Potassium voltage-gated channel subfamily Q member 1 and Potassium voltage-gated channel subfamily E member 1 complex (IKs) (IKs)

The KCNQ1/KCNE1 complex, commonly referred to as the slow delayed rectifier potassium channel (IKs), is a voltage-gated ion channel assembly critical for maintaining normal cardiac rhythm (UniProt P51787, P15382). It is formed by the association of the pore-forming alpha subunit KCNQ1 (KvLQT1) and the regulatory beta subunit KCNE1 (minK), which significantly modifies the channel's gating properties to produce a slowly activating current (PubMed: 10449337). This current is essential for the repolarization of the cardiac action potential, especially during periods of high heart rates or sympathetic stress, where it helps shorten the action potential duration (StatPearls: Long QT Syndrome). Genetic mutations in either KCNQ1 or KCNE1 are primary causes of hereditary Long QT Syndrome (LQT1 and LQT5) and Jervell and Lange-Nielsen syndrome, the latter of which also involves sensorineural deafness due to the channel's role in the inner ear (PubMed: 11854323). In the pharmaceutical industry, the IKs complex is a major focus of safety pharmacology, as drug-induced inhibition can lead to life-threatening arrhythmias like Torsades de Pointes. While several experimental compounds like HMR 1556 and Chromanol 293B act as potent inhibitors, research is also directed toward IKs activators as potential treatments for repolarization-related disorders.

Other names

KCNQ1-KCNE1 complexKvLQT1-minK complexSlow delayed rectifier potassium channelLQT1-LQT5 complex

Drugs targeting the IKs complex typically act as pore blockers to inhibit the outward potassium current, thereby prolonging the action potential duration, or as openers/activators to enhance the current and shorten the action potential.