Abstract
In contrast to its behavior as naked DNA, the MMTV promoter assembled in minichromosomes can be activated synergistically by the progesterone receptor and NF1 in a process involving ATP-dependent chromatin remodeling. The DNA-binding domain of NF1 is required and sufficient for stable occupancy of all receptor-binding sites and for functional synergism. Activation of purified minichromosomes is observed in the absence of SWI/SNF and can be enhanced by recombinant ISWI. Receptor binding to minichromosomes recruits ISWI and NURF38, but not brahma. We propose a two-step synergism in which the receptor triggers a chromatin remodeling event that facilitates access of NF1, which in turn stabilizes an open nucleosomal conformation required for efficient binding of further receptor molecules and full transactivation.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Adenosine Triphosphatases / genetics
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Adenosine Triphosphate / metabolism
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Animals
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CCAAT-Enhancer-Binding Proteins*
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Cell Cycle Proteins*
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Chromatin / metabolism
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Chromosomes / genetics*
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DNA Footprinting
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DNA-Binding Proteins / genetics*
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Drosophila / embryology
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Drosophila Proteins*
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Humans
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Insect Proteins / metabolism
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Mammary Tumor Virus, Mouse / genetics
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NFI Transcription Factors
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Nuclear Proteins
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Nucleic Acid Conformation
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Nucleosomes / genetics
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Promoter Regions, Genetic
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Pyrophosphatases*
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Receptors, Progesterone / genetics*
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Recombinant Proteins / genetics
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Trans-Activators / metabolism
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Transcription Factors / genetics
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Transcription, Genetic
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Y-Box-Binding Protein 1
Substances
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CCAAT-Enhancer-Binding Proteins
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Cell Cycle Proteins
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Chromatin
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DNA-Binding Proteins
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Drosophila Proteins
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ISWI protein
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Insect Proteins
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NFI Transcription Factors
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Nuclear Proteins
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Nucleosomes
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Receptors, Progesterone
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Recombinant Proteins
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Trans-Activators
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Transcription Factors
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Y-Box-Binding Protein 1
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YBX1 protein, human
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brm protein, Drosophila
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Adenosine Triphosphate
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Adenosine Triphosphatases
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Pyrophosphatases
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Nurf-38 protein, Drosophila