title: Role of p21-activated kinase in cell polarity and directional mesendoderm migration in the Xenopus gastrula.
abstract: The p21 activated kinases (Paks) are prominently involved in the regulation of cell motility. Using a kinase-dead mutant of xPak1, we show that during Xenopus gastrulation, the kinase activity of Pak1 is required upstream of Cdc42 for the establishment of cell polarity in the migrating mesendoderm. Overactivation of Pak1 function by the expression of constitutively active xPak1 compromises the maintenance of cell polarity, by indirectly inhibiting RhoA function. Inhibition of cell polarization does not affect the migration of single mesendoderm cells. However, Pak1 inhibition interferes with the guidance of mesendoderm migration by directional cues residing in the extracellular matrix of the blastocoel roof, and with mesendoderm translocation in the embryo.
authors.affiliation: Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Martina
authors.initials: M
authors.lastname: Nagel
authors.forename: Olivia
authors.initials: O
authors.lastname: Luu
authors.forename: Nicolas
authors.initials: N
authors.lastname: Bisson
authors.forename: Bojan
authors.initials: B
authors.lastname: Macanovic
authors.forename: Tom
authors.initials: T
authors.lastname: Moss
authors.forename: Rudolf
authors.initials: R
authors.lastname: Winklbauer
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D019521:Body Patterning / Q000235:genetics / Q000502:physiology; D002448:Cell Adhesion / Q000235:genetics; D002465:Cell Movement / Q000235:genetics*; D016764:Cell Polarity / Q000235:genetics*; D004625:Embryo, Nonmammalian; D005775:Gastrula / Q000196:embryology* / Q000378:metabolism; D008648:Mesoderm / Q000196:embryology* / Q000378:metabolism; D008954:Models, Biological; D014982:Xenopus laevis / Q000196:embryology* / Q000235:genetics; D054462:p21-Activated Kinases / Q000235:genetics / Q000502:physiology*; D020742:rhoA GTP-Binding Protein / Q000502:physiology
chemical_list: D054462:p21-Activated Kinases; D020742:rhoA GTP-Binding Protein