Figure 5
Perk is dispensable for the effects of NaSal on ATF6α activity. (a) Effect of NaSal on the Tm-induced ATF6α transcriptional activity in the absence of Perk. Twenty-fours post-transfection with p5xATF6-GL3 and pRL-TK plasmids, Perk KO MEFs were left untreated or pretreated for one hour with NaSal 20 mM, followed by treatment or not with with tunicamycin 3 μg/mL for six hours. Cells were also left in the presence of NaSal 20 mM only for the additional time. (b and c) Effect of NaSal on DTT-induced expression of ATF6α target genes in the absence of Perk. Wild type and Perk KO MEFs were treated as similar as in Fig. 4, except that DTT (1 mM) was used as the ER stress inducer. Total RNA was isolated for cDNA synthesis and further analyses of Hrd-1 and Pdia4 expression by RT-qPCR. *, ** or *** indicate statistical significant differences between groups (p < 0.05; p < 0.01 or p < 0.001, respectively) as determined by unpaired two-tailed Student’s T-test. n = 3 for each experiment and results are plotted as mean ± SD.
