UPR

The unfolded protein response (UPR), a wide-ranging process overseen by the endoplasmic reticulum (ER), regulates basal and acute cellular function. It entails maintenance of protein homeostasis through removal of unfolded (or misfolded) proteins and affects processes as diverse as lipid and glucose metabolism and innate immunity. Under normal conditions, buildup of unfolded proteins is detected by activating transcription factor 6 (ATF6), inositol-requiring protein 1 (IRE1), and protein kinase RNA-like ER kinase (PERK), triggering the ER stress response, including UPR. Chronic activation of these pathways can lead to cancer, neurodegeneration, and metabolic diseases.