Glycoprotein requirement for neurite outgrowth in goldfish retina explants: effects of tunicamycin

The role of glycoproteins in neurite outgrowth in vitro has been examined using the protein glycosylation inhibitor, tunicamycin. The concentration-dependent inhibitory effects of tunicamycin on neuritic outgrowth from goldfish retinal explants closely paralleled its effects on the dolichol pathway of glycoprotein biosynthesis. The neurite membrane assembled in the presence of an intermediate dose of tunicamycin (5 micrograms/ml) was deficient in carbohydrate, as indicated by a reduced capacity to bind the lectins Concanavalin A, wheat germ agglutinin and ricin. These results suggest that tunicamycin may prove useful in assessing the role of cell surface carbohydrate in neuronal recognition phenomena.