Cloning and chromosomal mapping of human glucuronyltransferase involved inbiosynthesis of the HNK-1 carbohydrate epitope

The HNK-1 carbohydrate is expressed on various cell adhesion molecules in t he nervous system and is suggested to play a role in cell-cell and cell-sub strate interactions. Here we describe the isolation of a cDNA encoding huma n glucuronyltransferase (GlcAT-P), which is a key enzyme in the biosynthesi s of the HNK-1 carbohydrate. The primary structure deduced from the cDNA se quence predicted a type II transmembrane protein of 334 amino acids. Human GlcAT-P was 98.2% identical with rat GlcAT-P in amino acid sequence, the ex ception being the length of the cytoplasmic tail. Northern blot analysis in dicated that human GlcAT-P is expressed mainly in the brain. There is a sin gle copy of the human GlcAT-P gene (HGMW-approved symbol BSGAT1), and it wa s mapped to chromosome 11q25. (C) 2000 Academic Press.