GO:1905026 positive regulation of membrane repolarization during ventricular cardiac muscle cell action potential: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:1905026 describes any process that activates or increases the frequency, rate or extent of membrane repolarization during ventricular cardiac muscle cell action potential.
• This process shapes the T wave of the electrocardiogram and determines the QT interval, making it central to arrhythmia risk assessment.
• Key ion channels include KCNQ1/KCNE1 (IKs), hERG (IKr), and KCND3 (Ito), whose gating and regulation directly control repolarization speed.
• PRMT1-mediated modulation of IKs channel-PIP2 interaction is a critical control point for cardiac repolarization.
• RyR2-dependent Ca2+ signaling regulates Cx43 hemichannel activation in cardiomyocytes, linking intracellular calcium to repolarization-related electrical stability.
• Electrical stimulation promotes maturation of cardiomyocytes derived from human embryonic stem cells, providing a model to study repolarization development.
Description
GO:1905026, positive regulation of membrane repolarization during ventricular cardiac muscle cell action potential, is a biological process that increases the rate or extent of repolarization in ventricular cardiomyocytes. Repolarization is the phase of the cardiac action potential during which the cell returns to its resting membrane potential, and its timing determines the QT interval and T wave morphology on the electrocardiogram. Disruption of this process can lead to life-threatening arrhythmias, making its positive regulation a key area of cardiovascular research. Experimental studies have shown that modulation of IKs channel-PIP2 interaction by PRMT1 plays a critical role in the control of cardiac repolarization, directly linking protein arginine methylation to repolarization speed. Additionally, the transient outward current (Ito) contributes to the early phase of repolarization and influences mechanical properties of ventricular myocytes. Understanding the molecular players and regulatory mechanisms of GO:1905026 is essential for developing therapeutic strategies against arrhythmias and for interpreting genetic variants associated with sudden cardiac death.
positive regulation of membrane repolarization during ventricular cardiac muscle cell action potential At A Glance
| GO ID | GO:1905026 |
|---|---|
| GO term | positive regulation of membrane repolarization during ventricular cardiac muscle cell action potential |
| Ontology | biological_process |
| Synonym | positive regulation of ventricular repolarization; activation of electrocardiogram T wave; upregulation of membrane repolarization during ventricular cardiac muscle cell action potential |
| Major function | Accelerates the return of ventricular cardiomyocyte membrane potential to resting state, shaping the T wave and QT interval |
| Key ion channels | KCNQ1/KCNE1 (IKs), hERG (IKr), KCND3 (Ito), and their regulatory proteins |
| Regulatory proteins | PRMT1, PIP2, RyR2, Cx43 |
| Associated disease | Long QT syndrome, short QT syndrome, ventricular arrhythmias, sudden cardiac death |
| Research models | Human embryonic stem cell-derived cardiomyocytes, canine ventricular myocytes, heterologous expression systems |
What Is GO:1905026?
GO:1905026 is defined as any process that activates or increases the frequency, rate or extent of membrane repolarization during ventricular cardiac muscle cell action potential. In simpler terms, it covers the molecular events that make ventricular heart muscle cells repolarize faster or more efficiently after an action potential. This includes the opening of potassium channels, the inactivation of calcium and sodium channels, and the modulation of these channels by signaling molecules, all of which accelerate the return of the membrane potential to its resting state.
Why Is positive regulation of membrane repolarization during ventricular cardiac muscle cell action potential Important in Cell Biology?
Positive regulation of membrane repolarization during ventricular cardiac muscle cell action potential is critical because the speed of repolarization determines the duration of the action potential and the QT interval, which are directly linked to arrhythmia susceptibility. Abnormal repolarization can cause early afterdepolarizations and triggered activity, leading to ventricular tachycardia and fibrillation. Understanding how this process is positively regulated offers targets for antiarrhythmic drugs and helps interpret genetic variants in ion channel genes associated with inherited arrhythmia syndromes.
• Determines QT interval and T wave morphology on the electrocardiogram, key clinical markers of arrhythmia risk.
• Dysregulation can lead to long QT syndrome, short QT syndrome, and ventricular arrhythmias.
• IKs channel-PIP2 interaction modulated by PRMT1 is a critical control point for repolarization speed.
• Transient outward current (Ito) influences both electrical and mechanical properties of ventricular myocytes.
• RyR2-mediated calcium signaling regulates Cx43 hemichannel activation, linking calcium handling to electrical stability.
• hERG channel gating is sensitive to divalent cations such as cobalt and lanthanum, affecting repolarization.
• Electrical stimulation promotes maturation of stem cell-derived cardiomyocytes, enabling study of repolarization development.
• Provides a target for antiarrhythmic drug development and safety pharmacology screening.
• Helps interpret genetic variants in KCNQ1, KCNH2, and other channel genes in inherited arrhythmia syndromes.
• Essential for understanding how metabolic and signaling pathways modulate cardiac electrical function.
What Happens During positive regulation of membrane repolarization during ventricular cardiac muscle cell action potential?
Initiation of repolarization by potassium channel activation
In simple terms: Potassium channels open to let positive charge leave the cell, starting the return to resting state.
During the plateau phase of the ventricular action potential, the opening of potassium channels such as IKs (KCNQ1/KCNE1) and IKr (hERG) initiates repolarization. Positive regulation of this process involves increasing the open probability or conductance of these channels, which accelerates the efflux of potassium ions and speeds up the return of the membrane potential to its resting value. The transient outward current (Ito) also contributes to early repolarization, and its modulation affects the overall repolarization rate.
Modulation of IKs channel-PIP2 interaction by PRMT1
In simple terms: A protein called PRMT1 modifies the IKs channel, changing how it interacts with a lipid called PIP2 to control repolarization speed.
PRMT1-mediated arginine methylation of the IKs channel modulates its interaction with phosphatidylinositol 4,5-bisphosphate (PIP2), a critical lipid for channel function. This modulation plays a critical role in the control of cardiac repolarization, as disruption of this interaction alters IKs current amplitude and kinetics, thereby affecting the rate of membrane repolarization. This represents a key positive regulatory mechanism at the molecular level.
Calcium-dependent regulation via RyR2 and Cx43 hemichannels
In simple terms: Calcium release from internal stores activates channels that can influence the electrical stability of heart cells.
RyR2, the cardiac ryanodine receptor, regulates Cx43 hemichannel intracellular Ca2+-dependent activation in cardiomyocytes. This calcium-dependent activation of hemichannels can affect membrane potential and repolarization by allowing ionic fluxes that modulate the electrical environment. Thus, RyR2-mediated calcium signaling indirectly contributes to the regulation of repolarization.
Influence of divalent cations on hERG channel gating
In simple terms: Certain metal ions can change how the hERG potassium channel opens and closes, affecting repolarization.
The hERG potassium channel (IKr) is a major determinant of repolarization. Its gating can be altered by divalent cations such as cobalt and lanthanum, which modify channel opening and closing kinetics. Such alterations can either accelerate or delay repolarization, demonstrating that environmental and ionic factors can positively or negatively regulate this process.
Maturation and electrical stimulation in cardiomyocyte models
In simple terms: Electrical pacing helps heart cells grown from stem cells mature so they repolarize more like adult heart cells.
Electrical stimulation promotes maturation of cardiomyocytes derived from human embryonic stem cells, leading to more adult-like action potential profiles including repolarization characteristics. This maturation process involves changes in ion channel expression and function, providing a model to study the development and regulation of repolarization.
Key Genes Involved in GO:1905026 positive regulation of membrane repolarization during ventricular cardiac muscle cell action potential
The following genes and proteins are central to the positive regulation of membrane repolarization during ventricular cardiac muscle cell action potential, based on experimental evidence from the cited literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| KCNQ1 | Alpha subunit of IKs potassium channel; mediates slow delayed rectifier current | Mutations cause long QT syndrome; target for repolarization-prolonging drugs |
| KCNE1 | Beta subunit of IKs channel; modulates channel kinetics and PIP2 sensitivity | Essential for IKs function; interacts with PRMT1 regulation |
| KCNH2 (hERG) | Alpha subunit of IKr potassium channel; rapid delayed rectifier current | Blockade causes acquired long QT; gating affected by divalent cations |
| KCND3 | Alpha subunit of Ito transient outward current | Contributes to early repolarization; influences mechanical properties |
| PRMT1 | Protein arginine methyltransferase; methylates IKs channel to modulate PIP2 interaction | Critical regulator of cardiac repolarization |
| PIP2 | Phosphatidylinositol 4,5-bisphosphate; lipid that regulates ion channel activity | Interaction with IKs channel controlled by PRMT1 |
| RYR2 | Ryanodine receptor 2; mediates calcium release from sarcoplasmic reticulum | Regulates Cx43 hemichannel activation and electrical stability |
| GJA1 (Cx43) | Connexin 43; forms gap junction and hemichannels | Ca2+-dependent activation regulated by RyR2 |
| SCN5A | Voltage-gated sodium channel; responsible for phase 0 depolarization | Inactivation kinetics influence repolarization timing |
| CACNA1C | L-type calcium channel; maintains plateau phase | Inactivation contributes to repolarization onset |
| KCNJ2 | Inward rectifier potassium channel; sets resting potential | Modulates final phase of repolarization |
| ATP1A1 | Na+/K+-ATPase; maintains ionic gradients | Indirectly supports repolarization by restoring ion balance |
| CALM1 | Calmodulin; calcium sensor | Regulates calcium-dependent inactivation of channels |
| CAMK2D | Calcium/calmodulin-dependent protein kinase II | Phosphorylates ion channels and modulates repolarization |
| PRKACA | Protein kinase A catalytic subunit | Phosphorylates IKs and other channels, affecting repolarization |
| PPP1CA | Protein phosphatase 1 catalytic subunit | Dephosphorylates channels, counteracting kinase effects |
| KCNE2 | Beta subunit for various potassium channels | Modulates IKr and IKs currents |
| KCNE3 | Beta subunit that modulates Kv channels | Can influence repolarization reserve |
How Is positive regulation of membrane repolarization during ventricular cardiac muscle cell action potential Regulated?
The positive regulation of membrane repolarization during ventricular cardiac muscle cell action potential is tightly controlled by multiple signaling pathways. PRMT1-mediated methylation of the IKs channel modulates its interaction with PIP2, thereby controlling repolarization speed. Protein kinases such as PKA and CAMK2D can phosphorylate ion channels, altering their gating and contributing to repolarization regulation. Calcium release via RyR2 activates Cx43 hemichannels, which can influence membrane potential and thus repolarization. Additionally, divalent cations like cobalt and lanthanum can directly alter hERG channel gating, providing another layer of regulation. These mechanisms collectively ensure appropriate repolarization timing and electrical stability.
positive regulation of membrane repolarization during ventricular cardiac muscle cell action potential and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| KCNQ1 | Long QT syndrome type 1 | Knockout or point-mutation iPSC-derived cardiomyocytes |
| KCNH2 | Long QT syndrome type 2; drug-induced arrhythmia | hERG overexpression or knockout HEK293 cells; cardiomyocytes |
| RYR2 | Catecholaminergic polymorphic ventricular tachycardia | RyR2 knock-in mouse; patient-derived iPSC cardiomyocytes |
| GJA1 (Cx43) | Arrhythmogenic cardiomyopathy; electrical uncoupling | Cx43 knockout or knock-in cardiomyocytes |
| PRMT1 | Arrhythmia susceptibility via IKs modulation | PRMT1 knockout or overexpression in cardiomyocytes |
Long QT Syndrome and Ventricular Arrhythmias
Impaired positive regulation of repolarization can lead to delayed repolarization, manifesting as prolonged QT interval and increased risk of torsades de pointes and ventricular fibrillation. Mutations in KCNQ1, KCNH2, and other channel genes reduce IKs or IKr currents, slowing repolarization. PRMT1-mediated modulation of IKs is critical; its disruption may contribute to arrhythmogenesis.
Short QT Syndrome
Excessive positive regulation of repolarization can cause accelerated repolarization, resulting in short QT interval and increased risk of atrial and ventricular fibrillation. Gain-of-function mutations in potassium channels or enhanced channel activity can underlie this condition.
Calcium Handling Disorders and Arrhythmias
RyR2 dysfunction leads to aberrant calcium release, which can activate Cx43 hemichannels and alter repolarization, contributing to arrhythmias such as catecholaminergic polymorphic ventricular tachycardia.
From positive regulation of membrane repolarization during ventricular cardiac muscle cell action potential-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of PRMT1 affect IKs-PIP2 interaction and repolarization? | PRMT1 knockout cardiomyocytes (CRISPR KO) |
| How do point mutations in KCNQ1 alter IKs gating? | KCNQ1 point-mutation knock-in iPSC-derived cardiomyocytes |
| Can overexpression of KCNE1 accelerate repolarization? | KCNE1 overexpression in HEK293 or cardiomyocytes |
| What is the role of RyR2 in Cx43 hemichannel activation? | RyR2 knockout or point-mutation cardiomyocytes |
| Does electrical stimulation mature repolarization in stem cell-derived cardiomyocytes? | Human embryonic stem cell-derived cardiomyocytes with electrical pacing |
| How do divalent cations affect hERG gating? | hERG overexpression in heterologous cells with cobalt/lanthanum treatment |
How to Study the positive regulation of membrane repolarization during ventricular cardiac muscle cell action potential Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Patch-clamp | Action potential duration, ionic currents | Assess repolarization speed in cardiomyocytes |
| Calcium imaging | Intracellular Ca2+ transients | Study RyR2 and Cx43 hemichannel activation |
| CRISPR-Cas9 knockout | Gene function loss | Determine causal role of PRMT1, KCNQ1, etc. |
| CRISPR point mutation | Specific amino acid changes | Model inherited arrhythmia mutations |
| Overexpression | Gain-of-function effects | Test KCNE1 or hERG overexpression |
| RNA-seq | Transcriptome changes | Identify repolarization-related gene networks |
| Proteomics | Protein expression and modifications | Detect PRMT1-mediated methylation |
| Electrical stimulation | Cardiomyocyte maturation | Enhance repolarization properties in stem cell-derived cells |
Patch-Clamp Electrophysiology
Patch-clamp recordings measure action potentials and ionic currents (IKs, IKr, Ito) in cardiomyocytes to directly assess repolarization speed and the effects of genetic or pharmacological manipulations.
Calcium Imaging and Hemichannel Assays
Calcium imaging using fluorescent dyes or genetically encoded indicators monitors intracellular Ca2+ dynamics, while hemichannel activity can be assessed by dye uptake assays to study RyR2-Cx43 coupling.
CRISPR-Cas9 Genome Editing
CRISPR-Cas9 is used to create knockout, point-mutation, or knock-in models in cardiomyocytes or cell lines to dissect the causal roles of specific genes in repolarization.
Transcriptomics and Proteomics
RNA-seq and proteomics can quantify expression changes in ion channels and regulatory proteins under conditions that alter repolarization, identifying novel regulators.
How CRISPR Can Be Used to Study GO:1905026 positive regulation of membrane repolarization during ventricular cardiac muscle cell action potential
Knockout
CRISPR knockout of genes such as PRMT1, KCNQ1, or RYR2 in cardiomyocytes or cell lines can reveal their essential roles in repolarization. For example, PRMT1 knockout would test its requirement for IKs-PIP2 interaction and normal repolarization.
Point Mutation
Introducing disease-associated point mutations (e.g., in KCNH2 or KCNQ1) via CRISPR allows precise modeling of inherited arrhythmia syndromes and assessment of repolarization defects.
Knock-in
Knock-in of reporter tags or human disease alleles into endogenous loci enables tracking of channel trafficking and function in a physiological context, providing insights into repolarization regulation.
Overexpression
CRISPR activation or lentiviral overexpression of genes like KCNE1 or hERG can test gain-of-function effects on repolarization speed and identify therapeutic targets.
How EDITGENE Supports positive regulation of membrane repolarization during ventricular cardiac muscle cell action potential Research
Researchers studying positive 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 repolarization or merely correlated with it. EDITGENE provides a comprehensive suite of CRISPR-based services to enable such causal studies in relevant cardiac cell models.
Contact EDITGENE today to design your custom CRISPR model for positive regulation of membrane repolarization during ventricular cardiac muscle cell action potential research.
Frequently Asked Questions About positive regulation of membrane repolarization during ventricular cardiac muscle cell action potential
What is GO:1905026?
GO:1905026 is a Gene Ontology biological process term defined as any process that activates or increases the frequency, rate or extent of membrane repolarization during ventricular cardiac muscle cell action potential.
What genes are involved in positive regulation of membrane repolarization during ventricular cardiac muscle cell action potential?
Key genes include KCNQ1, KCNE1, KCNH2 (hERG), KCND3, PRMT1, RYR2, and GJA1 (Cx43), among others.
How does PRMT1 regulate cardiac repolarization?
PRMT1 modulates the interaction between IKs channels and PIP2, which is critical for controlling repolarization speed.
What is the role of hERG in repolarization?
hERG encodes the IKr potassium channel, a major determinant of repolarization; its gating can be altered by divalent cations like cobalt and lanthanum.
How is RyR2 linked to repolarization?
RyR2 regulates Cx43 hemichannel activation in a calcium-dependent manner, which can influence membrane potential and repolarization.
What diseases are associated with abnormal repolarization?
Long QT syndrome, short QT syndrome, and ventricular arrhythmias are associated with impaired or excessive repolarization.
Can electrical stimulation affect cardiomyocyte repolarization?
Yes, electrical stimulation promotes maturation of human embryonic stem cell-derived cardiomyocytes, leading to more adult-like repolarization properties.
What methods are used to study repolarization?
Patch-clamp electrophysiology, calcium imaging, CRISPR genome editing, and omics approaches are commonly used.
How can CRISPR help study repolarization genes?
CRISPR allows knockout, point mutation, knock-in, and overexpression of specific genes to test their causal roles in repolarization.
What is the clinical significance of the T wave?
The T wave on the electrocardiogram reflects ventricular repolarization; its abnormalities indicate repolarization defects and arrhythmia risk.
Conclusion
GO:1905026, positive regulation of membrane repolarization during ventricular cardiac muscle cell action potential, is a fundamental biological process that ensures proper electrical recovery of the heart. Its dysregulation underlies life-threatening arrhythmias, and key molecular players such as PRMT1, IKs, hERG, and RyR2 are promising therapeutic targets. Continued research using advanced CRISPR models and electrophysiological techniques will deepen our understanding and aid in the development of safer antiarrhythmic therapies.
References
- 1. An X et al.. 2022. Modulation of I(Ks) channel-PIP(2) interaction by PRMT1 plays a critical role in the control of cardiac repolarization.. J Cell Physiol 237(7):3069-3079 PMID: 35580065
- 2. Lissoni A et al.. 2021. RyR2 regulates Cx43 hemichannel intracellular Ca2+-dependent activation in cardiomyocytes.. Cardiovasc Res 117(1):123-136 PMID: 31841141
- 3. Dong M et al.. 2010. Role of the transient outward current in regulating mechanical properties of canine ventricular myocytes.. J Cardiovasc Electrophysiol 21(6):697-703 PMID: 20132386
- 4. Chan YC et al.. 2013. Electrical stimulation promotes maturation of cardiomyocytes derived from human embryonic stem cells.. J Cardiovasc Transl Res 6(6):989-99 PMID: 24081385
- 5. Sanchez-Chapula JA et al.. 2000. Altered gating of HERG potassium channels by cobalt and lanthanum.. Pflugers Arch 440(2):264-74 PMID: 10898527
