E3 ubiquitin-protein ligase that regulates cell proliferation ( ). Involved in apoptosis regulation (, ). Mediates ER stress-induced activation of JNK signaling pathway and apoptosis by promoting ERN1 activation and splicing of XBP1 mRNA (, ). Also involved in protein trafficking and localization .
Subcellular locations: Endoplasmic reticulum membrane, Late endosome membrane, Lysosome membrane, Nucleus inner membrane
Under certain conditions, relocalizes to recycling endosomes and to the inner nuclear membrane.
Widely expressed (at protein level). In normal pancreas, expressed in islets, but not in ducts, nor in acini (at protein level).