FXYD3

This gene belongs to a small family of FXYD-domain containing regulators of Na+/K+ ATPases which share a 35-amino acid signature sequence domain, beginning with the sequence PFXYD, and containing 7 invariant and 6 highly conserved amino acids. This gene encodes a cell membrane protein that may regulate the function of ion-pumps and ion-channels. This gene may also play a role in tumor progression. Alternative splicing results in multiple transcript variants encoding distinct isoforms.

FXYD Domain Containing Ion Transport Regulator 3

Associates with and regulates the activity of the sodium/potassium-transporting ATPase (NKA) which transports Na+ out of the cell and K+ into the cell (PubMed:17077088).

Reduces glutathionylation of the NKA beta-1 subunit ATP1B1, thus reversing glutathionylation-mediated inhibition of ATP1B1 (PubMed:21454534).

Induces a hyperpolarization-activated chloride current when expressed in Xenopus oocytes (PubMed:7836447).

Isoform 1:
Decreases the apparent K+ and Na+ affinity of the sodium/potassium-transporting ATPase over a large range of membrane potentials.

Isoform 2:
Decreases the apparent K+ affinity of the sodium/potassium-transporting ATPase only at slightly negative and positive membrane potentials and increases the apparent Na+ affinity over a large range of membrane potentials.

Chloride transport Source: ProtInc
Potassium ion transport Source: UniProtKB-KW
Regulation of sodium ion transmembrane transporter activity Source: GO_Central
Sodium ion transport Source: UniProtKB-KW

Cell membrane

Extracellular: 21-38
Helical: 39-59
Cytoplasmic: 60-87

Glutathionylated.