Zinc transporter whose role depends on the zinc status of the cells. It helps to balance zinc levels between the cytosol and the secretory pathway. It transports zinc into the secretory pathway in a zinc-adequate environment and in a high zinc medium. In high zinc medium, transport of zinc into the secretory pathway is a way to eliminate zinc from the cytosol. Under low cytosolic zinc conditions, it removes zinc from the secretory pathway and acts as zinc importer that helps to alleviate ER stress. Belongs to the ZIP transporter (TC 2.A.5) family. KE4/Catsup subfamily.