Switch to
| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
29
|
| pubmed:dateCreated |
1993-11-18
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| pubmed:abstractText |
Poly-N-acetyllactosamine (PL) sequences (repeating (3Gal beta 1-4GlcNAc beta 1)n) in complex-type N-linked oligosaccharides often occur in branched tri- and tetraantennary chains containing alpha-linked mannosyl residues disubstituted by N-acetyllactosaminyl units at C-2 and C-6 (2,6-branched mannose). We report here our studies on the factors affecting PL biosynthesis and the branching of N-linked oligosaccharides in glycoproteins from Chinese hamster ovary (CHO) cells. For our studies, we utilized a mutant CHO cell line designated Lec8 CHO, which lacks the ability to galactosylate its glycoproteins and consequently synthesizes glycoproteins containing terminal GlcNAc residues and lacking poly-N-acetyl-lactosamine and sialic acid. Glycoproteins in extracts of [3H]glucosamine- or [3H]mannose-labeled Lec8 CHO cells were galactosylated by exogenous beta 1-4-galactosyltransferase and analyzed by chromatography on leukoagglutinating phytohemagglutinin-Sepharose, a lectin reactive with glycoproteins containing 2,6-branched mannosyl residues. Approximately 10% of the radiolabeled glycoproteins were bound, and these were primarily of high molecular mass. Structural analyses of the bound glycoproteins demonstrated that they quantitatively contained 2,6-branched mannose. We then determined whether the "small i" N-acetylglucosaminyl-transferase (iGNT), which initiates PL biosynthesis, could specifically recognize glycoproteins in vitro and whether recognition was dependent on the presence of 2,6-branched mannose. When the galactosylated glycoproteins in extracts of Lec8 CHO cells were incubated with UDP-[3H]GlcNAc, the endogenous iGNT quantitatively added GlcNAc in beta 1-3-linkage to terminal galactosyl residues in the leukoagglutinating phytohemagglutinin-bound glycoproteins. These results demonstrate for the first time that 2,6-branched mannosyl residues are restricted to a subset of CHO glycoproteins and that the iGNT in vitro preferentially recognizes glycoproteins containing the 2,6-branched mannose determinant.
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| pubmed:grant | |
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Amino Sugars,
http://linkedlifedata.com/resource/pubmed/chemical/Antigens, CD,
http://linkedlifedata.com/resource/pubmed/chemical/Lysosome-Associated Membrane...,
http://linkedlifedata.com/resource/pubmed/chemical/Mannose,
http://linkedlifedata.com/resource/pubmed/chemical/Membrane Glycoproteins,
http://linkedlifedata.com/resource/pubmed/chemical/N-Acetylglucosaminyltransferases,
http://linkedlifedata.com/resource/pubmed/chemical/N-acetyllactosamine,
http://linkedlifedata.com/resource/pubmed/chemical/N-acetyllactosaminide...,
http://linkedlifedata.com/resource/pubmed/chemical/Oligosaccharides,
http://linkedlifedata.com/resource/pubmed/chemical/Tritium,
http://linkedlifedata.com/resource/pubmed/chemical/Uridine Diphosphate Galactose,
http://linkedlifedata.com/resource/pubmed/chemical/Uridine Diphosphate...
|
| pubmed:status |
MEDLINE
|
| pubmed:month |
Oct
|
| pubmed:issn |
0021-9258
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| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:day |
15
|
| pubmed:volume |
268
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
22028-35
|
| pubmed:dateRevised |
2007-11-14
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| pubmed:meshHeading |
pubmed-meshheading:8408060-Amino Sugars,
pubmed-meshheading:8408060-Animals,
pubmed-meshheading:8408060-Antigens, CD,
pubmed-meshheading:8408060-CHO Cells,
pubmed-meshheading:8408060-Carbohydrate Sequence,
pubmed-meshheading:8408060-Cricetinae,
pubmed-meshheading:8408060-Humans,
pubmed-meshheading:8408060-Lysosome-Associated Membrane Glycoproteins,
pubmed-meshheading:8408060-Mannose,
pubmed-meshheading:8408060-Membrane Glycoproteins,
pubmed-meshheading:8408060-Molecular Sequence Data,
pubmed-meshheading:8408060-N-Acetylglucosaminyltransferases,
pubmed-meshheading:8408060-Oligosaccharides,
pubmed-meshheading:8408060-Substrate Specificity,
pubmed-meshheading:8408060-Tritium,
pubmed-meshheading:8408060-Uridine Diphosphate Galactose,
pubmed-meshheading:8408060-Uridine Diphosphate N-Acetylglucosamine
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| pubmed:year |
1993
|
| pubmed:articleTitle |
2,6-branched mannose and the regulation of poly-N-acetyllactosamine biosynthesis in N-linked oligosaccharides of Chinese hamster ovary cells.
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| pubmed:affiliation |
Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City 73190.
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| pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
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