Functions of GADD34 and CReP in early stages of UPR. (A) Translational activity in WT, GADD34−/−, and CReP−/− cells during Tg-induced ER stress, as measured by pulse-labeling with [35S]Met-Cys (n = 3). Data for WT cells are reproduced from reference 22. max, maximum. (B) Time-dependent changes in GADD34 mRNA and translation in WT MEFs following exposure to 1 μM Tg, assessed by RNA-seq and ribosome profiling (n = 2).