Zinc transporter 8

Zinc transporter 8 (ZNT8) is a protein that in humans is encoded by the SLC30A8 gene. ZNT8 is a zinc transporter related to insulin secretion in humans. In particular, ZNT8 is critical for the accumulation of zinc into beta cell secretory granules and the maintenance of stored insulin as tightly packaged hexamers. Certain alleles of the SLC30A8 gene may increase the risk for developing type 2 diabetes, but a loss-of-function mutation appears to greatly reduce the risk of diabetes.

Association with type 2 diabetes (T2D)
Twelve rare variants in SLC30A8 have been identified through the sequencing or genotyping of approximately 150,000 individuals from 5 different ancestry groups. SLC30A8 contains a common variant (p.Trp325Arg), which is associated with T2D risk and levels of glucose and proinsulin. Individuals carrying protein-truncating variants collectively had 65% reduced risk of T2D. Additionally, non-diabetic individuals from Iceland harboring a frameshift variant p. Lys34Serfs*50 demonstrated reduced glucose levels. Earlier functional studies of SLC30A8 suggested that reduced zinc transport increased T2D risk. Conversely, loss-of-function mutations in humans indicate that SLC30A8 haploinsufficiency protects against T2D. Therefore, ZnT8 inhibition can serve as a therapeutic strategy in preventing T2D.