Zinc ion transporter mediating zinc entry from the cytosol into the lumen of organelles along the secretory pathway (PubMed:15525635, PubMed:15994300). By contributing to zinc ion homeostasis within the early secretory pathway, regulates the activation and folding of enzymes like alkaline phosphatases (PubMed:15525635, PubMed:15994300). {ECO:0000269|PubMed:15525635, ECO:0000269|PubMed:15994300}. This is the function of SLC30A7 (solute carrier family 30 member 7, Ensembl gene identifier ENSG00000162695).