Functional analysis of Arabidopsis transporters for nucleobases and derivatives

• Applicant: Dr. Marcelo Desimone
• Subject Area: Plant Biochemistry and Biophysics
• Term: from 2007 to 2011
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 56276362

Nucleobases and derivatives play essential roles in the cells of all living organisms. Since the site of their synthesis frequently differs from the site of use, transport is required in multicellular organisms. In plants, crucial transport processes involving nucleobases or derivatives are not well understood at the molecular level. This includes the uptake of purines and pyrimidines into the cell for salvaging, the long distance transport of purine degradation products, with the ureides as prominent compounds in tropical legumes, and the allocation of cytokinins. The aim of this proposal is to evaluate the role of the members of two different protein families of Arabidopsis, which are potentially involved in these processes. A. thaliana knockout mutants defective in Ureide Permease (AtUPS) functions will be phenotypically characterized to point out (i) the role of AtUPS1 in the utilization of pyrimidines during germination, (ii) and the role of AtUPS5 in the allocation of allantoin, uric acid and xanthine during stress and senescence. In addition, two A. thaliana members belonging to a novel protein family, which are potentially involved in cytokinin transport (designated as AtAzg1 and AtAzg2), will be characterized with respect to their transport properties, gene expression and subcellular localization. Knockout and overexpressor plants will be obtained and partially characterized.

• DFG Programme: Research Grants