Fig. S5.

CReP controls basal level of eIF2α phosphorylation maintained by constitutive activity of eIF2α-specific kinases (related to Fig. 8). HeLa cells were transfected with a mixture of siRNAs targeting PERK, PKR, HRI, and GCN2. Twenty-four hours later, a second transfection with nonrelevant (NR) or two different CReP-specific siRNAs was performed. After 24 h, cells were analyzed by WB with the indicated antibodies. Results show that in the absence of the four stress kinases PERK, PKR, HRI, and GCN2, CReP silencing-mediated ATF4 induction is abolished. Tubulin (Tbl) is used as the loading control.