Ether-à-go-go-related gene potassium channel (ERG) (ERG)

The ether-à-go-go-related gene (ERG) potassium channels are a family of voltage-gated potassium channels, with the ERG1 (hERG or KCNH2) subtype being the most clinically significant due to its role in cardiac repolarization (Sanguinetti & Tristani-Firouzi, 2006). These channels conduct the rapid delayed rectifier potassium current (IKr), which is essential for terminating the cardiac action potential and maintaining normal sinus rhythm. Genetic mutations in the KCNH2 gene or pharmacological blockade of the channel can lead to Long QT syndrome (LQTS), a condition characterized by delayed repolarization and an increased risk of life-threatening ventricular arrhythmias like Torsades de Pointes (Vandenberg et al., 2012). While ERG1 is primarily associated with the heart, ERG2 (KCNH3) and ERG3 (KCNH4) are expressed in the central nervous system, where they modulate neuronal excitability and have been linked to cognitive functions and psychiatric disorders (Bauer & Schwarz, 2001). Due to the high susceptibility of the hERG channel to blockade by a wide variety of structurally diverse drugs, it is a major focus of safety pharmacology, and regulatory guidelines (e.g., ICH S7B) mandate screening of all new drug candidates for hERG activity to prevent cardiotoxicity (Redfern et al., 2003).

Other names

hERGKv11.1KCNH2ERG1Ether-à-go-go-related protein 1Potassium voltage-gated channel subfamily H member 2HERG1

Blockade of the pore-forming subunit of the potassium channel, specifically inhibiting the outward rapid delayed rectifier current (IKr) by binding to the inner cavity of the channel, thereby prolonging the cardiac action potential duration (Vandenberg et al., 2012).