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 Δ8-Δ7-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. Copyright (C) 2000 Federation of European Biochemical Societies.
Soustre, I., Dupuy, P. H., Silve, S., Karst, F., & Loison, G. (2000). Sterol metabolism and ERG2 gene regulation in the yeast Saccharomyces cerevisiae. FEBS Letters, 470(2), 102–106. https://doi.org/10.1016/S0014-5793(00)01300-4