Fig. 1: Micromolar concentrations of PERK inhibitor GSK’157 activate GCN2 and the ISR in stressed cells.
From: Activation of the integrated stress response by inhibitors of its kinases
a Schematic of mice treatments with 0.1 mg/kg Tm and increasing concentrations of GSK’157. Immunoblots of indicated proteins from lysates of liver samples from mice subjected to the indicated treatments. Active (A) and Inactive (I) PERK are indicated with arrows. Quantification of P-eIF2α and eIF2α from immunoblots such as the ones shown in the left panel. Data are shown as mean ± SD (n = 3), number of animals. **p = 0.0046; n.s.: not significant, as determined by one-way ANOVA with Dunnett’s multiple comparison test. b Immunoblots of indicated proteins from lysates of HeLa cells pre-treated with GSK’157 for 30 min and then co-treated with Tm and GSK’157 for 2 h. Representative experiment from n = 4, biologically independent experiments. Ratio of P-eIF2α to eIF2α and ATF4 to Tubulin quantified from immunoblots and normalised to untreated cells. Data are shown as mean ± SEM (n = 4), biologically independent experiments. *p ≤ 0.0412, **p ≤ 0.0067, ***p = 0.0006, as determined by one-way ANOVA with Dunnett’s multiple comparison test. c Newly synthesized proteins labelled for 10 min with 35S-methionine in HeLa cells following treatment with Tm for the indicated times and a Coomassie-stained gel as control. Representative experiment from n = 2, biologically independent experiments. d Same as panel (c), with HeLa cells pre-treated with GSK’157 for 30 min and then co-treated with Tm and GSK’157 for 2 h. Representative experiment from n = 2, biologically independent experiments. e Same as panel (c), with HeLa cells pre-treated with GSK’157 for 30 min and then co-treated with Tm and 5 μM of GSK’157 for the indicated times. Representative experiment from n = 2, biologically independent experiments. f Immunoblots of indicated proteins from lysates of HeLa cells pre-treated with GSK’157 for 30 min and then co-treated with Tm and GSK’157 for 2 h. Active (A) and Inactive (I) PERK and GCN2 are indicated with arrows. Representative experiment from n = 4, biologically independent experiments. Source data are provided as a Source data file.
