Voltage-gated potassium channel subunit Kv1.3 (Kv1.3)

Kv1.3 (Voltage-gated potassium channel subunit Kv1.3), encoded by the KCNA3 gene, is a member of the voltage-gated potassium (Kv) channel family. It plays a critical role in regulating membrane potential and cellular excitability, particularly in immune cells such as T lymphocytes. It is a tetramer composed of four α-subunits, each with six transmembrane helices. Kv1.3 mediates outward K+ efflux upon membrane depolarization and is essential for repolarization during action potentials. In immune cells, it regulates calcium signaling required for activation, proliferation, and cytokine production. Kv1.3 is expressed in the immune system, nervous system, and other tissues. Overexpression or hyperactivity is linked to autoimmune diseases, while mitochondrial/nuclear Kv1.3 is implicated in apoptosis regulation in cancer. Kv1.3 is an attractive target for immunomodulatory therapies, and structural studies have elucidated mechanisms of inhibition using nanobodies or antibody-toxin fusions.

Other names

KCNA3HGK5

Inhibition of potassium ion flow through the Kv1.3 channel, either by inducing inactive conformation or physically blocking the pore.