Molecular cloning and expression of the 32-kDa subunit of human TFIID reveals interactions with VP16 and TFIIB that mediate transcriptional activation.
Transcription factor TFIID consists of TATA binding protein (TBP) and at least eight TBP-associated factors (TAFs). As TAFs are required for activated but not basal transcription, we have proposed that TAFs act as coactivators to mediate signals between activators and the basal transcription machinery. Here we report the cloning, expression, and biochemical characterization of the 32-kDa subunit of human (h) TFIID, termed hTAFII32. We find that hTAFII32 is the human homologue of Drosophila TAFII40. In vitro protein-protein interaction assays reveal that as observed with Drosophila TAFII40, hTAFII32 interacts with the C-terminal 39-amino acid activation domain of the acidic transactivator viral protein 16 (VP16) as well as with the general transcription factor TFIIB. Moreover, a partial recombinant TFIID complex containing hTAFII32 was capable of mediating in vitro transcriptional activation by the VP16 activation domain. These findings indicate that specific activator-coactivator interactions have been conserved between human and Drosophila and provide additional support for the function of these interactions in mediating transcriptional activation.
Klemm
R D
RD
Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley 94720-3202, USA.
Goodrich
J A
JA
Zhou
S
S
Tjian
R
R
D000595:Amino Acid Sequence; D000818:Animals; D002467:Cell Nucleus; D003001:Cloning, Molecular; D017124:Conserved Sequence; D004268:DNA-Binding Proteins / Q000378:metabolism; D004330:Drosophila / Q000378:metabolism; D015870:Gene Expression; D006367:HeLa Cells; D017405:Herpes Simplex Virus Protein Vmw65 / Q000378:metabolism*; D006801:Humans; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D016385:TATA Box; D035181:TATA-Box Binding Protein; D035581:Transcription Factor TFIIB; D035362:Transcription Factor TFIID; D014157:Transcription Factors / Q000096:biosynthesis / Q000378:metabolism*; D014158:Transcription, Genetic; D015533:Transcriptional Activation
D004268:DNA-Binding Proteins; D017405:Herpes Simplex Virus Protein Vmw65; D046911:Macromolecular Substances; D011994:Recombinant Proteins; D035181:TATA-Box Binding Protein; D035581:Transcription Factor TFIIB; D035362:Transcription Factor TFIID; D014157:Transcription Factors