Identification of a novel Ezrin-binding site in syndecan-2 cytoplasmic domain

FEBS Lett. 2003 Jul 17;547(1-3):212-6. doi: 10.1016/s0014-5793(03)00712-9.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Binding Sites
  • Binding, Competitive
  • Cloning, Molecular
  • Cytoskeletal Proteins
  • Humans
  • Kinetics
  • Membrane Glycoproteins / chemistry*
  • Membrane Glycoproteins / metabolism*
  • Molecular Sequence Data
  • Peptide Fragments / chemistry
  • Peptide Fragments / metabolism
  • Phosphoproteins / chemistry*
  • Phosphoproteins / metabolism*
  • Proteoglycans / chemistry*
  • Proteoglycans / metabolism*
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / metabolism
  • Syndecan-2

Substances

  • Cytoskeletal Proteins
  • Membrane Glycoproteins
  • Peptide Fragments
  • Phosphoproteins
  • Proteoglycans
  • Recombinant Fusion Proteins
  • SDC2 protein, human
  • ezrin
  • Syndecan-2