ArticleHeart rhythm2007
Kir2.3 isoform confers pH sensitivity to heteromeric Kir2.1/Kir2.3 channels in HEK293 cells.
Article in Heart rhythm, 2007. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 12 papers.
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Who cites it
12 citing papers in PubMed, 21 citations in OpenAlex.
- KCNJ4 variants disrupt inward-rectifier potassium channel function and cause refractory epilepsy.Epilepsia · 2026Article
- Abnormal myocardial expression of SAP97 is associated with arrhythmogenic risk.American journal of physiology. Heart and circulatory physiology · 2020Article
- The inward rectifier potassium channel Kir2.1 is expressed in mouse neutrophils from bone marrow and liver.American journal of physiology. Cell physiology · 2015Article
- Strain differences in pH-sensitive K+ channel-expressing cells in chemosensory and nonchemosensory brain stem nuclei.Journal of applied physiology (Bethesda, Md. : 1985) · 2014Article
- Epidermal growth factor receptor tyrosine kinase regulates the human inward rectifier potassium K(IR)2.3 channel, stably expressed in HEK 293 cells.British journal of pharmacology · 2011Article
- Functional consequences of Kir2.1/Kir2.2 subunit heteromerization.Pflugers Archiv : European journal of physiology · 2010Article
- Regulation of cardiac inward rectifier potassium current (I(K1)) by synapse-associated protein-97.The Journal of biological chemistry · 2010Article
- Cardiac strong inward rectifier potassium channels.Journal of molecular and cellular cardiology · 2010Review
- SAP97 regulates Kir2.3 channels by multiple mechanisms.American journal of physiology. Heart and circulatory physiology · 2009Article
- Article
- A single-cell model of phase-driven control of ventricular fibrillation frequency.Biophysical journal · 2009Article
- RXP-E: a connexin43-binding peptide that prevents action potential propagation block.Circulation research · 2008Article
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Authors and funding
6 authors at 1 institution in 1 country.
Funding
Abstract
backgroundData on pH regulation of the cardiac potassium current I(K1) suggest species-dependent differences in the molecular composition of the underlying Kir2 channel proteins.
objectiveThe purpose of this study was to test the hypothesis that the presence of the Kir2.3 isoform in heterotetrameric channels modifies channel sensitivity to pH.
methodsVoltage clamp was performed on HEK293 cells stably expressing guinea pig Kir2.1 and/or Kir2.3 isoforms and on sheep cardiac ventricular myocytes at varying extracellular pH (pH(o)) and in the presence of CO(2) to determine the sensitivity of macroscopic currents to pH. Single-channel activity was recorded from the HEK293 stables to determine the mechanisms of the changes in whole cell current.
resultsBiophysical characteristics of whole-cell and single-channel currents in Kir2.1/Kir2.3 double stables displayed properties attributable to isoform heteromerization. Whole-cell Kir2.1/Kir2.3 currents rectified in a manner reminiscent of Kir2.1 but were significantly inhibited by extracellular acidification in the physiologic range (pK(a) approximately 7.4). Whole-cell currents were more sensitive to a combined extracellular and intracellular acidification produced by CO(2). At pH(o) = 6.0, unitary conductances of heteromeric channels were reduced. Ovine cardiac ventricular cell I(K1) was pH(o) and CO(2) sensitive, consistent with the expression of Kir2.1 and Kir2.3 in this species.
conclusionKir2.1 and Kir2.3 isoforms form heteromeric channels in HEK293. The presence of Kir2.3 subunit(s) in heteromeric channels confers pH sensitivity to the channels. The single and double stable cells presented in this study are useful models for studying physiologic regulation of heteromeric Kir2 channels in mammalian cells.
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