Molecular cloning and functional expression of a novel potassium channel β‐subunit from human atrium

摘要

>We report the cloning and functional expression of a novel K+ channel β-subunit from human atrium, hKvβ3. hKvβ3 is highly homologous to the two β-subunits cloned from rat brain, Kvβ1 and Kvβ2, but has an essentially unique stretch of 79 N-terminal residues. Upon expression in Xenopus oocytes, hKvβ3 accelerates the inactivation of co-injected hKv1.4 currents and induces fast inactivation of non-inactivating co-injected hKv1.5 currents. By contrast, hKvβ3 had no effect on hKv1.1, hKv1.2, or hKv2.1 currents. Thus, hKvβ3 represents a third type of K+ channel β-subunit which modulates the kinetics of a unique subset of channels in the Kv1 subfamily.