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

The slow delayed rectifier potassium current (IKs) is a fundamental ionic current in the heart, essential for the repolarization phase of the cardiac action potential (StatPearls, NBK430840). It is generated by a macromolecular protein complex composed of the KCNQ1 alpha-subunit and the KCNE1 beta-subunit (UniProt P51787, P15382). This channel is characterized by its slow activation kinetics and its role in providing a "repolarization reserve," which helps maintain cardiac stability during physiological stress or sympathetic activation (PubMed: 15814415). Mutations in the KCNQ1 or KCNE1 genes are the primary cause of Long QT Syndrome Type 1 (LQT1) and Jervell and Lange-Nielsen syndrome, both of which increase the risk of sudden cardiac death due to ventricular arrhythmias (NIH, GTR: GTR000500358). While many Class III antiarrhythmic drugs primarily target the rapid component (IKr), IKs is an important target for developing treatments for atrial fibrillation and other rhythm disorders (PubMed: 11886701). Pharmacological blockers like HMR 1556 and Chromanol 293B are used in research to study the current's contribution to the action potential, while activators are being investigated for their potential to shorten the QT interval in patients with LQT1 (PubChem CID: 104618). The complex is also expressed in other tissues, such as the inner ear and intestinal epithelium, where it plays roles in endolymph secretion and salt transport (UniProt P51787).

Other names

Slow delayed rectifier potassium channelKCNQ1/KCNE1 complexKv7.1/minK channelI(Ks) channelLQT1 channel

Drugs typically act as inhibitors (blockers) to prolong the cardiac action potential duration or as activators to shorten the QT interval and enhance repolarization reserve.