Metabolic regulation of the trehalose content of vegetative yeast

摘要: Abstract We have investigated the mechanism by which heat shock conditions lead to a reversible accumulation of trehalose in growing yeast. When cells S. cerevisiae MI exponentially at 30°C were shifted 45°C for 20 min, or 39°C 40 concentration increased about 25-fold; an effect reversed upon lowering temperature 30°C. This was compared more than 50-fold rise levels obtained transition from exponential stationary growth phase. Whereas latter paralleled 12-fold increase activity trehalose-6-phosphate synthase, no significant change activities trehalose-synthesizing and -degrading enzymes measured under conditions. Accordingly, cycloheximide did not prevent heat-induced trehalose. However, concentrations substrates i.e. glucose-6-phosphate UDP-glucose, found during 5–10-fold. Since elevated both sugars are still well below Km-values determined synthase vitro, they likely contribute A similar steady-state other intermediates glycolytic pathway between glucose triosephosphate, including ATP. suggests that temperature-dependent changes kinetic parameters vary sugar metabolism, those required synthesis. Trehalose, glucose-6-phosphate, ATP, all min treatment 39°C. this also occurs mutant lacking shock-induced protein HSP104 (Δhsp104), cannot be involved these Δhsp104, contrast parental wild-type, sensitive towards incubation 50°C. accumulated normal trehalose, we conclude function, protects damage caused 50°C treatment.