Molecular cloning and functional characterization of novel zinc transporter rZip10 (Slc39a10) involved in zinc uptake across rat renal brush-border membrane

Abstract

Kaler P, Prasad R. Molecular cloning and functional characterization of novel zinc transporter rZip10 (Slc39a10) involved in zinc uptake across rat renal brush-border membrane. Am J Physiol Renal Physiol 292: F217-F229, 2007. First published June 27, 2006 doi:10.1152/ajprenal.00014.2006.-Previously, in our laboratory a 40-kDa zinc transporter protein was purified and functionally reconstituted in proteoliposomes (Kumar R, Prasad R. Biochim Biophys Acta 1419: [23][24][25][26][27][28][29][30][31][32] 1999). Furthermore, we now report the identification of Slc39a10 cDNA encoding the 40-kDa zinc transporter protein by isolating a cloned DNA complementary to zinc transporter mRNA. cDNA was constructed from immunoenriched mRNA encoding the zinc transporter. cDNA was inserted into pBR322 using poly(dC)-poly(dG) tailing. Escherichia coli DH5␣ cells were transformed, and colonies were screened for zinc transporter cDNA by insertional inactivation. Plasmid DNA was purified from the ampicillin-sensitive clones, and the cDNA was sequenced from both strands. A basic local alignment research tool (BLAST) search of cDNA revealed that it belongs to the Slc39 gene family of zinc transporters and was designated as Slc39a10. Zinc transporter protein deduced on the basis of cDNA sequence was named rZip10 and consists of 385 amino acids with 9 predicted transmembrane domains. The Slc39a10 gene was abundantly expressed in both rat and human tissues. Increased extracellular zinc concentration resulted in upregulation of Slc39a10 in LLC-PK1 cells expressing rZip10, which was downregulated at higher zinc concentrations. These cells accumulated more zinc than control cells. rZip10-mediated zinc uptake activity was time-, temperature-, and concentration-dependent and saturable which followed Michaelis-Menten kinetics with a Km of 19.2 M and Vmax of 50 pmol⅐min Ϫ1 ⅐mg protein Ϫ1

Zinc transporter mRNA expression in the RWPE-1 human prostate epithelial cell line

“…The Zip-7 gene and its expression has not been examined in normal and malignant prostate cells or tissues. Messenger RNA expression was also found for the Zip-10 family member which has been shown to be involved in zinc uptake across the brush border membrane of the kidney (Kaler and Prasad 2007). It has also been shown to be regulated by thyroid hormone in intestine and kidney (Pawan et al 2007).…”

Characterization of the GufA subfamily member SLC39A11/Zip11 as a zinc transporter

“…Zip10 is found abundantly expressed in tissues such as small intestine, pancreas, testes, brain, liver and kidney. In mice, Zip10 has the highest expression in the liver and brain [10,15]. Additionally, in the C57BL/ 6J mouse, Zip14a expression is highest in liver, duodenum, kidney and testes, whereas Zip14b expression is highest in liver, duodenum, brain and testes [5].…”

“…Members of the ZIP family have been demonstrated to be involved in zinc uptake and in the release of stored zinc into the cytoplasm of cells when zinc is deficient. In mammals, Zip1-8, Zip10 and Zip14 proteins have been reported to function as zinc uptake proteins [5,[8][9][10]. For instance, in transfected cells, mZip5 functions in zinc uptake and is specific for zinc as a substrate [8].…”

“…The mammalian ZIP family consists of 14 members in 4 subfamilies: ZIP subfamily I (ZIP9), ZIP subfamily II (ZIP1, ZIP2 and ZIP3), LIV-1 family (ZIP4, ZIP5, ZIP6, ZIP7, ZIP8, ZIP10, ZIP12, ZIP13 and ZIP14) and gufA family (ZIP11). Previously, ZIP1-8, ZIP10, and ZIP14 have been shown to facilitate zinc uptake in cells [5,[8][9][10].…”

Kidney Cadmium Toxicity, Diabetes and High Blood Pressure: The Perfect Storm

“…In a recent study, the transgenic mice with three more copies of the ZIP8 gene were found to accumulate twice as much Cd in the kidney after Cd exposure, and the PT from these mice had elevated ZIP8 expression levels at the apical membrane, accounting for their high sensitivity to Cd toxicity (Nebert et al 2012). ZIP10 has been found in high abundance in renal cortical epithelial cells, suggesting the potential role for this zinc transporter in Cd reabsorption (Kaler and Prasad 2007). There is little evidence for an exit route for Cd once it has entered PT cells.…”