Figure 3.

Expression of the plakophilin 1 head domain in HaCaT cells. Plasmid DNAs encoding the plakophilin 1 head domain in pCMV5 were transfected into HaCaT cells. Cells were fixed in methanol and extracted in Triton X-100 and double labeled with the plakophilin 1 head domain antibody (a–e) and antibodies against desmoplakin (a′), desmoglein (b′), desmocollin (c′), plakoglobin (d′), and keratin (e′). In a and b, single transfected cells are in the center; arrows in c–e denote the plasma membranes between two transfected cells. The plakophilin 1 head domain was found in the nucleus and at cell borders; it enhanced the recruitment of desmoplakin (a′), desmoglein (b′), desmocollin (arrows, c′) and, to a lesser extent, of plakoglobin (arrows, d′) to the plasma membrane. Keratins colocalized with plakophilin 1 at the borders of transfected cells (arrows, e′). Bar, 20 μm.