title: Proline accumulation by mutation or disruption of the proline oxidase gene improves resistance to freezing and desiccation stresses in Saccharomyces cerevisiae.
abstract: We examined the role of intracellular proline under freezing and desiccation stress conditions in Saccharomyces cerevisiae. When cultured in liquid minimal medium, the proline-nonutilizing mutant containing the put1 mutation (proline oxidase-deficient) produced more intracellular proline, and increased the cell survival rate as compared to the wild-type strain after freezing and desiccation. We also constructed two PUT1 gene disruptants. PUT1-disrupted mutants in minimal medium supplemented with external proline at 0.1% accumulated higher proline levels than those of the control strains (17-22-fold). These disruptants also had a 2-5-fold increase in cell viability compared to the control strains after freezing and desiccation stresses. These results indicate that proline has a stress-protective function in yeast.
authors.affiliation: Department of Bioscience, Fukui Prefectural University, 4-1-1 Kenjojima, Matsuoka-cho, Yoshida-gun, Fukui, Japan. hiro@fpu.ac.jp
authors.forename: H
authors.initials: H
authors.lastname: Takagi
authors.forename: K
authors.initials: K
authors.lastname: Sakai
authors.forename: K
authors.initials: K
authors.lastname: Morida
authors.forename: S
authors.initials: S
authors.lastname: Nakamori
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics; D005615:Freezing; D005838:Genotype; D018698:Glutamic Acid / Q000494:pharmacology; D016254:Mutagenesis, Insertional; D009154:Mutation; D010641:Phenotype; D011392:Proline / Q000378:metabolism* / Q000494:pharmacology; D011394:Proline Oxidase / Q000235:genetics* / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D014867:Water / Q000494:pharmacology
chemical_list: D014867:Water; D018698:Glutamic Acid; D011392:Proline; D011394:Proline Oxidase