Referenced in: none

Automatically associated channels: Kv1.1 , Kv1.4 , Kv1.5 , Slo1

Title: Modulation of gating of cloned rat and human K+ channels by micromolar Zn2+.

Authors: N L Harrison, H K Radke, M M Tamkun, D M Lovinger

Journal, date & volume: Mol. Pharmacol., 1993 Mar , 43, 482-6

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/8450837

Abstract
The actions of zinc ions on three species of K+ channels were studied using mouse fibroblasts stably transfected with a plasmid containing both the appropriate K+ channel gene and a steroid-inducible promotor. The channels studied were rKv1.1 and hKv1.5, delayed rectifiers cloned from rat and human tissue, respectively, and hKv1.4, an inactivating human K+ channel. Zn2+ shifted the activation curves for all three K+ currents in the depolarizing direction and also shifted the steady state inactivation curve for hKv1.4 in the depolarizing direction. The effect of Zn2+ was concentration dependent between 2 and 1000 microM. As a consequence of the modulation of gating, the activation kinetics of the K+ currents were slowed by Zn2+, an effect likely to delay repolarization of the neuronal action potential. The action of Zn2+ on these diverse K+ channels suggests the existence of a common Zn2+ binding domain, the occupation of which influences the voltage sensor. The resulting modulation of gating of hKv1.4 by Zn2+ may well be of physiological significance, in view of the localization of this channel in mossy fiber nerve terminals in the hippocampus, where Zn2+ is found in abundance.