SLC30ZnT

SLC30ZnT, commonly referred to as the ZnT family, denotes the zinc transporters encoded by the SLC30A gene family (SLC30A1 through SLC30A10). These proteins move Zn2+ from the cytosol into intracellular compartments such as the Golgi apparatus and secretory vesicles, or, in some cases, across the plasma membrane to the outside of the cell. In this way, ZnTs contribute to cellular zinc homeostasis and to zinc-dependent enzymatic and signaling processes. The family exhibits diverse tissue distribution and subcellular localization, enabling specialized roles in different cell types.

Notable members include ZnT1 (SLC30A1), typically located at the plasma membrane where it participates in zinc efflux; ZnT3 (SLC30A3), which localizes to neuronal synaptic vesicles; and ZnT8 (SLC30A8), found in insulin secretory granules of pancreatic beta cells. Other ZnTs, such as ZnT4 (SLC30A4) and ZnT5–ZnT7 (SLC30A5–SLC30A7), are associated with the Golgi apparatus and the secretory pathway, supporting zinc loading into secretory compartments.

Structural and mechanistic notes are common across the family: most ZnTs are predicted to have six transmembrane helices with cytosolic N- and C-termini and a histidine-rich region that may participate in metal binding. They generally operate as zinc transporters that move Zn2+ in relation to proton gradients, thereby regulating cytosolic and organellar zinc levels.

Clinically, variants in SLC30A genes have been linked to disturbances in zinc homeostasis. In particular, SLC30A8 (ZnT8) variants are associated with altered type 2 diabetes risk, while mutations in SLC30A2 (ZnT2) can affect zinc content in breast milk and contribute to neonatal zinc deficiency.