Fig. 2.

Endoplasmic reticulum stress (ERS) activates pro-apoptotic signaling pathways. ER: endoplasmic reticulum; GRP78: glucose regulated protein78; IRE1: inositol-requiring enzyme 1; PERK: protein kinase RNA (PKR)-like ER kinase; ATF: activating transcription factor; eIF2α: eukaryotic translation initiation factor 2α; ATF4: activating transcription factor 4; ATF6: activating transcription factor 6; TRAF2: tumor necrosis factor receptor-associated factor 2; ASK1: apoptotic signaling kinase-1; JNK: c-Jun N-terminal kinase; S1P: site 1 protease; S2P: site 2 protease; IP3R1: inositol 1,4,5-trisphosphate receptor type 1; CaMKII: Ca²⁺/calmodulin-dependent protein kinase II; FAS: Fas cell surface death receptor; CHOP: C/EBP homologous protein; Bcl-2: BCL2 apoptosis regulator.