Differential asparagine-linked glycosylation of voltage-gated K+ channels in mammalian brain and in transfected cells

G. Shi, James Trimmer

Research output: Contribution to journalArticle

69 Scopus citations

Abstract

Glycosylation of ion channel proteins dramatically impacts channel function. Here we characterize the asparagine (N)-linked glycosylation of voltage-gated K+ channel α subunits in rat brain and transfected cells. We find that in brain Kv1.1, Kv1.2 and Kv1.4, which have a single consensus glycosylation site in the first extracellular interhelical domain, are N- glycosylated with sialic acid-rich oligosaccharide chains. Kv2.1, which has a consensus site in the second extracellular interhelical domain, is not N- glycosylated. This pattern of glycosylation is consistent between brain and transfected cells, providing compelling support for recent models relating oligosaccharide addition to the location of sites on polytopic membrane proteins. The extent of processing of N-linked chains on Kv1.1 and Kv1.2 but not Kv1.4 channels expressed in transfected cells differs from that seen for native brain channels, reflecting the different efficiencies of transport of K+ channel polypeptides from the endoplasmic reticulum to the Golgi apparatus. These data show that addition of sialic acid-rich N-linked oligosaccharide chains differs among highly related K+ channel α subunits, and given the established role of sialic acid in modulating channel function, provide evidence for differential glycosylation contributing to diversity of K+ channel function in mammalian brain.

Original languageEnglish (US)
Pages (from-to)265-273
Number of pages9
JournalJournal of Membrane Biology
Volume168
Issue number3
DOIs
StatePublished - 1999
Externally publishedYes

Keywords

  • Biosynthesis
  • Central nervous system
  • Immunoblot
  • Ion channel
  • Neuronal excitability
  • Pulse- chase

ASJC Scopus subject areas

  • Biophysics
  • Physiology
  • Cell Biology

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