FIGURE 9:

YA/VD-Cx43 is likely internalized in the form of annular gap junctions that are detergent resistant and degraded by autophagy. (A) Bx43KD and CP43KD cells expressing YA/VD-Cx43 were immunostained for Cx43 (green) and β-catenin (red). Cells were extracted in situ with 1% TX100 (b and d) or starved in PBS without (PBS e and g) or with bafilomycin A1 (BFL PBS+BFL, f and h) for 3 h. (B) CP43KD (left) or Bx43KD (right) cells expressing YA/VD-Cx43 were starved in PBS with or without bafilomycin A1 for the indicated times, and cell lysates were immunoblotted for Cx43. Note that the level of YA/VD-Cx43 decreases upon starvation, and the decrease is prevented by BFL. (A) Gap junctions at the areas of cell–cell contact are indicated by the pink arrows, whereas annular gap junctions are indicated by the white arrows. Note that both in normal medium and in PBS, the mutant YA/VD is internalized in the form of annular gap junctions and internalization is not prevented upon treatment with BFL.