Elongation of outer transmembrane domain alters function of miniature K+ channel Kcv

Brigitte Hertel, Sascha Tayefeh, Mario Mehmel, Stefan M. Kast, James Van Etten, Anna Moroni, Gerhard Thiel

Research output: Contribution to journalArticle

12 Scopus citations

Abstract

The virus-coded channel Kcv has the typical structure of a two-transmembrane domain K+ channel. Exceptional are its cytoplasmic domains: the C terminus basically ends inside the membrane and, hence, precludes the formation of a cytoplasmic gate by the so-called bundle crossing; the cytoplasmic N terminus is composed of only 12 amino acids. According to structural predictions, it is positioned in the membrane/aqueous interface and connected via a proline kink to the outer transmembrane domain (TM1). Here, we show that this proline kink affects channel function by determining the position of TM1 in the membrane bilayer. Extension of the hydrophobic length of TM1 by either eliminating the proline kink or introducing an alanine in TM1 augments a time- and voltage-dependent inward rectification of the channel. This suggests that the positional information of TM1 in the bilayer is transmitted to a channel gate, which is not identical with the cytoplasmic bundle crossing.

Original languageEnglish (US)
Pages (from-to)21-29
Number of pages9
JournalJournal of Membrane Biology
Volume210
Issue number1
DOIs
Publication statusPublished - Mar 1 2006

    Fingerprint

Keywords

  • Hydrophobic mismatch
  • Ion selectivity
  • K channel gating
  • Transmembrane domain
  • Viral channel Kcv

ASJC Scopus subject areas

  • Biophysics
  • Physiology
  • Cell Biology

Cite this