Figure 6.

PP2Ce is essential to normal UPR in response to ER stress in vitro. (A) Immunoblots of phosphor—IRE1α and ΙΡΕ1α following immunoprecipitation with anti-IRE1α, or immunoblot for p-JNK, total JNK and β-actin from total protein extracts prepared from primary MEFs of P12 wildtype and PP2Ce-/- mouse embryo under control (CTL) or DTT treatment as described in Methods. ⁎ Indicates phosphorylated oligomerized IRE1 species. (B–E) Quantitative RT-PCR for mRNA levels of PP2Ce, BIP, CHOP and XBP-1 normalized against GAPDH as indicated in wildtype (WT) and PP2Ce-/- (KO) MEFs following control (CTL) and DTT treatment.