Figure 1.

Deletion of CIT1 causes increased sensitivity to heat stress. (A) Analysis of growth of yeast strains at elevated temperatures. Yeast strains (wild type, Δcit1, Δcit2, Δ cit1Δcit2, Δcit1Δcit2/YCpCit1, Δcit1Δcit2/YEp Cit1, Δcit1Δcit2/YCpCit2, Δcit1Δcit2/YEpCit2, Δcit1/YCpCit2, and Δcit1/YEpCit2) grown in SCD were serially diluted, spotted on SCD agar plates, and incubated at 30 or 40°C for 3 d. (B) Analysis of survival rates of yeast strains at lethal temperatures. Cells of the yeast strains listed above were shifted to 50°C, and aliquots of the samples were taken at intervals. Surviving cells were evaluated by CFU assays carried out in triplicate. □, wild type; ▵, Δcit1; ▴, Δcit2; ■, Δcit1Δcit2; ◇, Δcit1Δcit2/YCpCit1; ♦, Δcit1 Δcit2/YEpCit1; ○, Δcit1Δcit2/YCpCit2; ·, Δcit1 Δcit2/YEpCit2; ▿, Δcit1/YCpCit2; ▾, Δcit1/YEpCit2.