The functions of voltageâgated potassium (Kv) channels in neurons have been well defined, whereas their roles in glial cells are not fully understood. Kv1.1, Kv1.3 and Kv1.6 are endogenously expressed in C6 astrocytoma cells, but their trafficking and subcellular localization have not been well studied. In C6 cells, Kv1.1 was localized to the cell surface, Kv1.3 was predominantly localized in the cisâGolgi, and Kv1.6 was enriched in the endoplasmic reticulum. Disruption of the Golgi stacks with brefeldin A treatment redirected Kv1.3 to the endoplasmic reticulum, further confirming that Kv1.3 was localized in the Golgi. Denaturing and reducing immunoblot analysis identified an expected Kv1.3 monomer and an unexpected Kv1.3 dimer/aggregate. These two forms had different protein halfâlives: that of the monomer form T1/2 was 5.1 h, whereas the dimer/aggregate form was stable over the 8âh measurement period. The Kv1.3 dimer/aggregate form on immunoblots appeared to be correlated with its Golgi retention, based on examination with several cell types that expressed Kv1.3. Glycosidase treatment showed that Kv1.3 contained complexâtype Nâglycans terminated with sialic acids, suggesting that Kv1.3 had traveled to the transâGolgi network for sialylation before it was recycled to the cisâGolgi for retention. Inhibition of Nâglycosylation did not affect Kv1.3 localization, indicating that Nâglycans did not play a role in its Golgi retention. Thus, Kv1.3 appears to be distributed to the cisâGolgi membrane of rat astrocytes in a similar way as a Golgi resident protein, and this unusual distribution appears to be correlated with its SDS/2âmercaptoethanolâresistant dimer/aggregate forms on immunoblots.