On the Mechanism By Which a Heat-shock Induces Trehalose Accumulation in Saccharomyces-cerevisiae
(1992) Biochemical Journal — Vol. 288, p. 859-864 (1992)
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- Abstract
- When the temperature of exponential-phase cultures of Saccharomyces cerevisiae was abruptly raised from 28 to 40-degrees-C, trehalose immediately accumulated, whereas the activities of trehalase and trehalose-6-phosphate synthase/trehalose-6-phosphate phosphatase complex increased after a lag period of about 10 min. Heat shock also induced a sudden rise in intracellular glucose, simultaneously with a decrease in the concentration of hexose phosphate and fructose 2,6-bisphosphate. The increase of trehalose-metabolizing enzymes, but not the accumulation of glucose and trehalose, was prevented by cycloheximide. Investigation of the kinetic properties of partially purified enzymes showed that both nonactivated and cyclic AMP-dependent-protein-kinase-activated forms of trehalase are almost inactive in the absence of Ca2+ and that the concentration of free Ca2+ required for half-maximal activity increased with increasing temperature, being approx. 1 mum at 30-degrees-C and 20 mum at 40-degrees-C for the activated form of trehalase. In contrast, trehalose-6-phosphate synthase and trehalose-6-phosphate phosphatase were three times more active at 40-degrees-C. It is proposed that the rapid accumulation of trehalose induced by heat shock may be in part explained by changes in the kinetic properties of trehalase and trehalose-6-phosphate synthase/trehalose-6-phosphate phosphatase.
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Neves, MJ., & François, J. (1992). On the Mechanism By Which a Heat-shock Induces Trehalose Accumulation in Saccharomyces-cerevisiae. Biochemical Journal, 288, 859-864. https://hdl.handle.net/2078.5/99717 (Original work published 1992)