GO:0086055 Purkinje myocyte to ventricular cardiac muscle cell communication by electrical coupling: Cardiac Conduction Pathway, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0086055 describes the biological process by which electrical current flows directly between a Purkinje myocyte and a ventricular cardiac muscle cell through intercellular protein channels, enabling rapid, synchronized ventricular activation.
• This process is essential for normal cardiac excitation-contraction coupling; disruption leads to arrhythmias and conduction block.
• Connexin43 (GJA1) is the principal gap junction protein mediating this electrical coupling in the postnatal heart.
• Computational multiscale modeling of the Purkinje system is a key research method for studying this process.
• Experimental modulation of coupling resistance between Purkinje and ventricular myocytes reveals its role in repolarization and action potential duration.
• CRISPR-based gene editing enables precise interrogation of genes such as GJA1 in this communication pathway.
Description
The biological process defined by GO:0086055, Purkinje myocyte to ventricular cardiac muscle cell communication by electrical coupling, is a specialized form of intercellular signaling that ensures the rapid and coordinated spread of electrical excitation from the cardiac conduction system to the working myocardium. This process is fundamental for normal heart rhythm and pump function, as it directly governs the timing and synchrony of ventricular contraction. Researchers study this process to understand the mechanisms of cardiac arrhythmias, conduction disorders, and the development of the ventricular activation pattern. The term encompasses the transfer of current between adjacent cytoplasms of a Purkinje myocyte and a ventricular cardiac muscle cell via intercellular protein channels, primarily gap junctions.
Purkinje myocyte to ventricular cardiac muscle cell communication by electrical coupling At A Glance
| GO ID | GO:0086055 |
|---|---|
| GO term | Purkinje myocyte to ventricular cardiac muscle cell communication by electrical coupling |
| Ontology | biological_process |
| Synonym | None |
| Major function | Transfer of electrical current between Purkinje myocytes and ventricular cardiac muscle cells via intercellular protein channels |
| Cellular components involved | Gap junctions, connexin proteins (e.g., Connexin43), intercalated discs |
| Key physiological role | Synchronization of ventricular activation and contraction |
| Associated genes | GJA1 (Connexin43), other connexins |
| Research methods | Multiscale modeling, electrophysiology, gap junction blockers, genetic manipulation |
What Is GO:0086055?
GO:0086055 is defined as the process that mediates signaling interactions between a Purkinje myocyte and a ventricular cardiac muscle cell by transfer of current between their adjacent cytoplasms via intercellular protein channels. In simpler terms, it is the electrical handshake between the heart's fast conduction fibers (Purkinje cells) and the main pumping muscle cells (ventricular myocytes), allowing the electrical signal to pass directly from one cell to the next through specialized channels.
Why Is Purkinje myocyte to ventricular cardiac muscle cell communication by electrical coupling Important in Cell Biology?
This process is critical for the heart's ability to pump blood effectively. It ensures that the electrical impulse generated by the sinoatrial node is rapidly transmitted through the Purkinje network and then to the ventricular muscle cells in a coordinated manner, allowing the ventricles to contract almost simultaneously. Disruptions in this communication pathway can lead to lethal arrhythmias, such as ventricular tachycardia and fibrillation, and are implicated in various cardiac diseases.
• Essential for normal cardiac rhythm and efficient pumping.
• Dysfunction leads to conduction block and arrhythmias.
• Key to understanding the epicardial activation pattern in the postnatal heart.
• Target for anti-arrhythmic drug development.
• Involved in cardiac development and maturation.
• Provides a model for studying gap junction communication.
• Relevant to inherited cardiac conditions like arrhythmogenic right ventricular cardiomyopathy.
• Important for tissue engineering and regenerative medicine approaches to cardiac repair.
• Enables computational modeling of cardiac electrophysiology.
• Helps explain sex differences in cardiac conduction.
What Happens During Purkinje myocyte to ventricular cardiac muscle cell communication by electrical coupling?
Initiation of the electrical signal in Purkinje myocytes
In simple terms: The electrical signal arrives at the Purkinje cell.
The process begins when an action potential reaches the terminal branches of the Purkinje network. Purkinje myocytes are specialized for rapid conduction, and their action potential is characterized by a fast upstroke and a prominent plateau phase. This electrical activity is driven by ion channels, and the signal must be transmitted to the adjacent ventricular muscle cells to ensure coordinated contraction.
Gap junction coupling between Purkinje and ventricular myocytes
In simple terms: The Purkinje cell and the ventricular cell are physically connected by tiny channels.
The transfer of current occurs through gap junctions, which are intercellular protein channels that directly connect the cytoplasms of adjacent cells. In the heart, Connexin43 (encoded by GJA1) is the predominant gap junction protein forming these channels between Purkinje fibers and working myocytes. These channels allow ions and small molecules to pass, enabling electrical coupling.
Current flow and depolarization of ventricular myocytes
In simple terms: The electrical current flows from the Purkinje cell into the ventricular cell, causing it to fire.
Once gap junctions are formed, the current from the Purkinje myocyte flows into the ventricular myocyte, depolarizing its membrane. This depolarization triggers the ventricular action potential, which then propagates through the ventricular muscle via cell-to-cell coupling. The coupling resistance between the two cell types modulates the efficiency of this transfer and can affect repolarization.
Modulation of repolarization and action potential duration
In simple terms: The connection strength can change how long the heart cells stay excited.
The electrical coupling between Purkinje and ventricular myocytes is not static; it can be modulated. Experimental studies using variable resistance coupling have shown that changes in coupling resistance alter the repolarization phase of both cell types, affecting action potential duration and potentially contributing to arrhythmogenesis. This modulation is important for adapting to changes in heart rate and metabolic demand.
Role in the epicardial activation pattern
In simple terms: This communication helps determine the sequence in which the heart's outer surface is activated.
In the postnatal heart, gap junctional communication via Connexin43 between Purkinje fibers and working myocytes is crucial for establishing the epicardial activation pattern in the left ventricle. This pattern ensures that the ventricles contract in a coordinated, efficient manner. Disruption of this communication can lead to altered activation sequences and mechanical dyssynchrony.
Key Genes Involved in GO:0086055 Purkinje myocyte to ventricular cardiac muscle cell communication by electrical coupling
The following genes and proteins are central to the process of Purkinje myocyte to ventricular cardiac muscle cell communication by electrical coupling.
| Gene | Major Role | Research Relevance |
|---|---|---|
| GJA1 | Encodes Connexin43, the major gap junction protein mediating electrical coupling between Purkinje fibers and ventricular myocytes | Knockout leads to conduction defects; studied in arrhythmias and heart development |
| SCN5A | Encodes Nav1.5 sodium channel, responsible for rapid depolarization in Purkinje and ventricular cells | Mutations cause Brugada syndrome and conduction disease; affects coupling efficiency |
| KCNQ1 | Encodes Kv7.1 potassium channel, contributing to repolarization | Mutations cause long QT syndrome; influences action potential duration in coupled cells |
| KCNH2 | Encodes hERG potassium channel, important for repolarization | Mutations cause long QT syndrome; affects repolarization in Purkinje-ventricular coupling |
| CACNA1C | Encodes Cav1.2 calcium channel, mediating plateau phase | Mutations cause Timothy syndrome; affects calcium handling and coupling |
| GJC1 | Encodes Connexin45, another gap junction protein expressed in the heart | May compensate for Connexin43; studied in conduction system |
| GJA5 | Encodes Connexin40, expressed in Purkinje fibers | Important for fast conduction; knockout leads to conduction abnormalities |
| HCN4 | Encodes pacemaker channel, involved in spontaneous activity | Relevant to Purkinje automaticity; may influence coupling |
| ATP1A2 | Encodes Na+/K+-ATPase alpha2 subunit, maintaining ionic gradients | Mutations cause familial hemiplegic migraine; may affect cardiac excitability |
| RYR2 | Encodes ryanodine receptor 2, mediating calcium release | Mutations cause catecholaminergic polymorphic ventricular tachycardia; affects contraction |
| PLN | Encodes phospholamban, regulating SERCA | Mutations cause cardiomyopathy; affects calcium cycling and coupling |
| NPPA | Encodes atrial natriuretic peptide, a marker of cardiac stress | Used as a marker in cardiac hypertrophy and heart failure models |
| MYH7 | Encodes beta-myosin heavy chain, a contractile protein | Mutations cause hypertrophic cardiomyopathy; affects mechanical function |
| TNNT2 | Encodes cardiac troponin T, involved in contraction | Mutations cause cardiomyopathy; affects contractility |
| ACTN2 | Encodes alpha-actinin-2, a cytoskeletal protein | Mutations cause cardiomyopathy; may affect gap junction organization |
| DSP | Encodes desmoplakin, a desmosomal protein | Mutations cause arrhythmogenic right ventricular cardiomyopathy; affects cell adhesion and coupling |
| PKP2 | Encodes plakophilin-2, a desmosomal protein | Mutations cause ARVC; linked to gap junction remodeling |
| JUP | Encodes plakoglobin, a desmosomal and adherens junction protein | Mutations cause Naxos disease; affects cell-cell adhesion and coupling |
How Is Purkinje myocyte to ventricular cardiac muscle cell communication by electrical coupling Regulated?
The process of Purkinje myocyte to ventricular cardiac muscle cell communication by electrical coupling is regulated at multiple levels. The expression and phosphorylation of gap junction proteins, particularly Connexin43, can be modulated by kinases such as protein kinase C and mitogen-activated protein kinases. Additionally, the number and conductance of gap junction channels can be dynamically regulated by trafficking, assembly, and degradation. The coupling resistance between cells can be influenced by intracellular pH, calcium concentration, and second messengers. Furthermore, the electrical properties of the cells themselves, including ion channel expression and function, are regulated by neurohormonal signaling and can affect the efficacy of coupling.
Purkinje myocyte to ventricular cardiac muscle cell communication by electrical coupling and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| GJA1 | Arrhythmias, conduction block, oculodentodigital dysplasia | Cardiac-specific knockout mouse; induced pluripotent stem cell-derived cardiomyocytes |
| SCN5A | Brugada syndrome, long QT syndrome, conduction disease | Knock-in mouse models; heterologous expression systems |
| KCNQ1 | Long QT syndrome, atrial fibrillation | Transgenic mouse models; iPSC-derived cardiomyocytes |
| DSP | Arrhythmogenic right ventricular cardiomyopathy | Knock-in mouse models; cardiac tissue engineering |
| PKP2 | Arrhythmogenic right ventricular cardiomyopathy | Knockout mouse models; iPSC-derived cardiomyocytes |
Arrhythmias and Conduction Disorders
Disruption of electrical coupling between Purkinje myocytes and ventricular cardiac muscle cells is a major contributor to cardiac arrhythmias. Reduced expression or function of Connexin43 has been observed in ischemic heart disease, heart failure, and arrhythmogenic right ventricular cardiomyopathy, leading to slowed conduction and increased risk of reentrant arrhythmias. Mutations in SCN5A, which encodes the cardiac sodium channel, can also impair electrical coupling and cause Brugada syndrome and progressive cardiac conduction disease.
Heart Failure
In heart failure, remodeling of gap junctions and altered expression of connexins contribute to mechanical and electrical dyssynchrony. The communication between Purkinje fibers and working myocytes becomes less efficient, exacerbating pump dysfunction. Targeting this communication pathway may offer therapeutic benefits in heart failure management.
Cardiac Development and Regeneration
Proper electrical coupling is essential for normal cardiac development. In the postnatal heart, the establishment of the epicardial activation pattern depends on gap junctional communication via Connexin43 between Purkinje fibers and working myocytes. Understanding this process is also critical for regenerative medicine approaches, such as generating functional cardiac tissue from stem cells, where proper electromechanical coupling is required.
From Purkinje myocyte to ventricular cardiac muscle cell communication by electrical coupling-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| What is the role of Connexin43 in Purkinje-ventricular coupling? | Cardiac-specific GJA1 knockout mouse |
| How do SCN5A mutations affect electrical coupling? | Knock-in mouse carrying SCN5A mutation |
| Can overexpression of Connexin43 rescue conduction defects? | Transgenic mouse overexpressing GJA1 in the heart |
| What is the effect of a point mutation in KCNQ1 on repolarization? | Knock-in mouse with KCNQ1 mutation |
| How does tagging Connexin43 with a fluorescent protein affect its localization? | Knock-in mouse expressing tagged GJA1 |
| Can CRISPR activation of GJA1 improve coupling in heart failure? | Overexpression model using CRISPRa in cardiomyocytes |
How to Study the Purkinje myocyte to ventricular cardiac muscle cell communication by electrical coupling Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Multiscale modeling | Simulated electrical activation and coupling | Predicting arrhythmia risk and drug effects |
| Patch-clamp | Ion currents and action potentials | Measuring gap junction conductance and excitability |
| Optical mapping | Activation patterns and conduction velocity | Assessing epicardial activation in animal models |
| Immunofluorescence | Localization of connexins and other proteins | Studying gap junction distribution at the Purkinje-ventricular junction |
| CRISPR/Cas9 knockout | Gene function | Creating GJA1 knockout models to study coupling |
| RNA sequencing | Gene expression profiles | Identifying changes in ion channels and connexins in disease |
| Proteomics | Protein expression and modifications | Quantifying connexin phosphorylation and interactions |
Multiscale Modeling of Cardiac Electrophysiology
Computational modeling that integrates the Purkinje system with ventricular tissue allows researchers to simulate electrical coupling and predict activation patterns. Fast multiscale modeling techniques have been developed to efficiently compute the electrical behavior of the heart, including the Purkinje-ventricular junction. These models can incorporate detailed ion channel kinetics and gap junction conductances to study the effects of genetic mutations or drug interventions.
Electrophysiological Techniques
Patch-clamp and voltage-sensitive dye imaging can measure action potentials and conduction velocities in isolated Purkinje and ventricular myocytes or in intact tissue preparations. Dual patch-clamp of coupled cell pairs can directly assess gap junction conductance and its modulation. These techniques are essential for validating computational predictions and understanding the biophysical properties of electrical coupling.
Genetic and Molecular Approaches
CRISPR/Cas9 gene editing enables the creation of knockout, knock-in, and point-mutation models to study the function of specific genes in electrical coupling. For example, knockout of GJA1 in mice has revealed its critical role in cardiac conduction. Additionally, overexpression or knockdown of connexins using viral vectors can modulate coupling in vitro and in vivo.
Imaging and Histology
Immunofluorescence and confocal microscopy can visualize the localization of gap junction proteins at the Purkinje-ventricular interface. Optical mapping with voltage-sensitive dyes provides high-resolution activation maps to assess the functional consequences of altered coupling. These methods help correlate molecular changes with electrophysiological outcomes.
How CRISPR Can Be Used to Study GO:0086055 Purkinje myocyte to ventricular cardiac muscle cell communication by electrical coupling
Knockout
CRISPR/Cas9-mediated knockout of genes such as GJA1 (Connexin43) in cardiomyocytes or animal models allows researchers to study the loss-of-function effects on Purkinje-ventricular electrical coupling. Knockout models have demonstrated the essential role of Connexin43 in maintaining normal conduction and activation patterns. These models are valuable for understanding the contribution of specific genes to cardiac electrophysiology.
Point Mutation
Introducing precise point mutations using CRISPR/Cas9 and homology-directed repair (HDR) enables the study of disease-associated variants in genes like SCN5A, KCNQ1, and KCNH2. Such models can reveal how single amino acid changes affect ion channel function and electrical coupling, providing insights into inherited arrhythmia syndromes. Point mutation models are also useful for testing the efficacy of targeted therapies.
Knock-in
Knock-in of reporter genes or tags (e.g., fluorescent proteins) into endogenous loci allows real-time visualization of protein localization and dynamics. For example, tagging Connexin43 with GFP can help track gap junction formation and turnover at the Purkinje-ventricular interface. Knock-in models can also be used to express mutant proteins under endogenous regulatory control, providing more physiologically relevant conditions.
Overexpression
CRISPR activation (CRISPRa) or transgenic approaches can overexpress genes of interest to study gain-of-function effects. Overexpression of Connexin43 in the heart has been shown to enhance electrical coupling and improve conduction in some disease models. This approach can help identify therapeutic targets for arrhythmias and heart failure.
How EDITGENE Supports Purkinje myocyte to ventricular cardiac muscle cell communication by electrical coupling Research
Researchers studying Purkinje myocyte to ventricular cardiac muscle cell communication by electrical coupling-related genes often need to determine whether a candidate gene is causally involved in the process or merely a bystander. EDITGENE provides a comprehensive suite of CRISPR-based services to enable precise genetic manipulation and functional interrogation of these genes in relevant cardiac cell models.
Contact EDITGENE today to design your custom CRISPR model for Purkinje myocyte to ventricular cardiac muscle cell communication by electrical coupling research.
Frequently Asked Questions About Purkinje myocyte to ventricular cardiac muscle cell communication by electrical coupling
What is GO:0086055?
GO:0086055 is a Gene Ontology biological process term that describes the communication between a Purkinje myocyte and a ventricular cardiac muscle cell via electrical coupling through intercellular protein channels.
What genes are involved in Purkinje myocyte to ventricular cardiac muscle cell communication by electrical coupling?
Key genes include GJA1 (Connexin43), SCN5A, KCNQ1, KCNH2, and other ion channel and gap junction genes.
Why is electrical coupling between Purkinje and ventricular cells important?
It ensures rapid and coordinated ventricular activation, which is essential for efficient heart pumping; disruption leads to arrhythmias.
What diseases are associated with defects in this process?
Arrhythmias, conduction block, heart failure, and arrhythmogenic right ventricular cardiomyopathy are associated with defects in this communication.
How can I study Purkinje myocyte to ventricular cardiac muscle cell communication by electrical coupling?
Methods include multiscale modeling, patch-clamp, optical mapping, and CRISPR-based genetic manipulation.
What is the role of Connexin43 in this process?
Connexin43 forms gap junctions between Purkinje fibers and ventricular myocytes, mediating electrical coupling and establishing the epicardial activation pattern.
Can CRISPR be used to study this process?
Yes, CRISPR/Cas9 can create knockout, knock-in, and point mutation models to study genes involved in electrical coupling.
What model systems are available for studying this process?
Mouse models, induced pluripotent stem cell-derived cardiomyocytes, and heterologous expression systems are commonly used.
How does electrical coupling affect action potential duration?
Changes in coupling resistance can modulate repolarization and action potential duration in both Purkinje and ventricular myocytes.
What are the research methods for analyzing this GO term?
Multiscale modeling, electrophysiology, imaging, and molecular biology techniques are key methods.
Conclusion
GO:0086055, Purkinje myocyte to ventricular cardiac muscle cell communication by electrical coupling, is a fundamental biological process that ensures the heart's electrical signal is rapidly and reliably transmitted from the conduction system to the working myocardium. Understanding its molecular players, particularly gap junction proteins like Connexin43, and its regulation is crucial for deciphering cardiac physiology and disease. Continued research using advanced models and techniques, including CRISPR-based gene editing, will further illuminate this process and may lead to novel therapeutic strategies for arrhythmias and heart failure.
References
- 1. Huelsing DJ et al.. 1999. Modulation of repolarization in rabbit Purkinje and ventricular myocytes coupled by a variable resistance.. Am J Physiol 276(2):H572-81 PMID: 9950859
- 2. Olejnickova V et al.. 2021. Gap Junctional Communication via Connexin43 between Purkinje Fibers and Working Myocytes Explains the Epicardial Activation Pattern in the Postnatal Mouse Left Ventricle.. Int J Mol Sci 22(5) PMID: 33804428
- 3. Pashaei A et al.. 2011. Fast multiscale modeling of cardiac electrophysiology including Purkinje system.. IEEE Trans Biomed Eng 58(10):2956-60 PMID: 21791407
