title: Sterol metabolism and ERG2 gene regulation in the yeast Saccharomyces cerevisiae.
abstract: Certain exogenously-supplied sterols, like ergost-8-enol, are efficiently converted into ergosterol in yeast. We have taken advantage of this property to study the regulation of the Delta8-Delta7-sterol isomerase-encoding ERG2 gene in an ergosterol auxotrophic mutant devoid of squalene-synthase activity. Ergosterol starvation leads to an 8-16-fold increase in ERG2 gene expression. Such an increase was also observed in wild-type cells either grown anaerobically or treated with SR31747A a sterol isomerase inhibitor. Exogenously-supplied zymosterol is entirely transformed into ergosterol, which represses ERG2 transcription. By contrast, exogenously-supplied ergosterol has little or no effect on ERG2 transcription.
authors.affiliation: Université Louis Pasteur, INRA, 28, rue de Herrlisheim, P.O. Box 507, 68021, Colmar, France.
authors.forename: I
authors.initials: I
authors.lastname: Soustre
authors.forename: P H
authors.initials: PH
authors.lastname: Dupuy
authors.forename: S
authors.initials: S
authors.lastname: Silve
authors.forename: F
authors.initials: F
authors.lastname: Karst
authors.forename: G
authors.initials: G
authors.lastname: Loison
mesh_terms: D000693:Anaerobiosis; D001692:Biological Transport; D002784:Cholesterol / Q000378:metabolism / Q000494:pharmacology; D003510:Cyclohexanes / Q000494:pharmacology; D004875:Ergosterol / Q000031:analogs & derivatives / Q000096:biosynthesis / Q000378:metabolism / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects; D005800:Genes, Fungal / Q000235:genetics / Q000502:physiology; D017930:Genes, Reporter / Q000235:genetics; D007810:Lanosterol / Q000378:metabolism / Q000494:pharmacology; D009025:Morpholines / Q000494:pharmacology; D009154:Mutation / Q000235:genetics; D010100:Oxygen / Q000378:metabolism; D012331:RNA, Fungal / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D013251:Steroid Isomerases / Q000037:antagonists & inhibitors / Q000235:genetics*; D013261:Sterols / Q000378:metabolism* / Q000494:pharmacology; D014158:Transcription, Genetic / Q000187:drug effects / Q000235:genetics
chemical_list: D003510:Cyclohexanes; D009025:Morpholines; D012331:RNA, Fungal; D012333:RNA, Messenger; D013261:Sterols; D007810:Lanosterol; C050435:fenpropimorph; D002784:Cholesterol; C088447:SR 31747; D013251:Steroid Isomerases; C022669:delta(8)-delta(7)-sterol isomerase; C015582:zymosterol; D010100:Oxygen; D004875:Ergosterol