title: Identification of a novel Ezrin-binding site in syndecan-2 cytoplasmic domain.
abstract: ERM (Ezrin/Radixin/Moesin) proteins are crosslinkers between plasma membrane proteins and the actin cytoskeleton, thereby involved in the formation of cell adhesion sites. Earlier work showed that Ezrin links syndecan-2 to the actin cytoskeleton. Here we provide evidence that the Ezrin N-terminal domain binds to the syndecan-2 cytoplasmic domain with an estimated K(D) of 0.71 microM and without the requirement of other proteins. We also studied the regions in the syndecan-2 cytoplasmic domain implicated in the binding to Ezrin. By truncating the syndecan-2 cytoplasmic domain and by oligopeptide competition assays we show that the Ezrin-binding sequence is not located in the positively charged juxtamembrane region (RMRKK), but in the neighboring sequence DEGSYD. We therefore conclude that the consensus sequence for Ezrin binding is unique among membrane proteins, suggesting a distinct regulation.
authors.affiliation: Department of Cellular Biology, Faculty of Biology, University of Barcelona, Barcelona, Spain.
authors.forename: Francesc
authors.initials: F
authors.lastname: Granés
authors.forename: Christine
authors.initials: C
authors.lastname: Berndt
authors.forename: Christian
authors.initials: C
authors.lastname: Roy
authors.forename: Paul
authors.initials: P
authors.lastname: Mangeat
authors.forename: Manuel
authors.initials: M
authors.lastname: Reina
authors.forename: Senén
authors.initials: S
authors.lastname: Vilaró
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D001667:Binding, Competitive; D003001:Cloning, Molecular; D003598:Cytoskeletal Proteins; D006801:Humans; D007700:Kinetics; D008562:Membrane Glycoproteins / Q000737:chemistry* / Q000378:metabolism*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D010750:Phosphoproteins / Q000737:chemistry* / Q000378:metabolism*; D011509:Proteoglycans / Q000737:chemistry* / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D053669:Syndecan-2; D000099149:Ezrin
chemical_list: D003598:Cytoskeletal Proteins; D008562:Membrane Glycoproteins; D010446:Peptide Fragments; D010750:Phosphoproteins; D011509:Proteoglycans; D011993:Recombinant Fusion Proteins; D053669:Syndecan-2; D000099149:Ezrin; C508245:SDC2 protein, human