GO:0086069 bundle of His cell to Purkinje myocyte communication: Cardiac Conduction, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0086069 describes the biological process by which bundle of His cells communicate with Purkinje myocytes to propagate electrical signals through the ventricular conduction system.
• This communication depends on gap junction channels, particularly those formed by Connexin40 (GJA5) and Connexin43 (GJA1), which mediate cell-to-cell electrical coupling.
• Disruption of bundle of His to Purkinje myocyte communication causes conduction abnormalities including atrioventricular block and bundle branch block.
• Connexin43-mediated coupling between Purkinje fibers and working myocytes explains epicardial activation patterns in the postnatal mouse left ventricle.
• The existence and morphology of internodal conduction pathways, which include bundle of His to Purkinje myocyte communication, remain an active area of debate and research.
• CRISPR-based knockout, point mutation, and knock-in models are powerful tools for dissecting the molecular players in this communication process.
Description
The bundle of His cell to Purkinje myocyte communication process, annotated as GO:0086069, is a specialized biological process within the cardiac conduction system that enables the rapid and coordinated spread of electrical excitation from the bundle of His to the Purkinje fiber network. This communication is essential for synchronous ventricular contraction and normal heart rhythm. The process encompasses all interactions between a bundle of His cell and its surroundings that contribute to signaling to a Purkinje myocyte, including direct cell-cell signaling and attachment. Understanding this process is critical because disruptions in the ventricular conduction system are linked to life-threatening arrhythmias and conduction blocks. Research into the molecular basis of this communication has revealed key roles for gap junction proteins, particularly connexins, which form low-resistance channels between adjacent cells. Studies in mouse models have shown that loss of Connexin40 leads to atrioventricular block and bundle branch block, directly implicating this protein in bundle of His to Purkinje myocyte communication. Similarly, Connexin43-mediated communication between Purkinje fibers and working myocytes is required for the normal epicardial activation pattern in the postnatal heart. These findings highlight the importance of GO:0086069 in cardiac physiology and disease.
bundle of His cell to Purkinje myocyte communication At A Glance
| GO ID | GO:0086069 |
|---|---|
| GO term | bundle of His cell to Purkinje myocyte communication |
| Ontology | biological_process |
| Synonym | atrioventricular junction myocyte to bundle branch myocyte; bundle branch myocyte to Purkinje myocyte communication; bundle of His cardiac muscle cell to Purkinje myocyte communication; bundle of His myocyte to atrioventricular junction myocyte; ventricular conduction system cell to cell communication |
| Major function | Mediates electrical and signaling communication between bundle of His cells and Purkinje myocytes for coordinated ventricular conduction |
| Related cellular components | Gap junctions, intercalated discs, connexons |
| Key molecules | Connexin40 (GJA5), Connexin43 (GJA1), ion channels |
| Associated diseases | Atrioventricular block, bundle branch block, arrhythmias |
What Is GO:0086069?
GO:0086069, bundle of His cell to Purkinje myocyte communication, is defined as the process that mediates interactions between a bundle of His cell and its surroundings that contributes to the process of the bundle of His cell communicating with a Purkinje myocyte in cardiac conduction. This includes interactions such as signaling or attachment between one cell and another cell, between a cell and an extracellular matrix, or between a cell and any other aspect of its environment.
Why Is bundle of His cell to Purkinje myocyte communication Important in Cell Biology?
GO:0086069 is critically important because it represents a fundamental step in the cardiac conduction pathway that ensures rapid and synchronized ventricular activation. Defects in this communication process can lead to conduction blocks, arrhythmias, and sudden cardiac death. Understanding the molecular mechanisms of bundle of His to Purkinje myocyte communication can inform the development of targeted therapies for cardiac conduction disorders and improve our knowledge of heart development and function.
• Essential for normal cardiac rhythm and synchronous ventricular contraction.
• Disruption causes atrioventricular block and bundle branch block, as shown in Connexin40 knockout mice.
• Connexin43-mediated communication between Purkinje fibers and working myocytes is required for normal epicardial activation.
• Provides a model for studying cell-to-cell communication in excitable tissues.
• Relevant to congenital heart defects and acquired conduction diseases.
• Potential target for gene therapy and pharmacological interventions.
• Key to understanding the postnatal maturation of the ventricular conduction system.
• Informs the interpretation of electrocardiographic patterns and arrhythmia mechanisms.
• Basis for developing CRISPR-based models of conduction system disorders.
• Contributes to the broader field of cardiac electrophysiology and developmental biology.
What Happens During bundle of His cell to Purkinje myocyte communication?
Initiation of Electrical Signal at the Bundle of His
In simple terms: The electrical signal arrives at the bundle of His, ready to be passed on.
The bundle of His cells receive electrical excitation from the atrioventricular node and propagate it rapidly along the ventricular conduction system. This initial depolarization is driven by ion channels and is a prerequisite for communication with Purkinje myocytes.
Cell-to-Cell Coupling via Gap Junctions
In simple terms: Special channels between cells allow electrical current to flow directly from bundle of His cells to Purkinje cells.
Gap junction channels, primarily composed of Connexin40 and Connexin43, provide low-resistance pathways for electrical and small-molecule communication between bundle of His cells and Purkinje myocytes. Connexin40 is highly expressed in the ventricular conduction system, and its loss leads to conduction abnormalities.
Signal Propagation Along Purkinje Fibers
In simple terms: Once the signal reaches Purkinje cells, it spreads quickly through the Purkinje network.
After communication from bundle of His cells, Purkinje myocytes propagate the electrical impulse to the ventricular working myocardium. This propagation is facilitated by gap junctions between Purkinje fibers and working myocytes, as demonstrated by Connexin43-mediated coupling in the postnatal mouse left ventricle.
Coordination with Working Myocytes
In simple terms: The Purkinje cells then pass the signal to the main heart muscle cells for contraction.
The final step involves communication between Purkinje fibers and working myocytes, which ensures coordinated ventricular contraction. This process relies on gap junctional communication via Connexin43 and determines the epicardial activation pattern.
Key Genes Involved in GO:0086069 bundle of His cell to Purkinje myocyte communication
The following genes and proteins are key players in bundle of His cell to Purkinje myocyte communication, based on published literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| GJA5 (Connexin40) | Forms gap junction channels in the ventricular conduction system; mediates electrical coupling between bundle of His and Purkinje cells | Knockout causes atrioventricular block and bundle branch block |
| GJA1 (Connexin43) | Forms gap junctions between Purkinje fibers and working myocytes; essential for epicardial activation | Knockout or conditional deletion affects ventricular activation pattern |
| SCN5A | Voltage-gated sodium channel; generates action potential upstroke in conduction cells | Mutations linked to Brugada syndrome and conduction disease |
| HCN4 | Pacemaker channel; contributes to spontaneous depolarization in conduction system | Relevant to sinus node dysfunction and conduction blocks |
| CACNA1C | L-type calcium channel; supports action potential plateau in conduction cells | Mutations cause Timothy syndrome and arrhythmias |
| KCNQ1 | Potassium channel; repolarization in conduction system | Mutations cause long QT syndrome |
| KCNH2 | Potassium channel; repolarization | Mutations cause long QT syndrome |
| SCN1B | Sodium channel auxiliary subunit | Mutations linked to Brugada syndrome |
| NKX2-5 | Transcription factor; regulates conduction system development | Mutations cause congenital heart defects and conduction abnormalities |
| TBX5 | Transcription factor; regulates conduction system gene expression | Mutations cause Holt-Oram syndrome with conduction defects |
| TBX3 | Transcription factor; represses working myocardial genes in conduction system | Important for conduction system identity |
| IRX3 | Transcription factor; regulates ventricular conduction system development | Knockout affects Purkinje fiber maturation |
| IRX5 | Transcription factor; regulates ion channel expression in conduction system | Knockout alters repolarization gradients |
| HOPX | Homeodomain protein; regulates conduction system development | Knockout causes conduction defects |
| PITX2 | Transcription factor; regulates left-right asymmetry and conduction | Mutations linked to atrial fibrillation |
| SHOX2 | Transcription factor; regulates pacemaker and conduction system | Knockout causes conduction abnormalities |
| BMP2 | Signaling molecule; regulates conduction system development | Involved in differentiation of conduction cells |
| NOTCH1 | Signaling receptor; regulates cardiac development and conduction | Mutations linked to bicuspid aortic valve and conduction defects |
How Is bundle of His cell to Purkinje myocyte communication Regulated?
The process of bundle of His cell to Purkinje myocyte communication is regulated at multiple levels. Transcriptional control by cardiac transcription factors such as NKX2-5, TBX5, and IRX3/5 establishes the expression of gap junction proteins and ion channels in the conduction system. Post-translational modifications, including phosphorylation of connexins, can modulate gap junction assembly and function. Additionally, the process is influenced by developmental signals such as Notch and BMP pathways, which pattern the ventricular conduction system. However, specific regulatory mechanisms for GO:0086069 remain an active area of research, and no single master regulator has been definitively established in the literature provided.
bundle of His cell to Purkinje myocyte communication and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| GJA5 (Connexin40) | Atrioventricular block, bundle branch block | Knockout mouse |
| GJA1 (Connexin43) | Arrhythmias, altered epicardial activation | Conditional knockout mouse |
| SCN5A | Brugada syndrome, conduction disease | Knock-in mouse expressing mutant SCN5A |
| NKX2-5 | Congenital heart defects with conduction abnormalities | Knockout or knock-in mouse |
| TBX5 | Holt-Oram syndrome with conduction defects | Knockout mouse |
Atrioventricular Block and Bundle Branch Block
Disruption of bundle of His to Purkinje myocyte communication leads to conduction blocks. Mice lacking Connexin40 exhibit atrioventricular block and bundle branch block, demonstrating the critical role of this gap junction protein in the process. These findings suggest that human mutations in GJA5 may predispose to similar conduction disorders.
Arrhythmias and Sudden Cardiac Death
Impaired communication between bundle of His and Purkinje myocytes can cause reentrant arrhythmias and sudden cardiac death. The precise coordination of electrical activation depends on gap junctional coupling, and its disruption creates substrates for ventricular tachycardia and fibrillation.
Developmental Conduction Defects
Abnormal development of the ventricular conduction system, including bundle of His to Purkinje myocyte communication, is associated with congenital heart defects. Studies in postnatal mouse hearts show that Connexin43-mediated coupling between Purkinje fibers and working myocytes is required for normal epicardial activation, and its absence leads to altered activation patterns.
From bundle of His cell to Purkinje myocyte communication-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of GJA5 disrupt bundle of His to Purkinje communication? | GJA5 knockout mouse |
| What is the role of GJA1 in Purkinje-to-myocyte coupling? | GJA1 conditional knockout mouse |
| Can a point mutation in SCN5A mimic human conduction disease? | SCN5A knock-in mouse |
| How does NKX2-5 haploinsufficiency affect conduction system development? | NKX2-5 knockout mouse |
| What is the effect of TBX5 overexpression on conduction gene expression? | TBX5 overexpression transgenic mouse |
| Can tagged Connexin40 be used to visualize gap junctions in live cells? | Tagged knock-in of GJA5 |
How to Study the bundle of His cell to Purkinje myocyte communication Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Optical mapping | Activation patterns and conduction velocity | Assessing conduction defects in mutant hearts |
| Patch clamp | Action potential properties of individual conduction cells | Characterizing ion channel function |
| Immunofluorescence | Localization and abundance of connexins | Visualizing gap junctions at bundle of His-Purkinje interface |
| RNA-seq | Transcriptional profiles of conduction cells | Identifying genes involved in communication |
| Single-cell RNA-seq | Cell-type-specific gene expression | Dissecting heterogeneity of conduction system |
| CRISPR knockout | Loss-of-function phenotypes | Testing causality of candidate genes |
| Voltage imaging | Real-time electrical activity | Monitoring communication in live tissue |
Electrophysiological Mapping
Electrophysiological techniques such as optical mapping and microelectrode arrays are used to measure conduction velocity and activation patterns in the ventricular conduction system. These methods can reveal deficits in bundle of His to Purkinje myocyte communication in genetically modified animal models.
Immunohistochemistry and Confocal Imaging
Immunostaining for connexins and other junctional proteins allows visualization of gap junctions at the bundle of His-Purkinje interface. Confocal microscopy can quantify gap junction plaque size and distribution in normal and diseased hearts.
Transcriptomics and Single-Cell RNA Sequencing
RNA sequencing of isolated conduction system cells can identify genes enriched in bundle of His and Purkinje myocytes. Single-cell approaches reveal heterogeneity and candidate regulators of communication.
Genetically Encoded Voltage Indicators
Voltage-sensitive fluorescent proteins expressed in conduction cells enable real-time monitoring of electrical communication between bundle of His and Purkinje myocytes in intact hearts.
How CRISPR Can Be Used to Study GO:0086069 bundle of His cell to Purkinje myocyte communication
Knockout
CRISPR knockout of genes such as GJA5 or GJA1 in mice or cell models can recapitulate conduction defects and demonstrate their essential role in bundle of His to Purkinje myocyte communication.
Point Mutation
Introducing patient-specific point mutations (e.g., in SCN5A or GJA5) via CRISPR base editing or homology-directed repair allows precise modeling of conduction disorders and assessment of communication defects.
Knock-in
Knock-in of reporter genes (e.g., fluorescent tags) into connexin loci enables live imaging of gap junctions and tracking of communication between bundle of His and Purkinje cells.
Overexpression
CRISPR activation (CRISPRa) or transgenic overexpression of candidate genes can test sufficiency for enhancing or rescuing communication in disease models.
How EDITGENE Supports bundle of His cell to Purkinje myocyte communication Research
Researchers studying bundle of His cell to Purkinje myocyte communication-related genes often need to determine whether a candidate gene is causally involved in the process or merely correlated with it. EDITGENE provides a comprehensive suite of CRISPR-based services to enable such functional studies with high precision and efficiency.
Contact EDITGENE today to design your custom CRISPR model for bundle of His cell to Purkinje myocyte communication research.
Frequently Asked Questions About bundle of His cell to Purkinje myocyte communication
What is GO:0086069?
GO:0086069 is the Gene Ontology term for bundle of His cell to Purkinje myocyte communication, a biological process that mediates interactions between bundle of His cells and Purkinje myocytes in cardiac conduction.
What genes are involved in bundle of His cell to Purkinje myocyte communication?
Key genes include GJA5 (Connexin40), GJA1 (Connexin43), SCN5A, and transcription factors such as NKX2-5 and TBX5.
Why is bundle of His to Purkinje communication important?
It ensures rapid and coordinated electrical activation of the ventricles; its disruption causes conduction blocks and arrhythmias.
What diseases are associated with defects in this process?
Atrioventricular block, bundle branch block, Brugada syndrome, and other conduction disorders.
How can I study bundle of His cell to Purkinje myocyte communication?
Electrophysiological mapping, immunohistochemistry, RNA-seq, and CRISPR-based genetic models are commonly used.
What is the role of Connexin40 in this process?
Connexin40 forms gap junctions in the ventricular conduction system; its loss leads to atrioventricular and bundle branch block.
What is the role of Connexin43 in this process?
Connexin43 mediates coupling between Purkinje fibers and working myocytes, essential for normal epicardial activation.
Can CRISPR be used to model conduction disorders?
Yes, CRISPR knockout, point mutation, and knock-in models can recapitulate human conduction defects and test gene function.
What model organisms are used to study this process?
Mice are the most common model, with knockout and transgenic lines available for key genes.
How does EDITGENE support research on this GO term?
EDITGENE offers CRISPR knockout, point mutation, knock-in, overexpression, library screening, and bioinformatics services tailored to cardiac conduction research.
Conclusion
GO:0086069, bundle of His cell to Purkinje myocyte communication, is a vital biological process for normal cardiac conduction. Research has identified key molecular players, particularly connexins, and linked their dysfunction to serious conduction disorders. Continued investigation using advanced CRISPR models and multi-omics approaches will further elucidate the mechanisms and provide new therapeutic targets.
References
- 1. Cavero I et al.. 2023. Internodal conduction pathways: revisiting a century-long debate on their existence, morphology, and location in the context of 2023 best science.. Adv Physiol Educ 47(4):838-850 PMID: 37675468
- 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. Simon AM et al.. 1998. Mice lacking connexin40 have cardiac conduction abnormalities characteristic of atrioventricular block and bundle branch block.. Curr Biol 8(5):295-8 PMID: 9501069
