Alterations in cellular lipids may be responsible for the transient nature of the yeast heat shock response

• Published in: Microbiology (Society for General Microbiology) 1997-09, Vol.143 (9), p.3063-3068
• Main Authors: Chatterjee, Mahua T, Khalawan, Seunath A, Curran, Brendan P. G
• Format: Article
• Language: English
• Subjects: Action of physical and chemical agents; Aerobiosis; Anaerobiosis; Biological and medical sciences; Fatty Acids, Unsaturated - metabolism; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Fungal; Genes, Fungal; Hot Temperature; Kinetics; Linoleic Acid - metabolism; Lipid Metabolism; Microbiology; Mycology; Saccharomyces cerevisiae; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - growth & development; Saccharomyces cerevisiae - metabolism
• ISSN: 1350-0872; 1465-2080
• DOI: 10.1099/00221287-143-9-3063

School of Biological Sciences, Queen Mary and Westfield College, Mile End Road, London E1 4NS, UK Author for correspondence: Brendan P. G. Curran. Tel: + 44 171 775 3013. Fax: [phone]. e-mail: [e-mail] ABSTRACT Summary: The stress-sensing systems leading to the cellular heat shock response (HSR) and the mechanism responsible for the desensitizing of this response in stress-acclimated cells are largely unknown. Here it is demonstrated that there is a close correlation between a 3 ° increase in the temperature required for maximal activation of a heat-shock (HS)-inducible gene in Saccharomyces cerevisiae and an increase in the percentage of cellular unsaturated fatty acids when cells are subjected to extended periods of growth at 37 °. The latter occurs with the same kinetics as HS gene down-regulation during a prolonged HS and is reversed by reacclimation to growth at 25 °. The transient nature of the HS may therefore be due to a lipid-mediated decrease in cellular heat sensitivity. Further evidence that unsaturated fatty acids desensitize cells to heat, with a resultant down-regulation of the HSR, is provided by demonstrating a 9 ° increase in the temperature required for maximal induction of this HS-inducible gene in cells containing high levels of unsaturated fatty acids assimilated during anaerobic growth at 25 °.