EFFECT OF TEMPERATURE ON THE ROLE OF HSP104 AND TREHALOSE IN BAROTOLERANCE OF SACCHAROMYCES-CEREVISIAE

We have studied the effect of temperature on the contribution of Hsp10 4 and trehalose to barotolerance using mutants deficient in Hsp104 and trehalose synthesis. When compared with a corresponding mild type str ain, mutants of Hsp104 did not show temperature dependent barotoleranc e when the incubation temperature during the hydrostatic pressure trea tment was increased. However, a mutant deficient in trehalose synthesi s showed features similar to a wild type strain. Furthermore, the Hsp1 04 level was low in the insoluble fraction of the wild type strain aft er pressure treatment at 35 degrees C but not at 4 degrees C, and the protein profiles in the insoluble fraction were different between 35 d egrees C and 4 degrees C. In contrast to the Hsp104 deficient mutants, the protein profile of the wild type after pressure treatment at 35 d egrees C favors the role of Hsp104 as a disaggregator of proteins duri ng hydrostatic pressure stress. These results suggest that the role of Hsp104 in barotolerance is temperature dependent in contrast to treha lose. (C) 1997 Federation of European Biochemical Societies.