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Is thermotolerance of yeast dependent on trehalose accumulation?
Author(s) -
Nwaka Solomon,
Kopp Meinrad,
Burgert Markus,
Deuchler Inge,
Kienle Iris,
Holzer Helmut
Publication year - 1994
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(94)00385-8
Subject(s) - trehalose , trehalase , yeast , mutant , biochemistry , saccharomyces cerevisiae , biology , microbiology and biotechnology , chemistry , gene
During heat stress, trehalose concentration increases in yeast cells in parallel to thermotolerance. This parallelism suggested that trehalose mediated thermotolerance. We show in this work that, under certain conditions, trehalose accumulation and increase in thermotolerance do not go in parallel. A mutant deficient in the trehalose‐degrading neutral trehalase shows, after shift from 40°C to 30°C, low thermotolerance in spite of a high trehalose concentration. When glucose is added to stationary yeast cells with high trehalose concentration and high thermotolerance, trehalose concentration decreases while thermotolerance remains high. A mutant deficient in ubiquitin‐conjugating genes, ubc4ubc5 , shows during exponential growth a low trehalose concentration, but a high thermotolerance, in contrast to wild‐type cells. Because the ubc4ubc5 mutant synthesizes heat‐shock proteins constitutively, it is proposed that, under these conditions, accumulation of heat‐shock proteins, and not trehalase, mediates thermotolerance.