Structural elements determining activation kinetics in Kv2.1.
Voltage-dependent K+ channels open when depolarizing the membrane voltage. Among the different alpha-subunits, the time course of current activation spreads over a wide range. The structural basis underlying this diversity is not known. We constructed multiple chimeras between two voltage-dependent K+ channels, the rapidly activating Kv1.2 and the slowly activating Kv2.1, and we focused on the C-terminal half of the core region. The general strategy was to substitute parts of Kv2.1 by corresponding parts of Kv1.2 and to test for an acceleration of activation. We identified three regions which contribute to the determination of the activation kinetics: the S5-pore linker, the deep pore, and the S4-segment.
Scholle
A
A
Institut für Physiologie, Herz-Kreislauf-Physiologie, Friedrich-Schiller-Universität, Jena, Germany.
Koopmann
R
R
Leicher
T
T
Ludwig
J
J
Pongs
O
O
Benndorf
K
K
D000595:Amino Acid Sequence; D000818:Animals; D051668:Delayed Rectifier Potassium Channels; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D016296:Mutagenesis; D015221:Potassium Channels / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D024642:Potassium Channels, Voltage-Gated; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D051669:Shab Potassium Channels; D013329:Structure-Activity Relationship; D014982:Xenopus laevis
D051668:Delayed Rectifier Potassium Channels; C496988:KCNB1 protein, human; C496991:Kcnb1 protein, rat; D015221:Potassium Channels; D024642:Potassium Channels, Voltage-Gated; D011993:Recombinant Fusion Proteins; D051669:Shab Potassium Channels