Zinc-efflux transporter which allocates the cytoplasmic zinc to the trans-Golgi network (TGN) as well as the vesicular compartment. Heterooligomer. Interacts with ZNT5 (By similarity). Found in vesicles. Expressed in brain; especially in cerebellum, hippocampus, parahippocampal gyrus, superior and middle temporal gyrus. Also expressed in B-cells, colon, eye, and lung. Lower expression was present in bone, brain, cervix, ear, heart, kidney, muscle, nerve, pancreas, prostate, skin, stomach, and testis. Seems to have lost most of the histidine residues in the loop between the fourth and fifth transmembrane regions and appears to exert transport function by forming complexes with ZNT5. Belongs to the cation diffusion facilitator (CDF) transporter (TC 2.A.4) family. SLC30A subfamily.