IRE1α/ERN1 [10B2B2]

Accumulation of misfolded proteins in the endoplasmic reticulum (ER) activates the unfolded protein response (UPR) and upregulates ER molecular chaperones in order to cope with ER stress. UPR is initiated by three ER-localized protein sensors: PERK (PKR-like ER kinase), ATF (activating transcription factor 6), and IRE1 alpha (inositol-requiring enzyme 1 alpha). IRE1 alpha is correlated with X-box binding protein (XBP1) as a potent UPR transcriptional activator. IRE1 alpha acts as the sensor of unfolded proteins in the ER. IRE1 alpha not only promotes cell survival but can initiate apoptosis when accumulation of unfolded proteins in the ER causes stress. IRE1 alpha is essential for viability under stress conditions that cause unfolded proteins to accumulate in the ER. IRE1 alpha is a transmembrane protein that has both serine-threonine kinase and endoribonuclease activities and has a theoretical molecular weight of 110 kDa. When detecting phospho-IRE1 alpha, it is recommended to normalize its band intensity with total IRE1 alpha.