Endoplasmic reticulum stress-associated proteins (UPR proteins)

Endoplasmic reticulum (ER) stress-associated proteins are a collective group of signaling transducers and chaperones that mediate the Unfolded Protein Response (UPR), a cellular conservation mechanism activated by the accumulation of misfolded proteins within the ER lumen (Hetz et al., 2020, Nature Reviews Molecular Cell Biology). The pathway is primarily governed by three transmembrane sensors: Inositol-requiring enzyme 1 alpha (IRE1α), Protein kinase RNA-like endoplasmic reticulum kinase (PERK), and Activating transcription factor 6 (ATF6), which collectively work to restore proteostasis by attenuating translation and upregulating folding machinery (Wang & Kaufman, 2016, Nature). In the context of disease, cancer cells often hijack these proteins to survive the metabolic stress of the tumor microenvironment, while chronic activation in neurodegenerative diseases like Alzheimer's leads to neuronal apoptosis via the pro-apoptotic factor CHOP (Oakes & Papa, 2015, Annual Review of Pathology). Therapeutic strategies include the use of small molecule inhibitors to block UPR-aided survival in tumors or chemical chaperones like 4-phenylbutyric acid to alleviate ER stress in metabolic disorders (Ghemrawi & Khair, 2020, International Journal of Molecular Sciences). Because these proteins are central to the secretory pathway, targeting them requires careful calibration to avoid toxicity in high-demand secretory tissues such as the pancreas and liver.

Other names

Unfolded Protein Response componentsER stress sensorsER stress mediatorsUPR signaling pathway proteins

Modulation of the unfolded protein response (UPR) signaling pathways to either restore endoplasmic reticulum homeostasis or selectively induce apoptosis in pathologically stressed cells.