Zinc ion transporter that mediates zinc efflux and plays a crucial role in intracellular zinc homeostasis (PubMed:25130899, PubMed:31697912, PubMed:36204728). Binds the divalent cations Zn(2+), Ni(2+), and to a minor extent Cu(2+) (By similarity). Is a functional modulator of P2X purinoceptors, including P2RX1, P2RX3, P2RX4 and P2RX7 (PubMed:32492420). Plays a role in central nervous system development and is required for myelination, and survival and proliferation of oligodendrocytes (PubMed:35455965).