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 . Reduces glutathionylation of the NKA beta-1 subunit ATP1B1, thus reversing glutathionylation-mediated inhibition of ATP1B1 . Induces a hyperpolarization-activated chloride current when expressed in Xenopus oocytes .
Decreases the apparent K+ and Na+ affinity of the sodium/potassium-transporting ATPase over a large range of membrane potentials.
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.
Subcellular locations: Cell membrane
Isoform 1: Expressed mainly in differentiated cells (at protein level). Isoform 2: Expressed mainly in undifferentiated cells (at protein level).