title: Control of lymphocyte shape and the chemotactic response by the GTP exchange factor Vav.
abstract: Rho GTPases control many facets of cell polarity and migration; namely, the reorganization of the cellular cytoskeleton to extracellular stimuli. Rho GTPases are activated by GTP exchange factors (GEFs), which induce guanosine diphosphate (GDP) release and the stabilization of the nucleotide-free state. Thus, the role of GEFs in the regulation of the cellular response to extracellular cues during cell migration is a critical step of this process. In this report, we have analyzed the activation and subcellular localization of the hematopoietic GEF Vav in human peripheral blood lymphocytes stimulated with the chemokine stromal cell-derived factor-1 (SDF-1alpha). We show a robust activation of Vav and its redistribution to motility-associated subcellular structures, and we provide biochemical evidence of the recruitment of Vav to the membrane of SDF-1alpha-activated human lymphocytes, where it transiently interacts with the SDF-1alpha receptor CXCR4. Overexpression of a dominant negative form of Vav abolished lymphocyte polarization, actin polymerization, and migration. SDF-1alpha-mediated cell polarization and migration also were impaired by overexpression of an active, oncogenic Vav, although the mechanism appears to be different. Together, our data postulate a pivotal role for Vav in the transmission of the migratory signal through the chemokine receptor CXCR4.
authors.affiliation: Servicio de Inmunología, Hospital Universitario de la Princesa, Madrid, Spain.
authors.forename: Miguel
authors.initials: M
authors.lastname: Vicente-Manzanares
authors.forename: Aranzazu
authors.initials: A
authors.lastname: Cruz-Adalia
authors.forename: Noa B
authors.initials: NB
authors.lastname: Martín-Cófreces
authors.forename: José R
authors.initials: JR
authors.lastname: Cabrero
authors.forename: Mercedes
authors.initials: M
authors.lastname: Dosil
authors.forename: Brenda
authors.initials: B
authors.lastname: Alvarado-Sánchez
authors.forename: Xosé R
authors.initials: XR
authors.lastname: Bustelo
authors.forename: Francisco
authors.initials: F
authors.lastname: Sánchez-Madrid
mesh_terms: D000818:Animals; D018797:Cell Cycle Proteins / Q000235:genetics* / Q000378:metabolism; D016764:Cell Polarity / Q000276:immunology; D048430:Cell Shape / Q000276:immunology; D054377:Chemokine CXCL12; D019743:Chemokines, CXC / Q000494:pharmacology; D002634:Chemotaxis, Leukocyte / Q000187:drug effects / Q000502:physiology*; D015870:Gene Expression / Q000276:immunology; D006801:Humans; D008214:Lymphocytes / Q000166:cytology* / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D011518:Proto-Oncogene Proteins / Q000235:genetics* / Q000378:metabolism; D051567:Proto-Oncogene Proteins c-vav; D019718:Receptors, CXCR4 / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000276:immunology
chemical_list: C515255:CXCL12 protein, human; D018797:Cell Cycle Proteins; D054377:Chemokine CXCL12; D019743:Chemokines, CXC; C515256:Cxcl12 protein, mouse; D011518:Proto-Oncogene Proteins; D051567:Proto-Oncogene Proteins c-vav; D019718:Receptors, CXCR4; C496618:VAV1 protein, human; C496619:Vav1 protein, mouse