Abstract
Many of the genes for membrane proteins are encoded in the genome of land plants. Although most of these gene products are predicted to function as solute transporters, only a relatively small number of plant membrane proteins have been functionally characterized to date, mostly because of the experimental difficulties associated with their biochemical analysis. Here we report an improvement of proteoliposome reconstituting system for analyzing plant transporters by modifying wheat germ cell-free translation system. We established optimized conditions for the reconstitution system with Arabidopsis thaliana phosphoenolpyruvate/phosphate translocator 1 (AtPPT1) as a model transporter. A high activity of AtPPT1 was achieved by synthesis of the protein in the presence of Brij35 and liposomes. We also determined the substrate specificities of three putative rice PPT homologs with this system. The cell-free proteoliposome reconstitution system provides a valuable tool for functional analysis of transporter proteins. Nozawa et al. PCP, 48, 2007
