Carbohydrate (chondroitin 6) sulfotransferase 3; carbohydrate (N-acetylglucosamine 6-o) sulfotransferase 7 (CHST3,7)

Abstract

Chondroitin sulfate chains are composed of GlcAβ1-3GalNAcβ1-4 repeating unit with sulfate groups on GalNAc residues or on both GalNAc and GlcA residues. Sulfate groups attached to the backbone sugar chain produce various chondroitin sulfate isomers. Chondroitin 6-sulfate, which contains sulfate at position 6 of the GalNAc residue, is one of the major components of aggrecan and is thought to be involved in the formation and maintenance of cartilage. Chondroitin 6-sulfate is also contained in other various proteoglycans, such as phosphacan/PTPz, and is proposed to be involved in neuronal cell interactions with growth factors pleiotrophin and midkine (Maeda et al. 1996, 1999). Chondroitin 6-sulfotransferase (C6ST) catalyzes the transfer of sulfate to position 6 of GalNAc residues of chondroitin. Two C6STs, C6ST-1 (CHST-3) and C6ST-2 (CHST-7), were cloned. C6ST-1 also sulfates 6-position of the Gal residue of keratan sulfate and sialyl N-acetyllactosamine oligosaccharides.