External pH regulates the slowly activating potassium current IsK expressed in Xenopus oocytes
- 22 March 1993
- journal article
- Published by Wiley in FEBS Letters
- Vol. 319 (3) , 229-232
- https://doi.org/10.1016/0014-5793(93)80552-6
Abstract
A slowly activating, delayed rectifier potassium current, I sK, was expressed in Xenopus laevis oocytes by injection of cRNA transcribed from a rat kidney cDNA clone. External acidification reversibly decreased the current amplitude. The effects were concentration dependent on protons with K d at pH ≈ 5.5 and a Hill coefficient of 1.0. External acidification reduced the maximal conductance (G max) without affecting the activation kinetics; this effect was not dependent on membrane voltages. These data suggest that H+ ions bind to the channel with a one-to-one stoichiometry, and this binding site may be located outside of the membrane electric field.Keywords
This publication has 17 references indexed in Scilit:
- Hypotonic solution increases the slowly activating potassium current IsK expressed in Xenopus oocytesBiochemical and Biophysical Research Communications, 1992
- Immunohistochemical study of a rat membrane protein which induces a selective potassium permeation: Its localization in the apical membrane portion of epithelial cellsThe Journal of Membrane Biology, 1990
- Molecular cloning and sequence analysis of human genomic DNA encoding A novel membrane protein which exhibits a slowly activating potassium channel activityBiochemical and Biophysical Research Communications, 1989
- The Use ofXenopusOocytes for the Study of Ion ChannelCritical Reviews in Biochemistry, 1987
- The effect of extracellular low pH on the plateau current in isolated, single rat ventricular cells - A voltage clamp study.The Japanese Journal of Physiology, 1983
- Action of extracellular pH on Na+ and K+ membrane currents in the giant axon ofLoligo VulgarisThe Journal of Membrane Biology, 1978
- Sensitivity of the sodium and potassium channels of Myxicola giant axons to changes in external pH.The Journal of general physiology, 1976
- EFFECTS OF pH ON THE PROCESSES OF EXCITATION-CONTRACTION COUPLING OF BULLFROG ATRIUMThe Japanese Journal of Physiology, 1975
- Effect of Surface Charge on the Steady-state Potassium Conductance of Nodal MembraneNature, 1970
- Charges and Potentials at the Nerve SurfaceThe Journal of general physiology, 1968