Gosset Molecular Classification
Ion channel, Potassium channel, Inwardly rectifying potassium channel, G protein-gated ion channel
Other Names
Muscarinic-gated K+ channel, G-protein-gated inward rectifier K+ channel
Disease Roles
Acetylcholine-sensitive potassium channel Overview
The acetylcholine-sensitive potassium channel (IKACh) is a G-protein-gated inwardly rectifying potassium channel predominantly found in cardiac tissue. It is formed by Kir3.1 and Kir3.4 subunits and activated by acetylcholine via M2 receptors, leading to heart rate reduction. IKACh plays a critical role in regulating heart rate and rhythm, and its dysfunction is associated with increased risk of arrhythmias.
Mechanism of Action
Activated by G protein βγ subunits following M2 muscarinic receptor stimulation, leading to potassium efflux and cell hyperpolarization.
Biological Functions
Regulation of heart rate
Modulation of pacemaker activity
Regulation of membrane potential
Parasympathetic signaling
Disease Associations
Arrhythmia
Atrial fibrillation
Cardiac rhythm instability
Safety Considerations
- Loss-of-function mutations can lead to arrhythmias
- Altered signaling dynamics can increase arrhythmia susceptibility
Interacting Drugs
Acetylcholine