voltage-gated potassium channel activity involved in SA node cell action potential depolarization

Definition

Target type: molecularfunction

Enables the transmembrane transfer of a potassium ion by a voltage-gated channel through the plasma membrane of an SA node cardiac muscle cell contributing to the depolarization phase of an action potential. A voltage-gated channel is a channel whose open state is dependent on the voltage across the membrane in which it is embedded. [GOC:BHF, GOC:mtg_cardiac_conduct_nov11]

Voltage-gated potassium channels play a critical role in the depolarization phase of the sinoatrial (SA) node cell action potential, which is responsible for initiating the heartbeat. These channels are responsible for the rapid repolarization phase of the action potential. During the initial depolarization phase, sodium channels open, allowing sodium ions to flow into the cell, causing a rapid increase in membrane potential. However, this depolarization is transient, and the membrane potential quickly repolarizes due to the opening of voltage-gated potassium channels. The efflux of potassium ions through these channels restores the negative membrane potential, bringing the cell back to its resting state. This rapid repolarization is crucial for the initiation of the next action potential. There are several types of voltage-gated potassium channels expressed in SA node cells, each with distinct kinetic properties and contributions to the action potential. These channels, along with other ion channels, work together to create the characteristic shape and timing of the SA node action potential, ensuring the regular and rhythmic beating of the heart.'
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Proteins (1)

Compounds (2)