Pursuing the voltage sensor of a voltage-gated mammalian potassium channel.
Ion channels are generally classified as voltage- or ligand-gated channels based upon their ability to respond to a change in the transmembrane voltage or to a specific ligand interaction. The voltage sensor of voltage-gated ion channels is thought to be contained within the fourth putative transmembrane segment, S4, and is characterized by basic residues typically spaced apart. Thus far, a full understanding of all charges contributing to the voltage sensor of voltage-gated potassium channels has been lacking since several neutralization mutants in S4 could not be functionally expressed. By construction of multimeric cDNAs encoding a mammalian RCK1 (Kv1.1) potassium channel, we now report functional expression of all charge neutralizations in the S4 segment, providing a more comprehensive insight into the functioning of the voltage sensor.
Tytgat
J
J
Department of Cellular and Molecular Physiology, Harvard Medical School, Boston, Massachusetts 02115.
Nakazawa
K
K
Gross
A
A
Hess
P
P
D000818:Animals; D002478:Cells, Cultured; D003001:Cloning, Molecular; D018076:DNA, Complementary; D015640:Ion Channel Gating; D051662:Kv1.1 Potassium Channel; D008322:Mammals; D009154:Mutation; D009865:Oocytes; D015221:Potassium Channels / Q000737:chemistry*; D024642:Potassium Channels, Voltage-Gated; D014982:Xenopus laevis
D018076:DNA, Complementary; C489293:Kcna1 protein, rat; D015221:Potassium Channels; D024642:Potassium Channels, Voltage-Gated; D051662:Kv1.1 Potassium Channel