Figure 3

Involvement of the proteasome system in the degradation of p62 under hypoxia. (A) Hep3B cells were treated with vehicle (DMSO) or 10 μM cycloheximide and cultured under normoxia or hypoxia (O₂ = 1%) for 12 h. The protein abundance of p62 was then examined by immunoblotting. (B) Hep3B cells were treated with 10 μM cycloheximide and cultured under normoxia or hypoxia (O₂ = 1%) for the indicated period of time. p62 protein levels were then assessed by immunoblotting. (C) Hep3B cells were treated with vehicle (DMSO), 5 μM MG132, or 10 mM NH₄Cl and cultured under normoxia or hypoxia (O₂ = 1%) for 12 h followed by immunoblotting for the measurement of p62 protein levels. (D) Hep3B cells were treated with vehicle (DMSO), 5 μM MG132, or 10 nM bafilomycin and cultured under normoxia or hypoxia (O₂ = 1%) for 12 h. p62 protein levels were quantified by immunoblotting. Data are presented as the mean ± S.D. of triplicate experiments. N.S. not significant, *p < 0.05, **p < 0.01 versus the indicated group, calculated with a one-way ANOVA with Tukey’s post-hoc test.