A novel auxiliary subunit critical to BK channel function in Caenorhabditis elegans

J Neurosci. 2010 Dec 8;30(49):16651-61. doi: 10.1523/JNEUROSCI.3211-10.2010.


The BK channel is a Ca²+- and voltage-gated potassium channel with many important physiological functions. To identify proteins important to its function in vivo, we screened for Caenorhabditis elegans mutants that suppressed a lethargic phenotype caused by expressing a gain-of-function (gf) isoform of the BK channel α-subunit SLO-1. BKIP-1 (for BK channel interacting protein), a small peptide with no significant homology to any previously characterized molecules, was thus identified. BKIP-1 and SLO-1 showed similar expression and subcellular localization patterns and appeared to interact physically through discrete domains. bkip-1 loss-of-function (lf) mutants phenocopied slo-1(lf) mutants in behavior and synaptic transmission and suppressed the lethargy, egg-laying defect, and deficient neurotransmitter release caused by SLO-1(gf). In heterologous expression systems, BKIP-1 decreased the activation rate and shifted the conductance-voltage relationship of SLO-1 in a Ca²+-dependent manner and increased SLO-1 surface expression. Thus, BKIP-1 is a novel auxiliary subunit critical to SLO-1 function in vivo.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Animals, Genetically Modified
  • Behavior, Animal
  • Biotinylation / methods
  • Caenorhabditis elegans
  • Caenorhabditis elegans Proteins / genetics
  • Caenorhabditis elegans Proteins / physiology*
  • Excitatory Postsynaptic Potentials / genetics
  • Humans
  • Immunoprecipitation / methods
  • Large-Conductance Calcium-Activated Potassium Channels / chemistry*
  • Large-Conductance Calcium-Activated Potassium Channels / genetics
  • Large-Conductance Calcium-Activated Potassium Channels / physiology*
  • Locomotion / genetics
  • Luminescent Proteins / genetics
  • Membrane Potentials / drug effects
  • Membrane Potentials / genetics
  • Models, Molecular
  • Molecular Sequence Data
  • Mutation / genetics
  • Neurons / physiology
  • Oocytes
  • Patch-Clamp Techniques / methods
  • Protein Subunits / genetics
  • Protein Subunits / physiology*
  • Reproductive Behavior / physiology
  • Synaptic Transmission / genetics
  • Xenopus


  • Caenorhabditis elegans Proteins
  • Large-Conductance Calcium-Activated Potassium Channels
  • Luminescent Proteins
  • Protein Subunits
  • slo-1 protein, C elegans