Fig. 5
From: Cooperative cell–cell actin network remodeling to perform Gap junction endocytosis
Remodeling of actin organization during the last steps of GJP endocytosis. A High magnification of part of a U-shaped plaque (inset) shows that the cytoplasmic fold of the Acceptor cell that encloses the GJP mouth contains numerous actin filaments more or less elongated (arrows). Actin filaments are more condensed in this particular region. B Pair of stereoscopic images, examined with a stereoscope, reveals the 3D organization of the actin filaments present in the small membranous region delimited by the Acceptor membrane. The fine spatial examination of actin distribution reveals that most actin filaments ran parallel to the others and that they are also directed parallel to the plasma membrane (arrows in right panel). C In Cx43-GFP transfected Sertoli cells, the U-shaped round plaque (green) is prolonged by two red actin cables (white arrows). Their fusion point (F) is located close to the plaque. A ring-like structure formed by actin filaments is close to the mouth region of the GJP (large white arrow). 3D reconstruction of the GJP (inset) clearly indicates actin cables (arrows) inserted on the periphery of the plaque (P). Confirmation of the presence of an actin ring that embraces the region of the final closure of the GJP is given by analysis of Z series of this image (lower panels in C, arrows)