Absence of Cbf11 leads to activation of stress-response genes.

(A) Venn diagram of genes upregulated more than 2-fold in WT cells after 15 min treatment with 1 mM H₂O₂ in EMM medium (data from [34]), and genes upregulated more than 2-fold in cbf11Δ cells growing exponentially in YES medium (data from [15]). The group membership of stress genes from panel B is indicated with symbols. Overlap significance was determined by two-sided Fisher’s exact test. (B) Expression of the indicated stress genes in WT and cbf11Δ cells treated or not with the indicated concentrations of H₂O₂ for 15 min in YES was analyzed by RT-qPCR. Mean and SD values of three independent replicates are shown. One-sided Mann-Whitney U test was used to determine statistical significance. (C) Survival and growth under oxidative stress of WT, cbf11Δ, cbf12Δ and cbf11Δ cbf12Δ cultures spotted on YES plates containing 1.5 mM H₂O₂. (D) cbf11Δ displays lower steady-state intracellular H₂O₂ levels, and detoxifies extracellular peroxides faster than WT cells. The indicated concentrations of H₂O₂ were directly added to EMM cultures of WT and cbf11Δ cells transformed with plasmid p407.C169S. The degree of probe oxidation on scale from 0 (fully reduced) to 1 (fully oxidized) is indicated on the Y axis (OxD roGFP2). The starting levels of probe oxidation in each strain background (OxD₀) are indicated by dashed horizontal lines. Mean values from three biological replicates are shown. (E) Venn diagram of genes upregulated more than 2-fold in WT cells after 15 min treatment with 1 mM H₂O₂ in EMM medium (data from [34]), and genes upregulated more than 2-fold in cells overexpressing Cbf12 grown in EMM (data from [15]). The group membership of stress genes from panel B is indicated with symbols. Overlap significance was determined by two-sided Fisher’s exact test. (F) Expression of the indicated stress genes in WT and cbf12Δ cells treated or not with 1 mM H₂O₂ for 15 min in YES was analyzed by RT-qPCR. Mean and SD values of three independent replicates are shown. One-sided Mann-Whitney U test was used to determine statistical significance.