Characterization of the ZAT1p zinc transporter from Arabidopsis thaliana in microbial model organisms and reconstituted proteoliposomes.
The ZAT1p zinc transporter from Arabidopsis thaliana (L.) Heynh. is a member of the cation diffusion facilitator (CDF) protein family. When heterologously expressed in Escherichia coli, ZAT1p bound zinc in a metal blot. Binding of zinc occurred mainly to the hydrophilic amino acid region from H182 to H232. A ZAT1p/ZAT1p*Delta(M1-I25) protein mixture was purified and reconstituted into proteoliposomes. Uptake of zinc into the proteoliposomes did not require a proton gradient across the liposomal membrane. ZAT1p did not transport cobalt, and transported cadmium at only 1% of the zinc transport rate. ZAT1p functioned as an uptake system for 65Zn2+ in two strains of the Gram-negative bacterium Ralstonia metallidurans, which were different in their content of zinc-efflux systems. The ZAT1 gene did not rescue increased zinc sensitivity of a Delta ZRC1single-mutant strain or of a Delta ZRC1 Delta COT1 double-mutant strain of Saccharomyces cerevisiae, but ZAT1 complemented this phenotype in a Delta SpZRC1 mutant strain of Schizosaccharomyces pombe.
Bloss
Tanja
T
Institut für Mikrobiologie, Kurt-Mothes-Strasse 3, 06099 Halle, Germany.
Clemens
Stephan
S
Nies
Dietrich H
DH
D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D001419:Bacteria / Q000235:genetics / Q000254:growth & development; D002104:Cadmium / Q000378:metabolism / Q000494:pharmacology; D002352:Carrier Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D027682:Cation Transport Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D003035:Cobalt / Q000378:metabolism / Q000494:pharmacology; D004926:Escherichia coli / Q000235:genetics; D005786:Gene Expression Regulation / Q000187:drug effects; D008081:Liposomes / Q000737:chemistry; D019216:Metals, Heavy / Q000378:metabolism / Q000494:pharmacology; D009154:Mutation; D010641:Phenotype; D011510:Proteolipids / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development; D012568:Schizosaccharomyces / Q000235:genetics / Q000254:growth & development; D013379:Substrate Specificity; D015032:Zinc / Q000378:metabolism* / Q000494:pharmacology
D029681:Arabidopsis Proteins; D002104:Cadmium; D002352:Carrier Proteins; D027682:Cation Transport Proteins; D003035:Cobalt; D008081:Liposomes; D019216:Metals, Heavy; D011510:Proteolipids; D015032:Zinc; C020485:proteoliposomes; C017800:zinc-binding protein; C500829:ZAT protein, Arabidopsis