Potassium voltage-gated channel subfamily A member 5 (Kv1.5) (Kv1.5)

Potassium voltage-gated channel subfamily A member 5 (Kv1.5) is a transmembrane protein that forms the pore of the ultra-rapid delayed rectifier potassium current (IKur). It is primarily expressed in the human atrial myocardium and vascular smooth muscle cells, where it plays a critical role in action potential repolarization and the regulation of resting membrane potential and vascular tone [1, 2, 14]. In the heart, Kv1.5 is a major therapeutic target for atrial fibrillation (AF) because its atrial-specific expression allows for the prolongation of the atrial refractory period without affecting the ventricles, thereby minimizing the risk of ventricular arrhythmias [10, 11]. In the pulmonary vasculature, downregulation or inhibition of Kv1.5 is associated with the development of pulmonary arterial hypertension (PAH) by promoting vasoconstriction and smooth muscle cell proliferation [7, 15]. Pharmacological modulators include IKur blockers like vernakalant for AF and potential activators for treating PAH [1, 3]. Beyond its cardiovascular roles, Kv1.5 is also involved in regulating cell volume, apoptosis, and the proliferation of various cancer cells [12, 15].

Other names

KCNA5IKur channelVoltage-gated potassium channel subunit Kv1.5Shaker-related subfamily member 5HK2HUK1PCN1RK4RCK7Cardiac potassium channelInsulinoma and islet potassium channel

Blockade of the ultra-rapid delayed rectifier potassium current (IKur) to prolong atrial action potential duration and refractory period; activation to reduce vascular resistance and inhibit smooth muscle cell proliferation.