The J1 glycoprotein--a novel nervous system cell adhesion molecule of the L2/HNK-1 family.

The neural cell adhesion molecules LI (refs 1,2) and N-CAM (refs 3–5) share a common carbohydrate epitope that is recognized by the monoclonal antibodies L2 and HNK-1 (ref. 6). The L2/HNK-1 epitope is also present on the myelin-associated glycoprotein (MAG) which is thought to mediate surface interactions between the axon and myelinating cell7. Other, as yet unidentified, cell-surface glycoproteins are recognized by the two antibodies and are believed to belong to a family of neural cell adhesion molecules1,2,6. To test this hypothesis, we have prepared polyclonal antibodies to a prominent member of the L2/HNK-1 family, the 160K (relative molecular mass (Mr)160,000) glycoprotein. Here we report that these antibodies, designated J1 antibodies, react with astrocytes and oligodendrocytes and interfere with neurone–astrocyte adhesion, but not with neurone–neurone or astrocyte–astrocyte adhesion. This result suggests the involvement of the J1 antigen in cell–cell interactions.