Referenced in: none

Automatically associated channels: Kv3.1

Title: Complex oligosaccharides are N-linked to Kv3 voltage-gated K+ channels in rat brain.

Authors: Tara A Cartwright, Melissa J Corey, Ruth A Schwalbe

Journal, date & volume: Biochim. Biophys. Acta, 2007 Apr , 1770, 666-71

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/17197096

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.