Voltage-gated potassium channel subfamily C (Kv3 channel)

Kv3 voltage-gated potassium channel refers to a family of ion channels critical for rapid repolarization in fast-spiking neurons, enabling high-frequency neurotransmission and precise signal timing. Kv3 voltage-gated potassium channels are membrane proteins composed of four alpha subunits (either homo- or heterotetrameric), each containing six transmembrane helices (S1–S6). The S1–S4 segments form the voltage sensing domain (VSD), with S4 carrying positively charged arginine and lysine residues that sense changes in membrane potential; S5 and S6 form the pore domain (PD) responsible for selective K⁺ ion conduction. The N-terminal T1 domain mediates tetramerization, often stabilized by Zn²⁺. Kv3 channels activate at high membrane potentials and show extremely rapid activation and deactivation kinetics, closing within milliseconds after repolarization. Distinctive features include a twisted T1 domain arrangement, a PVP motif in S6 for gating flexibility, and a unique turret domain involved in electromechanical coupling. Kv3 channels' ability to support high-frequency neuronal firing is essential for certain brain functions. Dysfunction or mutations in these channels are linked to human diseases (e.g., epilepsy, ataxia, developmental delay). Kv3.1 and other Kv3 subfamily members are becoming a focus in CNS drug development, particularly for addressing cognitive deficits and seizure disorders.

Other names

Kv3 channelVoltage-gated potassium channel subfamily C (Kv3)KCNC channelsHigh-threshold potassium channelKv3.1Kv3.2Kv3.3Kv3.4

Positive modulators: Increase channel activity, enabling more rapid repolarization and neuronal firing. Blockers/inhibitors: Reduce Kv3 channel activity, potentially dampening neuronal excitability.