Fig. 5

Internalization of a gap junction plaque. a Schematic depicting the internalization of a complete gap junction. The process leads to the formation of an annular gap junction (AGJ) vesicle in the cytoplasm of one of the coupled cells. b, c The process schemed in (a) imaged by time-lapse microscopy in Cx43-GFP expressing HeLa cells (only fluorescence shown in (b), merged fluorescence and DIC channels shown in (c)). Note that the small gap junction plaque in (b) (depicted by the upper arrow) does not internalize and remains in the plasma membrane while the large gap junction (depicted by the lower arrow) invaginates into the left cell of the coupled pair and forms an annular gap junction; and that in (c) a new gap junction (depicted with arrow) forms at the location were the previous internalized gap junction plaque (depicted with arrowhead) was localized. Time in c is in hours:minutes. (B.N.G. Giepmans and C. Lehmann recorded time-lapse movie sequences shown in (b) and (c), respectively when working in the Falk lab.)