DE-NOVO PROTEIN-SYNTHESIS IS ESSENTIAL FOR THERMOTOLERANCE ACQUISITION IN A SACCHAROMYCES-CEREVISIAE TREHALOSE SYNTHASE MUTANT

Heat shock (25 degrees C to 37 degrees C for 30 min) acquisition of th ermotolerance (at 50 degrees C) was observed in a yeast trehalose synt hase mutant and the corresponding control strain. The acquisition of t hermotolerance in the control strain was maintained for a significantl y longer time than in the trehalose synthase mutant. The heat shock wa s associated with the synthesis of specific heat shock proteins and, i n the case of the control strain, also trehalose accumulation. Inhibit ion of protein synthesis during the heat shock totally abolished acqui sition of thermotolerance in both strains but not trehalose accumulati on in the control. It was concluded that trehalose may only be require d for prolonged stress protection while heat shock proteins are requir ed for heat shock acquisition of thermotolerance.