gap junction channel activity involved in cardiac conduction electrical coupling

Definition

Target type: molecularfunction

A wide pore channel activity that enables a direct cytoplasmic connection from one cardiomyocyte to an adjacent cardiomyocyte. The gap junction passes electrical signals between the cells contributing to cardiac conduction. [GOC:BHF, GOC:mtg_cardiac_conduct_nov11]

Gap junction channels, composed of connexin proteins, play a crucial role in electrical coupling between cardiac myocytes. This coupling facilitates the rapid and coordinated spread of electrical signals throughout the heart, ensuring efficient and synchronized contractions. The molecular function of gap junction channel activity in cardiac conduction can be described as follows:

1. **Channel Formation:** Connexins assemble into hexameric structures called connexons, which form half-channels within individual cells. Two connexons from adjacent cells align and dock to create a complete gap junction channel, spanning the intercellular space.
2. **Permeability and Selectivity:** The gap junction channel acts as a selective pore, allowing the passage of small molecules and ions, including potassium (K+), sodium (Na+), and calcium (Ca2+). These ions are crucial for the generation and propagation of action potentials.
3. **Electrical Coupling:** The passage of ions through the gap junction channels creates a low-resistance pathway for electrical current to flow directly from one cell to another. This electrical coupling allows for rapid and efficient propagation of action potentials between myocytes, ensuring synchronized contractions.
4. **Synchronization of Cardiac Rhythm:** The coordinated spread of electrical signals via gap junction channels is essential for the synchronization of heartbeats. It allows for the coordinated contraction of the atria and ventricles, ensuring efficient blood pumping.
5. **Regulation of Conduction Velocity:** The permeability and conductance of gap junction channels can be regulated by various factors, including intracellular pH, Ca2+ concentration, and phosphorylation. These regulations influence the speed of electrical signal propagation, affecting cardiac conduction velocity.
6. **Protection against Arrhythmias:** Proper functioning of gap junction channels is crucial for maintaining regular heart rhythm. Disruptions in gap junction function can lead to impaired electrical coupling, causing arrhythmias and other cardiac disorders.

In summary, gap junction channel activity is essential for electrical coupling in cardiac conduction. It allows for the rapid and coordinated spread of electrical signals, ensuring synchronized contractions and maintaining a regular heart rhythm. The precise regulation of gap junction channel permeability and conductance is crucial for efficient and healthy cardiac function.'
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Proteins (1)

Compounds (1)