent experiments were performed and results were quantified by ImageJ software and plotted (right panel). g, h 14–3-3ζ knockdown cells were treated with 20 μM MG132 or dimethylsulfoxide for 10 h. The cells were harvested and analyzed by western blotting with the indicated antibodies. i, j 14–3-3ζ knockdown cells were treated with 20 μM MG132 for 10 h, and the cell lysates were immunoprecipitated with an anti-HO-1 antibody followed by immunoblotting with an anti-ubiquitin antibody