Fig. 6.

Expression of total and ubiquitinated α-subunit of the epithelial Na⁺ channel (αENaC) from kidneys of rats on the control diet or low-Na⁺ diet. A: whole kidney homogenates of animals fed either control diet or low-Na⁺ food for 1 wk. Lanes of the Western blots were loaded with 30 μg protein. B: eluates from ubiquitin-affinity beads. Lanes were loaded with 45 μL of eluates. Blots were stained using anti-αENaC antibody. C: quantitation of expression in kidney homogenates. D: quantitation of the ubiquitin pulldown. Data were normalized to values for the control diet and are shown as means ± SE for 4 rats in each condition. Full-length αENaC: P = 0.005; cleaved αENaC: P = 0.0007; ubiquitinated αENaC: P = 0.04 vs. control.