title: Stereochemically distinct roles for sterol in Saccharomyces cerevisiae.
abstract: Cholesterol, (E)- but not (Z)-17(20)-dehydrocholesterol, 5 alpha-cholestan-3 beta-ol, sitosterol, and certain other sterols lacking a 24 beta-methyl group will replace (spare) most but not all of the 24 beta-methylsterol which has recently been found to be absolutely necessary for growth of oxygen-deprived wild type Saccharomyces cerevisiae in the presence of 2,3-iminosqualene. The results imply the existence of two stereochemically distinct roles for sterol in this organism. One of them (perhaps regulatory) requires, whereas the other (probably playing the so-called "bulk" membranous role) does not require the presence of the 24 beta-methyl group. The latter function, for which most of the sterol is needed, can be performed by various 24-alkyl- and 24-desalkylsterols.
mesh_terms: D002784:Cholesterol / Q000502:physiology; D004875:Ergosterol / Q000502:physiology; D019751:Intramolecular Transferases; D007535:Isomerases / Q000037:antagonists & inhibitors; D008745:Methylation; D010840:Phytosterols / Q000502:physiology*; D012441:Saccharomyces cerevisiae / Q000254:growth & development*; D013185:Squalene / Q000031:analogs & derivatives / Q000494:pharmacology; D013237:Stereoisomerism; D013329:Structure-Activity Relationship
chemical_list: D010840:Phytosterols; C037691:2,3-iminosqualene; D013185:Squalene; D002784:Cholesterol; D007535:Isomerases; D019751:Intramolecular Transferases; C021924:lanosterol synthase; D004875:Ergosterol