Evidence for mannolipids as intermediates in mannose transfer to thyroid rough microsomal glycoproteins.
Thyroid rough microsomes catalyzed the transfer of mannose from GDP-mannose to endogeneous glycoprotein(s) and to glycolipids comprising a recently described dolichol phosphomannose extractable with usual organic solvents and a material tentatively identified as an oligosaccharide lipid. The labeling of the two lipids was consistent with a role in mannose transfer to glycoprotein(s). When partially purified dolichol phospho[14C] mannose was incubated with rough microsomes, a part of the label appeared in the second lipid, suggesting a role as intermediate, and less rapidly in glycoprotein(s). Sodium dodecyl sulfate/polyacrylamide gel electrophoresis did not allow to ascertain whether or not the glycoproteins receiving label from these sugar lipids comprised thyroglobulin precursors.
D000818:Animals; D006017:Glycolipids / Q000378:metabolism*; D006023:Glycoproteins / Q000096:biosynthesis; D006155:Guanosine Diphosphate Mannose / Q000378:metabolism; D007700:Kinetics; D008358:Mannose / Q000378:metabolism*; D008861:Microsomes / Q000378:metabolism*; D010743:Phospholipids / Q000378:metabolism*; D012756:Sheep; D013552:Swine; D013961:Thyroid Gland / Q000378:metabolism*
D006017:Glycolipids; D006023:Glycoproteins; D010743:Phospholipids; D006155:Guanosine Diphosphate Mannose; D008358:Mannose