Formation of dolichol monophosphate 2-deoxy-D-glucose and its interference with the glycosylation of mannoproteins in yeast.
A crude membrane fraction from Saccharomyces cerevisiae has been found to catalyze 2-deoxy-D-glucose transfer from GDP-2-deoxy-D-glucose to endogeneous lipid and glycoprotein acceptor. Evidence will be represented that the glycolipid formed has properties characteristic dolichol monophosphate 2-deoxy-D-glucose. The 2-deoxy-D-glucosyl group can further be transferred from the glycolipid into a membrane-bound polymer fraction. More than 95% of the radioactivity incorporated can be released by beta-elimination, indicating an O-glycosidic linkage to serine or threonine. The only radioactive product obtained is 2-deoxy-D-glucose. When dolichol monophosphate 2-deoxy-[14C]glucose is incubated together with non-radioactive GDP-mannose subsequent beta-elimination yields no higher oligosaccharides in contrast to an experiment where dolichol monophosphate [14C]mannose and GDP-mannose are used as donors. The results are consistent with the assumption that the non-physiological nucleotide sugar interferes with GDP-mannose for mannosylation and terminates further elongation of the serine/threonine-bound oligomannose side chains. UDP-2-deoxy-D-glucose, used as donor, results also in the formation of a glycolipid. In this case, however, no polyprenol derivative is formed. Instead, the glycolipid displays properties characteristic of sphingolipid or a sterol glucoside.
D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002518:Ceramides / Q000378:metabolism; D003837:Deoxy Sugars / Q000378:metabolism*; D003847:Deoxyglucose / Q000378:metabolism*; D004224:Diterpenes / Q000378:metabolism*; D004286:Dolichols / Q000378:metabolism*; D006023:Glycoproteins / Q000096:biosynthesis*; D006155:Guanosine Diphosphate Mannose / Q000378:metabolism; D007700:Kinetics; D010743:Phospholipids / Q000378:metabolism / Q000494:pharmacology; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000378:metabolism*
D002518:Ceramides; D003837:Deoxy Sugars; D004224:Diterpenes; D004286:Dolichols; D006023:Glycoproteins; D010743:Phospholipids; D006155:Guanosine Diphosphate Mannose; D003847:Deoxyglucose