Increased WNK1 and WNK4 protein levels, and the activation of the WNK-OSR1/SPAK-NCC phosphorylation signaling cascade in the kidneys of KLHL3−/− mice. (A) Representative immunoblots of WNK1 and WNK4 in the kidneys of KLHL3+/+, KLHL3+/−, and KLHL3−/− mice. The expression levels of WNK1 and WNK4 and the phosphorylation of SPAK, OSR1, and NCC were significantly higher in the kidneys of KLHL3−/− mice but not in KLHL3+/− mice. (B) Densitometric analysis. Values are expressed as a ratio of the average signal in wild-type mice. n = 3 to 6; *, P < 0.05.