Multiple interactions between hTAFII55 and other TFIID subunits. Requirements for the formation of stable ternary complexes between hTAFII55 and the TATA-binding protein.
We have cloned and characterized the human TATA-binding protein (TBP)-associated factor hTAFII55. hTAFII55, which has no known Drosophila counterpart, is present in both of the previously described TFIIDalpha and TFIIDbeta subpopulations. We describe the interactions of hTAFII55 with other subunits of the transcription factor TFIID. By cotransfection in COS cells, we show that hTAFII55 interacts with hTAFII250, hTAFII100, hTAFII28, hTAFII20, and hTAFII18, but not with hTAFII30 or TBP. Analysis of the binding of hTAFII55 and TBP to hTAFII28 deletion mutants indicates that distinct regions of hTAFII28 are required for these interactions. Although hTAFII55 does not interact by itself with TBP, stable ternary complexes containing hTAFII55 and TBP can be formed in the presence of hTAFII250, hTAFII100, or hTAFII28. These results not only show that hTAFII100 and hTAFII28 interact with TBP, but also that they can nucleate the formation of partial TFIID complexes.
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Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/ULP, Collège de France, B. P. 163, 67404 Illkirch Cédex, France.
Mengus
G
G
May
M
M
Dubrovskaya
V
V
Tora
L
L
Chambon
P
P
Davidson
I
I
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D017931:DNA Primers / Q000737:chemistry; D018076:DNA, Complementary / Q000235:genetics; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000378:metabolism; D010446:Peptide Fragments / Q000737:chemistry; D011485:Protein Binding; D035381:TATA-Binding Protein Associated Factors; D035181:TATA-Box Binding Protein; D015534:Trans-Activators / Q000378:metabolism*; D035362:Transcription Factor TFIID; D014157:Transcription Factors / Q000378:metabolism*
D017931:DNA Primers; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D046911:Macromolecular Substances; D009687:Nuclear Proteins; D010446:Peptide Fragments; C091537:TAF7 protein, human; D035381:TATA-Binding Protein Associated Factors; D035181:TATA-Box Binding Protein; D015534:Trans-Activators; D035362:Transcription Factor TFIID; D014157:Transcription Factors