Cloning and biochemical characterization of TAF-172, a human homolog of yeast Mot1.
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.
Chicca
J J
JJ
Center for Gene Regulation, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park 16802, USA.
Auble
D T
DT
Pugh
B F
BF
D000251:Adenosine Triphosphatases / Q000235:genetics* / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000494:pharmacology; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D003001:Cloning, Molecular; D004265:DNA Helicases / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D018076:DNA, Complementary; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000302:isolation & purification; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D018411:Spodoptera / Q000166:cytology; D035381:TATA-Binding Protein Associated Factors; D035181:TATA-Box Binding Protein; D035362:Transcription Factor TFIID; D014157:Transcription Factors / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D014158:Transcription, Genetic
C109035:BTAF1 protein, human; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D035381:TATA-Binding Protein Associated Factors; D035181:TATA-Box Binding Protein; D035362:Transcription Factor TFIID; D014157:Transcription Factors; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; C073676:MOT1 protein, S cerevisiae; D004265:DNA Helicases