Recruits the serine/threonine-protein phosphatase PPP1CA to prevents excessive phosphorylation of the translation initiation factor eIF-2A/EIF2S1, thereby reversing the shut-off of protein synthesis initiated by stress-inducible kinases and facilitating recovery of cells from stress. Down-regulates the TGF-beta signaling pathway by promoting dephosphorylation of TGFB1 by PP1. May promote apoptosis by inducing TP53 phosphorylation on 'Ser-15'. Plays an essential role in autophagy by tuning translation during starvation, thus enabling lysosomal biogenesis and a sustained autophagic flux. Interacts with PPP1CA. Interacts with EIF2S1 (By similarity). Interacts with PCNA (By similarity). Interacts with LYN and KMT2A/MLL1. Interacts with PPP1R1A and SMARCB1. Interacts with SMAD7. Interacts with BAG1. Interacts with NOX4 (By similarity). Associates with membranes via an N-terminal amphipathic intramembrane region. By lipopolysaccharide. Phosphorylated at multiple Ser/Thr residues. Phosphorylated on tyrosine by LYN; which impairs its antiproliferative activity. Phosphorylation at Tyr-236 enhances proteasomal degradation, this position is dephosphorylated by PTPN2. Polyubiquitinated. Exhibits a rapid proteasomal degradation with a half-life under 1 hour, ubiquitination depends on endoplasmic reticulum association. Belongs to the PPP1R15 family. The sequence described initially (PubMed:9256446) corresponds to a mutant, frameshifted form named PEG-3 that frequently arises during cell transformation and does not seem to exist in normal cells. PEG-3 functions as a dominant negative of GADD34-mediated pro-apoptotic pathway and promotes cancer aggressiveness.