| First Author | Kambe T | Year | 2002 |
| Journal | J Biol Chem | Volume | 277 |
| Issue | 21 | Pages | 19049-55 |
| PubMed ID | 11904301 | Mgi Jnum | J:76849 |
| Mgi Id | MGI:2180427 | Doi | 10.1074/jbc.M200910200 |
| Citation | Kambe T, et al. (2002) Cloning and characterization of a novel mammalian zinc transporter, zinc transporter 5, abundantly expressed in pancreatic beta cells. J Biol Chem 277(21):19049-55 |
| abstractText | Intracellular homeostasis for zinc is achieved through the coordinate regulation of specific transporters engaged in zinc influx, efflux, and intracellular compartmentalization. We have identified a novel mammalian zinc transporter, zinc transporter 5 (ZnT-5), by virtue of its similarity to ZRC1, a zinc transporter of Saccharomyces cerevisiae, a member of the cation diffusion facilitator family. Human ZnT-5 (hZnT-5) cDNA encodes a 765-amino acid protein with 15 predicted membrane-spanning domains. hZnT-5 was ubiquitously expressed in all tested human tissues and abundantly expressed in the pancreas. In the human pancreas, hZnT-5 was expressed abundantly in insulin-containing beta cells that contain zinc at the highest level in the body. The hZnT-5 immunoreactivity was found to be associated with secretory granules by electron microscopy. The hZnT-5-derived zinc transport activity was detected using the Golgi-enriched vesicles prepared from hZnT-5-induced HeLa/hZnT-5 cells in which exogenous hZnT-5 expression is inducible by the Tet-on gene regulation system. This activity was dependent on time, temperature, and concentration and was saturable. Moreover, zinc at a high concentration (10 mm) inhibited the growth of yeast expressing hZnT-5. These results suggest that ZnT-5 plays an important role for transporting zinc into secretory granules in pancreatic beta cells. |
