Characterization of two SHP-2-associated binding proteins and potential substrates in hematopoietic cells

J Biol Chem. 1997 Jun 27;272(26):16421-30. doi: 10.1074/jbc.272.26.16421.

Abstract

Multiple studies have demonstrated an important role for the Src homology 2-containing tyrosine phosphatase 2 (SHP-2) in receptor tyrosine kinase-regulated cell proliferation and differentiation. Recent studies have identified potential SHP-2 substrates which mediate these effects. SHP-2 also is implicated in several cytokine receptor signaling pathways and in Bcr-Abl transformation. However, its precise role and targets in normal and abnormal hematopoietic cells remain to be determined. We identified two novel tyrosyl-phosphorylated proteins associated with SHP-2 in hematopoietic cells. The first, a 97-kDa cytosolic protein (p97), associates inducibly with SHP-2 upon cytokine stimulation and constitutively in Bcr-Abl-transformed cells. In contrast, p135, a 135-kDa transmembrane glycoprotein, forms a distinct complex with SHP-2, independent of cytokine stimulation or Bcr-Abl transformation. Far Western analysis reveals that SHP-2, via its Src homology 2 domains, can interact directly with either protein. In vitro dephosphorylation experiments, as well as transient transfection studies using wild type and mutant SHP-2 constructs, suggest that p97 and p135 also are SHP-2 substrates. Our results indicate that SHP-2 forms at least two separate complexes in hematopoietic cells and point to new potential SHP-2 targets.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Carrier Proteins / analysis
  • Carrier Proteins / metabolism*
  • Cell Transformation, Neoplastic
  • Cells, Cultured
  • Cytokines / pharmacology
  • Fusion Proteins, bcr-abl / physiology
  • Hematopoietic Stem Cells / metabolism
  • Humans
  • Intracellular Signaling Peptides and Proteins
  • Mice
  • Protein Phosphatase 2
  • Protein Tyrosine Phosphatase, Non-Receptor Type 11
  • Protein Tyrosine Phosphatase, Non-Receptor Type 6
  • Protein Tyrosine Phosphatases / metabolism*
  • SH2 Domain-Containing Protein Tyrosine Phosphatases
  • src Homology Domains

Substances

  • Carrier Proteins
  • Cytokines
  • Intracellular Signaling Peptides and Proteins
  • Fusion Proteins, bcr-abl
  • Protein Phosphatase 2
  • PTPN11 protein, human
  • PTPN6 protein, human
  • Protein Tyrosine Phosphatase, Non-Receptor Type 11
  • Protein Tyrosine Phosphatase, Non-Receptor Type 6
  • Protein Tyrosine Phosphatases
  • Ptpn11 protein, mouse
  • Ptpn6 protein, mouse
  • SH2 Domain-Containing Protein Tyrosine Phosphatases