Objective
Iron is an essential nutrient. It is involved in a great variety of biological processes, such as photosynthesis or the oxidative respiration. Iron deficiency is a factor limiting crop production, and the most important dietary deficiency in humans. In order to address these problems, plant iron uptake has been studied with detail. As a result, metal transporters of the ZIP family have been identified as the main responsibles for iron uptake from soil in plants, with the exception of some grasses. However, very little is known on their biochemistry and on the shuttling of iron in the cytosol. The aim of this proposal is to biochemically characterized these ZIP transporters, using as a model Arabidopsis thaliana IRT1. This transporter has successfully been expressed in yeast, where it is still active and therefore is susceptible of being purified in an active form. Oligomeric state of the protein, metal specificity and kinetical parameters will be determined in vitro, by means of fluorescent probes specific for the different transport substrates. Similarly, the possibility of cotransport will be evaluated. Metal affinity, metal binding site/-s will be determined by the use of fluorescent probes and site directed mutagenesis, and further verified with X-ray spectroscopy. The acceptor from the iron introduced by IRT1 will be identified by means of copurification, coimmunoprecipitation or by chemical crosslinking. All these results will be further validated in vivo in an Arabidopsis irt1-1 background. As a result of this work we will determine how IRT1 works, the first time that this would be done in a ZIP transporter. These results will be used in the characterization of other ZIP transporters regardless their origin, plant, animal, bacteria ,…. and explain at a molecular level the etiology of some diseases. However, primarily, these results could indicate new strategies to improve plant iron nutrition in areas where deficiency is prevalent, such as eastern Spain
Fields of science
Topic(s)
Call for proposal
FP7-PEOPLE-IEF-2008
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Funding Scheme
MC-IEF - Intra-European Fellowships (IEF)Coordinator
75794 Paris
France