Molecular cloning and expression of cERG, the ether à go-go-related gene from canine myocardium.
Given the anatomical and physiological similarities to the human heart, canine in vivo heart models may facilitate the analysis of molecular mechanisms underlying cardiac repolarization abnormalities. The development of such models depends, however, on information about canine K+ channels responsible for the establishment of IK currents. In this context, we isolated and sequenced the reverse transcript of the canine ether à go-go-related gene (cERG). The complementary deoxyribonucleic acid (cDNA-derived cERG polypeptide consists of 1,158 amino acids, the sequence of which shows striking homology to human, rat and mouse ERG subunits (97%, 94% and 95% identity respectively). In highly conserved peptide domains like the PAS domain, the membrane-spanning segments S1, S3-S6 and the pore-forming region, there was 100% identity. Analysis of cERG transcription revealed abundant expression of cERG messenger ribonucleic acid (mRNA) in heart and brain and low expression in liver, spleen and kidney. Membrane currents recorded in Xenopus oocytes expressing cERG channels showed functional properties very similar to the human K+ channel hERG, which encodes the alpha-subunit of the cardiac rapidly activating, delayed rectifier (IKr) channel.
Zehelein
J
J
Innere Medizin III, Universitätsklinik Heidelberg, Bergheimerstrasse 58, 69115 Heidelberg, Germany. joerg_zehelein@med.uni-heidelberg.de
Zhang
W
W
Koenen
M
M
Graf
M
M
Heinemann
S H
SH
Katus
H A
HA
D000818:Animals; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D004285:Dogs; D000072237:ERG1 Potassium Channel; D004594:Electrophysiology; D051638:Ether-A-Go-Go Potassium Channels; D015870:Gene Expression; D007473:Ion Channels / Q000502:physiology; D009865:Oocytes; D015221:Potassium Channels / Q000235:genetics* / Q000378:metabolism*; D024642:Potassium Channels, Voltage-Gated; D012333:RNA, Messenger / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013997:Time Factors; D014018:Tissue Distribution; D014981:Xenopus
D018076:DNA, Complementary; D000072237:ERG1 Potassium Channel; D051638:Ether-A-Go-Go Potassium Channels; D007473:Ion Channels; C000606913:KCNH2 protein, human; C000606915:Kcnh2 protein, mouse; D015221:Potassium Channels; D024642:Potassium Channels, Voltage-Gated; D012333:RNA, Messenger