Abstract
Nuclear histone acetyltransferases, DNA-dependent ATPases, and transcriptional intermediary factors (TIFs) all harbor a distinct structural module known as the bromodomain (BrD). Although the BrD can interact with histones H3 and H4 and their acetylated N-terminal tails in vitro, its function in a chromosomal environment remains elusive. We used the nuclear receptor coregulator TIF1alpha, a protein kinase that associates tightly with euchromatin, to analyze the properties of the BrD in a nucleosomal environment in vitro. Here, we report that TIF1alpha-chromatin association is direct and involves DNA and nucleosome interactions mediated by the BrD. Mutation of the BrD signature peptide, PMDL, abolishes DNA binding and disrupts BrD-nucleosome interactions. Based on our results, we propose that the BrD plays a critical role in vivo by directing transregulators to their cognate location on nucleosomal DNA.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Amino Acid Sequence
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Animals
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Base Sequence
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Binding Sites
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Chromatin / metabolism
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Cloning, Molecular
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Drosophila / embryology
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Drosophila Proteins / chemistry
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Drosophila Proteins / metabolism*
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Histones / metabolism
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Molecular Sequence Data
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Nuclear Proteins / chemistry
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Nuclear Proteins / genetics
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Nuclear Proteins / metabolism*
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Nucleosomes / metabolism*
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Peptide Fragments / chemistry
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Peptide Fragments / metabolism*
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Protein Kinases / chemistry
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Protein Kinases / genetics
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Protein Kinases / metabolism
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Recombinant Proteins / chemistry
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Recombinant Proteins / metabolism
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Transcription Factors / chemistry
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Transcription Factors / genetics
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Transcription Factors / metabolism*
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Transcription, Genetic*
Substances
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Chromatin
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Drosophila Proteins
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Histones
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Nuclear Proteins
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Nucleosomes
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Peptide Fragments
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Recombinant Proteins
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Transcription Factors
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transcriptional intermediary factor 1
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Protein Kinases
Associated data
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GENBANK/AY155467
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GENBANK/AY155468