Figure 5.

Na/K ATPase abundance in the plasma membrane of airway epithelia is unaffected by FXYD3 knockdown. A: a representative Western blot probed with Na/K ATPase and FXYD3 antibodies for airway epithelia from a single human donor. Lanes 2 and 3 contain whole cell protein, and lanes 4 and 5 contain biotinylated surface protein after streptavidin purification. B: the blot shown in A with the LUT linearly compressed displays the FXYD3 bands. C: total protein stain (loading control) of the blot shown in A and B. D: densitometry of raw Western blot intensities. Each donor’s FXYD3 siRNA condition is shown as a % of the donor’s siRNA control condition. Whole cell FXYD3 = 53.35 ± 26.30, whole cell Na/K ATPase = 98.13 ± 16.50, surface Na/K ATPase = 106.0 ± 49.31; means ± SD. FXYD3 bands were below the limit of detection for streptavidin-purified samples (i.e., FXYD3 surface), thus are not reported. For all summary data, each dot represents a blot from 1 human donor (n = 8 donors) and error bars represent the standard error of the mean. P values were calculated using a one-sample t test with a hypothetical mean of 100% (dotted line). Precision Plus Protein Dual Color (Bio-Rad) was used as a molecular weight marker in all blots. C, siRNA control; KD, knockdown (FXYD3 siRNA); L, ladder; LUT, look-up table; S, surface; SD, standard deviation; WC, whole cell.