title: G-protein-coupled signals control cortical actin assembly by controlling cadherin expression in the early Xenopus embryo.
abstract: During embryonic development, each cell of a multicellular organ rudiment polymerizes its cytoskeletal elements in an amount and pattern that gives the whole cellular population its characteristic shape and mechanical properties. How does each cell know how to do this? We have used the Xenopus blastula as a model system to study this problem. Previous work has shown that the cortical actin network is required to maintain shape and rigidity of the whole embryo, and its assembly is coordinated throughout the embryo by signaling through G-protein-coupled receptors. In this paper, we show that the cortical actin network colocalizes with foci of cadherin expressed on the cell surface. We then show that cell-surface cadherin expression is both necessary and sufficient for cortical actin assembly and requires the associated catenin p120 for this function. Finally, we show that the previously identified G-protein-coupled receptors control cortical actin assembly by controlling the amount of cadherin expressed on the cell surface. This identifies a novel mechanism for control of cortical actin assembly during development that might be shared by many multicellular arrays.
authors.affiliation: Children's Hospital Research Foundation, Division of Developmental Biology, and Molecular and Developmental Biology Graduate Program, University of Cincinnati College of Medicine, OH 45219, USA.
authors.forename: Qinghua
authors.initials: Q
authors.lastname: Tao
authors.forename: Sumeda
authors.initials: S
authors.lastname: Nandadasa
authors.forename: Pierre D
authors.initials: PD
authors.lastname: McCrea
authors.forename: Janet
authors.initials: J
authors.lastname: Heasman
authors.forename: Christopher
authors.initials: C
authors.lastname: Wylie
mesh_terms: D000199:Actins / Q000378:metabolism*; D000818:Animals; D036703:Blastula / Q000378:metabolism; D015820:Cadherins / Q000378:metabolism*; D051177:Catenins; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism*; D043562:Receptors, G-Protein-Coupled / Q000502:physiology*; D049368:Receptors, Lysophosphatidic Acid / Q000502:physiology; D015398:Signal Transduction; D029867:Xenopus Proteins / Q000378:metabolism* / Q000502:physiology*; D014982:Xenopus laevis / Q000196:embryology / Q000502:physiology*; D000095002:Delta Catenin
chemical_list: D000199:Actins; C074260:CDH3 protein, Xenopus; D015820:Cadherins; D051177:Catenins; D015815:Cell Adhesion Molecules; C502565:Flop protein, Xenopus; D010750:Phosphoproteins; D043562:Receptors, G-Protein-Coupled; D049368:Receptors, Lysophosphatidic Acid; D029867:Xenopus Proteins; D000095002:Delta Catenin