earticle

영어

Environmental or physiological influences that induce accumulation of unfolded proteins in the lumen of endoplasmic reticulum (ER) cause ER stress and activate signaling pathway called unfolded protein response (UPR). An ER-located transmembrane receptor protein kinase/ribonuclease called Ire1 plays an essential role in the UPR in yeasts and mammals. However, it has been unclear whether a similar mechanism is applicable to Arabidopsis. To elucidate the role of Arabidopsis IRE1, we performed functional analyses by isolating loss-of-function mutants of IRE1A and IRE1B. We found that a double mutant of Arabidopsis IRE1A and IRE1B (ire1a/ire1b) is more sensitive to the ER stress inducer tunicamycin than the wild-type. ire1a/ire1b result in a delayed induction of BiP3 which is well known ER chaperone by DTT treatment, whereas induction of BiP1 in ire1a/ire1b was similar with that of WT. Our result indicate that IRE1A and IRE1B are implicated in unfolded protein response signaling in plants.