Abstract
Using a yeast one-hybrid screen with a DNA-bound Ets-1 protein, we have identified MafB, an AP-1 like protein, as a direct interaction partner. MafB is specifically expressed in myelomonocytic cells and binds to the DNA-binding domain of Ets-1 via its basic region or leucine-zipper domain. Furthermore, it represses Ets-1 transactivation of synthetic promoters containing Ets binding sites and inhibits Ets-1-mediated transactivation of the transferrin receptor, which is known to be essential for erythroid differentiation. Accordingly, overexpression of MafB in an erythroblast cell line down-regulates the endogenous transferrin receptor gene and inhibits differentiation without affecting cell proliferation. These results highlight the importance of inhibitory interactions between transcription factors in regulating lineage-specific gene expression.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Avian Proteins*
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Base Sequence
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Binding Sites / physiology
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Cell Differentiation / drug effects
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Cell Differentiation / physiology
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Chick Embryo
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Clone Cells / physiology
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DNA, Complementary / physiology
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DNA-Binding Proteins / genetics*
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DNA-Binding Proteins / metabolism
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DNA-Binding Proteins / physiology
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Erythroblasts / cytology*
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Erythroblasts / physiology
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G-Box Binding Factors
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Gene Expression Regulation / physiology
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Genetic Testing
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Hematopoiesis / genetics
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Macrophages / physiology
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MafB Transcription Factor
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Molecular Sequence Data
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Oncogene Proteins / genetics*
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Oncogene Proteins / metabolism
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Protein-Tyrosine Kinases / metabolism*
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Proto-Oncogene Protein c-ets-1
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Proto-Oncogene Proteins / antagonists & inhibitors
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Proto-Oncogene Proteins / metabolism*
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Proto-Oncogene Proteins c-ets
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Receptors, Transferrin / genetics
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Repressor Proteins / genetics
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Trans-Activators / genetics*
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Trans-Activators / metabolism
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Transcription Factors / antagonists & inhibitors
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Transcription Factors / metabolism*
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Vertebrates
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Yeasts / genetics
Substances
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Avian Proteins
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DNA, Complementary
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DNA-Binding Proteins
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G-Box Binding Factors
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MafB Transcription Factor
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Oncogene Proteins
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Proto-Oncogene Protein c-ets-1
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Proto-Oncogene Proteins
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Proto-Oncogene Proteins c-ets
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Receptors, Transferrin
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Repressor Proteins
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Trans-Activators
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Transcription Factors
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maf-B protein, chicken
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Protein-Tyrosine Kinases