Surprising mechanisms and regulatory roles of yeast transcription factors [ChEC-seq]
DNA sequence-specific transcription factors (TFs) modulate transcription and chromatin architecture, acting from regulatory sites in enhancers and promoters of eukaryotic genes. How multiple TFs cooperate to regulate individual genes is still unclear. Most yeast TFs are thought to regulate transcription via binding to Upstream Activating Sequences, situated within a few hundred base pairs upstream of the regulated gene1. While this model has been validated for individual TFs and specific genes, it has not been tested in a systematic way. We integrated information on the binding and expression targets for the near-complete set of yeast TFs. Here we show that, contrary to expectations, there are few TFs with dedicated activator or repressor functions with most TFs having a dual role. While nearly all protein coding genes are regulated by one or more TFs, our analysis revealed limited overlap between TF binding and gene regulation. Rapid depletion of many TFs also revealed numerous regulatory targets distant from detectable TF binding sites, suggesting unexpected regulatory mechanisms. Our study provides a comprehensive survey of TF functions, offering insights into interactions between the set of TFs expressed in a single cell type and how they contribute to the complex program of gene regulation. Overall design: ChEC-seq method was used to map genome-wide binidng of transcription factors. Experiments were done in two, three (A,B,C) replicates