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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
38
pubmed:dateCreated
2002-9-16
pubmed:databankReference
pubmed:abstractText
A common terminal structure in glycans from animal glycoproteins and glycolipids is the lactosamine sequence Gal(beta)4GlcNAc-R (LacNAc or LN). An alternative sequence that occurs in vertebrate as well as in invertebrate glycoconjugates is GalNAc(beta)4GlcNAc-R (LacdiNAc or LDN). Whereas genes encoding beta4GalTs responsible for LN synthesis have been reported, the beta4GalNAcT(s) responsible for LDN synthesis has not been identified. Here we report the identification of a gene from Caenorhabditis elegans encoding a UDP-GalNAc:GlcNAc(beta)-R beta1,4-N-acetylgalactosaminyltransferase (Ce(beta)4GalNAcT) that synthesizes the LDN structure. Ce(beta)4GalNAcT is a member of the beta4GalT family, and its cDNA is predicted to encode a 383-amino acid type 2 membrane glycoprotein. A soluble, epitope-tagged recombinant form of Ce(beta)4GalNAcT expressed in CHO-Lec8 cells was active using UDP-GalNAc, but not UDP-Gal, as a donor toward a variety of acceptor substrates containing terminal beta-linked GlcNAc in both N- and O-glycan type structures. The LDN structure of the product was verified by co-chromatography with authentic standards and (1)H NMR spectroscopy. Moreover, Chinese hamster ovary CHO-Lec8 and CHO-Lec2 cells expressing Ce(beta)4GalNAcT acquired LDN determinants on endogenous glycoprotein N-glycans, demonstrating that the enzyme is active in mammalian cells as an authentic beta4GalNAcT. The identification and availability of this novel enzyme should enhance our understanding of the structure and function of LDN-containing glycoconjugates.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
20
pubmed:volume
277
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
34924-32
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:12167666-Amino Acid Sequence, pubmed-meshheading:12167666-Animals, pubmed-meshheading:12167666-Base Sequence, pubmed-meshheading:12167666-Caenorhabditis elegans, pubmed-meshheading:12167666-Carbohydrate Sequence, pubmed-meshheading:12167666-Chromatography, High Pressure Liquid, pubmed-meshheading:12167666-Chromatography, Ion Exchange, pubmed-meshheading:12167666-Cloning, Molecular, pubmed-meshheading:12167666-DNA, Complementary, pubmed-meshheading:12167666-Humans, pubmed-meshheading:12167666-Hydrogen-Ion Concentration, pubmed-meshheading:12167666-Molecular Sequence Data, pubmed-meshheading:12167666-N-Acetylgalactosaminyltransferases, pubmed-meshheading:12167666-Nuclear Magnetic Resonance, Biomolecular, pubmed-meshheading:12167666-Open Reading Frames, pubmed-meshheading:12167666-Sequence Homology, Amino Acid
pubmed:year
2002
pubmed:articleTitle
Molecular cloning and enzymatic characterization of a UDP-GalNAc:GlcNAc(beta)-R beta1,4-N-acetylgalactosaminyltransferase from Caenorhabditis elegans.
pubmed:affiliation
Department of Biochemistry and Molecular Biology, Oklahoma Center for Medical Glycobiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.