Dolichol kinase activity: a key factor in the control of N-glycosylation in inner mitochondrial membranes.
Inner mitochondrial membranes from liver contain a dolichol kinase which required CTP as a phosphoryl donor. Kinase activity was linear with protein concentration and unlike other reported kinases, activated almost equally well by Mg2+, Mn2+ or Ca2+. Thin-layer chromatography showed that the reaction product co-migrated with authentic dolichyl monophosphate. The phosphorylation of dolichol did not occur in presence of ATP, GTP or UTP but required exogenous dolichol for maximal activity. Newly synthesized [3H]dolichyl monophosphate has been shown to be glycosylated in the presence of GDP[14C]mannose or UDP[14C]glucose. The double labeled lipids formed by the sugar nucleotide-dependent reactions were identified respectively as [14C]mannosylphosphoryl[3H]dolichol and [14C]glucosylphosphoryl [3H]dolichol. These results are discussed in terms of regulation of N-glycosylation processes in inner mitochondrial membranes from liver.
Ardail
D
D
Department of Biochemistry, University of Lyon, INSERM-CNRS U. 189, Lyon-Sud Medical School, Oullins, France.
Lermé
F
F
Louisot
P
P
D000818:Animals; D002413:Cations, Divalent; D002458:Cell Fractionation; D003902:Detergents / Q000494:pharmacology; D004286:Dolichols / Q000378:metabolism*; D006031:Glycosylation; D066298:In Vitro Techniques; D007425:Intracellular Membranes / Q000378:metabolism*; D051379:Mice; D008930:Mitochondria, Liver / Q000378:metabolism* / Q000648:ultrastructure; D009711:Nucleotides / Q000378:metabolism; D010743:Phospholipids / Q000494:pharmacology; D010770:Phosphotransferases / Q000378:metabolism*; D017853:Phosphotransferases (Alcohol Group Acceptor)
D002413:Cations, Divalent; D003902:Detergents; D004286:Dolichols; D009711:Nucleotides; D010743:Phospholipids; D010770:Phosphotransferases; D017853:Phosphotransferases (Alcohol Group Acceptor); C020087:dolichol kinase