Ardail D, Lermé F, Louisot P. Dolichol kinase activity: a key factor in the control of N-glycosylation in inner mitochondrial membranes.
BIOCHIMICA ET BIOPHYSICA ACTA 1990;
1024:131-8. [PMID:
2159801 DOI:
10.1016/0005-2736(90)90216-b]
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Abstract
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.
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