Sulfation ofN-Acetylglucosamine by Chondroitin 6-Sulfotransferase 2 (GST-5)

Sunil Bhakta, Alexander Bartes, Kendra G. Bowman, Wei-Ming Kao, Irene Polsky, Jin Kyu Lee, Brian N. Cook, Richard E. Bruehl, Steven D. Rosen, Carolyn R. Bertozzi, Stefan Hemmerich
2000 Journal of Biological Chemistry  
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
more » ... a human GST-5 cDNA with a GlyCAM-1/IgG fusion protein in COS-7 cells and observed fourfold enhanced [ 35 S]sulfate incorporation into this mucin acceptor. All mucin-associated [ 35 S]sulfate was incorporated as GlcNAc-6-sulfate or Gal␤134GlcNAc-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 ␤-benzyl GlcNAc but not ␣or ␤-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-Osulfotransferase (GST-2), high endothelial cell GlcNAc 6-O-sulfotransferase (GST-3), and intestinal GlcNAc 6-Osulfotransferase (GST-4).
doi:10.1074/jbc.m006414200 pmid:10956661 fatcat:um3uuqpt35au5b3ugykq5hntnu