title: Activity of the RhoU/Wrch1 GTPase is critical for cranial neural crest cell migration.
abstract: The neural crest (NC) is a stem cell-like population that arises at the border of neural and non-neural ectoderm. During development, NC undergoes an epithelio-mesenchymal transition (EMT), i.e. loss of epithelial junctions and acquisition of pro-migratory properties, invades the entire embryo and differentiates into a wide diversity of terminal tissues. We have studied the implication of Rho pathways in NC development and previously showed that RhoV is required for cranial neural crest (CNC) cell specification. We show here that the non-canonical Wnt response rhoU/wrch1 gene, closely related to rhoV, is also expressed in CNC cells but at later stages. Using both gain- and loss-of-function experiments, we demonstrate that the level of RhoU expression is critical for CNC cell migration and subsequent differentiation into craniofacial cartilages. In in vitro cultures, RhoU activates pathways that cooperate with PAK1 and Rac1 in epithelial adhesion, cell spreading and directional cell migration. These data support the conclusion that RhoU is an essential regulator of CNC cell migration.
authors.affiliation: Universités Montpellier 2 et 1, CRBM, IFR122, Montpellier, France. philippe.fort@crbm.cnrs.fr
authors.forename: Philippe
authors.initials: P
authors.lastname: Fort
authors.forename: Linda
authors.initials: L
authors.lastname: Guémar
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Vignal
authors.forename: Nathalie
authors.initials: N
authors.lastname: Morin
authors.forename: Cécile
authors.initials: C
authors.lastname: Notarnicola
authors.forename: Pascal
authors.initials: P
authors.lastname: de Santa Barbara
authors.forename: Sandrine
authors.initials: S
authors.lastname: Faure
mesh_terms: D000818:Animals; D002465:Cell Movement; D016764:Cell Polarity; D002642:Chick Embryo; D051418:Focal Adhesion Kinase 2 / Q000502:physiology; D009432:Neural Crest / Q000166:cytology*; D029867:Xenopus Proteins / Q000502:physiology*; D014982:Xenopus laevis / Q000196:embryology*; D054462:p21-Activated Kinases / Q000502:physiology; D020744:rac GTP-Binding Proteins / Q000502:physiology; D020741:rho GTP-Binding Proteins / Q000502:physiology*
chemical_list: D029867:Xenopus Proteins; D051418:Focal Adhesion Kinase 2; D054462:p21-Activated Kinases; C556689:RhoU protein, Xenopus; D020744:rac GTP-Binding Proteins; D020741:rho GTP-Binding Proteins