Yeast Saccharomyces cerevisiae is auxotrophic for ergosterol in the absence of oxygen. We showed that complex changes in esterification of exogenously supplied sterols were also induced by anaerobiosis. Utilization of oleic acid for sterol esterification was significantly impaired in anaerobic cells. Furthermore, anaerobic cells fed different sterols exhibited striking variation in esterification efficiency (high levels of sterol esters for cholesterol and sitosterol, low levels for ergosterol, lanosterol or stigmasterol). Relative activities of two yeast acylCoA:sterol acyltransferases (Are1p and Are2p) changed in response to anaerobiosis: while Are2p was dominant under aerobic conditions, Are1p provided the major activity in the absence of oxygen. Our results indicate that sterol esters may fulfil different roles in aerobic and anaerobic cells.
Mild non-ionic detergents are used for solubilization of hydrophobic substrates in yeast growth media at concentrations 0.1-1%. Our data show that low concentrations of Nonidet P-40 may significantly affect lipid biogenesis in the yeast Saccharomyces cerevisiae. The uptake and esterification of external [4-14C]-cholesterol is strongly reduced in hem1 mutants treated with low concentrations of Nonidet P-40. Significant inhibitory effect of NP-40 on sterol uptake and esterification was evident both in non-growing and growing cells supplemented with external cholesterol. Increased levels of sterol precursors (squalene, lanosterol) in hem1 cells grown in complex medium with cholesterol indicated general interference of NP-40 with sterol biosynthesis. NP-40 in the growth medium affected also cell viability estimated as the colony forming ability. More attention should be therefore paid to possible effects of mild detergents at low concentrations generally considered to be harmless, especially in cells with disturbed lipid biogenesis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.