Linked Life Data

10929009

Source:http://linkedlifedata.com/resource/pubmed/id/10929009

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
2000-9-7
pubmed:abstractText
Congenital Disorders of Glycosylation (CDG) are human deficiencies in glycoprotein biosynthesis. Previous studies showed that 1 mM mannose corrects defective protein N-glycosylation in cultured fibroblasts from some CDG patients. We hypothesized that these CDG cells have limited GDP-mannose (GDP-Man) and that exogenous mannose increases the GDP-Man levels. Using a well established method to measure GDP-Man, we found that normal fibroblasts had an average of 23.5 pmol GDP-Man/10(6) cells, whereas phosphomannomutase (PMM)-deficient fibroblasts had only 2.3-2.7 pmol/10(6) cells. Adding 1 mM mannose to the culture medium increased the GDP-Man level in PMM-deficient cells to approximately 15.5 pmol/10(6) cells, but had no significant effect on GDP-Man levels in normal fibroblasts. Similarly, mannose supplementation increased GDP-Man from 4.6 pmol/10(6) cells to 24.6 pmol/10(6) cells in phosphomannose isomerase (PMI)-deficient fibroblasts. Based on the specific activity of the GDP-[(3)H]Man pool present in [2-(3)H]mannose labeled cells, mannose supplementation also partially corrected the impaired synthesis of mannosylphosphoryldolichol (Man-P-Dol) and Glc(0)(-)(3)Man(9)GlcNAc(2)-P-P-Dol. These results confirm directly that deficiencies in PMM and PMI result in lowered cellular GDP-Man levels that are corrected by the addition of mannose. In contrast to these results, GDP-Man levels in fibroblasts from a CDG-Ie patient, who is deficient in Man-P-Dol synthase, were normal and unaffected by mannose supplementation even though mannose addition was found to correct abnormal lipid intermediate synthesis in another study (Kim et al. [2000] J. Clin. Invest., 105, 191-198). The mechanism by which mannose supplementation corrects abnormal protein N-glycosylation in Man-P-Dol synthase deficient cells is unknown, but this observation suggests that the regulation of Man-P-Dol synthesis and utilization may be more complex than is currently understood.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0959-6658
pubmed:author
pubmed:issnType
Print
pubmed:volume
10
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
829-35
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Mannose supplementation corrects GDP-mannose deficiency in cultured fibroblasts from some patients with Congenital Disorders of Glycosylation (CDG).
pubmed:affiliation
Department of Biochemistry, A.B.Chandler Medical Center, University of Kentucky College of Medicine, Lexington, KY, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.