SENSITIVITY OF POLYAMINE-DEFICIENT SACCHAROMYCES-CEREVISIAE TO ELEVATED-TEMPERATURES

Saccharomyces cerevisiae cells that cannot synthesize spermidine or sp ermine because of a deletion in the gene coding for S-adenosylmethioni ne decarboxylase are very sensitive to elevated temperatures when incu bated in a polyamine-deficient medium; i.e., growth is inhibited and t he 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 f indings 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 auxotro phs.