A systematic approach for the identification of Msn2 partners that regulate Msn2 gene expression activity under different stress conditions. (A) Yeast strains deleted of Msn2 partners were generated on the background of a strain expressing the HSP12-GFP, the TPS2-GFP, or the PNC1-GFP reporter gene. Following exposure to diverse environmental conditions, reporter gene expression levels were analyzed by flow cytometry. Selected deletion strains with increased or decreased Hsp12-GFP expression relative to the nondeleted strain were further analyzed for survival, Msn2 nuclear localization, and Msn2 protein degradation. (B) Deletion of Msn2 partners can result in no change (left), in decrease (middle), or in increase (right) in reporter gene expression level. Deletion of Msn2 partners that resulted in decrease or increase in the reporter gene expression level allowed for identification of the absent protein as an Msn2 activator (green) or suppressor (red), respectively.