Cloning and Characterization of a Novel Mammalian Zinc Transporter, Zinc Transporter 5, Abundantly Expressed in Pancreatic β Cells

摘要: Abstract Intracellular homeostasis for zinc is achieved through the coordinate regulation of specific transporters engaged in influx, efflux, and intracellular compartmentalization. We have identified a novel mammalian transporter, transporter 5 (ZnT-5), by virtue its similarity to ZRC1, ofSaccharomyces cerevisiae, member cation diffusion facilitator family. Human ZnT-5 (hZnT-5) cDNA encodes 765-amino acid protein with 15 predicted membrane-spanning domains. hZnT-5 was ubiquitously expressed all tested human tissues abundantly pancreas. In pancreas, insulin-containing β cells that contain at highest level body. The immunoreactivity found be associated secretory granules electron microscopy. hZnT-5-derived transport activity detected using Golgi-enriched vesicles prepared from hZnT-5-induced HeLa/hZnT-5 which exogenous expression inducible Tet-on gene system. This dependent on time, temperature, concentration saturable. Moreover, high (10 mm) inhibited growth yeast expressing hZnT-5. These results suggest plays an important role transporting into pancreatic cells.