Disease relevance of KCNH2

• In isolated myocytes I(Kr) frequently is small in amplitude or absent, yet KCNH2 channels and I(Kr) are targets for drug block or mutations to cause long QT syndrome [1].
• While aldosterone receptor blockers improve survival of patients with congestive heart failure, spironolactone and its derivatives were recently shown to block ether-a-go-go-related gene (HERG) channels and native IKs and IKr currents in guinea pig ventricular myocytes [2].

High impact information on KCNH2

• Specific serine proteases selectively damage KCNH2 (hERG1) potassium channels and I(Kr) [1].
• These data provide 1) a new mechanism to account for low I(Kr) density in some isolated myocytes, 2) evidence that most complexly glycosylated KCNH2 channel protein is in the plasma membrane, and 3) new insight into the rate of biogenesis of KCNH2 channel protein within cells [1].
• KCNH2 (hERG1) encodes the alpha-subunit proteins for the rapidly activating delayed rectifier K+ current (I(Kr)), a major K+ current for cardiac myocyte repolarization [1].
• Electrical remodeling due to CAVB was also observed in the VS as was shown by approximately twofold lower levels in KCND3, KCNH2 and KCNQ1 mRNA (P <0.05) in the LVS compared to SR, thereby creating new or eliminating existing transseptal gradients [3].

Analytical, diagnostic and therapeutic context of KCNH2

• Western blots of ether-a-go-go-related gene (ERG) protein in three RA and corresponding LA regions showed significantly greater ERG expression in LA [4].

References