Evidence that TAF-TATA box-binding protein interactions are required for activated transcription in mammalian cells.
Surfaces of human TATA box-binding protein (hsTBP) required for activated transcription in vivo were defined by constructing a library of surface residue substitution mutations and assaying them for their ability to support activated transcription in transient-transfection assays. In earlier work, three regions were identified where mutations inhibited activated transcription without interfering with TATA box DNA binding. One region is on the upstream surface of the N-terminal TBP repeat with respect to the direction of transcription and corresponds to the TBP surface that interacts with TFIIA. A second region on the stirrup of the C-terminal TBP repeat corresponds to the TFIIB-binding surface. Here we report that the third region where mutations inhibit activated transcription in mammalian cells, the convex surface of the N-terminal repeat, corresponds to a surface on TBP that interacts with hsTAF1, the major scaffold subunit of TFIID. Since mutations at the center of the hsTAF1-interacting region inhibit the ability of the protein to support activated transcription in vivo, these results are consistent with the conclusion that an interaction between hsTBP and TAF(II)s is required for activated transcription in mammalian cells.
Martel
Lisa S
LS
Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, California, USA.
Brown
Helen J
HJ
Berk
Arnold J
AJ
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001665:Binding Sites; D001667:Binding, Competitive; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D056488:Histone Chaperones; D006801:Humans; D066298:In Vitro Techniques; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D035181:TATA-Box Binding Protein; D035561:Transcription Factor TFIIA; D035581:Transcription Factor TFIIB; D035362:Transcription Factor TFIID; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D019473:Transcription Factors, TFII / Q000378:metabolism; D015533:Transcriptional Activation; D014162:Transfection
D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D056488:Histone Chaperones; D012333:RNA, Messenger; D011994:Recombinant Proteins; C513473:SET protein, human; D035181:TATA-Box Binding Protein; D035561:Transcription Factor TFIIA; D035581:Transcription Factor TFIIB; D035362:Transcription Factor TFIID; D014157:Transcription Factors; D019473:Transcription Factors, TFII