FIGURE 3.
Depletion of ERp29 is associated with decrease in WT-CFTR expression. ERp29-specific or control siRNA was delivered to CFBE41o− WT bronchial epithelial cells that overexpress WT-CFTR (A and B) or T84 colonic adenocarcinoma cells that endogenously express WT-CFTR (C and D) as described under “Experimental Procedures.” After 48 h, cells were lysed, and equal amounts of whole-cell lysate protein were resolved by SDS-PAGE. A, ERp29, CFTR, BiP/grp78, and GAPDH (as a loading control) were detected by immunoblot in lysates of CFBE41o− WT cells. Data representative of three independent experiments are shown. B, relative expression of ERp29 (gray bars) and CFTR (open bars) in CFBE41o− WT was quantified by densitometry of n = 3 independent experiments as described under “Experimental Procedures.” C, ERp29, CFTR, BiP/grp78, and GAPDH (as a loading control) were detected by immunoblot in T84 cells. Data representative of three independent experiments are shown. D, relative expression of ERp29 (gray bars) and CFTR (open bars) in CFBE41o− WT was quantified by densitometry of n = 3 independent experiments as described under “Experimental Procedures.” For B and D, data (mean ± S.E.) were normalized to control siRNA values, and expression of ERp29 and CFTR in control versus ERp29-specific siRNA-treated cells was compared by t test.