Sp-tetraKCNG: A novel cyclic nucleotide gated K(+) channel

Biochem Biophys Res Commun. 2007 Mar 16;354(3):668-75. doi: 10.1016/j.bbrc.2007.01.035. Epub 2007 Jan 17.


The sequence of a novel cGMP-regulated, tetrameric, K(+) selective channel (Sp-tetraKCNG) was discovered in the sea urchin Strongylocentrotus purpuratus. The Sp-tetraKCNG is a single polypeptide made of four KCNG domains similar to voltage-dependent Na(+) and Ca(2+) channels. Each KCNG domain has six transmembrane segments (S1-S6), the ion pore having the K(+) selectivity signature GYGD and a cyclic nucleotide-binding domain (CNBD). This novel channel is evolutionary located between K(+)-selective and voltage-dependent EAG channels and voltage-independent cationic CNG channels. Bilayer reconstitutions demonstrate such a cGMP-regulated K(+) selective channel in sea urchin spermatozoa.

MeSH terms

  • Animals
  • Binding Sites
  • Cations / metabolism
  • Cyclic GMP / metabolism*
  • Lipid Bilayers / metabolism
  • Male
  • Molecular Sequence Data
  • Potassium Channels / chemistry
  • Potassium Channels / metabolism*
  • Potassium Channels, Voltage-Gated / chemistry
  • Potassium Channels, Voltage-Gated / metabolism*
  • Sequence Analysis, Protein
  • Spermatozoa / chemistry
  • Spermatozoa / cytology
  • Spermatozoa / metabolism*
  • Strongylocentrotus purpuratus / physiology*


  • Cations
  • Lipid Bilayers
  • Potassium Channels
  • Potassium Channels, Voltage-Gated
  • Cyclic GMP