Cloning and functional expression of a novel glucuronyltransferase involved in the biosynthesis of the carbohydrate epitope HNK-1

AUTOR(ES)

Terayama, Koji

FONTE

The National Academy of Sciences of the USA

RESUMO

The HNK-1 carbohydrate epitope is characteristically expressed on a series of cell adhesion molecules and also on some glycolipids in the nervous system over a wide range of species from insect to mammal. The HNK-1 epitope is involved in cell–cell and/or cell–substrate interaction and recognition during the development of the nervous system. In this study, we isolated a novel glucuronyltransferase from rat brain, which is a key enzyme of the biosynthesis of the HNK-1 epitope on glycoproteins. Based on the partial amino acid sequences, we isolated cDNA encoding the glucuronyltransferase. The primary structure deduced from the cDNA sequence predicted a type II transmembrane protein with 347 amino acids and had no detectable similarity with any other proteins of known functions, including glucuronyltransferases of the liver and olfactory epithelium. Expression of a soluble recombinant form of the enzyme in COS-1 cells produced an active glucuronyltransferase. The selective expression of the glucuronyltransferase gene in the nervous system was consistent with the almost exclusive localization of the HNK-1 epitope in the nervous system. Transfection of the glucuronyltransferase cDNA into COS-1 cells induced not only expression of the HNK-1 epitope on the cell surface but also marked morphological changes of the cells, suggesting that the HNK-1 epitope associates with the cell–substratum interaction.

Documentos Relacionados

• Learning/Memory Impairment and Reduced Expression of the HNK-1 Carbohydrate in β4-Galactosyltransferase-II-deficient Mice*S⃞
• HNK-1 Glyco-epitope Regulates the Stability of the Glutamate Receptor Subunit GluR2 on the Neuronal Cell Surface*
• A proteoglycan with HNK-1 antigenic determinants is a neuron-associated ligand for cytotactin.
• Cloning and Functional Expression of a Cytochrome P450 cDNA Encoding 2-Hydroxyisoflavanone Synthase Involved in Biosynthesis of the Isoflavonoid Skeleton in Licorice1
• The HNK-1 reactive sulfoglucuronyl glycolipids are ligands for L-selectin and P-selectin but not E-selectin.