Uniporter that transports zinc(2+) into polarized cells of enterocytes, pancreatic acinar and endoderm cells across the basolateral membrane and participates, notably, in zinc excretion from the intestine by the uptake of zinc from the blood into the intestine (By similarity). The transport mechanism is temperature- and concentration-dependent and saturable (By similarity). In addition, is also a high affinity copper transporter in vitro . Also may regulate glucose-stimulated insulin secretion (GSIS) in islets primarily through the zinc-activated SIRT1-PPARGC1A axis (By similarity). Could regulate the BMP/TGF-beta (bone morphogenetic protein/transforming growth factor-beta) signaling pathway and modulates extracellular matrix (ECM) proteins of the sclera . Plays a role in eye development .
Subcellular locations: Basolateral cell membrane
Localized to the basolateral surfaces of enterocytes, pancreatic acinar and endoderm cells. During zinc deficiency diet, the basolateral cell membrane localization is lost in the intestine, the visceral yolk sac and acinar cell. During zinc repletion, is relocalized to the basolateral membrane of enterocytes, visceral endoderm cells and pancreatic acinar cells. Zinc can regulate the turnover of protein at the membrane. During zinc deficiency, is internalized and degraded in enterocytes, acinar cells and endoderm cells. Endocytosed through the endolysosomal degradation pathway RAB5A pathway.
Expressed in liver, kidney, pancreas, small intestine, colon, spleen, fetal liver and fetal kidney.