Molecular cloning and expression of glucuronyltransferase I involved in the biosynthesis of the glycosaminoglycan-protein linkage region of proteoglycans

J Biol Chem. 1998 Mar 20;273(12):6615-8. doi: 10.1074/jbc.273.12.6615.


We isolated a cDNA encoding a novel glucuronyltransferase from human placenta cDNA with the use of the degenerate reverse transcriptase-polymerase chain reaction method. Degenerate primers were designed based upon the amino acid sequence alignment of rat glucuronyltransferase (GlcAT-P) involved in the biosynthesis of the carbohydrate epitope HNK-1 with putative proteins in Caenorhabditis elegans and Schistosoma mansoni. The new cDNA sequence revealed an open reading frame coding for a protein of 335 amino acids with a type II transmembrane protein topology. The amino acid sequence displayed 43% identity to the rat GlcAT-P, and the highest sequence identity was found in the COOH-terminal catalytic domain. The expression of a soluble recombinant form of the protein in COS-1 cells produced an active glucuronyltransferase with marked specificity for a glycoserine Galbeta1-3Galbeta1-4Xylbeta1-O-Ser. In contrast, asialoorosomucoid, which contains the Galbeta1-4GlcNAc sequence and is a good acceptor substrate for the GlcAT-P, did not serve as an acceptor. The reaction product was sensitive to beta-glucuronidase digestion and co-chromatographed with authentic GlcAbeta1-3Galbeta1-3Galbeta1-4Xylbeta1-O-Ser in high-performance liquid chromatography, suggesting that the enzyme is a beta1, 3-glucuronyltransferase. These results indicate that this new member of the glucuronyltransferase gene family is the enzyme previously described as glucuronyltransferase I that forms the glycosaminoglycan-protein linkage region, GlcAbeta1-3Galbeta1-3Galbeta1-4Xylbeta1-O-Ser, of proteoglycans.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Binding Sites
  • Carbohydrate Sequence
  • Chromatography, High Pressure Liquid
  • Cloning, Molecular
  • DNA, Complementary
  • Glucuronosyltransferase*
  • Glycosaminoglycans / metabolism*
  • Hexosyltransferases / genetics*
  • Humans
  • Molecular Sequence Data
  • Polymerase Chain Reaction
  • Proteoglycans / biosynthesis*
  • Proteoglycans / chemistry
  • Rats
  • Sequence Homology, Amino Acid


  • DNA, Complementary
  • Glycosaminoglycans
  • Proteoglycans
  • Hexosyltransferases
  • galactosylgalactoylxylosylprotein 3-beta-glucuronosyltransferase
  • Glucuronosyltransferase

Associated data

  • GENBANK/AB009598