Potassium voltage-gated channel subfamily Q member 1 (KCNQ1) and Potassium voltage-gated channel subfamily E regulatory subunit 1 (KCNE1) complex (IKs)

The slow delayed rectifier potassium current (IKs) is a fundamental component of the cardiac action potential repolarization process, particularly significant during sympathetic stimulation or increased heart rates [4]. It is mediated by a protein complex consisting of the pore-forming alpha subunit KCNQ1 (Kv7.1) and the regulatory beta subunit KCNE1 (minK) [1, 2]. In rabbit ventricular myocytes, as in humans, IKs provides a critical 'repolarization reserve' that helps maintain electrical stability in the heart under stress [4, 5]. Mutations in the genes encoding these subunits are linked to hereditary Long QT syndromes, specifically LQT1 and LQT5, which predispose individuals to life-threatening arrhythmias [5]. Pharmacological modulation of IKs is a target for anti-arrhythmic therapy, although excessive blockade can lead to pathological prolongation of the QT interval and increased risk of sudden cardiac death [4]. The rabbit model is frequently used in cardiovascular research because its IKs current properties closely mimic those of human ventricular myocytes [4].

Other names

Slow delayed rectifier potassium currentIKsKv7.1/minK complexKCNQ1/KCNE1KVLQT1/minK

Inhibition of the KCNQ1/KCNE1 channel complex reduces the outward potassium current during the plateau phase of the cardiac action potential, thereby prolonging the repolarization phase and increasing the action potential duration [4, 5].