Specificity of unsaturated fatty acid-regulated expression of the Saccharomyces cerevisiae OLE1 gene.

The effects of unsaturated fatty acid deprivation on lipid synthesis in Saccharomyces cerevisiae strain GL7 were determined by following the incorporation of [14C]acetate. Compared to yeast cells grown with oleic acid, unsaturated fatty acid-deprived cells contained 200 times as much 14C label in squalene, with correspondingly less label in 2,3-oxidosqualene and 2,3;22,23-dioxidosqualene. Cells deprived of either methionine or cholesterol did not accumulate squalene, demonstrating that the effect of unsaturated fatty acid starvation on squalene oxidation was not due to an inhibition of cell growth. Cells deprived of olefinic supplements displayed additional changes in lipid metabolism: (i) an increase in 14C-labeled diacylglycerides, (ii) a decrease in 14C-labeled triacylglycerides, and (iii) increased levels of 14C-labeled decanoic and dodecanoic fatty acids. The changes in squalene oxidation and acylglyceride metabolism in unsaturated fatty acid-deprived cells were readily reversed by adding oleic acid. Pulse-chase studies demonstrated that the [14C]squalene and 14C-labeled diacylglycerides which accumulated during starvation were further metabolized when cells were resupplemented with oleic acid. These results demonstrate that unsaturated fatty acids are essential for normal lipid metabolism in yeasts.

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Saccharomyces cerevisiae CWH43Is Involved in the Remodeling of the Lipid Moiety of GPI Anchors to Ceramides

Molecular Biology of the Cell ◽

10.1091/mbc.e07-05-0482 ◽

2007 ◽

Vol 18 (11) ◽

pp. 4304-4316 ◽

Cited By ~ 53

Author(s):

Mariko Umemura ◽

Morihisa Fujita ◽

Takehiko Yoko-o ◽

Akiyoshi Fukamizu ◽

Yoshifumi Jigami

Keyword(s):

Saccharomyces Cerevisiae ◽

Fatty Acid ◽

Unsaturated Fatty Acid ◽

Terminal Region ◽

Wild Type ◽

Yeast Saccharomyces Cerevisiae ◽

Lipid Moiety

The glycosylphosphatidylinositol (GPI)-anchored proteins are subjected to lipid remodeling during their biosynthesis. In the yeast Saccharomyces cerevisiae, the mature GPI-anchored proteins contain mainly ceramide or diacylglycerol with a saturated long-fatty acid, whereas conventional phosphatidylinositol (PI) used for GPI biosynthesis contains an unsaturated fatty acid. Here, we report that S. cerevisiae Cwh43p, whose N-terminal region contains a sequence homologous to mammalian PGAP2, is involved in the remodeling of the lipid moiety of GPI anchors to ceramides. In cwh43 disruptant cells, the PI moiety of the GPI-anchored protein contains a saturated long fatty acid and lyso-PI but not inositolphosphorylceramides, which are the main lipid moieties of GPI-anchored proteins from wild-type cells. Moreover, the C-terminal region of Cwh43p (Cwh43-C), which is not present in PGAP2, is essential for the ability to remodel GPI lipids to ceramides. The N-terminal region of Cwh43p (Cwh43-N) is associated with Cwh43-C, and it enhanced the lipid remodeling to ceramides by Cwh43-C. Our results also indicate that mouse FRAG1 and C130090K23, which are homologous to Cwh43-N and -C, respectively, share these activities.

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Comparative Studies on the Mitochondria of Saccharomyces cerevisiae and the Hydrocarbon-Utilizing Yeast Candida lipolytica: Unsaturated Fatty Acid and Cytochrome Composition

Biochemical Society Transactions ◽

10.1042/bst0011107 ◽

1973 ◽

Vol 1 (5) ◽

pp. 1107-1109

Author(s):

MICHAEL D. SKIPTON ◽

KENNETH WATSON ◽

RAYMOND L. HOUGHTON ◽

DAVID E. GRIFFITHS

Keyword(s):

Saccharomyces Cerevisiae ◽

Fatty Acid ◽

Unsaturated Fatty Acid ◽

Comparative Studies ◽

Candida Lipolytica

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Ethanol Tolerance in the Yeast Saccharomyces cerevisiae Is Dependent on Cellular Oleic Acid Content

Applied and Environmental Microbiology ◽

10.1128/aem.69.3.1499-1503.2003 ◽

2003 ◽

Vol 69 (3) ◽

pp. 1499-1503 ◽

Cited By ~ 205

Author(s):

Kyung Man You ◽

Claire-Lise Rosenfield ◽

Douglas C. Knipple

Keyword(s):

Saccharomyces Cerevisiae ◽

Oleic Acid ◽

Fatty Acid ◽

Unsaturated Fatty Acid ◽

Palmitoleic Acid ◽

Ethanol Tolerance ◽

Vaccenic Acid ◽

Yeast Cells ◽

Oleic Acid Content ◽

Yeast Saccharomyces Cerevisiae

ABSTRACT In this investigation, we examined the effects of different unsaturated fatty acid compositions of Saccharomyces cerevisiae on the growth-inhibiting effects of ethanol. The unsaturated fatty acid (UFA) composition of S. cerevisiae is relatively simple, consisting almost exclusively of the mono-UFAs palmitoleic acid (Δ9Z-C16:1) and oleic acid (Δ9Z-C18:1), with the former predominating. Both UFAs are formed in S. cerevisiae by the oxygen- and NADH-dependent desaturation of palmitic acid (C16:0) and stearic acid (C18:0), respectively, catalyzed by a single integral membrane desaturase encoded by the OLE1 gene. We systematically altered the UFA composition of yeast cells in a uniform genetic background (i) by genetic complementation of a desaturase-deficient ole1 knockout strain with cDNA expression constructs encoding insect desaturases with distinct regioselectivities (i.e., Δ9 and Δ11) and substrate chain-length preferences (i.e., C16:0 and C18:0); and, (ii) by supplementation of the same strain with synthetic mono-UFAs. Both experimental approaches demonstrated that oleic acid is the most efficacious UFA in overcoming the toxic effects of ethanol in growing yeast cells. Furthermore, the only other UFA tested that conferred a nominal degree of ethanol tolerance is cis-vaccenic acid (Δ11Z-C18:1), whereas neither Δ11Z-C16:1 nor palmitoleic acid (Δ9Z-C16:1) conferred any ethanol tolerance. We also showed that the most ethanol-tolerant transformant, which expresses the insect desaturase TniNPVE, produces twice as much oleic acid as palmitoleic acid in the absence of ethanol and undergoes a fourfold increase in the ratio of oleic acid to palmitoleic acid in response to exposure to 5% ethanol. These findings are consistent with the hypothesis that ethanol tolerance in yeast results from incorporation of oleic acid into lipid membranes, effecting a compensatory decrease in membrane fluidity that counteracts the fluidizing effects of ethanol.

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