Fig. 2. Interaction between endogenous Cx43 and Nedd4. (A) The anti-Cx43 antibody 71-0700 was used to immunoprecipitate protein complexes in lysates of WB-F344 cells. Cx43 and the associated Nedd4 were detected in the immunoblot with an anti-Cx43 antibody (71-0700) and anti-Nedd4 antibody, respectively. P1 and P2 label putatively different phosphorylation forms of Cx43; P0 indicates the non-phosphorylated form. (B) Colocalization of endogenous Cx43 and Nedd4 in plasma-membrane-associated and intracellular structures. Cultures of WB-F344 cells were double labelled for Cx43 (green; a,c,d) and Nedd4 (red; b,c,d). Cx43 and Nedd4 are colocalized at appositional membranes and within discrete intracellular structures (c, arrows; yellow). This distribution is evidenced in the enlarged part of c, shown in the inset (d, arrows). Bars, 20 µm.