title: The flavoprotein Tah18-dependent NO synthesis confers high-temperature stress tolerance on yeast cells.
abstract: Nitric oxide (NO) is a ubiquitous signaling molecule involved in the regulation of a large number of cellular functions. In the unicellular eukaryote yeast, NO may be involved in stress response pathways, but its role is poorly understood due to the lack of mammalian NO synthase (NOS) orthologues. Previously, we have proposed the oxidative stress-induced l-arginine synthesis and its physiological role under stress conditions in yeast Saccharomyces cerevisiae. Here, our experimental results indicated that increased conversion of l-proline into l-arginine led to NO production in response to elevated temperature. We also showed that the flavoprotein Tah18, which was previously reported to transfer electrons to the Fe-S cluster protein Dre2, was involved in NO synthesis in yeast. Gene knockdown analysis demonstrated that Tah18-dependent NO synthesis confers high-temperature stress tolerance on yeast cells. As it appears that such a unique cell protection mechanism is specific to yeasts and fungi, it represents a promising target for antifungal activity.
authors.affiliation: Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Nishimura
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Kawahara
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Takagi
mesh_terms: D001120:Arginine / Q000378:metabolism; D005420:Flavoproteins / Q000235:genetics / Q000502:physiology*; D055785:Gene Knockdown Techniques; D006358:Hot Temperature; D007506:Iron-Sulfur Proteins / Q000378:metabolism; D009569:Nitric Oxide / Q000096:biosynthesis*; D018384:Oxidative Stress / Q000235:genetics / Q000502:physiology*; D010088:Oxidoreductases / Q000235:genetics / Q000502:physiology*; D011392:Proline / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
chemical_list: C531900:Dre2 protein, S cerevisiae; D005420:Flavoproteins; D007506:Iron-Sulfur Proteins; D029701:Saccharomyces cerevisiae Proteins; D009569:Nitric Oxide; D001120:Arginine; D011392:Proline; D010088:Oxidoreductases; C552878:Tah18 protein, S cerevisiae