... of the UPR pathways but also highlight a surprising degree of specificity associated with each UPR branch in development. Unfolded protein response Endoplasmic reticulum IRE1 XBP1 PERK eIF2α ATF4 ATF6 Pancreas Eye In eukaryotic cells, the endoplasmic reticulum (ER) serves as the primary...

... to adjust secretory pathway capacity according to need. Ire1, the endoplasmic reticulum (ER) stress sensor and central activator of the UPR is conserved from the budding yeast Saccharomyces cerevisiae to humans. Under ER stress conditions, Ire1 clusters into foci that enable optimal UPR activation...

...Huai-Wei Huang; Xiaomei Zeng; Taiyoun Rhim; David Ron; Hyung Don Ryoo ABSTRACT IRE1 mediates the unfolded protein response (UPR) in part by regulating XBP1 mRNA splicing in response to endoplasmic reticulum (ER) stress. In cultured metazoan cells, IRE1 also exhibits XBP1-independent biochemical...

... Calfon , M. , Zeng , H. , Urano , F. , Till , J. H. , Hubbard , S. R. , Harding , H. P. , Clark , S. G. and Ron , D. (2002). IRE1 couples endoplasmic reticulum load to secretory capacity by processing the XBP-1 mRNA . Nature   415 , 92 - 96 . 10.1038/415092a...

...Zuyuan Xu; Madhusudana Rao Chikka; Hongai Xia; Donald F. Ready ABSTRACT The endoplasmic reticulum (ER) serves virtually all aspects of cell physiology and, by pathways that are incompletely understood, is dynamically remodeled to meet changing cell needs. Inositol-requiring enzyme 1 (Ire1...

... the unfolded protein response (UPR), an essential ER signaling pathway. Through molecular and genetic approaches, we show that loss of the ER-shaping GTPase Root Hair Defective 3 (RHD3) specifically disrupts the UPR by interfering with the mRNA splicing function of the master regulator IRE1. These findings...

... with 10% FBS and antibiotics. U87 were stably transfected with pcDNA3/IRE1-NCK1, an expression vector encoding a cytoplasmic-defective IRE1α mutant). U87 cells were selected using 450 µg/ml G418 and several isolated clones were tested: T1P5 (referred as EV in the text) and T2P4 as empty vector and 1C5...

... that death of ire1 α –/– cells was caspase dependent, whereas it was caspase independent in bak/bax –/– cells, rather suggests that Bak/Bax and IRE1α are acting on separate pathways. Fig. 8. Proposed model of ER stress-induced cell death in wild-type and Bak/Bax-defective cells. Left panel...

...Aya Uemura; Masaya Oku; Kazutoshi Mori; Hiderou Yoshida XBP1 is a key transcription factor that regulates the mammalian unfolded protein response. Its expression is regulated by unconventional mRNA splicing that is carried out by endonuclease IRE1 and a specific, as yet unknown, RNA ligase...