Structural basis of PSGL-1 binding to ERM proteins

Genes Cells. 2007 Dec;12(12):1329-38. doi: 10.1111/j.1365-2443.2007.01137.x.


P-selectin glycoprotein ligand-1 (PSGL-1), an adhesion molecule with O-glycosylated extracellular sialomucins, is involved in leukocyte inflammatory responses. On activation, ezrin-radixin-moesin (ERM) proteins mediate the redistribution of PSGL-1 on polarized cell surfaces to facilitate binding to target molecules. ERM proteins recognize a short binding motif, Motif-1, conserved in cytoplasmic tails of adhesion molecules, whereas PSGL-1 lacks Motif-1 residues important for binding to ERM proteins. The crystal structure of the complex between the radixin FERM domain and a PSGL-1 juxtamembrane peptide reveals that the peptide binds the groove of FERM subdomain C by forming a beta-strand associated with strand beta5C, followed by a loop flipped out towards the solvent. The Motif-1 3(10) helix present in the FERM-ICAM-2 complex is absent in PSGL-1 given the absence of a critical Motif-1 alanine residue, and PSGL-1 reduces its contact area with subdomain C. Non-conserved positions are occupied by large residues Met9 and His8, which stabilize peptide conformation and enhance groove binding. Non-conserved residues play an important role in compensating for loss of binding energy resulting from the absence of conserved residues important for binding.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Binding Sites
  • Cytoskeletal Proteins / chemistry*
  • Cytoskeletal Proteins / genetics
  • Cytoskeletal Proteins / metabolism
  • Cytoskeleton / metabolism
  • Membrane Glycoproteins / chemistry
  • Membrane Glycoproteins / metabolism*
  • Neurofibromin 2 / chemistry*
  • Neurofibromin 2 / metabolism
  • Protein Binding
  • Protein Conformation


  • Cytoskeletal Proteins
  • Membrane Glycoproteins
  • Neurofibromin 2
  • P-selectin ligand protein

Associated data

  • PDB/2EMT