Referenced in: none

Automatically associated channels: Kir2.1

Title: The intrinsic gating of inward rectifier K+ channels expressed from the murine IRK1 gene depends on voltage, K+ and Mg2+.

Authors: P R Stanfield, N W Davies, P A Shelton, I A Khan, W J Brammar, N B Standen, E C Conley

Journal, date & volume: J. Physiol. (Lond.), 1994 Feb 15 , 475, 1-7

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/8189383

Abstract
1. We describe the cloning of the inward rectifier K+ channel IRK1 from genomic DNA of mouse; the gene is intronless. 2. The IRK1 gene can be stably expressed in murine erythroleukaemia (MEL) cells. Such transfected cells show inward rectification under whole-cell recording. 3. Channels encoded by the IRK1 gene have an intrinsic gating that depends on voltage and [K+]o. Rate constants are reduced e-fold as the driving force on K+(V-EK) is reduced by 24.1 mV. 4. Removal of intracellular Mg2+ permits brief outward currents under depolarization. The instantaneous current-voltage relation may be fitted by an appropriate constant field expression. 5. Removal of intracellular Mg2+ speeds channel closure at positive voltages. In nominally zero [Mg2+]i, rate constants for the opening and closing of channels, processes which are first order, are similar to those of native channels.