Interaction of NHE3s with Nedd4 proteins.
A, NHE3s containing a VSVG tag were transiently expressed in HEK293 cells along with HA-Nedd4-1 or HA-Nedd4-2. NHE3 was immunoprecipitated (IP) using VSVG antibody followed by immunoblotting (IB) using anti-HA antibody to detect co-immunoprecipitated HA-Nedd4-1 or HA-Nedd4-2. 300 μg of cell lysates were used for immunoprecipitation. The bottom two panels show relative expression levels of HA-Nedd4-1, HA-Nedd4-2, and NHE3 in the cell lysate. B, PS120 fibroblasts stably expressing human, rabbit, or rat NHE3 were transiently transected with pcDNA/HA-Nedd4-2. NHE3 was immunoprecipitated with anti-VSVG antibody, and co-immunoprecipitated Nedd4-2 was detected by anti-HA antibody. Representative figures from three independent experiments are shown.