Plays an important role in cellular zinc homeostasis as a zinc transporter. Regulated in response to zinc availability. Colocalized with TFRC in the recycling endosomes. Cycles between endosomal compartments and the plasma membrane in response to zinc availability. Highly expressed in the small intestine and embryonic visceral yolk sac. Weakly expressed in the stomach and liver. Found to the apical surface of enterocytes and visceral endoderm cells during zinc deficiency. Up-regulated under conditions of dietary zinc deficiency. Down-regulated under conditions of dietary zinc excess. More abundant. Belongs to the ZIP transporter (TC 2.A.5) family.