Abstract
The reciprocal t(8;13) chromosome translocation results in a fusion gene (FUS) in which the N-terminal half of the zinc finger protein ZNF198 is combined with the cytoplasmic domain of the fibroblast growth factor receptor-1 (FGFR1). Expression of FUS is suggested to provide growth-promoting activity to myeloid cells similar to the activity of hematopoietic cytokine receptors. This study determined the specificity of FUS to activate signal transduction pathways. Because no tumor cell line expressing FUS was available, the mode of FUS action was identified in cells transiently and stably transfected with an expression vector for FUS. FUS acted as a constitutively active protein-tyrosine kinase and mediated phosphorylation of STAT1, 3, and 5 but not STAT4 and 6. The same specificity but lower activity was determined for normal FGFR1. STAT activation by FUS, similar to that by interleukin-6-type cytokines, promoted STAT-specific induction of genes. The functionality of FUS, as well as the relative recruitment of STAT isoforms, was determined by the dimerizing function of the zinc finger domain. Replacement of the ZNF198 portion by the Bcr portion as present in the t(8;22) translocation shifted the signaling toward a more prominent STAT5 activation. This study documents that both gene partners forming the fusion oncogene define the activity and the signaling specificity of the protein-tyrosine kinase of FGFR1.
Publication types
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Comparative Study
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Animals
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Carrier Proteins / chemistry
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Carrier Proteins / physiology*
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DNA-Binding Proteins / chemistry
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DNA-Binding Proteins / metabolism
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DNA-Binding Proteins / physiology*
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Dimerization
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Humans
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Intracellular Signaling Peptides and Proteins*
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Milk Proteins*
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Mitogen-Activated Protein Kinases / physiology
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Phosphorylation
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Proteins / physiology
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Receptor Protein-Tyrosine Kinases / physiology*
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Receptor, Fibroblast Growth Factor, Type 1
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Receptors, Fibroblast Growth Factor / physiology*
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Receptors, Interleukin-6 / physiology*
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Recombinant Fusion Proteins / physiology*
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Repressor Proteins*
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STAT3 Transcription Factor
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STAT4 Transcription Factor
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STAT5 Transcription Factor
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Suppressor of Cytokine Signaling 1 Protein
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Suppressor of Cytokine Signaling 3 Protein
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Suppressor of Cytokine Signaling Proteins
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Trans-Activators / metabolism
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Transcription Factors*
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Transcription, Genetic
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Zinc Fingers
Substances
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Carrier Proteins
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DNA-Binding Proteins
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Intracellular Signaling Peptides and Proteins
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Milk Proteins
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Proteins
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Receptors, Fibroblast Growth Factor
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Receptors, Interleukin-6
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Recombinant Fusion Proteins
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Repressor Proteins
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SOCS1 protein, human
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SOCS3 protein, human
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STAT3 Transcription Factor
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STAT3 protein, human
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STAT4 Transcription Factor
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STAT4 protein, human
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STAT5 Transcription Factor
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Suppressor of Cytokine Signaling 1 Protein
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Suppressor of Cytokine Signaling 3 Protein
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Suppressor of Cytokine Signaling Proteins
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Trans-Activators
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Transcription Factors
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ZMYM2 protein, human
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FGFR1 protein, human
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Receptor Protein-Tyrosine Kinases
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Receptor, Fibroblast Growth Factor, Type 1
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Mitogen-Activated Protein Kinases