Correlation of trenalose content and heat resistance in yeast mutants altered in the RAS/adenylate cyclase pathway: is trehalose a thermoprotectant?

Abstract

Trehalose content and thermotolerance were closely correlated in wild type yeast (Saccharomyces cerevisiae) and in cyr1-2 and bcy1-1 mutants both during exponential growth at 27°C and during heat shock at 40°C. Trehalose levels were high when heat shock proteins (hsps) were expected to be induced and low when hsps were presumably absent. It was tried to uncouple trehalose biosynthes and hsp-induction. Various non-heat stresses affected trehalose levels of wild type cells in a similar way as they would have affected hsps. However, no trehalose was accumulated when cells were treated with canavanine, a well-known inducer of hsps but not of the thermotolerant state.