Cell shape and contractility regulate ciliogenesis in cell cycle-arrested cells.
In most lineages, cell cycle exit is correlated with the growth of a primary cilium. We analyzed cell cycle exit and ciliogenesis in human retinal cells and found that, contrary to the classical view, not all cells exiting the cell division cycle generate a primary cilium. Using adhesive micropatterns to control individual cell spreading, we demonstrate that cell spatial confinement is a major regulator of ciliogenesis. When spatially confined, cells assemble a contractile actin network along their ventral surface and a protrusive network along their dorsal surface. The nucleus-centrosome axis in confined cells is oriented toward the dorsal surface where the primary cilium is formed. In contrast, highly spread cells assemble mostly contractile actin bundles. The nucleus-centrosome axis of spread cells is oriented toward the ventral surface, where contractility prevented primary cilium growth. These results indicate that cell geometrical confinement affects cell polarity via the modulation of actin network architecture and thereby regulates basal body positioning and primary cilium growth.
Laboratoire Biopuces, Institut de Recherche en Sciences et Technologies pour le Vivant, Direction des Sciences du Vivant, Commissariat à l'Energie Atomique et aux Energies Alternatives, 38054 Grenoble, Cedex 09, France.
Amandine
A
Pitaval
Qingzong
Q
Tseng
Michel
M
Bornens
Manuel
M
Théry
D008841:Actin Cytoskeleton / Q000378:metabolism; D000199:Actins / Q000378:metabolism; D018929:Cell Culture Techniques; D002453:Cell Cycle; D016764:Cell Polarity; D048430:Cell Shape; D002923:Cilia / Q000378:metabolism* / Q000648:ultrastructure; D006801:Humans; D012160:Retina / Q000166:cytology
D000199:Actins