Correction: IRE1–XBP1 pathway regulates oxidative proinsulin folding in pancreatic β cells

Physiological activation of the IRE1α–XBP1 pathway in pancreatic islets. (A) Xbp1 mRNA splicing was analyzed by RT-PCR using total RNA isolated from the tissues of 8-wk-old WT male mice. The ratio of Xbp1 mRNA splicing was quantified. Error bars show the means and SD. n = 3. Xbp1 splicing (%) = Xbp1s/total Xbp1 × 100. Lane 1, Xbp1u_pcDNA3.1(+). Lane 2, Xbp1s_pcDNA3.1(+). (B) Expression levels of IRE1α and ER-resident proteins harboring the KDEL motif (KDEL (ER)) in mouse tissues from an 8-wk-old WT male mouse based on immunoblotting. The expression levels of the cytosolic chaperone HSP90 (HSP90 (Cyt)) and the mitochondrial chaperone HSP60 (HSP60 (Mit)) were also examined. Positions of molecular mass markers are indicated on the left.