title: Sulfation of N-acetylglucosamine by chondroitin 6-sulfotransferase 2 (GST-5).
abstract: Based on sequence homology with a previously cloned human GlcNAc 6-O-sulfotransferase, we have identified an open reading frame (ORF) encoding a novel member of the Gal/GalNAc/GlcNAc 6-O-sulfotransferase (GST) family termed GST-5 on the human X chromosome (band Xp11). GST-5 has recently been characterized as a novel GalNAc 6-O-sulfotransferase termed chondroitin 6-sulfotransferase-2 (Kitagawa, H., Fujita, M., Itio, N., and Sugahara K. (2000) J. Biol. Chem. 275, 21075-21080). We have coexpressed a human GST-5 cDNA with a GlyCAM-1/IgG fusion protein in COS-7 cells and observed four-fold enhanced [(35)S]sulfate incorporation into this mucin acceptor. All mucin-associated [(35)S]sulfate was incorporated as GlcNAc-6-sulfate or Galbeta1-->4GlcNAc-6-sulfate. GST-5 was also expressed in soluble epitope-tagged form and found to catalyze 6-O-sulfation of GlcNAc residues in synthetic acceptor structures. In particular, GST-5 was found to catalyze 6-O-sulfation of beta-benzyl GlcNAc but not alpha- or beta-benzyl GalNAc. In the mouse genome we have found a homologous ORF that predicts a novel murine GlcNAc 6-O-sulfotransferase with 88% identity to the human enzyme. This gene was mapped to mouse chromosome X at band XA3.1-3.2. GST-5 is the newest member of an emerging family of carbohydrate 6-O-sulfotransferases that includes chondroitin 6-sulfotransferase (GST-0), keratan-sulfate galactose 6-O-sulfotransferase (GST-1), the ubiquitously expressed GlcNAc 6-O-sulfotransferase (GST-2), high endothelial cell GlcNAc 6-O-sulfotransferase (GST-3), and intestinal GlcNAc 6-O-sulfotransferase (GST-4).
authors.affiliation: Department of Respiratory Diseases, Roche Bioscience, Palo Alto, California 94304, USA.
authors.forename: S
authors.initials: S
authors.lastname: Bhakta
authors.forename: A
authors.initials: A
authors.lastname: Bartes
authors.forename: K G
authors.initials: KG
authors.lastname: Bowman
authors.forename: W M
authors.initials: WM
authors.lastname: Kao
authors.forename: I
authors.initials: I
authors.lastname: Polsky
authors.forename: J K
authors.initials: JK
authors.lastname: Lee
authors.forename: B N
authors.initials: BN
authors.lastname: Cook
authors.forename: R E
authors.initials: RE
authors.lastname: Bruehl
authors.forename: S D
authors.initials: SD
authors.lastname: Rosen
authors.forename: C R
authors.initials: CR
authors.lastname: Bertozzi
authors.forename: S
authors.initials: S
authors.lastname: Hemmerich
mesh_terms: D000117:Acetylglucosamine / Q000737:chemistry*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002384:Catalysis; D002874:Chromosome Mapping; D017931:DNA Primers; D018076:DNA, Complementary; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D013431:Sulfates / Q000737:chemistry*; D015238:Sulfotransferases / Q000235:genetics / Q000378:metabolism*; D014960:X Chromosome; D000097811:Carbohydrate Sulfotransferases
chemical_list: D000117:Acetylglucosamine; D017931:DNA Primers; D018076:DNA, Complementary; D007527:Isoenzymes; D013431:Sulfates; D015238:Sulfotransferases; D000097811:Carbohydrate Sulfotransferases