Molecular cloning and functional characterization of Shaw-related potassium channels of trout CNS.
Two Shaw-related potassium channels expressed in the CNS of trout were PCR cloned and sequenced: Traw1 was identified as a fish homologue to mammalian K(v)3.1, while Traw2 could not be exactly classified. Upon heterologous expression Traw1 exhibited a high threshold (-20 mV) non-inactivating delayed rectifier current that was efficiently blocked by submicromolar concentrations of TEA, 4-AP and quinine but not by alpha-DTX or apamin. The amplitude of the Traw1 induced current was reduced by the phorbol ester TPA, the effect being prevented by the proteinkinase inhibitor H7. Transcripts of both Shaw- related channels possess a widespread distribution in the mature brain tissue and outside the nervous system are detectable in muscle but not in liver. During brain development Traw1 mRNA was initially identified at stage 31 (shortly after hatching) while transcripts encoding Traw2 were detectable already at stage 28 (1 week before hatching).
Panofen
F
F
Department of Animal Physiology, University of Osnabrück, Barbarastr. 11 49069, Osnabrück, Germany.
Rabe
H
H
Henne
J
J
Jeserich
G
G
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / Q000494:pharmacology; D015761:4-Aminopyridine / Q000494:pharmacology; D000818:Animals; D001923:Brain Chemistry / Q000235:genetics*; D002273:Carcinogens / Q000494:pharmacology; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000302:isolation & purification; D004594:Electrophysiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018507:Gene Expression Regulation, Developmental; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D008969:Molecular Sequence Data; D009125:Muscle Relaxants, Central / Q000494:pharmacology; D017686:Oncorhynchus mykiss / Q000235:genetics*; D015221:Potassium Channels / Q000235:genetics* / Q000378:metabolism*; D024642:Potassium Channels, Voltage-Gated; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D011803:Quinine / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D051670:Shaw Potassium Channels; D013045:Species Specificity; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D019789:Tetraethylammonium / Q000494:pharmacology
D002273:Carcinogens; D018076:DNA, Complementary; D004791:Enzyme Inhibitors; D009125:Muscle Relaxants, Central; D015221:Potassium Channels; D024642:Potassium Channels, Voltage-Gated; D051670:Shaw Potassium Channels; D019789:Tetraethylammonium; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D011803:Quinine; D015761:4-Aminopyridine; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate