Abstract
The molecular mechanism of reduced incorporation of radioactively labeled mannose into hamster liver glycoconjugates during the progression of vitamin A deficiency was investigated. In particular the in vivo incorporation of [2-3H]mannose into GDP-mannose, dolichyl phosphate mannose (Dol-P-Man), lipid-linked oligosaccharides, and glycopeptides of hamster liver was examined. Hamsters maintained on a vitamin A-free diet showed a reduction in the incorporation of mannose into GDP-mannose about 10 days before clinical signs of vitamin A deficiency could be observed. The decrease in [2-3H]mannose incorporated into GDP-mannose was accompanied by a reduction in label incorporated into Dol-P-Man, lipid linked oligosaccharides and glycopeptides, which became more severe with the progression of vitamin A deficiency. By the time they reached a plateau stage of growth, hamsters fed the vitamin A-free diet showed a 50% reduction in the amount of [2-3H]mannose converted to GDP-mannose, and the radioactivity associated with Dol-P-Man and glycopeptides was reduced by approximately 60% as compared to retinoic acid-supplemented controls. These results strongly indicate that the reduced incorporation of mannose into lipidic intermediates and glycoproteins observed during vitamin A deficiency is due to impaired GDP-mannose synthesis.
Original language | English (US) |
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Pages (from-to) | 129-140 |
Number of pages | 12 |
Journal | Molecular and Cellular Biochemistry |
Volume | 93 |
Issue number | 2 |
DOIs | |
State | Published - Mar 1 1990 |
Externally published | Yes |
Keywords
- GDP-mannose
- glycosylation
- lipid intermediates
- liver
- vitamin A
ASJC Scopus subject areas
- Molecular Biology
- Clinical Biochemistry
- Cell Biology