Abstract
We analyzed the differential expression and regulation of three members of the Nur77 transcription factor family by the human T-lymphotropic virus type 1 (HTLV-1) Tax protein. We have demonstrated that in both HTLV-1-infected cells and Tax-expressing JPX-9 cells, TR3/nur77 is highly expressed, whereas neither NOR-1 nor NOT expression is detectable. Transient transfection analysis further confirmed the Tax transactivation of the TR3/nur77 promoter but not the NOR-1 promoter in different cell types. Furthermore, expression of a luciferase reporter gene driven by the NGFI-B (rat homolog of TR3/Nur77) response element (NBRE) provided evidence that Tax-mediated transactivation resulted in the induction of a functional protein. Cotransfection assays with the TR3/nur77 promoter sequence or the NBRE binding motif together with a series of Tax mutants have shown that Tax-induced TR3/nur77 expression is mediated by CREB/ATF-related transcription factors.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Activating Transcription Factor 1
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Cell Line, Transformed
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DNA-Binding Proteins / genetics*
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Gene Expression Regulation
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Gene Products, tax / genetics
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Gene Products, tax / metabolism*
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Human T-lymphotropic virus 1 / metabolism*
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Human T-lymphotropic virus 1 / physiology
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Humans
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Jurkat Cells
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NF-kappa B / genetics
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NF-kappa B / metabolism
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Nerve Tissue Proteins / genetics*
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Nuclear Receptor Subfamily 4, Group A, Member 1
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Nuclear Receptor Subfamily 4, Group A, Member 2
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Promoter Regions, Genetic
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Receptors, Cytoplasmic and Nuclear
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Receptors, Steroid
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Receptors, Thyroid Hormone
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Regulatory Sequences, Nucleic Acid
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T-Lymphocytes / metabolism*
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T-Lymphocytes / virology*
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Transcription Factors / genetics*
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Transcription Factors / metabolism
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Transcriptional Activation*
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Tumor Cells, Cultured
Substances
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Activating Transcription Factor 1
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DNA-Binding Proteins
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Gene Products, tax
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NF-kappa B
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NR4A1 protein, human
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NR4A2 protein, human
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NR4A3 protein, human
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Nerve Tissue Proteins
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Nr4a1 protein, rat
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Nr4a2 protein, rat
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Nuclear Receptor Subfamily 4, Group A, Member 1
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Nuclear Receptor Subfamily 4, Group A, Member 2
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Receptors, Cytoplasmic and Nuclear
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Receptors, Steroid
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Receptors, Thyroid Hormone
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Transcription Factors