FIG. 4.

The UPR is linked to insulin action, inflammation, oxidative stress, and apoptosis. The UPR is linked to insulin action via interactions with JNK, to inflammation via PKR, regulated intramembrane proteolysis of CREBH, and interactions with JNK, to protection from oxidative stress via phosphorylation of Nrf2, splicing of XBP1 and selective translation of ATF4, to apoptosis via interactions with JNK, upregulation of C/EBP homologous protein (Chop), activation of caspase-12, and extrusion of luminal calcium (see text).