Figure 7. Sir2 mediates synphilin-1 toxicity in yeast.

A: Relative quantification of viable cells as determined by their ability to form colonies at different times after inoculation of the wild-type strain or the isogenic sir2Δ mutant transformed with empty plasmids or constructs allowing for expression of α-Syn or SY^WT, either alone or in combination as indicated. The number of viable cells in samples taken after 24 h of growth of the two strains transformed with the empty plasmids was set at 100%. B and C: Quantification of viable cells (B) and cells producing ROS (C) during chronological ageing of the wild-type strain transformed with an empty plasmid (□) or expressing SY^WT (▪) and the isogenic sir2Δ mutant transformed with an empty plasmid (○) or expressing SY^WT (•). All data represent mean ± SEM of six independent transformants. Significance of the data was determined by t-tests (* = p<0.05; ** = p<0.01; *** = p<0.001).