Na+/K+ Transporting ATPase Interacting Protein 4 (NKAIN4)

NKAIN4 is a member of a family of mammalian proteins with similarity to Drosophila Nkain and interacts with the beta subunit of Na,K-ATPase (ATP1B1) .

NKAIN4 contains a predicted cleavable signal peptide and 3 putative transmembrane domains. Mouse Nkain4 shares 60% amino acid similarity with the first 200 amino acids of Drosophila Nkain, which extends for an additional 458 amino acids in a C-terminal tail absent from the vertebrate Nkain4. RT-PCR analysis of mouse tissues detected expression of a short Nkain4 splice variant in brain and testis only and a long Nkain4 splice variant in all brain regions, embryo head, heart, lung, spleen, and liver. Yeast 2-hybrid analysis to demonstrated that Nkain4 interacted with ATP1B1.