FXYD domain-containing ion transport regulator 3 (FXYD3)

FXYD domain-containing ion transport regulator 3 (FXYD3), also known as MAT-8 or mammary tumor 8 kDa protein, is a small membrane protein encoded by the *FXYD3* gene and a member of the FXYD protein family. FXYD3 associates with and modulates the activity and transport properties of the sodium/potassium-transporting ATPase (Na,K-ATPase), influencing sodium and potassium homeostasis in cells. It can also affect chloride conductance in certain experimental systems. FXYD3 is differentially expressed across tissues, including high levels in uterus, stomach, and colon, and is overexpressed in a range of human cancers, where it participates in regulating cell proliferation, apoptosis, and adhesion. The altered expression and regulatory effects on ion pumps have made FXYD3 a candidate biomarker for cancer diagnosis and prognosis, though it has not yet been validated as a direct drug target and few, if any, clinically actionable modulators are known.

Other names

MAT-8Mammary tumor 8 kDa proteinPhospholemman-like protein (PLML)Chloride conductance inducer protein Mat-8Sodium/potassium-transporting ATPase subunit FXYD3

Modulation of Na,K-ATPase activity and stability by direct association; Preventing pathologic glutathionylation of β1 subunit in Na,K-ATPase, particularly under oxidative stress; Induction or alteration of chloride conductance in some expression systems