Abstract
CBP functions as a key transcriptional coactivator for a variety of transcription factors. We show here that the hepatocyte nuclear factor 4 (HNF4), a transcription factor in the nuclear receptor superfamily with no defined ligand, is cloned by yeast two-hybrid system using CBP as a bait. GST-pull down assay with nuclear extracts or in vitro translation products revealed that CBP and HNF4 interact with each other at the middle portion (aa 119-375) of HNF4 and two distinct regions (aa 271-451 and 1626-2259) of CBP, respectively, in the ligand-independent manner. Co-transfection experiments indicated that CBP is capable of activating HNF4 site-mediated transcription. These results suggested a functional association between CBP and HNF4 in trans-activation.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Basic Helix-Loop-Helix Leucine Zipper Transcription Factors
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CREB-Binding Protein
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Cloning, Molecular
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DNA-Binding Proteins*
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Hepatocyte Nuclear Factor 4
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Liver / metabolism
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Mice
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Nuclear Proteins / genetics*
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Nuclear Proteins / isolation & purification
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Nuclear Proteins / physiology*
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Phosphoproteins / genetics*
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Phosphoproteins / isolation & purification
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Phosphoproteins / physiology*
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Rats
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Recombinant Fusion Proteins / biosynthesis
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Recombinant Fusion Proteins / isolation & purification
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Saccharomyces cerevisiae / genetics
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Trans-Activators*
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Transcription Factors / genetics*
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Transcription Factors / isolation & purification
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Transcription Factors / physiology*
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Transcription, Genetic
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Transfection
Substances
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Basic Helix-Loop-Helix Leucine Zipper Transcription Factors
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DNA-Binding Proteins
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Hepatocyte Nuclear Factor 4
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Nuclear Proteins
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Phosphoproteins
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Recombinant Fusion Proteins
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Tcfl4 protein, mouse
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Trans-Activators
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Transcription Factors
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CREB-Binding Protein
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Crebbp protein, mouse
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Crebbp protein, rat