Comparing DNA binding specificities between orthologous Pho4 transcription factors using extended length probes that include flanking genomic sequences.
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ABSTRACT: Combinatorial control by multiple transcription factors (TFs) is a hallmark of eukaryotic gene regulation. Despite its prevalence and crucial roles in enhancing specificity and integrating information, the mechanisms behind why eukaryotic TFs depend on one another, and whether such interdependence evolves, are not well understood. We exploit natural variation in co-TF dependence in the yeast phosphate starvation (PHO) response to address this question. In the model yeast Saccharomyces cerevisiae, the main TF, Pho4, relies on the co-TF Pho2 to regulate ~28 genes. In a related yeast pathogen, Candida glabrata, its Pho4 exhibits significantly reduced Pho2 dependence and has an expanded target set of ~70 genes. Chomatin IP based motifs for the two orthologous Pho4s are highly similar, with no detectable difference in their core E-box motif. However, past studies found that preference for sequences flanking the core motif can provide additional specificities to TFs in the same family. To determine if ScPho4 and CgPho4 differ in their flanking nucleotide preference, we conducted the genomic context Protein Binding Microarray (gcPBM) using 36 bp oligos centered on E-box motifs from ChIP-identified Pho4 binding locations in both S. cerevisiae and C. glabrata genomes. The results confirmed that the two Pho4 orthologs do not show divergence in their sequence preference even after including the genomic context.
ORGANISM(S): Nakaseomyces glabratus Saccharomyces cerevisiae
PROVIDER: GSE293214 | GEO | 2025/04/02
REPOSITORIES: GEO
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