Transcription factor IID (TFIID) plays a key role in regulating eukaryotic gene expression by directly binding promoters and enhancer-bound transactivator proteins. However, the precise mechanisms and outcomes of transactivator-TFIID interaction remain unclear. Transcription of yeast ribosomal protein genes (RPGs) requires TFIID and the DNA-binding transactivator Rap1. We have previously shown that Rap1 directly binds to the TFIID complex through interaction with its TBP Associated Factor (Taf) subunits Taf4, 5 and 12. Here we identify and characterize the Rap1 Binding Domains (RBDs) of Taf4 and Taf5. These RBDs are essential for viability but dispensable for Taf-Taf interactions and TFIID stability. Cells expressing altered Rap1 Binding Domains exhibit conditional growth, synthetic phenotypes when expressed in combination or with altered Rap1, and are selectively defective in RPG transcription. Taf4 and Taf5 proteins with altered RBDs bind Rap1 with reduced affinity. We propose that collectively the Taf4, Taf5 and Taf12 subunits of TFIID represent the physical and functional targets for Rap1 interaction, and further, that these interactions drive ribosomal protein gene transcription.
|Evidence ID||Analyze ID||Interactor||Interactor Systematic Name||Interactor||Interactor Systematic Name||Type||Assay||Annotation||Action||Modification||Phenotype||Source||Reference||Note|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Gene Ontology Term||Gene Ontology Term ID||Qualifier||Aspect||Method||Evidence||Source||Assigned On||Annotation Extension||Reference|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Phenotype||Experiment Type||Experiment Type Category||Mutant Information||Strain Background||Chemical||Details||Reference|
|Evidence ID||Analyze ID||Regulator||Regulator Systematic Name||Target||Target Systematic Name||Experiment||Assay||Construct||Conditions||Strain Background||Reference|