G protein-gated ion channel

G protein-gated ion channels (GIRKs) are a family of ion channels that are activated by G proteins. They play a crucial role in the regulation of neuronal excitability and heart rate.

Structure

G protein-gated ion channels are composed of four subunits, each of which has two transmembrane domains. The channel is formed by the assembly of these subunits around a central pore. The subunits can be either identical (homomeric) or different (heteromeric), which contributes to the diversity of G protein-gated ion channels.

Function

G protein-gated ion channels are activated by the binding of G proteins, which are in turn activated by G protein-coupled receptors (GPCRs). When a GPCR is activated by a ligand, it causes the release of a G protein, which can then bind to and open the ion channel. This allows ions to flow through the channel, changing the electrical properties of the cell and leading to various cellular responses.

Role in disease

Mutations in the genes encoding G protein-gated ion channels can lead to a variety of diseases. For example, mutations in the gene encoding the GIRK2 subunit have been associated with Parkinson's disease, while mutations in the gene encoding the GIRK4 subunit have been linked to atrial fibrillation.

Therapeutic potential

Because of their role in regulating neuronal excitability and heart rate, G protein-gated ion channels are potential targets for the treatment of a variety of conditions, including epilepsy, pain, depression, and cardiac arrhythmias.

See also

• Ion channel
• G protein
• G protein-coupled receptor
• Neuronal excitability
• Heart rate

References

G protein-gated ion channel Resources
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