Linked Life Data

17369258

Source:http://linkedlifedata.com/resource/pubmed/id/17369258

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
19
pubmed:dateCreated
2007-5-8
pubmed:abstractText
Proteoglycan modification is essential for development and early cell division in Caenorhabditis elegans. The specification of proteoglycan attachment sites is defined by the Golgi enzyme polypeptide xylosyltransferase. Here we evaluate the substrate specificity of this xylosyltransferase for its downstream targets by using reporter proteins containing proteoglycan modification sites from C. elegans syndecan/SDN-1. The N terminus of the SDN-1 contains a Ser-Gly proteoglycan site at Ser(71), flanked by potential mucin and N-glycosylation sites. However, Ser(71) was exclusively used as a proteoglycan site in vivo, based on mapping studies with a Ser(71) reporter protein, glycosyltransferase RNA interference, and co-expression of worm polypeptide xylosyltransferase. To elucidate the substrate requirements of this enzyme, a library of 42 point mutants of the Ser(71) reporter was expressed in tissue culture. The nematode proteoglycan modification site in SDN-1 required serine (not threonine), two flanking glycine residues (positions -1 and +1), and either one proximal acidic N-terminal amino acid (positions -4, -3, and -2) or a pair of distal N-terminal acidic amino acids (positions -6 and -5). C-terminal acidic amino acids, although present in many proteoglycan modification sites, had minimal impact on xylosylation at Ser(71). Proline inhibited glycosylation when present at -1, +1, or +2. The position of glycine, proline, and acidic amino acids allows the glycosylation machinery to discriminate between mucin and proteoglycan modification sites. The key residues that define proteoglycan modification sites also function with the Drosophila polypeptide xylosyltransferase, indicating that the specificity in the glycosylation process is evolutionarily conserved. Using a neural network method, a preliminary proteoglycan predictor has been developed.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
11
pubmed:volume
282
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
14586-97
pubmed:dateRevised
2007-12-3
pubmed:meshHeading
pubmed-meshheading:17369258-Amino Acid Sequence, pubmed-meshheading:17369258-Animals, pubmed-meshheading:17369258-Caenorhabditis elegans, pubmed-meshheading:17369258-Caenorhabditis elegans Proteins, pubmed-meshheading:17369258-Cells, Cultured, pubmed-meshheading:17369258-Drosophila melanogaster, pubmed-meshheading:17369258-Glycine, pubmed-meshheading:17369258-Glycosylation, pubmed-meshheading:17369258-Golgi Apparatus, pubmed-meshheading:17369258-Molecular Sequence Data, pubmed-meshheading:17369258-Mucins, pubmed-meshheading:17369258-Mutagenesis, Site-Directed, pubmed-meshheading:17369258-Pentosyltransferases, pubmed-meshheading:17369258-Proline, pubmed-meshheading:17369258-Proteoglycans, pubmed-meshheading:17369258-Recombinant Proteins, pubmed-meshheading:17369258-Sequence Homology, Amino Acid, pubmed-meshheading:17369258-Serine, pubmed-meshheading:17369258-Substrate Specificity, pubmed-meshheading:17369258-Syndecans
pubmed:year
2007
pubmed:articleTitle
Systematic Analysis of proteoglycan modification sites in Caenorhabditis elegans by scanning mutagenesis.
pubmed:affiliation
Department of Biochemistry and Biophysics, Center for Oral Biology, Aab Institute of Biomedical Sciences, University of Rochester Medical Center, Rochester, NY 14642, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural