Demonstration of functionally different interactions between phospholipase C-gamma and the two types of platelet-derived growth factor receptors

J Biol Chem. 1995 Mar 31;270(13):7773-81. doi: 10.1074/jbc.270.13.7773.


Phosphorylated tyrosine residues in receptor tyrosine kinases serve as binding sites for signal transduction molecules. We have identified two autophosphorylation sites, Tyr-988 and Tyr-1018, in the platelet-derived growth factor (PDGF) alpha-receptor carboxyl-terminal tail, which are involved in binding of phospholipase C-gamma (PLC-gamma). The capacities of the Y988F and Y1018F mutant PDGF alpha-receptors, expressed in porcine aortic endothelial cells, to bind PLC-gamma are 60 and 5% of that of the wild-type receptor, respectively. Phosphorylated but not unphosphorylated peptides containing Tyr-1018 are able to compete with the intact receptor for binding to immobilized PLC-gamma SH2 domains; a phosphorylated Tyr-988 peptide competes 10 times less efficiently. The complex between PLC-gamma and the PDGF alpha-receptor is more stable than that of PLC-gamma and the PDGF beta-receptor. However, PDGF stimulation results in a smaller fraction of tyrosine-phosphorylated PLC-gamma and a smaller accumulation of inositol trisphosphate in cells expressing the alpha-receptor as compared with cells expressing the beta-receptor. We conclude that phosphorylated Tyr-988 and Tyr-1018 in the PDGF alpha-receptor carboxyl-terminal tail bind PLC-gamma, but this association leads to only a relatively low level of tyrosine phosphorylation and activation of PLC-gamma.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Aorta
  • Base Sequence
  • Becaplermin
  • Binding, Competitive
  • Cell Division
  • Endothelium, Vascular / metabolism*
  • Isoenzymes / metabolism*
  • Kinetics
  • Molecular Sequence Data
  • Mutagenesis, Site-Directed
  • Oligodeoxyribonucleotides
  • Peptide Fragments / chemistry
  • Peptide Fragments / isolation & purification
  • Phospholipases / metabolism*
  • Phosphopeptides / pharmacology
  • Phosphorylation
  • Phosphotyrosine
  • Platelet-Derived Growth Factor / pharmacology
  • Point Mutation
  • Proto-Oncogene Proteins c-sis
  • Receptor Protein-Tyrosine Kinases / metabolism
  • Receptor, Platelet-Derived Growth Factor alpha
  • Receptor, Platelet-Derived Growth Factor beta
  • Receptors, Platelet-Derived Growth Factor / metabolism*
  • Recombinant Proteins / pharmacology
  • Sequence Homology, Amino Acid
  • Swine
  • Thymidine / metabolism
  • Tyrosine / analogs & derivatives
  • Tyrosine / metabolism


  • Isoenzymes
  • Oligodeoxyribonucleotides
  • Peptide Fragments
  • Phosphopeptides
  • Platelet-Derived Growth Factor
  • Proto-Oncogene Proteins c-sis
  • Recombinant Proteins
  • Becaplermin
  • Phosphotyrosine
  • Tyrosine
  • Receptor Protein-Tyrosine Kinases
  • Receptor, Platelet-Derived Growth Factor alpha
  • Receptor, Platelet-Derived Growth Factor beta
  • Receptors, Platelet-Derived Growth Factor
  • Phospholipases
  • Thymidine