Figure 8.

Nitric oxide reductase (NOR1) confers increased resistance to nitrosative stress. (A) The log₂ fold change for NOR1 is shown for each of the experimental conditions from Figure 2. In the DPTA NONOate and GSNO dose-response experiments, control treatments are represented by the gray bars. (B) Northern blot analysis of NOR1 transcripts at 0 and 2 h after DPTA NONOate treatment. These samples are identical to those used for gene expression profiling in dose-response experiment 2. This blot was stripped and reprobed for the ACT1 transcript as shown (bottom). An RNA ladder is shown to the left of the gel. (C) An alignment between the predicted H.c. Nor1p and F. oxysporum P450nor protein (Fo P450nor). Identical amino acids are shaded in black. The first ATG after the transcription start site was designated as the starting methionine of each of the two mapped NOR1 transcripts. The red arrowhead marks the start of the smallest predicted Nor1 protein. (D) Ectopic expression of NOR1 enhances growth in the presence of RNS. H. capsulatum G217B ura5^- cells transformed with either a vector control or NOR1 under the control of a copper-inducible promoter (P_CRP1-NOR1) were grown in 10 μM copper sulfate for 1 h and then subjected to RNS stress by the addition of 0, 1, or 2 mM DPTA NONOate. Spectrophotometric readings at OD₆₀₀ were taken at 0 and 25 h after treatment was initiated. The starting OD was set at 100% growth. SD is indicated for each measurement