Recruitment and activation of SHP-1 protein-tyrosine phosphatase by human platelet endothelial cell adhesion molecule-1 (PECAM-1). Identification of immunoreceptor tyrosine-based inhibitory motif-like binding motifs and substrates

J Biol Chem. 1998 Oct 23;273(43):28332-40. doi: 10.1074/jbc.273.43.28332.

Abstract

Stimulation of platelet aggregation leads to tyrosine phosphorylation of a number of receptors and signaling molecules including platelet endothelial cell adhesion molecule-1 (PECAM-1). In this report, we demonstrate that both protein-tyrosine phosphatases SHP-1 and SHP-2 physically associate with different kinetics of assembly with tyrosine-phosphorylated human PECAM-1 during integrin alphaIIbbeta3-mediated platelet aggregation. Peptido-precipitation analysis revealed that tyrosine-phosphorylated peptides encompassing residues 658-668 and 681-691 of PECAM-1 bound specifically to both protein-tyrosine phosphatases SHP-1 and SHP-2. We further show that the association of SHP-1 with PECAM-1 occurs through the direct interaction of the src homology region 2 domains of SHP-1 with two highly conserved phosphotyrosine binding motifs within PECAM-1 having the sequences NSDVQpY663TEVQV and DTETVpY686SEVRK (where pY represents phosphotyrosine). In vitro dephosphorylation experiments using phosphotyrosyl PECAM-1 peptides encompassing either Tyr-663 or Tyr-686 revealed induction of SHP-1 catalytic activity, suggesting that PECAM-1 serves as a SHP-1 substrate. Surface plasmon resonance studies reveal that recombinant SHP-2 binds PECAM-1 phosphopeptides with 5-fold higher affinity than recombinant SHP-1. These data suggest that in hematopoietic cells such as platelets, PECAM-1 cellular signaling is regulated by the selective recruitment and activation of two distinct protein-tyrosine phosphatases, SHP-1 and SHP-2, via a common immunoreceptor tyrosine-based inhibitory-like motif.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Binding Sites
  • Blood Platelets / metabolism*
  • Enzyme Activation
  • Humans
  • Intracellular Signaling Peptides and Proteins
  • Phosphopeptides / metabolism
  • Phosphorylation
  • Platelet Aggregation
  • Platelet Endothelial Cell Adhesion Molecule-1 / metabolism*
  • Platelet Glycoprotein GPIIb-IIIa Complex / metabolism
  • Protein Binding
  • Protein Tyrosine Phosphatase, Non-Receptor Type 11
  • Protein Tyrosine Phosphatase, Non-Receptor Type 6
  • Protein Tyrosine Phosphatases / metabolism*
  • Receptors, Immunologic / metabolism*
  • SH2 Domain-Containing Protein Tyrosine Phosphatases
  • src Homology Domains

Substances

  • Intracellular Signaling Peptides and Proteins
  • Phosphopeptides
  • Platelet Endothelial Cell Adhesion Molecule-1
  • Platelet Glycoprotein GPIIb-IIIa Complex
  • Receptors, Immunologic
  • PTPN11 protein, human
  • PTPN6 protein, human
  • Protein Tyrosine Phosphatase, Non-Receptor Type 11
  • Protein Tyrosine Phosphatase, Non-Receptor Type 6
  • Protein Tyrosine Phosphatases
  • SH2 Domain-Containing Protein Tyrosine Phosphatases