The effect of tunicamycin on prostacyclin (PGI2) receptors of neuronal hybrid cells

The number of PG12 receptors in NCB-20 neuronal hybrid cells assayed by specific [3H]iloprost binding is substantially reduced when cells are cultured in the presence of tunicamycin, the specific inhibitor of protein N-glycosylation. The effect is reversible, dose and time dependent, and is on the number of receptors not their affinity. Tunicamycin was shown to have a selective effect on glycoprotein synthesis under these conditions with only slight effects on total protein synthesis. These results are consistent with the PG12 receptor being a glycoprotein or closely associated with such a glycoprotein whose expression is dependent on N-glycosylation.