IDENTIFICATION OF SCHIZOSACCHAROMYCES-POMBE PRENOL AS DOLICHOL-16,17

The identity of the prenol involved in N-linked glycosylation in the f ission yeast Schizosaccharomyces pombe was unknown. In order to determ ine the identity of the prenol, S. pombe cells were incubated with a m etabolic precursor of prenol, tritiated mevalonolactone. The cells inc orporated only a modest amount of label, about 1000 dpm per million ce lls, into base-stable lipid and only 1% of that radioactivity was inco rporated into prenol. We found by normal phase silica HPLC and more di rectly by the lack of reactivity with MnO2 that the labeled lipid was predominantly dolichol, not polyprenol, Reverse phase HPLC demonstrate d that in S. pombe dolichol ranged between 14 and 18 isoprene units wi th dolichol-16,17 being the most abundant prenol. This dolichol is of an intermediate length, between the dolichol of S. cerevisiae and that of mammalian cells. (C) 1998 Academic Press.