title: The role of C-4-substituted mannose analogues in protein glycosylation. Effect of the guanosine diphosphate esters of 4-deoxy-4-fluoro-D-mannose and 4-deoxy-D-mannose on lipid-linked oligosaccharide assembly.
abstract: The effects of the guanosine diphosphate esters of 4-deoxy-4-fluoro-D-mannose (GDP-4FMan) and 4-deoxy-D-mannose (GDP-4dMan) on reactions of the dolichol pathway in chick-embryo cell microsomal membranes were investigated by studies with chick-embryo cell microsomal membranes in vitro and in baby-hamster kidney (BHK) cells in vivo. Each nucleotide sugar analogue inhibited lipid-linked oligosaccharide biosynthesis in a concentration-dependent manner. GDP-4FMan blocked in vitro the addition of mannose to Dol-PP-(GlcNAc)2Man from GDP-Man (where Dol represents dolichol), but did not interfere with the formation of Dol-P-Man, Dol-P-Glc and Dol-PP-(GlcNAc)2. Although GDP-4FMan and Dol-P-4FMan were identified as metabolites of 4FMan in BHK cells labelled with [1-14C]4FMan, GDP-4FMan was a very poor substrate for GDP-Man:Dol-P mannosyltransferase and Dol-P-4FMan could only be synthesized in vitro if the chick-embryo cell membranes were primed with Dol-P. It therefore appears that the inhibition of lipid-linked oligosaccharide formation in BHK cells treated with 4FMan [Grier & Rasmussen (1984) J. Biol. Chem. 259, 1027-1030] is due primarily to a blockage in the formation of Dol-PP-(GlcNAc)2Man2 by GDP-4FMan. In contrast, GDP-4dMan was a substrate for those mannosyltransferases that catalyse the transfer of the first five mannose residues to Dol-PP-(GlcNAc)2. In addition, GDP-4dMan was a substrate for GDP-Man:Dol-P mannosyltransferase, which catalysed the formation of Dol-P-4dMan. As a consequence of this, the formation of Dol-P-Man, Dol-P-Glc and Dol-PP-(GlcNAc)2 may be inhibited through competition for Dol-P. In BHK cells treated with 10 mM-4dMan, Dol-PP-(GlcNAc)2Man9 was the major lipid-linked oligosaccharide detected. Nearly normal extents of protein glycosylation were observed, but very little processing to complex oligosaccharides occurred, and the high-mannose structures were smaller than in untreated cells.
mesh_terms: D000818:Animals; D002642:Chick Embryo; D002850:Chromatography, Gel; D002855:Chromatography, Thin Layer; D006224:Cricetinae; D004287:Dolichol Monophosphate Mannose / Q000096:biosynthesis; D006031:Glycosylation; D006150:Guanine Nucleotides / Q000494:pharmacology*; D006153:Guanosine Diphosphate / Q000031:analogs & derivatives / Q000494:pharmacology*; D006155:Guanosine Diphosphate Mannose / Q000031:analogs & derivatives / Q000494:pharmacology*; D007425:Intracellular Membranes / Q000187:drug effects / Q000378:metabolism; D007668:Kidney / Q000187:drug effects / Q000378:metabolism; D008070:Lipopolysaccharides / Q000096:biosynthesis*; D008861:Microsomes / Q000187:drug effects / Q000378:metabolism; D009702:Nucleoside Diphosphate Sugars / Q000494:pharmacology*; D011103:Polyisoprenyl Phosphate Monosaccharides / Q000096:biosynthesis; D011506:Proteins / Q000378:metabolism*; D012210:Rhamnose / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: D006150:Guanine Nucleotides; D008070:Lipopolysaccharides; D009702:Nucleoside Diphosphate Sugars; D011103:Polyisoprenyl Phosphate Monosaccharides; D011506:Proteins; C023023:lipid-linked oligosaccharides; D006153:Guanosine Diphosphate; D006155:Guanosine Diphosphate Mannose; D004287:Dolichol Monophosphate Mannose; C002968:dolichol-D-glucosylmonophosphate; C018439:N-acetylglucosaminylpyrophosphoryldolichol; C048079:guanosine diphosphate 2-deoxy-2-fluoromannose ester; C054776:guanosine diphosphate-4-deoxymannose; D012210:Rhamnose