Fig. (2) The T261G WNK4 mutant behaves like wild type WNK4. A. Oocytes were injected with NCCT wt alone or in combination with WNK4 wt or WNK4 T261G. Mutant WNK4 reduced ²²Na⁺ flux equivalent to the same extent as WNK4 wt. * P< 0.0001vs NCCT alone. B. Confocal microscopy of the fluorescent signal from eCFP-NCCT showed that changes in WNK4 induced ²²Na⁺ flux were accompanied by similar changes in surface membrane expression of the cotransporter. * P< 0.0001 vs NCCT alone.