title: α6β4Integrin Regulates the Collective Migration of Epithelial Cells.
abstract: α6β4integrin is localized in a unique punctate distribution at the cell-substratum interface along the leading front of single, front-rear-polarized A549 cells. These puncta are interspersed between focal adhesions and lack association with the actin cytoskeleton. Knockdown of β4integrin in A549 cells inhibits their directed migration, with knockdown cells exhibiting large focal adhesions and reduced actin dynamics. Despite these changes, the speed of knockdown cells is equivalent to control cells. Interestingly, in such cells, α6integrin retains its punctate distribution. Moreover, in β4integrin knockdown cells, we observe a loss of β1integrin from focal adhesions and an enhanced association with α6integrin. We confirmed the switch in the β integrin binding partner of α6integrin in the knockdown cells by immunoprecipitation. We next investigated the role of β4integrin in collective cell migration. Wounded monolayers of β4integrin knockdown cells exhibit reduced collective migration compared with controls. When we forced expression of β4integrin in the leader cells of wounded monolayers, collective migration was restored. Similarly, forced expression of β4integrin in primary rat alveolar epithelial cells also promotes collective cell migration. In addition, we interrogated the pathway by which β4integrin regulates A549 cell-directed migration. Constitutively active Ras-related C3 botulinum toxin substrate 1 rescues motility defects resulting from β4integrin deficiency. Together, our results support the hypothesis that α6β4integrin is a positive regulator of collective cell migration of A549 cells through influence on signal pathways in leader cells.
authors.affiliation: School of Molecular Biosciences, Washington State University, Pullman, Washington.
authors.forename: Zachary T
authors.identifier: 0000-0003-1280-7613
authors.initials: ZT
authors.lastname: Colburn
authors.affiliation: School of Molecular Biosciences, Washington State University, Pullman, Washington.
authors.forename: Jonathan C R
authors.identifier: 0000-0002-1496-4922
authors.initials: JC
authors.lastname: Jones
mesh_terms: D000072283:A549 Cells; D002465:Cell Movement / Q000187:drug effects; D016764:Cell Polarity / Q000187:drug effects; D004815:Epidermal Growth Factor / Q000494:pharmacology; D004847:Epithelial Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D055785:Gene Knockdown Techniques; D006801:Humans; D039161:Integrin alpha6beta4 / Q000378:metabolism*; D019012:Integrin beta1 / Q000378:metabolism; D008954:Models, Biological; D021381:Protein Transport; D015398:Signal Transduction / Q000187:drug effects; D014212:Tretinoin / Q000494:pharmacology; D020830:rac1 GTP-Binding Protein / Q000378:metabolism
chemical_list: D039161:Integrin alpha6beta4; D019012:Integrin beta1; D014212:Tretinoin; D004815:Epidermal Growth Factor; D020830:rac1 GTP-Binding Protein
keywords: cell adhesion; cell motility; cytoskeleton; directed motility; matrix adhesions