title: Characterization of the GufA subfamily member SLC39A11/Zip11 as a zinc transporter.
abstract: Cellular zinc influx and efflux are maintained by two major transporter families, the ZIP (SLC39A) and ZnT (SLC30A or CDF) molecules. The functions of one molecule in this class, ZIP11/SLC39A11, remain unclear. Bioinformatics analysis of the distribution and evolutionary relationships of different ZIP members in eukaryotes and prokaryotes indicated that Zip11, the sole member of gufA subfamily, is an ancient ZIP family member that might have originated in early eukaryotic ancestors. Murine Zip11 mRNA is abundantly expressed in testes and the digestive system including stomach, ileum and cecum. Analysis of cellular zinc content, metallothionein levels, and cell viability under high or low zinc conditions in cells transfected with a murine Zip11 expression plasmid, suggest that Zip11 is a zinc importer. Further, cellular zinc concentrations and metallothionein levels decreased when Zip11 was knocked down. In mice supplemented with zinc, both mRNA and protein levels of Zip11 were slightly up-regulated in several tissues. The metal response element sequences (MREs) upstream of the first exon of Zip11 responded to elevated extracellular zinc concentrations, as assessed by luciferase reporter assays. Mutagenic analysis showed that several of the MREs could regulate Zip11 promoter activity, and metal-responsive transcription factor-1 (MTF-1) was shown to be involved in this process. Collectively, these data suggest that Zip11 has unique protein sequence and structure features, it functions as a cellular zinc transporter, and its expression is at least partially regulated by zinc via hMTF-1 binding to MREs of the Zip11 promoter.
authors: Department of Nutrition, Institute of Nutrition and Food Safety, School of Public Health, Zhejiang University, Hangzhou 310058, P.R. China; Key Laboratory of Nutrition and Metabolism, Shanghai Key Laboratory of Pediatric Gastroenterology and Nutrition, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, P.R. China.
authors: Yu
authors: Y
authors: Yu
authors: Aimin
authors: A
authors: Wu
authors: Zhuzhen
authors: Z
authors: Zhang
authors: Guang
authors: G
authors: Yan
authors: Fan
authors: F
authors: Zhang
authors: Lihong
authors: L
authors: Zhang
authors: Xiaoyun
authors: X
authors: Shen
authors: Ronggui
authors: R
authors: Hu
authors: Yan
authors: Y
authors: Zhang
authors: Keying
authors: K
authors: Zhang
authors: Fudi
authors: F
authors: Wang
mesh_terms: D000818:Animals; D027682:Cation Transport Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004285:Dogs; D055785:Gene Knockdown Techniques; D057809:HEK293 Cells; D006801:Humans; D061985:Madin Darby Canine Kidney Cells; D008297:Male; D008668:Metallothionein / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D011401:Promoter Regions, Genetic; D015032:Zinc / Q000378:metabolism*
chemical_list: D027682:Cation Transport Proteins; C000604569:SLC39A11 protein, human; C585914:Zip11 protein, mouse; D008668:Metallothionein; D015032:Zinc
keywords: MRE; MTF-1; SLC39A11/ZIP11; ZIP family; Zinc homeostasis; Zinc transporter