Fig 1: Copper is necessary and sufficient for PERK-eIF2α phosphorylation in the cell(A, C, and E) Representative western blot images, probed as indicated, of WT and KO PERK (blue) MEF whole-cell lysates from cells treated with 500 μM BCS for 24 h, and 10 μM PA for 1 h (A) or 200 μM sodium arsenite (Ars) for 2.5 h (C), or 100 μM Cu-ATSM alone for 1 h (E).(B) Quantification of n = 4 replicates of the experiment shown in (A). Top panel with black data point is for WT cells, while lower panel with blue data points is for KO PERK cells. Data are normalized by experimental replicates as fold change from PA alone, indicated by the dotted line at y = 1. One-way repeated measures ANOVA returned a significant effect of treatment for WT (**), with Holm-Sidak’s multiple comparisons test returning significance for the indicated preselected comparisons. One-way repeated measures ANOVA for KO PERK returned no significance for treatment (p = 0.1637).(D) Quantification of n = 3 replicates of the experiment in (C). Data are normalized by experimental replicate as fold changes from Ars alone as indicated by the dotted line at y = 1. One-way repeated measures ANOVA returned a significant effect for treatment (**), with Holm-Sidak’s multiple comparisons test returning significance for the indicated preselected comparisons.(F) Quantification of n = 4 replicates the experiment in (E). Two-way repeated measures ANOVA returned significance for treatment (***), genotype (*), and interaction (**). Holm-Sidak’s multiple comparisons test was conducted between treatments for each genotype, and between genotypes for each treatment. Significant comparisons are plotted. All quantifications plot individual n as data points, with replicates indicated by data point shape, and each bar represents mean ± SD. *p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001; and ns p > 0.05. Also see Figure S3.