Crystal Structure of a Mammalian Voltage-Dependent <i>Shaker</i> Family K ⁺ Channel

TLDR

Voltage‑dependent potassium ion (Kv) channels conduct K⁺ across the membrane in response to voltage changes, thereby regulating neuronal excitability by shaping action potentials. The study reports the crystal structure of the mammalian Kv1.2 channel at 2.9‑Å resolution. The structure was solved in complex with an oxidoreductase β subunit that regulates Kv channels in native cells. The structure shows an open activation gate, large side portals connecting the pore to the cytoplasm, and electrostatic properties of the side portals, T1 domain, and β subunit that are consistent with electrophysiological evidence of inactivation gating and β subunit regulation.

Abstract

Voltage-dependent potassium ion (K + ) channels (Kv channels) conduct K + ions across the cell membrane in response to changes in the membrane voltage, thereby regulating neuronal excitability by modulating the shape and frequency of action potentials. Here we report the crystal structure, at a resolution of 2.9 angstroms, of a mammalian Kv channel, Kv1.2, which is a member of the Shaker K + channel family. This structure is in complex with an oxido-reductase β subunit of the kind that can regulate mammalian Kv channels in their native cell environment. The activation gate of the pore is open. Large side portals communicate between the pore and the cytoplasm. Electrostatic properties of the side portals and positions of the T1 domain and β subunit are consistent with electrophysiological studies of inactivation gating and with the possibility of K + channel regulation by the β subunit.