A human TATA binding protein-related protein with altered DNA binding specificity inhibits transcription from multiple promoters and activators.
The TATA binding protein (TBP) plays a central role in eukaryotic and archael transcription initiation. We describe the isolation of a novel 23-kDa human protein that displays 41% identity to TBP and is expressed in most human tissue. Recombinant TBP-related protein (TRP) displayed barely detectable binding to consensus TATA box sequences but bound with slightly higher affinities to nonconsensus TATA sequences. TRP did not substitute for TBP in transcription reactions in vitro. However, addition of TRP potently inhibited basal and activated transcription from multiple promoters in vitro and in vivo. General transcription factors TFIIA and TFIIB bound glutathione S-transferase-TRP in solution but failed to stimulate TRP binding to DNA. Preincubation of TRP with TFIIA inhibited TBP-TFIIA-DNA complex formation and addition of TFIIA overcame TRP-mediated transcription repression. TRP transcriptional repression activity was specifically reduced by mutations in TRP that disrupt the TFIIA binding surface but not by mutations that disrupt the TFIIB or DNA binding surface of TRP. These results suggest that TFIIA is a primary target of TRP transcription inhibition and that TRP may modulate transcription by a novel mechanism involving the partial mimicry of TBP functions.
Moore
P A
PA
Human Genome Sciences, Rockville, Maryland 20850, USA.
Ozer
J
J
Salunek
M
M
Jan
G
G
Zerby
D
D
Campbell
S
S
Lieberman
P M
PM
D000595:Amino Acid Sequence; D001665:Binding Sites; D003001:Cloning, Molecular; D017124:Conserved Sequence; D018076:DNA, Complementary / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D019143:Evolution, Molecular; D005786:Gene Expression Regulation; D005982:Glutathione Transferase / Q000235:genetics; D006801:Humans; D008969:Molecular Sequence Data; D019384:Nucleic Acid Synthesis Inhibitors; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D020449:Repetitive Sequences, Amino Acid; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D035182:TATA Box Binding Protein-Like Proteins; D035181:TATA-Box Binding Protein; D014018:Tissue Distribution; D035561:Transcription Factor TFIIA; D035581:Transcription Factor TFIIB; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D019384:Nucleic Acid Synthesis Inhibitors; D012097:Repressor Proteins; D035182:TATA Box Binding Protein-Like Proteins; D035181:TATA-Box Binding Protein; D035561:Transcription Factor TFIIA; D035581:Transcription Factor TFIIB; D014157:Transcription Factors; D005982:Glutathione Transferase