Abstract
FUSE-binding protein (FBP) binds the single-stranded far upstream element of active c-myc genes, possesses potent transcription activation and repression domains, and is necessary for c-myc expression. A novel 60 kDa protein, the FBP interacting repressor (FIR), blocked activator-dependent, but not basal, transcription through TFIIH. Recruited through FBP's nucleic acid-binding domain, FIR formed a ternary complex with FBP and FUSE. FIR repressed a c-myc reporter via the FUSE. The amino terminus of FIR contained an activator-selective repression domain capable of acting in cis or even in trans in vivo and in vitro. The repression domain of FIR targeted only TFIIH's p89/XPB helicase, required at several stages in transcription, but not factors required for promoter selection. Thus, FIR locks TFIIH in an activation-resistant configuration that still supports basal transcription.
MeSH terms
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Amino Acid Sequence
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Binding Sites
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DNA Helicases / antagonists & inhibitors
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DNA-Binding Proteins / antagonists & inhibitors
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DNA-Binding Proteins / metabolism*
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HeLa Cells
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Humans
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Macromolecular Substances
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Models, Genetic
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Molecular Sequence Data
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Peptide Fragments / metabolism
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Protein Binding
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Proto-Oncogene Proteins c-myc / genetics*
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RNA Splicing Factors
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RNA-Binding Proteins
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Regulatory Sequences, Nucleic Acid
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Repressor Proteins / metabolism*
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Transcription Factor TFIIH
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Transcription Factors / metabolism*
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Transcription Factors, TFII*
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Transcriptional Activation*
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Two-Hybrid System Techniques
Substances
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DNA-Binding Proteins
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FUBP1 protein, human
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Macromolecular Substances
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Peptide Fragments
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Proto-Oncogene Proteins c-myc
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RNA Splicing Factors
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RNA-Binding Proteins
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Repressor Proteins
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Transcription Factors
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Transcription Factors, TFII
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poly-U binding splicing factor 60KDa
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XPBC-ERCC-3 protein
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Transcription Factor TFIIH
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DNA Helicases