title: A role for actin arcs in the leading-edge advance of migrating cells.
abstract: Epithelial cell migration requires coordination of two actin modules at the leading edge: one in the lamellipodium and one in the lamella. How the two modules connect mechanistically to regulate directed edge motion is not understood. Using live-cell imaging and photoactivation approaches, we demonstrate that the actin network of the lamellipodium evolves spatio-temporally into the lamella. This occurs during the retraction phase of edge motion, when myosin II redistributes to the lamellipodial actin and condenses it into an actin arc parallel to the edge. The new actin arc moves rearward, slowing down at focal adhesions in the lamella. We propose that net edge extension occurs by nascent focal adhesions advancing the site at which new actin arcs slow down and form the base of the next protrusion event. The actin arc thereby serves as a structural element underlying the temporal and spatial connection between the lamellipodium and the lamella during directed cell motion.
authors.affiliation: National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA.
authors.forename: Dylan T
authors.initials: DT
authors.lastname: Burnette
authors.forename: Suliana
authors.initials: S
authors.lastname: Manley
authors.forename: Prabuddha
authors.initials: P
authors.lastname: Sengupta
authors.forename: Rachid
authors.initials: R
authors.lastname: Sougrat
authors.forename: Michael W
authors.initials: MW
authors.lastname: Davidson
authors.forename: Bechara
authors.initials: B
authors.lastname: Kachar
authors.forename: Jennifer
authors.initials: J
authors.lastname: Lippincott-Schwartz
mesh_terms: D000199:Actins / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D002465:Cell Movement / Q000502:physiology*; D003599:Cytoskeleton / Q000378:metabolism* / Q000648:ultrastructure; D004847:Epithelial Cells / Q000166:cytology / Q000502:physiology; D022001:Focal Adhesions / Q000378:metabolism; D024462:Myosin Type II / Q000378:metabolism; D011554:Pseudopodia / Q000502:physiology* / Q000648:ultrastructure; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D000199:Actins; D011993:Recombinant Fusion Proteins; D024462:Myosin Type II