title: EBP50 promotes focal adhesion turnover and vascular smooth muscle cells migration.
abstract: The ezrin-radixin-moesin-binding phosphoprotein 50 (EBP50) is a PDZ-containing scaffolding protein that regulates a variety of physiological functions. In the vasculature, EBP50 promotes neointima formation following arterial injury. In this study the role of EBP50 on vascular smooth muscle cell (VSMC) migration was characterized. The spreading and motility of primary VSMC isolated from EBP50 knockout (KO) mice were significantly reduced compared to wild-type (WT) cells. EBP50-null VSMC had fewer and larger focal adhesions than wild-type cells. Assembly and disassembly of focal adhesion-assessed by live-cell total internal reflection fluorescence imaging-in response to epidermal growth factor (EGF) were significantly reduced in KO cells. Immunoprecipitation experiments showed that EBP50 interacts with EGF receptor via the PDZ2 domain and with focal adhesion kinase (FAK) via the C-terminal ERM domain. EBP50 promoted the formation of a complex containing both EGF receptor and FAK. Phosphorylation of Tyr-925 of FAK in response to EGF was significantly reduced in KO cell compared to WT cells. The residence time of FAK in focal adhesions-determined by fluorescence recovery after photobleaching-was increased in WT cells. Collectively, these studies indicate that EBP50, by scaffolding EGF receptor and FAK, facilitates activation of FAK, focal adhesion turnover, and migration of VSMC.
authors.affiliation: Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA. gys2@pitt.edu
authors.forename: Gyun Jee
authors.initials: GJ
authors.lastname: Song
authors.forename: Kristen L
authors.initials: KL
authors.lastname: Leslie
authors.forename: Stacey
authors.initials: S
authors.lastname: Barrick
authors.forename: Sylvain
authors.initials: S
authors.lastname: Bougoin
authors.forename: Juan M
authors.initials: JM
authors.lastname: Taboas
authors.forename: Alessandro
authors.initials: A
authors.lastname: Bisello
mesh_terms: D000818:Animals; D001808:Blood Vessels / Q000378:metabolism*; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects / Q000235:genetics; D004815:Epidermal Growth Factor / Q000494:pharmacology; D066246:ErbB Receptors / Q000378:metabolism; D051417:Focal Adhesion Kinase 1 / Q000378:metabolism; D022001:Focal Adhesions / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D032389:Myocytes, Smooth Muscle / Q000187:drug effects / Q000378:metabolism*; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D011485:Protein Binding; D017923:Sodium-Hydrogen Exchangers / Q000235:genetics / Q000378:metabolism*
chemical_list: D010750:Phosphoproteins; D017923:Sodium-Hydrogen Exchangers; C093376:sodium-hydrogen exchanger regulatory factor; D004815:Epidermal Growth Factor; D066246:ErbB Receptors; D051417:Focal Adhesion Kinase 1