In the presence of high concentrations of zinc and calcium, proinsulin spontaneously forms soluble complexes containing 6 molecules of proinsulin, 2 zinc ions, and 1 calcium ion. Zinc Transporters ZnT5, ZnT6, and ZnT7 are found in the membrane of the Golgi in pancreatic cells (and also in many other cell types). They play a role in maintaining the high zinc concentration in the Golgi lumen and thus catalyze the formation of the proinsulin-zinc-calcium complex. Other transporters, such as the newly identified ZnT9 and ZnT10, may also be involved but this is presently unknown.
Kambe, T, Yamaguchi-Iwai, Y, Sasaki, R, Nagao, M
Dodson, G, Steiner, D
Kaarsholm, NC, Ko, HC, Dunn, MF
Dunn, MF
Kadima, W
© 2021 Reactome
