Figure 6.

Deletion of YCA1 or inhibition of Yca1 activity suppresses the phenotype of cells with the cit1 deletion. (A) Effect of YCA1 deletion on the ts phenotype caused by deletion of CIT1. Yeast strains (wild type, Δyca1, Δcit1, Δcit1Δyca1, and Δcit1Δcit2Δyca1) grown in SCD were incubated at 50°C for 10 min, and aliquots of the samples were taken. Surviving cells were evaluated by CFU assays carried out in triplicate in all cases. (B) Effect of YCA1 deletion on the accelerated chronological aging caused by the deletion of CIT1. The yeast strains listed above were grown in SCD for 7 d, and surviving cells were then evaluated by CFU assay. (C) Effect of Yca1 inhibition on the ts phenotype caused by the deletion of CIT1. Cells of the Δcit1 strain grown in SCD were incubated at 50°C for 10 min in the presence of 0–20 μM zVAD-fmk, a metacaspase inhibitor, and surviving cells were then evaluated by CFU assay.