|Name:||solute carrier family 30 (zinc transporter), member 5|
|Aliases:||ZTL1, ZnT-5, FLJ12496, FLJ12756, ZNT5, MGC5499, ZNTL1|
|PubMed (11937503):|| Cragg RA, Christie GR, Phillips SR, Russi RM, Kury S, Mathers JC, Taylor PM,Ford D. A novel zinc-regulated human zinc transporter, hZTL1, is localized to theenterocyte apical membrane.J Biol Chem. 2002 Jun 21;277(25):22789-97. Epub 2002 Apr 05. PMID: 11937503 [PubMed - indexed for MEDLINE]|
Zinc is essential to a wide range of cellular processes; therefore, it is important to elucidate the molecular mechanisms of zinc homeostasis. To date, no zinc transporters expressed at the enterocyte apical membrane, and so essential to mammalian zinc homeostasis, have been discovered. We identified hZTL1 as a human expressed sequence tag with homology to the basolateral enterocyte zinc transporter ZnT1 and deduced the full-length cDNA sequence by PCR. The protein of 523 amino acids belongs to the cation diffusion facilitator family of membrane transporters. Unusually, the predicted topology comprises 12 rather than 6 transmembrane domains. ZTL1 mRNA was detected by reverse transcription-PCR in a range of mouse tissues. A Myc-tagged hZTL1 clone was expressed in transiently transfected polarized human intestinal Caco-2 cells at the apical membrane. Expression of hZTL1 mRNA in Caco-2 cells increased with zinc supplementation of the nutrient medium; however, in the placental cell line JAR hZTL1 appeared not to be regulated by zinc. Heterologous expression of hZTL1 in Xenopus laevis oocytes increased zinc uptake across the plasma membrane. The localization, regulatory properties, and function of hZTL1 indicate a role in regulating the absorption of dietary zinc across the apical enterocyte membrane.
|PubMed (11904301):|| Kambe T, Narita H, Yamaguchi-Iwai Y, Hirose J, Amano T, Sugiura N, Sasaki R,Mori K, Iwanaga T, Nagao M. Cloning and characterization of a novel mammalian zinc transporter, zinctransporter 5, abundantly expressed in pancreatic beta cells.J Biol Chem. 2002 May 24;277(21):19049-55. Epub 2002 Mar 19. PMID: 11904301 [PubMed - indexed for MEDLINE]|
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.
>tr|Q8TAD4 Zinc transporter 5 (Zinc transporter ZnT-5) - Homo sapiens (Human). MEEKYGGDVLAGPGGGGGLGPVDVPSARLTKYIVLLCFTKFLKAVGLFESYDLLKAVHIVQFIFILKLGTAFFMVLFQKP FSSGKTITKHQWIKIFKHAVAGCIISLLWFFGLTLCGPLRTLLLFEHSDIVVISLLSVLFTSSGGGPAKTRGAAFFIIAV ICLLLFDNDDLMAKMAEHPEGHHDSALTHMLYTAIAFLGVADHKGGVLLLVLALCCKVGFHTASRKLSVDVGGAKRLQAL SHLVSVLLLCPWVIVLSVTTESKVESWFSLIMPFATVIFFVMILDFYVDSICSVKMEVSKCARYGSFPIFISALLFGNFW THPITDQLRAMNKAAHQESTEHVLSGGVVVSAIFFILSANILSSPSKRGQKGTLIGYSPEGTPLYNFMGDAFQHSSQSIP RFIKESLKQILEESDSRQIFYFLCLNLLFTFVELFYGVLTNSLGLISDGFHMLFDCSALVMGLFAALMSRWKATRIFSYG YGRIEILSGFINGLFLIVIAFFVFMESVARLIDPPELDTHMLTPVSVGGLIVNLIGICAFSHAHSHAHGASQGSCHSSDH SHSHHMHGHSDHGHGHSHGSAGGGMNANMRGVFLHVLADTLGSIGVIVSTVLIEQFGWFIADPLCSLFIAILIFLSVVPL IKDACQVLLLRLPPEYEKELHIALEKIQKIEGLISYRDPHFWRHSASIVAGTIHIQVTSDVLEQRIVQQVTGILKDAGVN NLTIQVEKEAYFQHMSGLSTGFHDVLAMTKQMESMKYCKDGTYIM