Pleiotropic mutations in <i>Saccharomyces cerevisiae</i> affecting sterol uptake and metabolism

AbstractSterol uptake control mutants (upc−) have been isolated via ethylmethanesulfonate mutagenesis from wild‐type Saccharomyces cerevisiae. These mutants are heme and sterol competent but possess the ability to accumulate exogenous sterol(s) under aerobic conditions. Previous demonstrate sterol uptake only in a hem−, erg− background; however, the Upc− strains described here are Hem+ and do not require exogenous sterol for growth. We were unable to obtain viable hem+, erg−, upc+ recombinants; such combinations appear to be lethal. Isolates of Upc mutants demonstrated different levels of sterol uptake, and sterol analysis revealed a broad phenotypic range with regard to amounts and accumulation of ergosterol and non‐ergosterol sterols. Assays of acyl CoA: ergosterol acyltransferase and sterol ester hydrolase showed no apparent difference in activity between Upc mutants and the wild type.

Pleiotropic mutations in Saccharomyces cerevisiae affecting sterol uptake and metabolism Journal Articles