Phosphorylation of the oligosaccharide of uteroferrin by UDP-GlcNAc:glycoprotein N-acetylglucosamine-1-phosphotransferases from rat liver, Acanthamoeba castellani, and Dictyostelium discoideum requires alpha 1,2-linked mannose residues.
We have investigated the oligosaccharide requirements of the UDP-GlcNAc:glycoprotein N-acetylglucosamine-1-phosphotransferases from rat liver, Acanthamoeba castellani, and Dictyostelium discoideum. Uteroferrin, an acid hydrolase, was phosphorylated by the three N-acetylglucosaminylphosphotransferases, and the phosphorylated oligosaccharides were isolated and analyzed by ion suppression high performance liquid chromatography. In all three cases, the phosphorylated species contained 6 or more mannose residues. Phosphorylation of the Man5GlcNAc2 oligosaccharide could not be detected even though this was the major species on the native uteroferrin. The Man5GlcNAc2 oligosaccharides lack alpha 1,2-linked mannose residues, whereas the larger oligosaccharides contain 1 or more mannose residues in this linkage. Treatment of intact uteroferrin with an alpha 1,2-specific mannosidase-generated molecules whose oligosaccharides consisted almost entirely of species with 5 mannose residues. The N-acetylglucosaminylphosphotransferases could no longer phosphorylate such molecules. These data indicate that at least 1 alpha 1,2-linked mannose residue must be present on uteroferrin's oligosaccharide for phosphorylation to occur.
D000135:Acid Phosphatase; D000656:Amoeba / Q000201:enzymology*; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004023:Dictyostelium / Q000201:enzymology*; D005964:Glucosyltransferases / Q000378:metabolism*; D066298:In Vitro Techniques; D007527:Isoenzymes; D008099:Liver / Q000201:enzymology*; D008358:Mannose / Q000378:metabolism*; D008361:Mannosidases / Q000378:metabolism; D008667:Metalloproteins / Q000378:metabolism*; D017351:N-Acetylglucosaminyltransferases; D009844:Oligosaccharides / Q000378:metabolism; D010766:Phosphorylation; D051381:Rats; D000071681:Tartrate-Resistant Acid Phosphatase; D013954:Thyroglobulin / Q000032:analysis; D043323:alpha-Mannosidase
D007527:Isoenzymes; D008667:Metalloproteins; D009844:Oligosaccharides; D013954:Thyroglobulin; D005964:Glucosyltransferases; D017351:N-Acetylglucosaminyltransferases; C023224:alpha-1,3-mannosyl-glycoprotein 2-beta-N-acetylglucosaminyltransferase; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase; D008361:Mannosidases; D043323:alpha-Mannosidase; D008358:Mannose