title: A class of activation domains interacts directly with TFIIA and stimulates TFIIA-TFIID-promoter complex assembly.
abstract: TFIIA is a general transcription factor that interacts with the TFIID-promoter complex required for transcription initiation by RNA polymerase II. Two lines of evidence suggest that TFIIA is directly involved in the mechanism by which some activators stimulate transcription. First, binding of TFIIA to a TFIID-promoter complex is a rate-limiting step that is enhanced by transcriptional activators GAL4-AH and Zta. Second, recombinant TFIIA greatly enhances activator-dependent transcription. In this study, we found that the activation domains of Zta and VP16 bind directly to TFIIA. Both Zta and VP16 stimulated rapid assembly of a stable TFIID-TFIIA complex on promoter DNA. Analysis of deletion derivatives of the VP16 activation domain indicated that the ability to bind to TFIIA correlates with the ability to enhance TFIID-TFIIA-promoter ternary complex assembly. Thus, we propose that a class of activators stimulate transcription initiation through direct interactions with both TFIIA and TFIID, which stimulate the assembly of an activated TFIIA-TFIID-promoter complex.
authors.affiliation: Molecular Biology Institute, University of California, Los Angeles 90024-1570, USA.
authors.forename: N
authors.initials: N
authors.lastname: Kobayashi
authors.forename: T G
authors.initials: TG
authors.lastname: Boyer
authors.forename: A J
authors.initials: AJ
authors.lastname: Berk
mesh_terms: D000595:Amino Acid Sequence; D018983:DNA Footprinting; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005656:Fungal Proteins / Q000378:metabolism; D017405:Herpes Simplex Virus Protein Vmw65 / Q000378:metabolism*; D007700:Kinetics; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012319:RNA Polymerase II / Q000378:metabolism*; D015534:Trans-Activators / Q000378:metabolism*; D035561:Transcription Factor TFIIA; D035362:Transcription Factor TFIID; D014157:Transcription Factors / Q000378:metabolism*; D015533:Transcriptional Activation; D014764:Viral Proteins
chemical_list: C063676:BZLF1 protein, Herpesvirus 4, Human; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C070633:Gal-VP16; D017405:Herpes Simplex Virus Protein Vmw65; D046911:Macromolecular Substances; D015534:Trans-Activators; D035561:Transcription Factor TFIIA; D035362:Transcription Factor TFIID; D014157:Transcription Factors; D014764:Viral Proteins; D012319:RNA Polymerase II