A novel family of longer chain length dolichols present in oleate-induced yeast Saccharomyces cerevisiae

Abstract

The typical size of the yeast dolichol family ranges from 14 to 19 isoprene units D (14-19) with dolichol 16 being the dominating species. Induction of peroxisome proliferation by growing the cells in medium containing oleate as carbon source induces the synthesis of an additional family of longer dolichols D (19-24) with D 21 being the most prominent. This phenomenon is abolished in the peroxisome biogenesis deficient strain in which the PEX1 gene (encoding Pex1p peroxin) has been disrupted. The total amount of dolichols in pex1Δ cells is lower than in the wild-type cells, as is the amount of phosphatidylcholine. Moreover, the levels of 3-hydroxy-3-methylglutaryl CoA reductase and farnesyl diphosphate synthase, two key enzymes in dolichol biosynthesis, are decreased in the absence of a functional PEX1 gene. The presence of longer dolichols in oleate-induced Saccharomyces cerevisiae cells, the absence of this additional family in peroxisome deficient cells, and a decrease of the total amount of dolichols in these cells indicate the involvement of peroxisomes in the biosynthesis of dolichols in this organism.