Invitrogen™ Phospho-IRE1 alpha (Ser724) Polyclonal Antibody

ERN1 serine/threonine kinase or endoplasmic reticulum to nucleus signaling 1 is the ER to nucleus signaling 1 protein, a human homologue of the yeast Ire1 gene product which possesses intrinsic kinase activity and an endoribonuclease activity and it is important in endoplasmic reticulum-based stress signals. ERN1 controls IRE1 proteolysis in mammalian cells. ERN1 has a critical function in extraembryonic cells that is essential for fetal viability. Specifically, IRE1 acts as the sensor of unfolded proteins in the ER that initiates transmittance of the unfolded protein signal from the ER to the nucleus by splicing XBP1 mRNA converting it into a potent unfolded-protein response transcriptional activator. Null mutants are viable, but IRE1 is essential for viability under stress conditions that cause unfolded proteins to accumulate in the ER. Depletion of IRE1p through the expression of a dominant negative form of IRE1p has no effect on transfected cells, but cell death via apoptosis occurs under stress conditions that cause unfolded proteins to accumulate in the ER.