Details

Autor(en) / Beteiligte

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

Titel

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

Ist Teil von

• The Journal of physiology, 1994-02, Vol.475 (1), p.1-7

Ort / Verlag

Oxford: The Physiological Society

Erscheinungsjahr

1994

Quelle

MEDLINE

Beschreibungen/Notizen

• 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.