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

• Published in: Oncogene Vol. 26; no. 20; pp. 2950 - 2954
• Main Authors: CHIKAMORI, M, FUJIMOTO, J, TOKAI-NISHIZUMI, N, YAMAMOTO, T
• Format: Journal Article
• Language: English
• Published: Basingstoke Nature Publishing 03.05.2007; Nature Publishing Group
• Subjects: 1-Phosphatidylinositol 3-kinase; Adaptor proteins; Adaptor Proteins, Signal Transducing - genetics; Adaptor Proteins, Signal Transducing - metabolism; Anaplastic large-cell lymphoma; Animals; Binding Sites; Binding sites (Biochemistry); Biological and medical sciences; Cancer; Cell physiology; Cell transformation; Cell transformation and carcinogenesis. Action of oncogenes and antioncogenes; Cell Transformation, Neoplastic - metabolism; Cells, Cultured; Cellular signal transduction; Chromosome translocations; Fundamental and applied biological sciences. Psychology; Genetic aspects; Genetic transformation; Genetics; Health aspects; Hematologic and hematopoietic diseases; Humans; Immunoprecipitation; Leukemias. Malignant lymphomas. Malignant reticulosis. Myelofibrosis; Lymphocytes T; Lymphoma; Medical sciences; Membrane Proteins - genetics; Membrane Proteins - metabolism; Mice; Molecular and cellular biology; Mutants; Neurotrophic factors; NIH 3T3 Cells; Oncology; Oncoproteins; Phospholipase C; Phosphorylation; Physiological aspects; Protein Interaction Mapping; Protein-tyrosine kinase; Protein-Tyrosine Kinases - genetics; Protein-Tyrosine Kinases - metabolism; Proteins; Transfection; Tumorigenesis; Two-Hybrid System Techniques; United States; Tyrosine; Phosphorylation; NPM-ALK; Malignant hemopathy; Identification; Large cell lymphoma; Binding site; Malignant tumor; Non Hodgkin lymphoma; Cell transformation; Carcinogenesis; anaplastic large-cell lymphoma; Lymphoproliferative syndrome; C-Onc gene; SNT; tyrosine phosphorylation; Onc gene; oncoprotein
• DOI: 10.1038/sj.onc.1210095
• ISSN: 0950-9232

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.