Actin cable dynamics and Rho/Rock orchestrate a polarized cytoskeletal architecture in the early steps of assembling a stratified epithelium.
To enable stratification and barrier function, the epidermis must permit self-renewal while maintaining adhesive connections. By generating K14-GFP-actin mice to monitor actin dynamics in cultured primary keratinocytes, we uncovered a role for the actin cytoskeleton in establishing cellular organization. During epidermal sheet formation, a polarized network of nascent intercellular junctions and radial actin cables assemble in the apical plane of the monolayer. These actin fibers anchor to a central actin-myosin network, creating a tension-based plane of cytoskeleton across the apical surface of the sheet. Movement of the sheet surface relative to its base expands the zone of intercellular overlap, catalyzing new sites for nascent intercellular junctions. This polarized cytoskeleton is dependent upon alpha-catenin, Rho, and Rock, and its regulation may be important for wound healing and/or stratification, where coordinated tissue movements are involved.
D008841:Actin Cytoskeleton / Q000648:ultrastructure; D000199:Actins / Q000502:physiology*; D022005:Adherens Junctions / Q000502:physiology / Q000648:ultrastructure; D000577:Amides / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D015820:Cadherins / Q000378:metabolism; D002118:Calcium / Q000494:pharmacology; D016764:Cell Polarity; D002478:Cells, Cultured; D003598:Cytoskeletal Proteins / Q000378:metabolism; D003599:Cytoskeleton / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure*; D003896:Desmosomes / Q000648:ultrastructure; D004791:Enzyme Inhibitors / Q000494:pharmacology; D000078404:Epidermal Cells; D004817:Epidermis / Q000502:physiology / Q000648:ultrastructure*; D004847:Epithelial Cells / Q000648:ultrastructure; D049452:Green Fluorescent Proteins; D047908:Intracellular Signaling Peptides and Proteins; D015603:Keratinocytes / Q000502:physiology / Q000648:ultrastructure; D008164:Luminescent Proteins / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D008954:Models, Biological; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000502:physiology*; D011725:Pyridines / Q000494:pharmacology; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D019076:Transgenes / Q000502:physiology; D051178:alpha Catenin; D020741:rho GTP-Binding Proteins / Q000502:physiology*; D054460:rho-Associated Kinases
D000199:Actins; D000577:Amides; D015820:Cadherins; C495272:Ctnna1 protein, mouse; D003598:Cytoskeletal Proteins; D004791:Enzyme Inhibitors; D047908:Intracellular Signaling Peptides and Proteins; D008164:Luminescent Proteins; D011725:Pyridines; D011993:Recombinant Fusion Proteins; D051178:alpha Catenin; C108830:Y 27632; D049452:Green Fluorescent Proteins; D017346:Protein Serine-Threonine Kinases; D054460:rho-Associated Kinases; D020741:rho GTP-Binding Proteins; D002118:Calcium