Modulation of voltage-gated K(+) channels Kv11 and Kv1 4 by forskolin.
Forskolin (FSK) affects voltage-gated K(+) (Kv) currents in different cell types, but it is not known which of the various subunits form FSK-sensitive Kv channels. We compared the effect of the compound at Kv1.1 and Kv1.4 channels ectopically expressed in HEK 293 cells. Low FSK concentrations induced a phosphorylation-dependent potentiation of Kv1.1 currents. At higher concentrations, this effect was superimposed by a fast, cAMP-independent channel block. Kv1.4 currents were inhibited with lower potency by FSK but were not modified by phosphorylation. The variable effect of the compound might help to distinguish between Kv subunits expressed by native cells.
Matthias
K
K
Experimental Neurobiology, Neurosurgery, University of Bonn, Sigmund-Freud-Str. 25, 53105, Bonn, Germany.
Seifert
G
G
Reinhardt
S
S
Steinhäuser
C
C
D000465:Algorithms; D002478:Cells, Cultured; D005576:Colforsin / Q000494:pharmacology*; D000242:Cyclic AMP / Q000037:antagonists & inhibitors; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004594:Electrophysiology; D006801:Humans; D015640:Ion Channel Gating / Q000187:drug effects; D007700:Kinetics; D051662:Kv1.1 Potassium Channel; D051665:Kv1.4 Potassium Channel; D008564:Membrane Potentials / Q000502:physiology; D018408:Patch-Clamp Techniques; D010766:Phosphorylation; D015221:Potassium Channels / Q000187:drug effects*; D024642:Potassium Channels, Voltage-Gated
C496946:KCNA1 protein, human; C496977:KCNA4 protein, human; D051665:Kv1.4 Potassium Channel; D015221:Potassium Channels; D024642:Potassium Channels, Voltage-Gated; D051662:Kv1.1 Potassium Channel; D005576:Colforsin; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases