Composition of discontinuous adherens junction (AJ). (A) Human umbilical vein endothelial cells (HUVECs) were grown at confluency for 72 h in EGM-2 growth medium, fixed, permeabilized and stained with antibodies to the indicated junctional proteins. Top right panels show single staining of the merged image on the left. Arrows indicate discontinuous cell-cell junctions; arrowhead, linear cell-cell junctions. (B) HUVECs were nucleofected with plasmids coding for p120-catenin-green fluorescent protein (p120-GFP) or p120-catenin-red fluorescent protein (p120-dsRed), cells from the two transfections were mixed and plated at confluence for 24 h in growth medium. Cell images were acquired by fluorescence time-lapse microscopy, 1 frame/min. Representative images are shown. Arrows show discontinuous AJ.