Sensitivity of polyamine-deficient Saccharomyces cerevisiae to elevated temperatures.

Saccharomyces cerevisiae cells that cannot synthesize spermidine or spermine because of a deletion in the gene coding for S-adenosylmethionine decarboxylase are very sensitive to elevated temperatures when incubated in a polyamine-deficient medium; i.e., growth is inhibited and the cells are killed. This sensitivity is very pronounced at 39 degrees C, but a moderate effect is noted even at 33 to 34 degrees C. These findings support findings from other studies from our laboratory on the importance of polyamines in protecting cell components against damage. The sensitivity of spermidine-deficient cells to the temperature 39 degrees C provides a useful method for screening for polyamine auxotrophs.