Figure 4.

Effect of Cx46 and Cx50 truncations on coupling levels in HeLa cells. Bar graphs show the G_j values in HeLa cells transfected with cDNA corresponding to full-length Cx46 and Cx50 (light bars) as well as C-terminal truncations (gray bars) and cytoplasmic loop truncations (dark bars) in Cx46 and Cx50. Junctional conductance values in cells expressing the C-terminal truncations of Cx46 (A) and Cx50 (B) at residues 251 and 253, respectively, were comparable to those expressing their full-length counterparts. In contrast, the V284 truncation in Cx50 did not form functional intercellular channels. Junctional conductance (G_j) values in cells transfected with cDNA transfected with cytoplasmic loop truncations had very low levels of coupling, and not higher than those found in untransfected parental cells (data not shown). Each bar represents the mean ± SEM from multiple cells pairs, as described in the text.