FIGURE 3:

The sorting-motif mutant YA/VD-Cx43 restores gap junction assembly. (A) WT-Cx43 (WT) and YA/VD-Cx43 (YA/VD) were expressed in cells by transient transfection (top row) or by retroviral infection (bottom row). Cells were immunostained for Cx43. For transient expression, WT-Cx43 and YA/VD-Cx43 were cotransfected with EGFP to mark the transfected cells. Note the formation of gap junctions (arrows) in cells expressing YA/VD-Cx43. (B) The percentage of transfected cells that had gap junctions was determined by examining 20 cells from two experiments (blue bars: cells expressing WT-Cx43; red bars: cells expressing YA/VD-Cx43). Note the increase in gap junction number in cells transfected with YA/VD-Cx43. (C) Total (T), TX100-soluble (S), and TX100-insoluble (I) fractions were prepared from cells expressing retrovirally introduced WT-Cx43 or YA/VD-Cx43. Note the robust increases in the detergent-insoluble fractions in cells infected with YA/VD-Cx43.