ATP1A3

Sodium/potassium-transporting ATPase subunit alpha-3 is an enzyme that in humans is encoded by the ATP1A3 gene.

Function

The protein encoded by this gene belongs to the family of P-type cation transport ATPases, and to the subfamily of Na⁺/K⁺-ATPases. Na⁺/K⁺-ATPase is an integral membrane protein responsible for establishing and maintaining the electrochemical gradients of Na and K ions across the plasma membrane. These gradients are essential for osmoregulation, for sodium-coupled transport of a variety of organic and inorganic molecules, and for electrical excitability of nerve and muscle. This enzyme is composed of two subunits, a large catalytic subunit (alpha) and a smaller glycoprotein subunit (beta). The catalytic subunit of Na⁺/K⁺-ATPase is encoded by multiple genes. This gene encodes an alpha 3 subunit.

Clinical significance

Mutations in ATP1A3 are often seen in rapid-onset dystonia–parkinsonism (RDP) (also known as DYT12), and genetic testing is recommended in patients where this diagnosis is suspected.

In mice, mutations in this gene are associated with epilepsy. By manipulating this gene in the offspring of such mice, epilepsy can be avoided.

This gene is the likely genetic cause of alternating hemiplegia of childhood.

External links

• GeneReview/NCBI/NIH/UW entry on Rapid-Onset Dystonia Parkinsonism