Figure 2. Eukaryotic translation initiation factor 2 (eIF2α) is phosphorylated by various stresses in mouse embryonic fibroblasts (MEFs).

(A) Representative immunoblots of phosphorylated eIF2α, total eIF2α and ribophorin (Rb) 1 h after treatment with the indicated stress stimulus in the wild-type MEFs. The ratio of autophosphorylated versus total eIF2α is indicated. (B) Representative immunoblots of phosphorylated PKR, PERK, GCN2 and Rb 1 h after treatment with the indicated stress stimulus in MEFs. The stress condition abbreviations used in the Figure were as follows: untreated (UT), 400 μM arsenate (Ars), 10 ng/μl polyinosinic-polycytidylic acid (pIC), 200 nM thapsigargin (Tg), 2 mM histidinol (His), 1 mM H₂O₂ (H₂O₂), 500 mM NaCl (NaCl), 254 nm 200 J/m² ultraviolet irradiation (UV), 42 °C heat shock (heat), cold shock (cold), low glucose (LG), serum starvation (SS) and anoxia (Ano).