Identification and functional characterization of a K+ channel alpha-subunit with regulatory properties specific to brain.
The physiological diversity of K+ channels mainly depends on the expression of several genes encoding different alpha-subunits. We have cloned a new K+ channel alpha-subunit (Kv2.3r) that is unable to form functional channels on its own but that has a major regulatory function. Kv2.3r can coassemble selectively with other alpha-subunits to form functional heteromultimeric K+ channels with kinetic properties that differ from those of the parent channels. Kv2.3r is expressed exclusively in the brain, being concentrated particularly in neocortical neurons. The functional expression of this regulatory alpha-subunit represents a novel mechanism without precedents in voltage-gated channels, which might contribute to further increase the functional diversity of K+ channels necessary to specify the intrinsic electrical properties of individual neurons.
Castellano
A
A
Facultad de Medicina, Departamento de Fisiología Médica y Biofísica, Universidad de Sevilla, E-41009, Sevilla, Spain.
Chiara
M D
MD
Mellström
B
B
Molina
A
A
Monje
F
F
Naranjo
J R
JR
López-Barneo
J
J
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000378:metabolism*; D016466:CHO Cells; D002540:Cerebral Cortex / Q000378:metabolism; D003001:Cloning, Molecular; D006224:Cricetinae; D017931:DNA Primers; D018076:DNA, Complementary; D051668:Delayed Rectifier Potassium Channels; D019281:Dimerization; D049452:Green Fluorescent Proteins; D051662:Kv1.1 Potassium Channel; D008164:Luminescent Proteins / Q000096:biosynthesis; D008564:Membrane Potentials; D008969:Molecular Sequence Data; D009474:Neurons / Q000378:metabolism; D009928:Organ Specificity; D016133:Polymerase Chain Reaction; D015221:Potassium Channels / Q000096:biosynthesis / Q000737:chemistry / Q000502:physiology*; D024642:Potassium Channels, Voltage-Gated; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D051669:Shab Potassium Channels; D014162:Transfection
D017931:DNA Primers; D018076:DNA, Complementary; D051668:Delayed Rectifier Potassium Channels; D008164:Luminescent Proteins; D015221:Potassium Channels; D024642:Potassium Channels, Voltage-Gated; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D051669:Shab Potassium Channels; D051662:Kv1.1 Potassium Channel; D049452:Green Fluorescent Proteins