title: FAK is required for tension-dependent organization of collective cell movements in Xenopus mesendoderm.
abstract: Collective cell movements are integral to biological processes such as embryonic development and wound healing and also have a prominent role in some metastatic cancers. In migrating Xenopus mesendoderm, traction forces are generated by cells through integrin-based adhesions and tension transmitted across cadherin adhesions. This is accompanied by assembly of a mechanoresponsive cadherin adhesion complex containing keratin intermediate filaments and the catenin-family member plakoglobin. We demonstrate that focal adhesion kinase (FAK), a major component of integrin adhesion complexes, is required for normal morphogenesis at gastrulation, closure of the anterior neural tube, axial elongation and somitogenesis. Depletion of zygotically expressed FAK results in disruption of mesendoderm tissue polarity similar to that observed when expression of keratin or plakoglobin is inhibited. Both individual and collective migrations of mesendoderm cells from FAK depleted embryos are slowed, cell protrusions are disordered, and cell spreading and traction forces are decreased. Additionally, keratin filaments fail to organize at the rear of cells in the tissue and association of plakoglobin with cadherin is diminished. These findings suggest that FAK is required for the tension-dependent assembly of the cadherin adhesion complex that guides collective mesendoderm migration, perhaps by modulating the dynamic balance of substrate traction forces and cell cohesion needed to establish cell polarity.
authors.affiliation: Department of Cell Biology, School of Medicine, University of Virginia Health System, P.O.Box 800732, Charlottesville, VA 22908, USA.
authors.forename: Maureen A
authors.initials: MA
authors.lastname: Bjerke
authors.affiliation: Department of Cell Biology, School of Medicine, University of Virginia Health System, P.O.Box 800732, Charlottesville, VA 22908, USA.
authors.forename: Bette J
authors.initials: BJ
authors.lastname: Dzamba
authors.affiliation: Department of Cell Biology, School of Medicine, University of Virginia Health System, P.O.Box 800732, Charlottesville, VA 22908, USA.
authors.forename: Chong
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Cell Biology, School of Medicine, University of Virginia Health System, P.O.Box 800732, Charlottesville, VA 22908, USA. Electronic address: desimone@virginia.edu.
authors.forename: Douglas W
authors.initials: DW
authors.lastname: DeSimone
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D015153:Blotting, Western; D015820:Cadherins / Q000378:metabolism; D002465:Cell Movement / Q000502:physiology*; D016764:Cell Polarity / Q000502:physiology; D051417:Focal Adhesion Kinase 1 / Q000235:genetics / Q000378:metabolism*; D054262:Gastrulation / Q000502:physiology*; D055785:Gene Knockdown Techniques; D005855:Germ Layers / Q000196:embryology*; D047468:Immunoprecipitation; D007633:Keratins / Q000378:metabolism; D008856:Microscopy, Fluorescence; D060172:Morpholinos / Q000235:genetics; D018709:Statistics, Nonparametric; D014981:Xenopus / Q000196:embryology*
chemical_list: D015820:Cadherins; D060172:Morpholinos; D007633:Keratins; D051417:Focal Adhesion Kinase 1
keywords: Cadherin; Cell migration; Focal adhesion kinase; Gastrulation; Integrin; Keratin