Sp-tetraKCNG: A novel cyclic nucleotide gated K(+) channel.
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.
Galindo
Blanca Estela
BE
Depto. de Genética del Desarrollo y Fisiología Molecular del Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apdo Postal 510-3, Cuernavaca, Morelos 62271, Mexico. bgalindo@cinvestav.mx
de la Vega-Beltrán
José Luis
JL
Labarca
Pedro
P
Vacquier
Victor D
VD
Darszon
Alberto
A
D000818:Animals; D001665:Binding Sites; D002412:Cations / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism*; D008051:Lipid Bilayers / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D015221:Potassium Channels / Q000737:chemistry / Q000378:metabolism*; D024642:Potassium Channels, Voltage-Gated / Q000737:chemistry / Q000378:metabolism*; D020539:Sequence Analysis, Protein; D013094:Spermatozoa / Q000737:chemistry / Q000166:cytology / Q000378:metabolism*; D047270:Strongylocentrotus purpuratus / Q000502:physiology*
D002412:Cations; D008051:Lipid Bilayers; D015221:Potassium Channels; D024642:Potassium Channels, Voltage-Gated; D006152:Cyclic GMP