GSE133840
NRG1 as a regulator of pH adaptation in the Basidiomycota Ustilago maydis
A homologue of the transcriptional repressor ScNrg1 described previously in the budding yeast and Candida albicans NRG1 wich plays an essential role in repressing hyphal development in both Saccharomyces cerevisiae and C. albicans, was found in Ustilago maydis. In S. cerevisiae it regulates a set of stress-responsive genes, also in Cryptococcus neoformans is involved in pathogenesis. In this work, we describe the effect of the absence of the U. maydis NRG1 gene in cell response to acid pH, mannosylerithritol lipids production, and cellular response to several stressful conditions. In U. maydis, NRG1 is required for filamentous growth and appears to be essential to respond to pH changes, and oxidative stress accurately. By comparing gene expression in a wild type strain versus nrg1 mutant strain of the fungus trough RNA_Seq analyses, it turned out to act as transcriptional factor altering the expression of 368 genes (205 up-regulated, 163 downregulated). Most relevant cellular processes affected by NRG1 are osmotic stress pathway, pH response, internal environmental sensor mechanism, represented by the genes Hog1, Rim101, and WCO1 respectively, also, all the genes present in the mannosylerithritol lipids production pathway, even under conditions not favorable for the production of glycolipids. Among previous specific functions described before for this transcriptional regulator as a glucose repressor, it seems to have an important role in metabolic adaptation, cellular transport, cell rescue defense and interaction with the environment. Overall design: Transcriptomic comparison between wild type and NRG1 mutant of Ustilago maydis, replicates were analyzed.