Fig. 2: GSK’157 activates GCN2 and the ISR independently of ER stress and PERK.
From: Activation of the integrated stress response by inhibitors of its kinases
a Immunoblots of indicated proteins from lysates of HeLa cells treated with indicated concentrations of GSK’157 for 2.5 h. Active (A) and Inactive (I) GCN2 are indicated with arrows. 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 (P-eIF2α n = 5 and ATF4 n = 4, except 0.02 and 0.04 μM compound treatment n = 4 and n = 3 respectively), biologically independent experiments. *p ≤ 0.0435, **p ≤ 0.0038, ***p = 0.0002, as determined by one-way ANOVA with Dunnett’s multiple comparison test. b Newly synthesized proteins labelled for 10 min with 35S-methionine in HeLa cells treated with indicated concentrations of GSK’157 for 2.5 h and a Coomassie-stained gel as control. Representative experiment from n = 2, biologically independent experiments. c Immunoblots of indicated proteins in lysates of HeLa cells untreated or pre-treated with PERK siRNA for 60 h and subjected to increasing concentrations of GSK’157 for 2.5 h. Active (A) and Inactive (I) GCN2 are indicated with arrows. Representative experiment from n = 3, biologically independent experiments. d Immunoblots of indicated proteins from lysates of HeLa cells untreated or pre-treated with indicated siRNA for 60 h and subjected to increasing concentrations of GSK’157 for 2.5 h. Active (A) and Inactive (I) GCN2 are indicated with arrows. Newly synthesized proteins in the same lysates labelled with 35S-methionine for 10 min and a Coomassie-stained gel as control. Representative experiment from n = 2, biologically independent experiments. Source data are provided as a Source data file.
