A novel potassium channel with delayed rectifier properties isolated from rat brain by expression cloning.
Voltage-activated potassium channels play an important part in the control of excitability in nerve and muscle. Different K+ channels are involved in establishing the resting potential, determining the duration of action potentials, modulation of transmitter release, and in rhythmic firing patterns and delayed excitation. Using in vitro transcripts made from a directional complementary DNA library we have isolated, by expression cloning in Xenopus oocytes, a novel K+-channel gene (drk1). Functionally, drk1 encodes channels that are K+ selective and belong to the delayed rectifier class of channels, rather than the A-type class encoded by the Shaker gene of Drosophila. The channels show sigmoidal voltage-dependent activation and do not inactivate within 500 ms. Structurally, drk1 encodes an amino-acid sequence which is more closely related to the Drosophila Shab gene than to the Shaker gene.
Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas 77030.
G C
GC
Frech
A M
AM
VanDongen
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G
Schuster
A M
AM
Brown
R H
RH
Joho
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000502:physiology*; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D051668:Delayed Rectifier Potassium Channels; D004553:Electric Conductivity; D008969:Molecular Sequence Data; D011188:Potassium / Q000502:physiology; D015221:Potassium Channels / Q000502:physiology*; D024642:Potassium Channels, Voltage-Gated; D051381:Rats; D051669:Shab Potassium Channels; D014982:Xenopus laevis
D051668:Delayed Rectifier Potassium Channels; C496991:Kcnb1 protein, rat; D015221:Potassium Channels; D024642:Potassium Channels, Voltage-Gated; D051669:Shab Potassium Channels; D004247:DNA; D011188:Potassium