Electroneutral proton-coupled antiporter concentrating zinc ions into a variety of intracellular organelles including endosomes, zymogen granules and mitochondria. Thereby, plays a crucial role in cellular zinc homeostasis to confer upon cells protection against its potential cytotoxicity (  , ). Regulates the zinc concentration of milk, through the transport of zinc ions into secretory vesicles of mammary cells . By concentrating zinc ions into lysosomes participates to lysosomal-mediated cell death during early mammary gland involution .
Electroneutral proton-coupled antiporter mediating the efflux of zinc ions through the plasma membrane.
Subcellular locations: Cytoplasmic vesicle, Secretory vesicle membrane, Zymogen granule membrane, Endosome membrane, Lysosome membrane, Mitochondrion inner membrane
Localization to lysosomes is induced by TNF-alpha.
Subcellular locations: Cell membrane