GO:1905024 regulation of membrane repolarization during ventricular cardiac muscle cell action potential: Mechanism, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:1905024 describes any process that modulates the frequency, rate or extent of membrane repolarization during the ventricular cardiac muscle cell action potential, a biological_process central to normal heart rhythm.
• Repolarization of ventricular myocytes is driven by the coordinated decline of inward Na+ and Ca2+ currents and the activation of outward K+ currents, including Ito, IKur, IKr, IKs, IK1 and IK-AHP.
• Dysregulation of this process produces action potential duration prolongation or shortening, which underlies arrhythmia syndromes and is reflected in the electrocardiogram T wave.
• Key molecular players include voltage-gated Na+ channels (SCN5A), K+ channels (KCND3, KCNQ1, KCNH2, KCNJ2, KCNN2), auxiliary subunits (KCNE1, KCNE2, KCNE3, KCNIP2, FGF13) and structural proteins such as dystrophin.
• Hormonal and non-transcriptional regulation, for example by testosterone, can acutely modify repolarization currents and action potential duration.
• CRISPR-based knockout, point-mutation, knock-in and overexpression models enable causal testing of candidate genes in this pathway, and EDITGENE provides these services together with library screening and bioinformatics support.
Description
GO:1905024, regulation of membrane repolarization during ventricular cardiac muscle cell action potential, is a Gene Ontology biological_process term that captures all regulatory inputs controlling the return of the ventricular myocyte membrane potential to its resting state after excitation. Repolarization is not a passive decay but an actively regulated electrical event, and its timing determines the QT interval and T wave on the electrocardiogram. Because repolarization depends on a delicate balance between depolarizing inward currents and repolarizing outward currents, even modest changes in channel expression, trafficking or gating can shift action potential duration and create arrhythmogenic substrate. At the cellular level, the ventricular action potential is shaped by the fast inward Na+ current, the L-type Ca2+ current, and multiple K+ currents that activate and inactivate with distinct voltage and time dependencies. The ultra-rapid delayed rectifier current, the rapid and slow delayed rectifier currents, the inward rectifier current and small-conductance Ca2+-activated K+ currents all contribute to different phases of repolarization. Regulatory mechanisms include transcriptional and non-transcriptional control, subunit assembly, membrane trafficking and post-translational modification of channel proteins. For researchers, GO:1905024 provides a precise annotation target for functional genomics, disease modeling and drug discovery. Mutations or altered expression of repolarization genes are linked to long QT syndrome, short QT syndrome, Brugada syndrome and acquired arrhythmias, and the pathway is a major focus of antiarrhythmic drug development. Systematic interrogation of this process with CRISPR models, electrophysiology and transcriptomics is therefore essential for understanding both inherited and acquired electrical disease.
regulation of membrane repolarization during ventricular cardiac muscle cell action potential At A Glance
| GO ID | GO:1905024 |
|---|---|
| GO term | regulation of membrane repolarization during ventricular cardiac muscle cell action potential |
| Ontology | biological_process |
| Synonym | regulation of electrocardiogram T wave; regulation of ventricular cardiac muscle repolarization; regulation of ventricular repolarization |
| Definition | Any process that modulates the frequency, rate or extent of membrane repolarization during ventricular cardiac muscle cell action potential. |
| Major function | Controls the timing and extent of ventricular myocyte repolarization, thereby shaping action potential duration and the ECG T wave. |
| Key currents | Transient outward (Ito), ultra-rapid delayed rectifier (IKur), rapid delayed rectifier (IKr), slow delayed rectifier (IKs), inward rectifier (IK1) and small-conductance Ca2+-activated K+ (IK-AHP) currents. |
| Representative genes | SCN5A, KCND3, KCNQ1, KCNH2, KCNJ2, KCNN2, KCNE1, KCNE2, KCNE3, KCNIP2, FGF13, DMD. |
| Disease relevance | Long QT syndrome, short QT syndrome, Brugada syndrome, dystrophin-deficient cardiomyopathy and drug-induced arrhythmia. |
What Is GO:1905024?
In our own words, GO:1905024 encompasses any biological process that changes the frequency, rate or extent of membrane repolarization specifically during the ventricular cardiac muscle cell action potential. It includes modulation of the ion currents, channel subunits and signaling events that restore the ventricular myocyte membrane potential after depolarization, and it is distinct from repolarization in atrial or nodal cells.
Why Is regulation of membrane repolarization during ventricular cardiac muscle cell action potential Important in Cell Biology?
Regulation of ventricular repolarization is a core determinant of cardiac electrical stability. Because the ventricular action potential duration sets the QT interval and the T wave, even small regulatory changes can produce arrhythmogenic early afterdepolarizations or reentrant circuits. The process integrates multiple ion channel families, auxiliary subunits and signaling pathways, making it a rich but vulnerable node for genetic and pharmacological perturbation. Understanding GO:1905024 is therefore essential for interpreting ECG phenotypes, modeling inherited arrhythmia syndromes and developing safer antiarrhythmic therapies.
• Determines action potential duration and the ECG T wave, making it a direct readout of ventricular electrical function.
• Dysregulation causes long QT and short QT syndromes, which predispose to torsades de pointes and sudden cardiac death.
• Contributes to Brugada syndrome and other inherited arrhythmia phenotypes through altered Na+ and K+ current balance.
• Is impaired in dystrophin-deficient cardiomyocytes, linking muscular dystrophy to ventricular arrhythmia risk.
• Is a major mechanism of drug-induced cardiotoxicity, since many drugs block IKr and prolong repolarization.
• Involves non-transcriptional hormonal regulation, exemplified by testosterone modulation of repolarization currents.
• Requires precise trafficking and localization of channels such as connexin 43 and FGF13-dependent pathways.
• Provides a target for antiarrhythmic strategies including small-conductance Ca2+-activated K+ channel modulation.
• Serves as a functional annotation endpoint for CRISPR screens and variant interpretation in cardiac genetics.
• Underpins personalized medicine approaches that match antiarrhythmic therapy to a patient's repolarization genotype.
What Happens During regulation of membrane repolarization during ventricular cardiac muscle cell action potential?
Phase 1: Early repolarization and Ito
In simple terms: The first quick dip in voltage happens when potassium leaves the cell through transient outward channels.
After the rapid upstroke of the ventricular action potential, the transient outward potassium current Ito produces early phase 1 repolarization. Ito is carried by Kv4.x channels, including KCND3, and is modulated by auxiliary subunits such as KCNIP2. Regulation of this early phase influences the plateau voltage and the subsequent recruitment of other repolarizing currents.
Phase 2: Plateau and calcium balance
In simple terms: During the plateau, calcium entering the cell is balanced against potassium leaving, keeping the voltage high for a controlled time.
The plateau phase reflects a balance between inward L-type Ca2+ current and outward K+ currents. Ultra-rapid delayed rectifier current IKur, carried by KCNA5/Kv1.5 in some species, and other K+ currents counteract calcium entry. Regulatory modulation of these currents determines plateau duration and the transition to phase 3 repolarization.
Phase 3: Rapid and slow delayed rectifier currents
In simple terms: The main falling phase of the action potential is driven by potassium channels that open slowly and then close.
Phase 3 repolarization is dominated by IKr and IKs. IKr is carried by hERG (KCNH2) with KCNE2 as an auxiliary subunit, while IKs is carried by KCNQ1 with KCNE1. These channels activate slowly and their regulation by subunits, phosphorylation and trafficking controls the rate of repolarization and the QT interval.
Phase 4: Resting potential and IK1
In simple terms: Between beats, an inward rectifier current keeps the cell at its resting voltage.
The inward rectifier potassium current IK1, carried by KCNJ2 (Kir2.1), stabilizes the resting membrane potential and contributes to the final phase of repolarization. Reduced IK1, as observed in dystrophin-deficient cardiomyocytes, can prolong the action potential and increase arrhythmia susceptibility.
Calcium-activated and mitochondrial modulation
In simple terms: Calcium released inside the cell can open special potassium channels that help end the beat.
Small-conductance Ca2+-activated K+ channels, including KCNN2, contribute to the afterhyperpolarization current IK-AHP and link intracellular calcium handling to repolarization. Mitochondrial calcium and reactive oxygen species can further modulate these channels, bridging excitation-contraction coupling with repolarization control.
Non-transcriptional and hormonal regulation
In simple terms: Hormones and signaling molecules can change repolarization quickly without altering gene expression.
Repolarization currents are subject to acute regulation independent of transcription. Testosterone, for example, can modify cardiac repolarization currents and action potential duration, illustrating how hormonal status influences electrical phenotype. Such non-transcriptional control adds another layer to GO:1905024 beyond channel gene expression.
Key Genes Involved in GO:1905024 regulation of membrane repolarization during ventricular cardiac muscle cell action potential
The following genes and proteins are established contributors to regulation of membrane repolarization during the ventricular cardiac muscle cell action potential, based on electrophysiological and molecular studies.
| Gene | Major Role | Research Relevance |
|---|---|---|
| SCN5A | Voltage-gated sodium channel alpha subunit; determines upstroke and influences repolarization reserve | Mutations cause Brugada syndrome and long QT syndrome type 3 |
| KCND3 | Pore-forming subunit of transient outward potassium current Ito | Modulates early repolarization and action potential plateau |
| KCNIP2 | Auxiliary subunit regulating Kv4 channels and Ito | Controls Ito density and repolarization timing |
| KCNQ1 | Pore-forming subunit of slow delayed rectifier current IKs | Mutations cause long QT syndrome type 1 |
| KCNE1 | Beta subunit of IKs | Modulates IKs gating and repolarization rate |
| KCNH2 | Pore-forming subunit of rapid delayed rectifier current IKr (hERG) | Mutations and drug block cause long QT syndrome type 2 |
| KCNE2 | Beta subunit of IKr | Modulates IKr and drug sensitivity |
| KCNJ2 | Pore-forming subunit of inward rectifier current IK1 | Reduced IK1 prolongs action potential in dystrophin deficiency |
| KCNN2 | Small-conductance Ca2+-activated K+ channel contributing to IK-AHP | Links calcium handling to repolarization and antiarrhythmic therapy |
| FGF13 | Fibroblast growth factor homologous factor regulating sodium channel and connexin 43 trafficking | Modulates impulse propagation and repolarization indirectly |
| DMD | Dystrophin, a cytoskeletal protein affecting membrane stability and ion channel localization | Dystrophin deficiency reduces IK1 and alters repolarization |
| Cx43 (GJA1) | Connexin 43 gap junction protein | Trafficking regulated by FGF13 and influences electrical coupling |
| KCNA5 | Pore-forming subunit of ultra-rapid delayed rectifier current IKur | Contributes to atrial and ventricular repolarization in some species |
| KCNE3 | Beta subunit modulating K+ channel complexes | Modifies repolarizing current properties |
| CACNA1C | L-type calcium channel alpha subunit | Balances inward calcium against outward potassium during plateau |
| ATP2A2 (SERCA2a) | Sarcoplasmic reticulum calcium ATPase | Indirectly influences calcium-activated repolarization currents |
| RYR2 | Ryanodine receptor calcium release channel | Calcium release modulates IK-AHP and repolarization |
How Is regulation of membrane repolarization during ventricular cardiac muscle cell action potential Regulated?
Regulation of membrane repolarization during ventricular cardiac muscle cell action potential is controlled at multiple levels. Transcriptional programs set the expression levels of channel genes, while auxiliary subunits such as KCNE1, KCNE2, KCNE3 and KCNIP2 modify gating and trafficking. Non-transcriptional mechanisms, including hormonal modulation by testosterone, can acutely alter repolarization currents. Intracellular calcium and mitochondrial signaling regulate small-conductance Ca2+-activated K+ channels and thereby IK-AHP. In addition, trafficking pathways involving FGF13 and connexin 43 influence the surface availability of channels and gap junctions that shape electrical behavior. Together, these layers allow the ventricular myocyte to tune repolarization in response to physiological and pathological stimuli.
regulation of membrane repolarization during ventricular cardiac muscle cell action potential and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| KCNH2 | Long QT syndrome type 2 and drug-induced arrhythmia | Knockout or point-mutation iPSC-derived cardiomyocytes with electrophysiology |
| KCNQ1 | Long QT syndrome type 1 | Knock-in of patient variants in cardiomyocytes followed by action potential recording |
| SCN5A | Brugada syndrome and long QT syndrome type 3 | Point-mutation knock-in models to study sodium current inactivation |
| DMD | Dystrophin-deficient cardiomyopathy with repolarization defects | Dystrophin knockout cardiomyocytes to measure IK1 and action potential duration |
| KCNN2 | Calcium-dependent arrhythmia mechanisms | Overexpression or knockout models to test IK-AHP modulation |
Inherited arrhythmia syndromes
Mutations in genes encoding repolarization currents cause long QT syndrome, short QT syndrome and Brugada syndrome. Loss-of-function of KCNQ1 or KCNH2 reduces IKs or IKr, prolonging action potential duration and increasing risk of torsades de pointes. Gain-of-function changes can shorten repolarization and predispose to fibrillation.
Dystrophin-deficient cardiomyopathy
In dystrophin-deficient ventricular cardiomyocytes, decreased inward rectifier potassium current IK1 alters repolarization and contributes to arrhythmia susceptibility in muscular dystrophy. This links a structural protein to electrical remodeling through GO:1905024.
Drug-induced cardiotoxicity
Many pharmacological agents block IKr and prolong ventricular repolarization, producing acquired long QT syndrome. Because IKr is a central node in GO:1905024, preclinical assessment of repolarization liability is essential for drug safety.
Calcium-dependent arrhythmias
Altered calcium handling and small-conductance Ca2+-activated K+ channel function can modify repolarization and create substrates for afterdepolarizations. Targeting these channels is an emerging antiarrhythmic strategy.
From regulation of membrane repolarization during ventricular cardiac muscle cell action potential-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of a candidate gene prolong ventricular repolarization? | CRISPR knockout in iPSC-derived cardiomyocytes or animal models |
| Does a patient variant alter channel gating? | Point-mutation knock-in of the specific variant followed by patch clamp |
| Can a reporter track channel expression during repolarization? | Tagged knock-in of the endogenous locus with fluorescent protein |
| Does overexpression of an auxiliary subunit change action potential duration? | Overexpression cell model with electrophysiological readout |
| Which genes modify repolarization in a genome-wide manner? | CRISPR library screening combined with voltage or calcium imaging |
| How does hormonal signaling acutely regulate repolarization? | Pharmacological or overexpression models with acute current recording |
How to Study the regulation of membrane repolarization during ventricular cardiac muscle cell action potential Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Patch clamp | Ionic currents and action potential duration | Assigning function to channel genes |
| Optical mapping | Spatiotemporal repolarization patterns | Detecting arrhythmia substrates in monolayers |
| RNA-seq | Transcript levels of ion channel genes | Expression profiling after perturbation |
| Proteomics | Protein abundance and modifications | Identifying channel complex components |
| CRISPR screen | Gene effects on repolarization phenotype | Unbiased discovery of regulators |
| Calcium imaging | Intracellular calcium transients | Linking calcium handling to repolarization |
| Immunofluorescence | Subcellular localization of channels | Assessing trafficking and membrane targeting |
| ECG telemetry | In vivo QT interval and T wave | Preclinical drug safety assessment |
Patch clamp electrophysiology
Single-cell voltage clamp and current clamp directly measure the ionic currents and action potential duration that define repolarization. This method remains the gold standard for assigning function to candidate genes in GO:1905024.
Optical mapping and voltage-sensitive dyes
Optical mapping with voltage-sensitive dyes allows simultaneous recording of action potential duration and repolarization heterogeneity across cell monolayers or whole hearts, revealing arrhythmogenic substrates.
Transcriptomics and RNA-seq
RNA sequencing quantifies expression of ion channel and subunit genes after genetic or pharmacological perturbation, linking transcriptional changes to repolarization phenotypes.
Proteomics and interactomics
Mass spectrometry-based proteomics identifies channel complexes and post-translational modifications that regulate trafficking and gating of repolarization proteins.
CRISPR screening with functional readouts
Pooled CRISPR screens coupled to voltage or calcium imaging can identify novel regulators of ventricular repolarization, providing unbiased gene discovery for GO:1905024.
How CRISPR Can Be Used to Study GO:1905024 regulation of membrane repolarization during ventricular cardiac muscle cell action potential
Knockout
CRISPR knockout of candidate genes such as KCNH2, KCNQ1 or KCNJ2 in cardiomyocyte models removes the corresponding current and reveals its contribution to repolarization. Loss-of-function models are used to measure action potential duration prolongation and arrhythmia inducibility.
Point Mutation
Point-mutation knock-in introduces patient-specific variants into endogenous loci, preserving physiological expression levels. This approach is ideal for studying gating changes in SCN5A, KCNH2 or KCNQ1 that alter repolarization without confounding overexpression artifacts.
Knock-in
Tagged knock-in of channel genes with fluorescent or epitope tags enables real-time tracking of protein trafficking and localization, which is critical for understanding how FGF13 and connexin 43 regulate electrical coupling and repolarization.
Overexpression
Overexpression of auxiliary subunits such as KCNE1 or KCNIP2 in cell models can shift current properties and action potential duration, allowing gain-of-function studies that complement knockout approaches.
How EDITGENE Supports regulation of membrane repolarization during ventricular cardiac muscle cell action potential Research
Researchers studying regulation of membrane repolarization during ventricular cardiac muscle cell action potential-related genes often need to determine whether a candidate gene is causally involved in setting action potential duration, whether a specific variant alters channel function, and how the gene behaves in a physiological context. EDITGENE provides the CRISPR tools and cell models required to answer these questions with rigor and reproducibility.
Contact EDITGENE today to design your custom CRISPR model for regulation of membrane repolarization during ventricular cardiac muscle cell action potential research.
Frequently Asked Questions About regulation of membrane repolarization during ventricular cardiac muscle cell action potential
What is GO:1905024?
GO:1905024 is a Gene Ontology biological_process term defined as any process that modulates the frequency, rate or extent of membrane repolarization during ventricular cardiac muscle cell action potential.
What genes are involved in regulation of membrane repolarization during ventricular cardiac muscle cell action potential?
Key genes include SCN5A, KCND3, KCNQ1, KCNH2, KCNJ2, KCNN2, KCNE1, KCNE2, KCNE3, KCNIP2, FGF13 and DMD, which encode ion channels, subunits and regulatory proteins.
Why is ventricular repolarization important?
It determines action potential duration and the ECG T wave, and its dysregulation causes long QT syndrome, short QT syndrome and drug-induced arrhythmias.
Which potassium currents drive ventricular repolarization?
Ito, IKur, IKr, IKs, IK1 and IK-AHP are the principal repolarizing potassium currents in ventricular myocytes.
How does testosterone affect cardiac repolarization?
Testosterone can modulate repolarization currents and action potential duration through non-transcriptional mechanisms.
What happens to repolarization in dystrophin deficiency?
Dystrophin-deficient ventricular cardiomyocytes show decreased inward rectifier potassium current IK1, which alters repolarization and increases arrhythmia risk.
How can I study regulation of ventricular repolarization in the lab?
Patch clamp, optical mapping, RNA-seq, proteomics and CRISPR screening are commonly used to measure currents, action potentials and gene effects.
What CRISPR models are useful for repolarization research?
Knockout, point-mutation knock-in, tagged knock-in and overexpression models in cardiomyocytes allow causal testing of candidate genes.
Which diseases are linked to GO:1905024?
Long QT syndrome, short QT syndrome, Brugada syndrome, dystrophin-deficient cardiomyopathy and drug-induced cardiotoxicity are linked to altered ventricular repolarization.
How does FGF13 influence cardiac electrical function?
FGF13 regulates voltage-gated sodium channel-independent impulse propagation via connexin 43 trafficking, indirectly affecting electrical behavior and repolarization.
Conclusion
GO:1905024 captures the regulatory control of ventricular myocyte repolarization, a process that integrates multiple ion currents, auxiliary subunits and signaling pathways to shape the action potential and ECG T wave. Its dysfunction underlies inherited and acquired arrhythmia syndromes, making it a central target for cardiac research and drug safety assessment. CRISPR-based models, combined with electrophysiology and multi-omics, provide a powerful framework for dissecting the causal genes and mechanisms within this term.
References
- 1. Rubi L et al.. 2017. Decreased inward rectifier potassium current I(K1) in dystrophin-deficient ventricular cardiomyocytes.. Channels (Austin) 11(2):101-108 PMID: 27560040
- 2. Das LT et al.. 2025. FGF13 Regulates VGSC-Independent Cardiomyocyte Impulse Propagation via Cx43 Trafficking.. Circ Res 137(12):1522-1539 PMID: 41200819
- 3. Mangold KE et al.. 2017. Mechanisms and models of cardiac sodium channel inactivation.. Channels (Austin) 11(6):517-533 PMID: 28837385
- 4. Varró A et al.. 1992. The impact of single cell voltage clamp on the understanding of the cardiac ventricular action potential.. Cardioscience 3(3):131-44 PMID: 1384746
- 5. Li E et al.. 2024. The network of cardiac K(IR)2.1: its function, cellular regulation, electrical signaling, diseases and new drug avenues.. Naunyn Schmiedebergs Arch Pharmacol 397(9):6369-6389 PMID: 38683369
- 6. Bai CX et al.. 2005. Nontranscriptional regulation of cardiac repolarization currents by testosterone.. Circulation 112(12):1701-10 PMID: 16157773
- 7. Terentyev D et al.. 2026. Small-conductance Ca(2)⁺-activated K⁺ channels in cardiac excitation-contraction coupling: Bridging mitochondria, sarcolemma and antiarrhythmic therapy.. J Physiol 604(16):6691-6703 PMID: 41347808
- 8. Ravens U et al.. 2011. Ultra-rapid delayed rectifier channels: molecular basis and therapeutic implications.. Cardiovasc Res 89(4):776-85 PMID: 21159668
