Neuro2A cells were transiently transfected to express the indicated constructs and were paired as shown. GJ coupling was measured in nS. As expected, Cx43 homotypic pairs (WT/WT) were well coupled, as were pairs of cells in which both cells expressed Cx43WT, regardless of whether one (WT + G60S/WT) or both (WT + G60S/WT + G60S) cells also expressed G60S. Cell pairs expressing G60S alone (G60S/G60S) showed no coupling (significantly different from WT/WT at P < 0.05). Only one heterotypic Cx43G60S/Cx43WT pairing showed any coupling; the other six cell pairs showed no coupling.