Effects of cycloheximide on the temperature profile of Sacharomyces cerevisiae

Tmax, the maximum temperature for growth of Saccharomyces cerevisiae, decreased linearly with increasing concentrations of cycloheximide added to the medium, to about 20 degrees C at 2.5 microgram ml-1. In this concentration range thermal death was not enhanced. The Arrhenius plot of growth was shifted to lower temperatures as a function of the cycloheximide concentration and became dissociated from the Arrhenius plot of thermal death. It was concluded that the target site of cycloheximide, the cytoplasmic ribosome, is not identical with the physiological Tmax site of S. cerevisiae and that the binding of cycloheximide to its target sites is strongly enhanced by the temperature.