KCNJ9

KCNJ9 (Potassium Inwardly-Rectifying Channel, Subfamily J, Member 9) is a protein that in humans is encoded by the KCNJ9 gene. It is a member of the G-protein activated inwardly rectifying potassium channel (GIRK) family.

Function

KCNJ9 is a member of the G-protein coupled receptor superfamily. This G-protein coupled receptor is a transmembrane protein that functions to transmit cellular signals from various stimuli outside the cell to the inside of the cell. This particular receptor is known to be involved in the regulation of heart rate and neurotransmitter release.

Structure

The KCNJ9 protein is a subunit of the G-protein activated inwardly rectifying potassium channel. It is composed of four identical subunits, each with two transmembrane domains. The protein's structure allows it to selectively conduct potassium ions through the cell membrane, contributing to the resting membrane potential and action potential of neurons.

Clinical significance

Mutations in the KCNJ9 gene have been associated with various medical conditions. For example, a mutation in this gene has been linked to SeSAME syndrome, a rare disorder characterized by seizures, sensorineural deafness, ataxia, mental retardation, and electrolyte imbalance.

Research

Research into the KCNJ9 gene and its associated protein is ongoing. Studies have suggested a role for this gene in the pathogenesis of Type 2 diabetes, and it may also play a role in the development of certain types of cancer.

See also

• Potassium channel
• G protein-coupled receptor
• SeSAME syndrome