(B-D) Wild-type (B), GCN2-KO (C), and PERK-KO (D) MEF cells incubated in the presence of DMSO (Control) or Tunicamycin (0.1 µg/ml) as indicated in (A). Cells were fixed, permeabilized and stained with antibodies against TFE3 (green) and CHOP (red). Scale bar, 10 µm. Data are representative of three independent experiments.(E-F) Quantification of the percentage of MEF cells with nuclear TFE3 upon DMSO (Control), Tunicamycin treatments for 16 h (E), or starvation for 2 h (F) (mean ± SD of three independent experiments, one-way ANOVA analysis versus DMSO treated cells, ns= not significant, ***p < 0.001; n>400 cells per condition). 