The effects of level of expression of a jellyfish Shaker potassium channel: a positive potassium feedback mechanism.
1. When jellyfish Shaker potassium channels (jShak2) are heterologously expressed in Xenopus oocytes at different levels they demonstrate density-dependent changes in electrical and kinetic properties of macroscopic currents. 2. The activation and inactivation properties of jShak2 channels depend on the extracellular potassium concentration. In this study we present experimental data which show that expression-dependent changes in kinetic and electrical properties of jShak2 macroscopic currents can be explained by the positive feedback effect of dynamic accumulation of K+ in the perimembranal space.
Grigoriev
N G
NG
Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2E9 and Bamfield Marine Station, Bamfield, British Columbia, Canada V0R 1B0.
Spafford
J D
JD
Spencer
A N
AN
D000818:Animals; D004563:Electrochemistry; D005246:Feedback; D005260:Female; D015870:Gene Expression; D066298:In Vitro Techniques; D007700:Kinetics; D008564:Membrane Potentials; D009865:Oocytes / Q000378:metabolism; D011188:Potassium / Q000378:metabolism*; D026902:Potassium Channel Blockers; D015221:Potassium Channels / Q000235:genetics* / Q000378:metabolism*; D012313:RNA / Q000235:genetics / Q000378:metabolism; D037401:Scyphozoa / Q000235:genetics*; D051637:Shaker Superfamily of Potassium Channels; D014982:Xenopus laevis
D026902:Potassium Channel Blockers; D015221:Potassium Channels; D051637:Shaker Superfamily of Potassium Channels; D012313:RNA; D011188:Potassium