Cytoplasmic domains of the human granulocyte-macrophage colony-stimulating factor (GM-CSF) receptor beta chain (hbetac) responsible for human GM-CSF-induced myeloid cell differentiation

J Biol Chem. 1998 Jul 31;273(31):19411-8. doi: 10.1074/jbc.273.31.19411.

Abstract

Granulocyte-macrophage colony-stimulating factor (GM-CSF) regulates differentiation, survival, and proliferation of myeloid progenitor cells. The biologic actions of GM-CSF are mediated by its binding to the alpha and beta subunits of the GM-CSF receptor (GM-CSFRalpha and betac, respectively). To determine whether identical regions of the betac protein mediate both cell growth and differentiation, we expressed cDNA constructs encoding the human wild-type (897 amino acids) and truncated betac (hbetac) subunits along with the wild-type human GM-CSFRalpha subunit in the murine WT19 cell line, an FDC-P1-derived cell line that differentiates toward the monocytic lineage in response to murine GM-CSF. Whereas the WT19 cell line carrying the C-terminal deleted hbetac subunit of 627 amino acids was still able to grow in human GM-CSF (hGM-CSF), 681 amino acids of the hbetac were necessary for cell differentiation. The addition of hGM-CSF to WT19 cell lines containing the hbetac627 subunit stimulated the phosphorylation of ERK (extracellular signal-regulated kinase) and induced the tyrosine-phosphorylation of SHP-2 and STAT5, suggesting that the activation of these molecules is insufficient to mediate the induction of differentiation. A point mutation of tyrosine 628 to phenylalanine (Y628F) within hbetac681 abolished the ability of hGM-CSF to induce differentiation. Our results indicate that the signals required for hGM-CSF-induced differentiation and cell growth are mediated by different regions of the hbetac subunit.

Publication types

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

MeSH terms

  • Animals
  • Cell Differentiation / drug effects*
  • Cell Line
  • DNA-Binding Proteins / metabolism
  • Enzyme Inhibitors / pharmacology
  • Flavonoids / pharmacology
  • Flow Cytometry
  • Gene Expression Regulation / genetics
  • Granulocyte-Macrophage Colony-Stimulating Factor / pharmacology*
  • Humans
  • Intracellular Signaling Peptides and Proteins
  • Mice
  • Milk Proteins*
  • Mitogen-Activated Protein Kinases / metabolism
  • Nerve Tissue Proteins / metabolism
  • Phosphorylation
  • Phosphotyrosine / analysis
  • Point Mutation
  • Protein Tyrosine Phosphatase, Non-Receptor Type 11
  • Protein Tyrosine Phosphatase, Non-Receptor Type 6
  • Protein Tyrosine Phosphatases / metabolism
  • Receptors, Granulocyte-Macrophage Colony-Stimulating Factor / chemistry*
  • Recombinant Proteins / pharmacology
  • STAT5 Transcription Factor
  • Signal Transduction / physiology
  • Trans-Activators / metabolism

Substances

  • DNA-Binding Proteins
  • Enzyme Inhibitors
  • Flavonoids
  • Intracellular Signaling Peptides and Proteins
  • Milk Proteins
  • Nerve Tissue Proteins
  • Receptors, Granulocyte-Macrophage Colony-Stimulating Factor
  • Recombinant Proteins
  • STAT5 Transcription Factor
  • Trans-Activators
  • Phosphotyrosine
  • Granulocyte-Macrophage Colony-Stimulating Factor
  • Mitogen-Activated Protein Kinases
  • 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
  • 2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one