Section 42
Chapter 41,199

Reduced mannose incorporation into GDP-mannose and dolichol-linked intermediates of N-glycosylation in hamster liver during vitamin a deficiency

Rimoldi, D.; Creek, K.E.; De Luca, L.M.

Molecular and Cellular Biochemistry 93(2): 129-140


ISSN/ISBN: 0300-8177
PMID: 1693171
DOI: 10.1007/bf00226184
Accession: 041198619

Download citation:  

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.

PDF emailed within 0-6 h: $19.90