Modulation of Kv1.5 Potassium Channel Gating by Extracellular Zinc

Modulation of potassium channel gating by external divalent cations

We have examined the actions of Zn2+ ions on Shaker K channels. We found that low (100 microM) concentrations of Zn2+ produced a substantial (approximately three-fold) slowing of the kinetics of macroscopic activation and inactivation. Channel deactivation was much less affected. These results were obtained in the presence of 5 mM Mg2+ and 4 mM Ca2+ in the external solution and so are unlikely ...

Modulation of hERG potassium channel gating normalizes action potential duration prolonged by dysfunctional KCNQ1 potassium channel.

Long QT syndrome (LQTS) is a genetic disease characterized by a prolonged QT interval in an electrocardiogram (ECG), leading to higher risk of sudden cardiac death. Among the 12 identified genes causal to heritable LQTS, ∼90% of affected individuals harbor mutations in either KCNQ1 or human ether-a-go-go related genes (hERG), which encode two repolarizing potassium currents known as I(Ks) and I...

Modulation by Potassium Channel Blockade

The endothelium has the capacity to modulate vascular structure in response to hemodynamic stimuli. We tested the hypothesis that exposure of the endothelium to increased laminar shear stress induces the expression of TGFp1 via a signal transduction pathway modulated by K+ channel currents. Although TGFp1 is normally secreted in a latent, inactive form, exposure of cultured endothelial cells to...

hERG potassium channel inhibition by ivabradine requires channel gating.

Modulation of the Kir7.1 potassium channel by extracellular and intracellular pH.

Inwardly rectifying K(+) (K(ir)) channels in the apical membrane of the retinal pigment epithelium (RPE) contribute to extracellular K(+) homeostasis in the distal retina by mediating K(+) secretion. Multiple lines of evidence suggest that these channels are composed of Kir7.1. Previously, we showed that native K(ir) channels in bovine RPE are modulated by changes in intracellular pH in the phy...