Figure 5.

Expression of low-affinity sarcoendoplasmic reticulum calcium ATPase (SERCA) isoform SERCA3 in cystic fibrosis (CF) and non-CF airway epithelial cells. (A) Western blot for SERCA3 from whole cell lysates (20 μg of protein/lane) from non-CF and CF bronchial airway epithelial cell lines. Membranes were also probed for β-actin to verify equal loading of protein. (B) Northern blot for SERCA3 mRNA expression. About 15 μg of RNA was subjected to Northern blot analysis, and SERCA3 was identified using ³²P-labeled cDNA probe. Before hybridization membranes were analyzed with ultraviolet light exposure for visualization of 18S and 28S RNA bands to verify equality of RNA loading and transfer. Equal loading was further established by 28S RNA (bottom panel) analysis. Cell lysates from air-liquid interface cultures of primary airway epithelial cells from three non-CF (1–3) and three CF (4–6) subjects were also assessed for SERCA3 expression by Western blot (C). Results represent three individual experiments.