Fig 10.

Slt2 and Bck1 promote vacuole fusion and cell survival in grx5 and sod1 mutants, both of which are affected by chronic oxidative stress. (A) Cultures of the grx3 grx4 slt2 and grx5 mutants were transformed with a plasmid harboring SLT2, whereas sod1 cells were transformed with a plasmid containing BCK1-1. These cultures were grown exponentially in SD medium. Samples were taken and serially diluted to plate 1,000 cells onto two parallel sets of plates, both of which contained each of the following reagents: glycerol as the sole carbon source and HCl (1 M) or NaOH (1.5 M). LatB (5 μM) was additionally added to only one set. Cells were grown for 3 days at 30°C. The histograms represent cell viability calculated as described in Materials and Methods and in the legend to Fig. 6D. (B) Cultures of the sod1, sod1(pBck1-20), grx5, and grx5(pSlt2) strains were stained with the dye FM4-64 to observe the vacuolar morphology. To quantify vacuole fragmentation, the results for 500 cells were recorded in three independent experiments.