Figure 2.

Overexpression of Ppz1 causes oxidative stress and signals through Rad52. (a) Changes in mRNA levels for selected genes calculated from RNA-seq data (log2 of ZCZ01/WT ratio). Values are mean ± SEM from 3 experiments. (b) Cells grown on YP raffinose received 2% galactose to induce expression of Ppz1 and, at the same time, were loaded with dihydrorhodamine 123. Samples were taken at the indicated times and subjected to fluorescence microscopy (left panel) or processed for flow cytometry (right panel). The presence of ROS oxidizes dihydrorhodamine 123 to the fluorescent derivative rhodamine 123. Only the ZCZ01 strain is shown since wild type BY4741 cells produced no fluorescence at any time tested. c) The indicated strains were transformed with plasmid pWJ1344, which expressed an YFP-tagged version of Rad52. Upon growth on 2% raffinose, cells were shifted to 2% galactose. Samples were taken at different times and the percentage of cells positive for Rad52 foci was estimated. Data is presented as the mean ± SEM from four experiments (average 160–430 counted cells per experiment and time point). A representative micrograph taken after 20 h is shown on the right.