Has probably no intrinsic transporter activity but together with SLC30A5 forms a functional zinc ion:proton antiporter heterodimer, mediating zinc entry into the lumen of organelles along the secretory pathway (PubMed:15994300, PubMed:19366695, PubMed:19759014). As part of that zinc ion:proton antiporter, contributes to zinc ion homeostasis within the early secretory pathway and regulates the activation and folding of enzymes like alkaline phosphatases and enzymes involved in phosphatidylinositol glycan anchor biosynthesis (PubMed:15994300, PubMed:19759014, PubMed:35525268).
