Abstract
Peroxisome biogenesis involves transport of peroxisomal matrix and membrane protein to this organelle. This process is regulated by peroxins that are encoded by PEX genes. Pex7 is a soluble receptor that recognizes peroxisomal targeting signal type 2 (PTS2) containing proteins in the cytosol and transports them into peroxisomes across peroxisome membranes. Using transgenic plants overexpressing green fluorescence protein (GFP) tagged PEX7, we analyzed a protein complex involving PEX7. By combination of co-immunoprecipitation technique, proteomic analysis and BiFC experiment, we identified RabE1b and RabE1c as binding partners of PEX7. We further found that seedlings of rabe1b and rabe1c mutants showed resistance to 2,4 DB, which is metabolized to produce 2,4D by peroxisomal fatty acid beta-oxidation. Further analysis may provide us novel insights into the functions of RabE1b and RabE1c in relation to peroxisomal biogenesis.
