Fig. 2. Expression and localization of wildtype and Cx43 amino-acid substitution variants. (A) BHK cells were transfected with cDNAs encoding GFP-tagged wt and mutated Cx43, respectively, and expressed proteins were detected by western blot analysis using polyclonal antibodies directed against the C-terminal domain of Cx43. Equal amounts of full-length fusion proteins were expressed with all constructs (labeled with an arrowhead). Small amounts of endogenous Cx43 in BHK cells (labeled with an asterisk) and some unspecific reaction products were also detected in all lanes. (B) Localization of GFP-tagged connexins was detected by GFP auto-fluorescence 24 hours post transfection. Connexin clusters were detected with all constructs at cell-cell appositions (marked with arrows) besides intracellular fluorescence. Phase-contrast images are shown on the left; the corresponding fluorescence images are shown on the right. Bar, 10 µm.