PUBLICATION
Transcripts of Kv7.1 and MinK channels and slow delayed rectifier K+ current (IKs) are expressed in zebrafish (Danio rerio) heart.
- Authors
- Abramochkin, D.V., Hassinen, M., Vornanen, M.
- ID
- ZDB-PUB-180820-5
- Date
- 2018
- Source
- Pflugers Archiv : European journal of physiology 470(12): 1753-1764 (Journal)
- Registered Authors
- Keywords
- Action potential duration, Cardiac potassium channel, Kv7.1 α-subunit, MinK β-subunit, Ventricular IKs
- MeSH Terms
-
- Action Potentials*
- Animals
- CHO Cells
- Cricetinae
- Cricetulus
- KCNQ1 Potassium Channel/genetics
- KCNQ1 Potassium Channel/metabolism*
- Myocytes, Cardiac/metabolism*
- Myocytes, Cardiac/physiology
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Zebrafish
- Zebrafish Proteins/genetics
- Zebrafish Proteins/metabolism*
- PubMed
- 30116893 Full text @ Pflügers Archiv. / Eur. J. Physiol.
Citation
Abramochkin, D.V., Hassinen, M., Vornanen, M. (2018) Transcripts of Kv7.1 and MinK channels and slow delayed rectifier K+ current (IKs) are expressed in zebrafish (Danio rerio) heart.. Pflugers Archiv : European journal of physiology. 470(12):1753-1764.
Abstract
Zebrafish are increasingly used as a model for human cardiac electrophysiology, arrhythmias, and drug screening. However, K+ ion channels of the zebrafish heart, which determine the rate of repolarization and duration of cardiac action potential (AP) are still incompletely known and characterized. Here, we provide the first evidence for the presence of the slow component of the delayed rectifier K+channels in the zebrafish heart and characterize electrophysiological properties of the slow component of the delayed rectifier K+current, IKs. Zebrafish atrium and ventricle showed strong transcript expression of the kcnq1 gene, which encodes the Kv7.1 α-subunit of the slow delayed rectifier K+ channel. In contrast, the kcne1 gene, encoding the MinK β-subunit of the delayed rectifier, was expressed at 21 and 17 times lower level in ventricle and atrium, respectively, in comparison to the kcnq1. IKs was observed in 62% of ventricular myocytes with mean (± SEM) density of 1.23 ± 0.37 pA/pF at + 30 mV. Activation rate of IKs was 38% faster (τ50 = 1248 ± 215 ms) than kcnq1:kcne1 channels (1725 ± 792 ms) expressed in 3:1 ratio in Chinese hamster ovary cells. Microelectrode experiments demonstrated the functional relevance of IKs in the zebrafish heart, since 100 μM chromanol 293B produced a significant prolongation of AP in zebrafish ventricle. We conclude that AP repolarization in zebrafish ventricle is contributed by IKs, which is mainly generated by homotetrameric Kv7.1 channels not coupled to MinK ancillary β-subunits. This is a clear difference to the human heart, where MinK is an essential component of the slow delayed rectifier K+channel.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping