SHP-1 regulation of p62(DOK) tyrosine phosphorylation in macrophages

J Biol Chem. 1999 Dec 10;274(50):35855-65. doi: 10.1074/jbc.274.50.35855.

Abstract

SHP-1 plays key roles in the modulation of hematopoietic cell signaling. To ascertain the impact of SHP-1 on colony-stimulating factor-1 (CSF-1)-mediated survival and proliferative signaling, we compared the CSF-1 responses of primary bone marrow macrophages (BMM) from wild-type and SHP-1-deficient motheaten (me/me) mice. CSF-1-induced protein tyrosine phosphorylation levels were similar in wild-type and me/me BMM, except for the constitutive hyperphosphorylation of a 62-kDa phosphoprotein (pp62) in me/me macrophages. pp62 was identified as the RASGAP-associated p62(DOK) and was shown to be the major CSF-1R-associated tyrosine-phosphorylated protein in CSF-1-treated BMM. p62(DOK) was found to be constitutively associated with SHP-1 in BMM and in 293T cells, co-expressing p62(dok) and either wild-type or catalytically inert SHP-1 (SHP-1 C453S). In both cell types, the interaction of SHP-1 with p62(DOK) occurred independently of p62(DOK) tyrosine phosphorylation, but only the tyrosine-phosphorylated p62(DOK) was bound by SHP-1 C453S in a far Western analysis. These findings suggest a constitutive association of SHP-1 and p62(DOK) that is either conformation-dependent or indirect as well as a direct, inducible association of the SHP-1 catalytic domain with tyrosine-phosphorylated p62(DOK). p62(DOK) hyperphosphorylation is not associated with altered CSF-1-induced RAS signaling or proliferation. However, whereas wild-type macrophages undergo cell death following CSF-1 removal, me/me macrophages exhibit prolonged survival in the absence of growth factor. Thus, p62(DOK) is a major SHP-1 substrate whose tyrosine phosphorylation correlates with growth factor-independent survival in macrophages.

Publication types

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

MeSH terms

  • Animals
  • Bone Marrow Cells / cytology
  • Cell Line
  • Cells, Cultured
  • DNA-Binding Proteins*
  • Glutathione Transferase / genetics
  • Glutathione Transferase / metabolism
  • Humans
  • Intracellular Signaling Peptides and Proteins
  • Macrophage Colony-Stimulating Factor / pharmacology
  • Macrophages / cytology
  • Macrophages / drug effects
  • Macrophages / metabolism*
  • Mice
  • Mice, Mutant Strains
  • Phosphoproteins / metabolism*
  • Phosphorylation
  • Phosphotyrosine / metabolism
  • Protein Tyrosine Phosphatase, Non-Receptor Type 11
  • Protein Tyrosine Phosphatase, Non-Receptor Type 6
  • Protein Tyrosine Phosphatases / deficiency
  • Protein Tyrosine Phosphatases / genetics
  • Protein Tyrosine Phosphatases / metabolism*
  • RNA-Binding Proteins*
  • Recombinant Fusion Proteins / metabolism
  • SH2 Domain-Containing Protein Tyrosine Phosphatases
  • Transfection
  • src Homology Domains

Substances

  • DNA-Binding Proteins
  • DOK1 protein, human
  • Dok1 protein, mouse
  • GAP-associated protein p62
  • Intracellular Signaling Peptides and Proteins
  • Phosphoproteins
  • RNA-Binding Proteins
  • Recombinant Fusion Proteins
  • Phosphotyrosine
  • Macrophage Colony-Stimulating Factor
  • Glutathione Transferase
  • 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