Saccharomyces cerevisiae sterols

HUSSELSTEIN, T GACHOTTE, D., DESPREZ, T., BARD, M., BENVENISTE, P., Transformation of Saccharomyces cerevisiae with a cDNA encoding a sterol C-methyltransferase from Arabidopsis thaliana results in the synthesis of 24-ethyl sterols., FEBS Lett., 1996,381, 87-92. 

As discussed y)xevio xs, y,Saccharomyces cerevisiae does not need oxygen to obtain energy when fermenting grape juice. However, there are some essential biosynthetic pathways that use oxygen as substrate. This is the case for the biosynthesis of sterols and unsaturated fatty acids (Ratledge and Evans 1989). 

Moreover, during alcoholic fermentation very important changes take place in the yeast s environment. Basically, the ethanol concentration increases progressively and yeasts need to adapt their plasmatic membranes to this aggressive new environment (Weber and Bont 1996). Apparently, the presence of ethanol in the medium alters drastically the fluidity of the membrane (Jones and Greenfield 1987). Under these conditions, Saccharomyces cerevisiae must increase its proportion of sterols and unsaturated fatty acids to compensate for this effect and consequently... 

Nes, D.W., Janssen, G.G., Crumley, F.G., Kalinowska, M., AMhisa, T. (1993) The structural requirements of sterols for membrane function in Saccharomyces cerevisiae. Arch. Biochem. Bioph., 300, 724-733. 

Mauricio, J.C., Guijo, S., Ortega, J.M. (1991). Relationship between phospholipid and sterol contents in Saccharomyces cerevisiae and Torulaspora delbrueckii and their fermentation activity in grape musts. Am. J. Enol. Vitic., 42, 301-308. 

An enzyme system from the yeast Saccharomyces cerevisiae is able to incorporate isoprenoid precursors into the C30 phytoene analogue (200) only in the presence of Mn and absence of NADPH. If NAD PH is present and Mn is replaced by Mg, the sterol precursor squalene (201) is produced.The substrate specificity of the chloroplast enzyme violaxanthin deepoxidase has been examined.In addition to the normal substrate violaxanthin [(35,5/ ,65,3 5,5 i ,6 5)- 5,6,5, 6 -diepoxy-5,6,5, 6 -tetrahydro-/3,j8-carotene-3,3-diol, (196)] several all-trans-monoepoxy-carotenoids, such as anthera-xanthin [5,6-epoxy-5,6-dihydro-/3,/3-carotene-3,3 -diol (197)], diadinoxanthin [5,6-epoxy-7, 8 -didehydro-5,6-dihydro-j8, 8-carotene-3,3 -diol (198)], and /3-cryptoxanthin epoxide [5,6-epoxy-5,6-dihydro-/3,/3-caroten-3-ol (199)], all with the 38,5R,6S) configuration, were utilized. Violeoxanthin (9-cis-violaxanthin) and other 9-cis-isomers were not affected. A carrot Daucus carota) tissue culture has been shown to incorporate [ C]acetate into carotenoids. ... 

Wamecke, D., Erdmann, R., Fahl, A., Hube, B., Muller, R, Zank, T., Zahringer, U. and Heinz, E. (1999) Cloning and functional expression of UGT genes encoding sterol glucosyltransferases from Saccharomyces cerevisiae, Candida albicans, Pichia pastoris, and Dictyostelium discoideum. J. Biol. Chem., 274,13048-59. 

Vik, A. and Rrne, ). (2001) Upc2p and Fcrri22p, dual regulators of sterol biosynthesis in Saccharomyces cerevisiae. Molecular and Cellular Biology, 21. 6395-6405. 

Shianna, K.V., Dotson. W.D.. Tove, S., and Parks, L.W. (2001) Identification of a UPC2 homolog in Saccharomyces cerevisiae and its involvement in aerobic sterol uptake. Journal of Bacteriology, 183, 830-834. 

Henneberry, A.L., Sturley, S.L. 2005. Sterol homeostasis in the budding yeast, Saccharomyces cerevisiae. Semin. Cell Dev. Biol. 16 155-161. 

Kelly, S.L., D.C. Lamb, B.C. Baldwin, A.J. Corran, and D.E. Kelly (1997). Characterization of Saccharomyces cerevisiae CYP61, sterol A22-desaturated, and inhibition by azole antifungal agents. J. Biol. Chem. 272, 9986-9988. 

K.S. Schweitzer, K.T. Chun, C. Koegel et al. (1996). Cloning and characterization of the Saccharomyces cerevisiae C-22 sterol desaturase gene, encoding a second cytochrome P-450 involved in ergosterol biosynthesis. Gene 169, 105-109. 

Bard, M., N.D. Lees, T. Turi, D. Craft, L. Cofrin, R. Barbuch et al. (1993). Sterol synthesis and viability of ERG 11 (cytochrome P450 lanosterol demethylase) mutations in Saccharomyces cerevisiae and Candida albicans. Lipids 28, 963-967. 

Structure-Function Relati[Pg.252]

In most fungi, lichens and algae, ergosterol (mycosterol) occurs. This was isolated from ergot fungus (most prominent member Claviceps purpurea) in 1889 by the Parisian apothecary Gharles Tanret (1847-1917). It is the main sterol in baker s yeast Saccharomyces cerevisiae), and acts as provitamin D (Fig. 6.5). [7]... 

Kelly SL, Lamb DC, Corran AJ, Baldwin BC, Parks LW, Kelly DE (1995) Purification and reconstitution of activity of Saccharomyces cerevisiae P450 61, a sterol delta 22-desaturase. FEBS Lett 377 217-220... 

Kyler and co-workers have examined the effects of ultrasound on a suspension of baker s yeast Saccharomyces cerevisiae) as an inexpensive, convenient and direct source of sterol cyclase [174] (Scheme 78). This enabled them to produce sterols from squalene oxide and related substrates on a multigram scale. Previous experiments had relied on the use of microsomal cyclase. However, this process can only be used to convert extremely small quantities of substrate to the desired sterol (i.e. < 1-3 mg) and is obviously unsuitable for preparative purposes. In contrast, ultrasonically stimulated yeast cells could be used to convert 2,3-oxidosqualene to lanosterol in 42%... 

Pinto W J, Lozano R, Sekula B C, Nes W R 1983 Stereochemically distinct roles for sterol in Saccharomyces cerevisiae. Biochem Biophys Res Commun 112 47-54... 

Pinto W J, Nes W R 1983 Stereochemical specificity for sterols in Saccharomyces cerevisiae. J Biol Chem 258 4472-4476... 

---