Fig. 2.

Pulldown of the ubiquitinated β-subunit of the epithelial Na⁺ channel (βENaC) from the mouse kidney. Lanes of the Western blot were loaded with 50 μg of whole kidney extract (input to the affinity beads), 45 μL of eluates from the ubiquitin-affinity beads, or 45 μL eluates from the control-affinity beads. Blots were stained using anti-βENaC antibody. Animals were fed either a control diet or a low-Na⁺ diet for 1 wk. The bottom bands in the lanes for the whole cell extracts represent nonspecific staining, as they are also present in the absence of the COOH-terminal epitope (see Fig. 5). Results are representative of at least 3 experiments with mouse and rat kidneys.