HNK-1 Glucuronyltransferase

Abstract

The HNK-1 carbohydrate epitope, recognized by the monoclonal antibody HNK-1 (Abo and Balch 1981), is characteristically expressed on a series of cell adhesion molecules, including neural cell adhesion molecule (NCAM), myelin-associated glycoprotein (MAG), L1, PO, telencephalin, and others (McGarry et al. 1983; Kruse et al. 1984; Bollensen and Schachner 1987; Yoshihara et al. 1994), and on some glycolipids (Ilyas et al. 1984) in the nervous system. The HNK-1 epitope is spatially and temporally regulated during development of the nervous system (Schwarting et al. 1987); and characteristic expression of this epitope is observed in migrating neural crest cells (Bronner-Fraser 1986),rhombomeres (Kuratani 1991), and cerebellum (Eisenman and Hawkes 1993). The structure of the HNK-1 epitope is demonstrated to be the sulfated trisaccharide SO4-3GlcAβ1-3Galβ1-4GlcNAc, which is shared with glycolipid and glycoprotein epitope (Chou et al. 1986; Ariga et al. 1987; Voshol et al. 1996). The HNK-1 epitope associates with neural crest cell migration (Bronner-Fraser 1987), neuron to glial cell adhesion (Keilhauer et al. 1985), outgrowth of astrocytic processes and migration of the cell body (Kunemund et al. 1988), as well as the preferential outgrowth of neurites from motor neurons (Martini et al. 1992). These lines of evidence indicate that the HNK-1 epitope plays important roles in cell-cell and cell-substrate interaction during development ot the nervous system.