title: Fer-mediated cortactin phosphorylation is associated with efficient fibroblast migration and is dependent on reactive oxygen species generation during integrin-mediated cell adhesion.
abstract: The molecular details linking integrin engagement to downstream cortactin (Ctn) tyrosine phosphorylation are largely unknown. In this report, we show for the first time that Fer and Ctn are potently tyrosine phosphorylated in response to hydrogen peroxide (H2O2) in a variety of cell types. Working with catalytically inactive fer and src/yes/fyn-deficient murine embryonic fibroblasts (ferDR/DR and syf MEF, respectively), we observed that H2O2-induced Ctn tyrosine phosphorylation is primarily dependent on Fer but not Src family kinase (SFK) activity. We also demonstrated for the first time that Fer is activated by fibronectin engagement and, in concert with SFKs, mediates Ctn tyrosine phosphorylation in integrin signaling pathways. Reactive oxygen species (ROS) scavengers or the NADPH oxidase inhibitor, diphenylene iodonium, attenuated integrin-induced Fer and Ctn tyrosine phosphorylation. Taken together, these findings provide novel genetic evidence that a ROS-Fer signaling arm contributes to SFK-mediated Ctn tyrosine phosphorylation in integrin signaling. Lastly, a migration defect in ferDR/DR MEF suggests that integrin signaling through the ROS-Fer-Ctn signaling arm may be linked to mechanisms governing cell motility. These data demonstrate for the first time an oxidative link between integrin adhesion and an actin-binding protein involved in actin polymerization.
authors.affiliation: Queen's University Cancer Research Institute, Botterell Hall, Room A309, Kingston, Ontario, Canada K7L 3N6.
authors.forename: Waheed
authors.initials: W
authors.lastname: Sangrar
authors.forename: Yan
authors.initials: Y
authors.lastname: Gao
authors.forename: Michelle
authors.initials: M
authors.lastname: Scott
authors.forename: Peter
authors.initials: P
authors.lastname: Truesdell
authors.forename: Peter A
authors.initials: PA
authors.lastname: Greer
mesh_terms: D000818:Animals; D002448:Cell Adhesion / Q000502:physiology*; D002465:Cell Movement / Q000502:physiology*; D002478:Cells, Cultured; D051356:Cortactin / Q000235:genetics / Q000378:metabolism*; D050719:Crk-Associated Substrate Protein / Q000378:metabolism; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology / Q000502:physiology; D051416:Focal Adhesion Protein-Tyrosine Kinases / Q000378:metabolism; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D016023:Integrins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D019255:NADPH Oxidases / Q000378:metabolism; D016877:Oxidants / Q000378:metabolism; D010084:Oxidation-Reduction; D051419:Paxillin; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D019061:src-Family Kinases / Q000378:metabolism
chemical_list: D051356:Cortactin; D050719:Crk-Associated Substrate Protein; D004791:Enzyme Inhibitors; D016023:Integrins; D016877:Oxidants; D051419:Paxillin; D017382:Reactive Oxygen Species; C052602:proto-oncogene protein c-fes-fps; D006861:Hydrogen Peroxide; D019255:NADPH Oxidases; D011505:Protein-Tyrosine Kinases; D051416:Focal Adhesion Protein-Tyrosine Kinases; D019061:src-Family Kinases