title: Thiamine increases the resistance of baker's yeast Saccharomyces cerevisiae against oxidative, osmotic and thermal stress, through mechanisms partly independent of thiamine diphosphate-bound enzymes.
abstract: Numerous recent studies have established a hypothesis that thiamine (vitamin B1 ) is involved in the responses of different organisms against stress, also suggesting that underlying mechanisms are not limited to the universal role of thiamine diphosphate (TDP) in the central cellular metabolism. The current work aimed at characterising the effect of exogenously added thiamine on the response of baker's yeast Saccharomyces cerevisiae to the oxidative (1 mM H2 O2 ), osmotic (1 M sorbitol) and thermal (42 °C) stress. As compared to the yeast culture in thiamine-free medium, in the presence of 1.4 μM external thiamine, (1) the relative mRNA levels of major TDP-dependent enzymes under stress conditions vs. unstressed control (the 'stress/control ratio') were moderately lower, (2) the stress/control ratio was strongly decreased for the transcript levels of several stress markers localised to the cytoplasm, peroxisomes, the cell wall and (with the strongest effect observed) the mitochondria (e.g. Mn-superoxide dismutase), (3) the production of reactive oxygen and nitrogen species under stress conditions was markedly decreased, with the significant alleviation of concomitant protein oxidation. The results obtained suggest the involvement of thiamine in the maintenance of redox balance in yeast cells under oxidative stress conditions, partly independent of the functions of TDP-dependent enzymes.
authors.affiliation: Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland.
authors.forename: Natalia
authors.initials: N
authors.lastname: Wolak
authors.forename: Ewa
authors.initials: E
authors.lastname: Kowalska
authors.forename: Andrzej
authors.initials: A
authors.lastname: Kozik
authors.forename: Maria
authors.initials: M
authors.lastname: Rapala-Kozik
mesh_terms: D003470:Culture Media / Q000737:chemistry; D006358:Hot Temperature; D006861:Hydrogen Peroxide / Q000633:toxicity; D009997:Osmotic Pressure; D018384:Oxidative Stress; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000502:physiology / Q000528:radiation effects*; D013012:Sorbitol / Q000378:metabolism; D013312:Stress, Physiological; D013835:Thiamine Pyrophosphate / Q000378:metabolism*
chemical_list: D003470:Culture Media; D013012:Sorbitol; D006861:Hydrogen Peroxide; D013835:Thiamine Pyrophosphate
keywords: antioxidants; reactive nitrogen species; reactive oxygen species; thiamine diphosphate-dependent enzymes; vitamin B1