Abstract
The TATA binding protein (TBP) is a central component of the eukaryotic transcriptional machinery and is the target of positive and negative transcriptional regulators. Here we describe the cloning and biochemical characterization of an abundant human TBP-associated factor (TAF-172) which is homologous to the yeast Mot1 protein and a member of the larger Snf2/Swi2 family of DNA-targeted ATPases. Like Mot1, TAF-172 binds to the conserved core of TBP and uses the energy of ATP hydrolysis to dissociate TBP from DNA (ADI activity). Interestingly, ATP also causes TAF-172 to dissociate from TBP, which has not been previously observed with Mot1. Unlike Mot1, TAF-172 requires both TBP and DNA for maximal (approximately 100-fold) ATPase activation. TAF-172 inhibits TBP-driven RNA polymerase II and III transcription but does not appear to affect transcription driven by TBP-TAF complexes. As it does with Mot1, TFIIA reverses TAF-172-mediated repression of TBP. Together, these findings suggest that human TAF-172 is the functional homolog of yeast Mot1 and uses the energy of ATP hydrolysis to remove TBP (but apparently not TBP-TAF complexes) from DNA.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Adenosine Triphosphatases / genetics*
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Adenosine Triphosphatases / metabolism
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Adenosine Triphosphate / pharmacology
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Amino Acid Sequence
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Animals
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Base Sequence
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Cell Line
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Cloning, Molecular
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DNA Helicases / genetics*
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DNA Helicases / isolation & purification
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DNA Helicases / metabolism*
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DNA, Complementary
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DNA-Binding Proteins / genetics
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DNA-Binding Proteins / metabolism
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Fungal Proteins / genetics
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Fungal Proteins / metabolism
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HeLa Cells
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Humans
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Molecular Sequence Data
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Recombinant Fusion Proteins / genetics
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Recombinant Fusion Proteins / isolation & purification
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Saccharomyces cerevisiae / genetics
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Saccharomyces cerevisiae / metabolism
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Saccharomyces cerevisiae Proteins*
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Sequence Homology, Amino Acid
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Spodoptera / cytology
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TATA-Binding Protein Associated Factors*
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TATA-Box Binding Protein
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Transcription Factor TFIID*
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Transcription Factors / genetics*
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Transcription Factors / isolation & purification
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Transcription Factors / metabolism*
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Transcription, Genetic
Substances
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BTAF1 protein, human
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DNA, Complementary
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DNA-Binding Proteins
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Fungal Proteins
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Recombinant Fusion Proteins
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Saccharomyces cerevisiae Proteins
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TATA-Binding Protein Associated Factors
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TATA-Box Binding Protein
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Transcription Factor TFIID
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Transcription Factors
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Adenosine Triphosphate
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Adenosine Triphosphatases
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MOT1 protein, S cerevisiae
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DNA Helicases