Fig. 2.

Compound K induced ER-stress and activation of unfolded protein response. Cells were treated with various concentrations (5μM, 10μM, 15μM) of compound K (48 h) and various times (0 h, 6 h, 12 h, 24 h, 36 h, 48 h) with compound K (15μM). GRP78, IRE1α, XBP-1S, p-eIF2α, and CHOP were analyzed by Western blotting and β-actin was used as an internal control. eIF2α, eukaryotic translation initiation factor 2 subunit α; GADD153(CHOP), growth arrest and DNA damage 153(C/EBP homologous protein); GRP78(Bip), glucose-regulated protein-78(Binding immunoglobulin protein); IRE1α, inositol requiring kinase-1 α; XBP-1, X-box binding protein-1.