In budding yeast, many genes are induced early in the cell cycle. Induction of these genes has been predominantly attributed to two transcription factors, Swi4-Swi6 (SBF) and Mbp1-Swi6 (MBF). Swi4 and Mbp1 are related DNA-binding proteins with dissimilar target sequences. For most G1/S-regulated genes that we tested in a cdc20 block-release protocol for cell-cycle synchronization, removal of both Swi4 and Mbp1 was necessary and sufficient to essentially eliminate cell-cycle-regulated expression. Detectable SBF or MBF binding sites (SCBs or MCBs) in the promoters or available genome-wide promoter occupancy data do not consistently explain this functional overlap. The overlapping ability of these transcription factors to regulate many promoters with very similar cell-cycle kinetics may provide robustness to the G1/S transcriptional response, but poses a puzzle with respect to promoter-transcription factor specificity. In addition, for some genes, deletion of Mbp1 or Swi4 enhances transcription, suggesting that these factors can also function as transcriptional repressors. Finally, we observe residual G1/S transcriptional regulation in the absence of Swi4 and Mbp1.
|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|