Fig. 1.

Nelfinavir triggers an ATF4 transcriptional response. (A–C) Triplicates of HeLa cells treated 6 h with DMSO or 20 μM NFR were analyzed for gene expression by RNA-seq. (A) Heat map showing the 153 Nelfinavir up-regulated genes with a P value < 0.01. The genes are listed in order of statistical significance. The z score is based on the mean of the six samples; green color indicates high expression and red low expression. The Right panel shows the 20 most significantly induced genes. Each column represents the data of one experiment; purple and pink dots refer to ATF4 only and ATF4 and CHOP targets, respectively, as reported in C. (B) Gene ontology analysis for the genes identified in A. (C) Venn diagram showing the overlap between the NFR-induced genes (with a P value < 0.05) in HeLa cells (yellow) and the published tunicamycin (TM)-triggered ER-stress signature (orange) identified in MEFs (28). Note that 30 of the 32 overlapping genes were reported to be ATF4 only (purple) or ATF4 and CHOP (pink) target genes (28). (D) ATF4 WT and ATF4 ^−/− MEFs treated for 6 h with the indicated concentration of NFR or TM were analyzed for expression of indicated genes by real-time PCR relative to β-actin (data are presented as fold change compared with untreated cells, and mean and SEM of technical triplicates of one representative experiment are shown).