title: Production of polyunsaturated fatty acids in yeast Saccharomyces cerevisiae and its relation to alkaline pH tolerance.
abstract: Saccharomyces cerevisiae produces saturated and monounsaturated fatty acids of 16- and 18-carbon atoms and no polyunsaturated fatty acids (PUFAs) with more than two double bonds. To study the biological significance of PUFAs in yeast, we introduced Kluyveromyces lactis Delta12 fatty acid desaturase (KlFAD2) and omega3 fatty acid desaturase (KlFAD3) genes into S. cerevisiae to produce linoleic and alpha-linolenic acids in S. cerevisiae. The strain producing linoleic and alpha-linolenic acids showed an alkaline pH-tolerant phenotype. DNA microarray analyses showed that the transcription of a set of genes whose expressions are under the repression of Rim101p were downregulated in this strain, suggesting that Rim101p, a transcriptional repressor which governs the ion tolerance, was activated. In line with this activation, the strain also showed elevated resistance to Li(+) and Na(+) ions and to zymolyase, a yeast lytic enzyme preparation containing mainly beta-1,3-glucanase, indicating that the cell wall integrity was also strengthened in this strain. Our findings demonstrate a novel influence of PUFA production on transcriptional control that is likely to play an important role in the early stage of alkaline stress response. The Accession No. for microarray data in the Center for Information Biology Gene Expression database is CBX68.
authors.affiliation: National Institute of Advanced Industrial Science and Technology, AIST Tsukuba Central 6, Tsukuba, Ibaraki, Japan.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Yazawa
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Iwahashi
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Kamisaka
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Kimura
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Uemura
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism; D027682:Cation Transport Proteins / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D044943:Fatty Acid Desaturases / Q000235:genetics / Q000378:metabolism; D005231:Fatty Acids, Unsaturated / Q000096:biosynthesis*; D020869:Gene Expression Profiling; D015966:Gene Expression Regulation, Fungal; D018869:Heat-Shock Response; D006863:Hydrogen-Ion Concentration; D007716:Kluyveromyces / Q000201:enzymology / Q000235:genetics; D019787:Linoleic Acid / Q000096:biosynthesis; D020411:Oligonucleotide Array Sequence Analysis; D012097:Repressor Proteins; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development / Q000378:metabolism* / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase; D017962:alpha-Linolenic Acid / Q000096:biosynthesis
chemical_list: D027682:Cation Transport Proteins; D004268:DNA-Binding Proteins; C086375:ENA1 protein, S cerevisiae; D005231:Fatty Acids, Unsaturated; C489601:RIM101 protein, S cerevisiae; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D017962:alpha-Linolenic Acid; D019787:Linoleic Acid; D044943:Fatty Acid Desaturases; C040448:delta-12 fatty acid desaturase; D000251:Adenosine Triphosphatases; D000254:Sodium-Potassium-Exchanging ATPase