Identification of multiple SNT-binding sites on NPM-ALK oncoprotein and their involvement in cell transformation

Oncogene. 2007 May 3;26(20):2950-4. doi: 10.1038/sj.onc.1210095. Epub 2006 Nov 6.

Abstract

The t(2;5) chromosomal translocation occurs in anaplastic large-cell lymphoma arising from activated T lymphocytes. This genomic rearrangement generates the nucleophosmin (NPM)-anaplastic lymphoma kinase (ALK) oncoprotein that is a chimeric protein consisting of parts of the nuclear protein NPM and ALK receptor protein-tyrosine kinase. We used yeast two-hybrid screening to identify an adaptor protein Suc1-associated neurotrophic factor-induced tyrosine-phosphorylated target (SNT)-2 as a new partner that interacted with the cytoplasmic domain of ALK. Immunoprecipitation assay revealed that SNT-1 and SNT-2 interacted with NPM-ALK and kinase-negative NPM-ALK mutant. Y156, Y567 and a 19-amino-acid sequence (aa 631-649) of NPM-ALK were essential for this interaction. The interaction through Y156 and Y567 was dependent on phosphorylation of these tyrosines, whereas the interaction through the 19-amino-acid sequence was independent of phosphorylation. NPM-ALK mutant protein mutated at these three binding sites showed significantly reduced transforming activity. This transformation-defective NPM-ALK mutant still interacted with signal transducing proteins such as phospholipase C-gamma and phosphatidylinositol 3-kinase, which were previously reported to be relevant to NPM-ALK-dependent tumorigenesis. These observations indicate that the three SNT-binding sites of NPM-ALK are important for its transforming activity. This raises a possibility that SNT family proteins play significant roles in cellular transformation triggered by NPM-ALK, which though remains to be verified.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / genetics
  • Adaptor Proteins, Signal Transducing / metabolism*
  • Animals
  • Binding Sites
  • Cell Transformation, Neoplastic / metabolism*
  • Cells, Cultured
  • Humans
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Mice
  • NIH 3T3 Cells
  • Protein Interaction Mapping
  • Protein-Tyrosine Kinases / genetics
  • Protein-Tyrosine Kinases / metabolism*
  • Transfection
  • Two-Hybrid System Techniques

Substances

  • Adaptor Proteins, Signal Transducing
  • FRS2alpha protein, mouse
  • Frs3 protein, mouse
  • Membrane Proteins
  • p80(NPM-ALK) protein
  • Protein-Tyrosine Kinases