Mutants of a temperature-sensitive two-P domain potassium channel

J Neurosci. 2000 Oct 15;20(20):7517-24. doi: 10.1523/JNEUROSCI.20-20-07517.2000.


Within the Caenorhabditis elegans genome there exist at least 42 genes encoding TWK (two-P domain K(+)) channels, potassium channel subunits that contain two pore regions and four transmembrane domains. We now report the first functional characterization of a TWK channel from C. elegans. Although potassium channels have been reported to be activated by a variety of factors, TWK-18 currents increase dramatically with increases in temperature. Two mutant alleles of the twk-18 gene confer uncoordinated movement and paralysis in C. elegans. Expression of wild-type and mutant TWK-18 channels in Xenopus oocytes showed that mutant channels express much larger potassium currents than wild-type channels. Promoter-green fluorescent protein fusion experiments indicate that TWK-18 is expressed in body wall muscle. Our genetic and physiological data suggest that the movement defects observed in mutant twk-18 animals may be explained by an increased activity of the mutant TWK-18 channels.

Publication types

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

MeSH terms

  • Animals
  • Caenorhabditis elegans
  • Caenorhabditis elegans Proteins*
  • Cells, Cultured
  • Chromosome Mapping
  • Gene Expression
  • Green Fluorescent Proteins
  • Locomotion / genetics
  • Luminescent Proteins / genetics
  • Molecular Sequence Data
  • Muscles / metabolism
  • Mutagenesis
  • Mutation*
  • Oocytes / cytology
  • Oocytes / metabolism
  • Organ Specificity
  • Patch-Clamp Techniques
  • Potassium / metabolism
  • Potassium Channels / genetics*
  • Potassium Channels / metabolism
  • Promoter Regions, Genetic / genetics
  • Protein Structure, Tertiary / genetics
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Temperature*
  • X Chromosome / genetics
  • Xenopus


  • Caenorhabditis elegans Proteins
  • Luminescent Proteins
  • Potassium Channels
  • Recombinant Fusion Proteins
  • TWK-18 protein, C elegans
  • Green Fluorescent Proteins
  • Potassium

Associated data

  • GENBANK/AF083650