Using the sequences of a galactose 6-O-sulfotransferase and an N-acetylglucosamine 6-O-sulfotransferase as probes in an EST approach, we have identified a highly related cDNA in human and an apparent orthologue in mouse. The cDNAs predict type II transmembrane proteins that constitute new members of the Gal/GalNAc/GlcNAc 6-O-sulfotransferase (GST) family. Members of this family have previously been implicated in the sulfation of GAG chains within proteoglycans and the sulfation of O-linked chains within sialomucin ligands for l-selectin. Expression of the newly identified cDNA in COS cells led to the addition of sulfate to C-6 of GlcNAc in an acceptor glycoprotein. The tissue expression of transcripts corresponding to the cDNA was highly restricted to the small intestine and colon in humans. Based on these characteristics, the novel sulfotransferase is designated I-GlcNAc6ST for intestinal GlcNAc 6-O-sulfotransferase.
Copyright 1999 Academic Press.