Thermotolerance is independent of induction of the full spectrum of heat shock proteins and of cell cycle blockage in the yeast Saccharomyces cerevisiae.

摘要: Cells of the yeast Saccharomyces cerevisiae are known to acquire thermotolerance in response stresses starvation or heat shock. We show here through use cell cycle inhibitors that blockage cells G1, S, G2 phases mitotic is not a stress induces thermotolerance; arrested remained as sensitive thermal killing proliferating cells. These G1- S-phase-arrested were unimpaired acquisition when subjected mild shock by incubation at 37 degrees C. One inhibitor, o-phenanthroline, did fact cause become thermotolerant but without induction characteristic pattern proteins. Thermal protein synthesis was unaffected; o-phenanthroline-treated could still synthesize proteins upon transfer Use novel mutant conditionally defective only for resumption proliferation from stationary phase (M. A. Drebot, G. Johnston, and R. Singer, Proc. Natl. Acad. Sci. USA 84:7948-7952, 1987) indicated o-phenanthroline inhibition produces stationary-phase arrest, finding which consistent with increased regulated cessation exhibited inhibited findings acquired unrelated rapid spectrum