FXYD domain containing ion transport regulator 4 (FXYD4)

FXYD domain containing ion transport regulator 4 (FXYD4) is a small transmembrane protein and auxiliary subunit of the Na,K-ATPase. It belongs to the FXYD family, sharing a conserved 35-amino acid signature domain. FXYD4 modulates Na,K-ATPase by altering its affinity for Na+ and enhancing pump activity, fine-tuning sodium and potassium transport across membranes in a tissue-specific manner. This activity is crucial in tissues such as the kidney, where it regulates sodium reabsorption and electrolyte balance. Abnormal expression or function of FXYD4 has been linked to genetic disorders (e.g., hypomagnesemia, deafness) and is downregulated in some cancers, notably clear cell renal cell carcinoma, making it of interest both as a therapeutic target and a disease biomarker[1][2][3][4][6].

Other names

Channel-inducing factor (CHIF)FXYD4_HUMAN (Uniprot designation)Corticosteroid hormone-induced factor (may refer to its expression regulation)

Modulation of Na,K-ATPase activity (would alter sodium/potassium transport, affecting cell and tissue electrolyte balance). Drugs or hormones that regulate FXYD4 expression may indirectly impact ion transport and homeostasis.