Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1948661 | Biochimica et Biophysica Acta (BBA) - General Subjects | 2007 | 6 Pages |
Abstract
Neuronal Kv3 voltage-gated K+ channels have two absolutely conserved N-glycosylation sites. Here, it is shown that Kv3.1, 3.3, and 3.4 channels are N-glycosylated in rat brain. Digestion of total brain membranes with peptide N glycosidase F (PNGase F) produced faster migrating immunobands than those of undigested membranes. Additionally, partial PNGase F digests showed that both sites are occupied by oligosaccharides. Neuraminidase treatment produced a smaller immunoband shift relative to PNGase F treatment. These results indicate that both sites are highly available and occupied by N-linked oligosaccharides for Kv3.1, 3.3, and 3.4 in rat brain, and furthermore that at least one oligosaccharide is of complex type. Additionally, these results point to an extracytoplasmic S1-S2 linker in Kv3 proteins expressed in native membranes. We suggest that N-glycosylation processing of Kv3 channels is critical for the expression of K+ currents at the surface of neurons, and perhaps contributes to the pathophysiology of congenital disorders of glycosylation.
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Authors
Tara A. Cartwright, Melissa J. Corey, Ruth A. Schwalbe,