Figure 1.

nro1⁺ is a positive regulator of Sre1N. (A) Sre1N is the soluble N terminus of Sre1. (B) Diagram of the integrated 2xSRE-ura4⁺ reporter gene in the sre1N reporter strain. Two tandem SRE sequences fused to a minimal promoter drive the expression of ura4⁺. (C) sre1N SRE-ura4⁺ reporter strains with the indicated number of tandem SREs driving ura4⁺ and sre1Δ 7xSRE-ura4⁺ cells were spotted in five-fold serial dilutions on rich medium, minimal medium lacking uracil or minimal medium containing 5-FOA. (D) sre1N 2xSRE-ura4⁺ cells containing empty vector or a plasmid expressing nro1⁺ from the adh promoter were plated on a minimal medium lacking leucine or lacking leucine and uracil. (E) sre1N 2xSRE-ura4⁺ cells containing empty vector or a plasmid expressing nro1⁺ from the adh promoter were grown in the absence of oxygen for the indicated times. (F) sre1N and sre1N nro1Δ cells were grown in the absence of oxygen for the indicated times. For western blotting, whole-cell extracts (40 μg) were subjected to western blot analysis using anti-Sre1 antibody. Molecular mass markers (kDa) are given to left.