Cellular stress responses oscillate in synchronization with the ultradian oscillation of energy metabolism in the yeast Saccharomyces cerevisiae

We investigated whether cellular responses to various stress conditions are regulated in synchronization with the ultradian rhythm of. respiratory-fermentative metabolism which is coupled to the cell cycle rhythm in continuous cultures of the ye ast Saccharomyces cerevisiae. The cellular resistance to heat oscillated with a peak at the late respiro-fermentative phase, which approximately corresponds to the unbudding period of the cell cycle. Cellular resistance to H2O2 and that to the superoxide-generating agent menadione oscillated in the same phase as that of heal resistance. The resistance to cadmium and that to 1-chloro-2,4-dinitrobenzene, an uncoupler of energy metabolism in mitochondria, both oscillated with a peak advanced by about 80 degrees relative to that of heat resistance: approximately covering the respiro-fermentative phase. Thus, cellular resistance to various stresses in S. cerevisiae oscillated in synchronization with the metabolic oscillation in the continuous culture. (C) 2000 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.