Figure 1.

HRI controls aggresome formation in response to proteasome inhibition.A–C, HeLa cells transduced with lentiviral particles, targeting either a scrambled (SC) sequence or HRI (shHRI), were treated with either DMSO (control) or 5 μM MG132 for 4 h and stained with anti-p62 and anti-ubiquitin antibodies and analyzed by immunofluorescence (A) (the scale bar represents 5 or 2 μm, as indicated) and quantified for the percentage of cells that have aggresomes larger and smaller than 2 μm (B) and for the frequency that these aggresomes have p62 and ubiquitin colocalization (C). D, HEK293T cells transduced with lentiviral particles targeting a scrambled sequence (SC) and HRI (shHRI) and treated for 4 h with 10 μM MG132 and 10 nM bafilomycin and Western blot analysis was carried out using antibodies against ubiquitinated proteins. A and D are representative of three independent experiments. Bar graphs in B and C represent means ± SEM of aggresomes quantified from five images each from the three independent experiments indicated in A. ∗ and ∗∗∗ represent p < 0.05 and 0.001, respectively.