Figure 2.

Ssa1 deacetylation alters yeast thermotolerance. (A) Yeast expressing acetylation site mutations were grown to exponential phase, serially diluted fivefold and plated onto YPD plates. Plates were photographed after 3 days incubation at the indicated temperatures. (B) Assessment of acetylation site mutant recovery after acute heat shock. Fresh cultures were heat shocked at 47 °C for the indicated times and then were serially diluted fivefold and plated onto YPD plates. Plates were photographed after 3 days incubation at 30 °C. (C) WT, 4Q and 4R cells were inoculated at an OD₆₀₀ of 0.1 into 96 well format and were shaken in a plate reader at 30 °C. OD₆₀₀ was measured at 1 h intervals. (D) Assessment of [PSI⁺] propagation. Single colonies of cells expressing WT, 4Q and 4R Ssa1 were streaked on YPD and −ADE plates which were then incubated at RT for 5–7 days. [psi⁻] cells were red colonies on YPD and unable to grow −ADE plates; [PSI⁺] cells were white colonies on YPD and viable on −ADE plates; [psi⁻] cells were attained by streaking [PSI⁺] colonies on YPD plates containing 3 mM GdnHCl and incubating for 2–3 days. The curing of [psi⁻] cells was repeated at least twice to obtain a stable [psi⁻] heritage. (E) Growth assay of acetylation site mutants for [PSI⁺] and [psi⁻] cells. Yeast were grown and treated as in (A). (F) Response of acetylation site mutants to stresses that perturb DNA integrity or the yeast cell wall. Cells grown as in (A) were five-fold serially diluted and plated onto media containing the indicated stressors.