Genome-wide characterization of CreA-mediated transcriptional regulation in Aspergillus oryzae under carbon...

Carbon catabolite repression (CCR) enables microorganisms to preferentially utilize energetically favorable carbon sources. In Aspergillus oryzae, the transcription factor CreA plays a central role in carbon source metabolism via CCR, although its function under various culture conditions remains insufficiently determined. In this study, we performed genomic systematic evolution of ligands via exponential enrichment-sequencing (gSELEX-Seq) using the DNA-binding domain of CreA to identify candidate CreA-binding regions within the genome. Motif analysis revealed a consensus binding site overlapping the previously reported 5'-SYGGRG-3' core. RNA-Seq analysis using the A. oryzae ΔcreA strain cultured under CCR release conditions revealed significant differences in the expression of 486 genes, including transporters, transcription factors, and sugar metabolism enzymes. Integration of gSELEX-Seq data and transcriptome profiles revealed nine candidate genes directly regulated by CreA. These findings enhance our understanding of the multifaceted regulatory network of CreA in A. oryzae, providing a framework for further functional studies.