35 Scopus citations

Abstract

Many K+ channels are oligomeric complexes with intrinsic structural symmetry arising from the homo-tetrameric core of their pore-forming subunits. Allosteric regulation of tetramerically symmetric proteins, whether by intrinsic sensing domains or associated auxiliary subunits, often mirrors the fourfold structural symmetry. Here, through patch-clamp recordings of channel population ensembles and also single channels, we examine regulation of the Ca2+- and voltage-activated large conductance Ca2+- activated K+ (BK) channel by associated γ1-subunits. Through expression of differing ratios of γ1:α-subunits, the results reveal an all-or-none functional regulation of BK channels by γ-subunits: channels either exhibit a full gating shift or no shift at all. Furthermore, the γ1- induced shift exhibits a state-dependent labile behavior that recapitulates the fully shifted or unshifted behavior. The γ1-induced shift contrasts markedly to the incremental shifts in BK gating produced by 1-4 β-subunits and adds a new layer of complexity to the mechanisms by which BK channel functional diversity is generated.

Original languageEnglish
Pages (from-to)4868-4873
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume111
Issue number13
DOIs
StatePublished - Apr 1 2014

Keywords

  • Allostery
  • Asymmetry
  • Slo1 channels

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