Figure 3. Comparison of ER chaperone expression levels, and UPR signaling in Grp94+/+ and +/− mouse embryonic fibroblasts (MEFs).

(A) Whole cell lysates from Grp94+/+ and +/− MEFs were either untreated (Ctrl), or treated with 300 nM thapsigargin (Tg), 1.5 µg/ml tunicamycin (Tu), or 5 mM azetidine (AzC) for 16 hr and subjected to Western blot with anti-KDEL and anti-β-actin antibodies. (B) Same as in (A) with Western blot with anti-XBP-1, anti-CHOP, and anti-β-actin antibodies. XBP-1(s) and XBP-1(u) indicate the spliced and non-spliced form of XBP-1 respectively.