title: Human TAFII250 interacts with RAP74: implications for RNA polymerase II initiation.
abstract: Accurate and regulated transcription by RNA polymerase II requires the assembly of an initiation complex involving multiple protein-DNA and protein-protein interactions. A key event is binding of TFIID, a complex consisting of TBP and associated factors (TAFs) to the template DNA. The TAF subunits of TFIID carry out diverse functions critical for transcription, including specific contact with enhancer proteins and binding to core promoter DNA. However, the role of TAFs in RNA polymerase II-mediated transcription initiation and cross talk with other basal factors remains poorly characterized. Here, we report the specific interaction of TAFII250 with RAP74, an essential subunit of the basal transcription factor IIF. Using various in vitro binding assays we have mapped recognition interfaces between TAFII250 and RAP74. In vivo complementation of a temperature-sensitive TAFII250 cell line reveals that the RAP74 interaction is critical for cell viability. Because TFIIF is thought to be responsible for binding and recruiting RNA polymerase II, the ability of TAFII250 to interact selectively with RAP74 is likely to contribute a critical contact for the assembly of an active transcription complex.
authors.affiliation: Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley 94720-3204, USA.
authors.forename: S
authors.initials: S
authors.lastname: Ruppert
authors.forename: R
authors.initials: R
authors.lastname: Tjian
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D001483:Base Sequence; D001665:Binding Sites; D002352:Carrier Proteins / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006367:HeLa Cells; D051548:Histone Acetyltransferases; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D009687:Nuclear Proteins / Q000378:metabolism*; D009841:Oligonucleotides; D010750:Phosphoproteins / Q000378:metabolism*; D035381:TATA-Binding Protein Associated Factors; D013696:Temperature; D015534:Trans-Activators / Q000378:metabolism*; D035362:Transcription Factor TFIID
chemical_list: D000596:Amino Acids; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D009841:Oligonucleotides; D010750:Phosphoproteins; C046282:RNA polymerase II-binding proteins; D035381:TATA-Binding Protein Associated Factors; D015534:Trans-Activators; D035362:Transcription Factor TFIID; D051548:Histone Acetyltransferases; C069001:TATA-binding protein associated factor 250 kDa