ZNF198-FGFR1 transforms Ba/F3 cells to growth factor independence and results in high level tyrosine phosphorylation of STATS 1 and 5

Neoplasia. 1999 Oct;1(4):349-55. doi: 10.1038/sj.neo.7900035.

Abstract

The ZNF198- FGFR1 fusion gene arises as a result of the t(8;13)(p11;q12) in the 8p11 myeloproliferative syndrome. To determine the transforming properties of this chimeric protein we transfected ZNF198-FGFR1 into the interleukin (IL)-3 dependent cell line Ba/F3. Growth factor independent subclones were obtained in which ZNF198-FGFR1, STAT1, and STAT5 were constitutively tyrosine phosphorylated, as determined by immunoprecipitation and Western blot analysis. To test the hypothesis that constitutive activation of ZNF198-FGFR1 tyrosine kinase activity is a result of self-association of the fusion protein, we in vitro transcribed and translated ZNF198-FGFR1 and a derivative construct, ZNF198- FGFR1deltaC-myc, in which the C-terminal FGFR1 epitope was replaced by a c-myc tag. As expected, an anti-FGFR1 antibody immunoprecipitated ZNF198-FGFR1 but not ZNF198-FGFRdeltaC-myc. However when both products were translated together, both were coimmunoprecipitated by anti-FGFR1 antisera. Similar results were obtained by using an anti-myc antibody and demonstrated a physical interaction between the two proteins. Analysis of COS-7 cells transfected with ZNF198-FGFR1 demonstrated that the fusion gene, in contrast to normal FGFR1, is located in the cytoplasm. We conclude that ZNF198-FGFR1 is a cytoplasmic protein that self-associates and has constitutive transformation activity. These data suggest that ZNF198-FGFR1 plays a primary role in the pathogenesis of the t(8;13) myeloproliferative syndrome and is the first report to implicate STAT proteins in FGFR1-mediated signaling.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blotting, Western
  • COS Cells
  • Cell Line
  • Cytoplasm / metabolism
  • DNA-Binding Proteins / metabolism*
  • Fluorescent Antibody Technique
  • Growth Substances / metabolism*
  • Humans
  • Interleukin-3 / metabolism
  • Mice
  • Milk Proteins*
  • Myeloproliferative Disorders / genetics
  • Phosphorylation
  • Precipitin Tests
  • Protein Biosynthesis
  • Proto-Oncogene Proteins c-myc / metabolism
  • Receptor Protein-Tyrosine Kinases / metabolism*
  • Receptor, Fibroblast Growth Factor, Type 1
  • Receptors, Fibroblast Growth Factor / metabolism*
  • Recombinant Fusion Proteins / metabolism
  • Recombination, Genetic
  • STAT1 Transcription Factor
  • STAT5 Transcription Factor
  • Signal Transduction
  • Time Factors
  • Trans-Activators / metabolism*
  • Transcription, Genetic
  • Transfection
  • Tyrosine / metabolism*

Substances

  • DNA-Binding Proteins
  • Growth Substances
  • Interleukin-3
  • Milk Proteins
  • Proto-Oncogene Proteins c-myc
  • Receptors, Fibroblast Growth Factor
  • Recombinant Fusion Proteins
  • STAT1 Transcription Factor
  • STAT1 protein, human
  • STAT5 Transcription Factor
  • Stat1 protein, mouse
  • Trans-Activators
  • Tyrosine
  • FGFR1 protein, human
  • Fgfr1 protein, mouse
  • Receptor Protein-Tyrosine Kinases
  • Receptor, Fibroblast Growth Factor, Type 1