caa a22 4500 445321199 CHVBK 20180317142704.0 cr unu---uuuuu 170323e20110201xx s 000 0 eng 10.1007/s10534-010-9373-6 doi (NATIONALLICENCE)springer-10.1007/s10534-010-9373-6 Characterization of zinc transport by divalent metal transporters of the ZIP family from the model legume Medicago truncatula [Elektronische Daten] [Brian Stephens, Douglas Cook, Michael Grusak] To understand how plants from the Fabaceae family maintain zinc (Zn) homeostasis, we have characterized the kinetics of three Zn transporting proteins from the ZIP family of divalent metal transporters in the model legume Medicago truncatula. Of six ZIP's studied, MtZIP1, MtZIP5 and MtZIP6 were the only members from this family determined to transport Zn and were further characterized. MtZIP1 has a low affinity for Zn with a Km of 1μM as compared to MtZIP5 and MtZIP6 that have a higher affinity for Zn with Km of 0.4μM and 0.3μM, respectively. Zn transport by MtZIP1 was more sensitive to inhibition by copper (Cu) concentrations than MtZIP5 and MtZIP6, because 3μM Cu inhibited Zn transport by 80% in MtZIP1 while 5μM Cu was required to achieve the same inhibition of Zn transport in MtZIP5 and MtZIP6. Cadmium (Cd) had a greater effect on the ability of MtZIP1 to transport Zn than MtZIP5 and MtZIP6, because at a concentration of 3μM Cd, the Zn transport by MtZIP1 was inhibited 55% and the transport of Zn by MtZIP5 and MtZIP6 was inhibited by 20-30%. However, only MtZIP6 transported Cd at higher rates than those observed in the control plasmid pFL61, demonstrating a low affinity for Cd based on a Km of 57μM. These results suggest that Medicago truncatula has both high and low affinity Zn transporters to maintain Zn homeostasis and that these transporters may function in different compartments within the plant. U.S. Government, 2010 Zinc nationallicence Membrane transport nationallicence Kinetics nationallicence Cadmium nationallicence Copper nationallicence Medicago truncatula nationallicence Stephens Brian Department of Pediatrics, USDA-ARS Children's Nutrition Research Center, Baylor College of Medicine, 1100 Bates Street, Houston, TX, USA aut Cook Douglas Department of Plant Pathology, Plant Biology Graduate Group, University of California-Davis, One Shields Drive, 95616, Davis, CA, USA aut Grusak Michael Department of Pediatrics, USDA-ARS Children's Nutrition Research Center, Baylor College of Medicine, 1100 Bates Street, Houston, TX, USA aut BioMetals Springer Netherlands 24/1(2011-02-01), 51-58 0966-0844 24:1<51 2011 24 10534 https://doi.org/10.1007/s10534-010-9373-6 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10534-010-9373-6 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Stephens Brian Department of Pediatrics, USDA-ARS Children's Nutrition Research Center, Baylor College of Medicine, 1100 Bates Street, Houston, TX, USA aut NATIONALLICENCE 700 1- Cook Douglas Department of Plant Pathology, Plant Biology Graduate Group, University of California-Davis, One Shields Drive, 95616, Davis, CA, USA aut NATIONALLICENCE 700 1- Grusak Michael Department of Pediatrics, USDA-ARS Children's Nutrition Research Center, Baylor College of Medicine, 1100 Bates Street, Houston, TX, USA aut NATIONALLICENCE 773 0- BioMetals Springer Netherlands 24/1(2011-02-01), 51-58 0966-0844 24:1<51 2011 24 10534 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer