Incorporation of one N-glycosylation-deficient subunit within a tetramer of HCN2 channel is tolerated

Ryuji Kaku, Yoshikazu Matsuoka, Jay Yang

Research output: Contribution to journalArticle

Abstract

Hyperpolarization-Activated cyclic nucleotide-gated (HCN) channels are glycoproteins N-glycosylated at a specific asparagine residue in the S5-S6 linker region. Previous reports suggested that N-glycosylation-deficient HCN2 N380Q (NQ) channels fail to properly target to the plasma membrane and are unable to form functional ion channels. HCN channels are known to homo-And hetero-oligomerize and it is not known whether HCN2-NQ subunits can oligomerize with wild type (wt) N-glycosylated subunits to form a tetrameric assembly. In the present study, homomeric NQ-mutant resulted in no current, cRNA titration experiments controlling the amount of wt-To-NQ injected into Xenopus oocytes indicated that the observed currents were consistent with a model where presence of a single nonglycosylated subunit in a tetrameric oligomer is tolerated forming functional channels. The activation voltage-dependence described by half-Activation voltage and slope factor, and the reversal potential of the wt-NQ oligomeric channels were identical to the wt only tetrameric channels. Further incorporation of the nonglycosylated subunit rendered the channels nonconductive or not incorporated into the plasma membrane.

Original languageEnglish
Pages (from-to)998-1003
Number of pages6
JournalNeuroReport
Volume30
Issue number15
DOIs
Publication statusPublished - Jan 1 2019

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Keywords

  • binomial model
  • cRNA titration
  • electrophysiology
  • HCN2
  • hetero-oligomerization
  • N-glycosylation
  • Xenopus oocyte

ASJC Scopus subject areas

  • Neuroscience(all)

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