Abstract
In mammals, yeast and plant, the peroxisome biogenesis factors (peroxin) have been identified, but their functions remain unclear. Many peroxisomal proteins have peroxisomal targeting signal (PTS). The PTS are recognized by specific receptors. The PTS-containing proteins are delivered to peroxisomal membrane and translocated across the membrane via a translocation apparatus to the peroxisomal matrix.
So far, we attempted to identify peroxisomal targeting signal of pumpkin catalase (Cat1) by observing the cellular localization of the GFP-Cat1 fusion protein in transgenic tobacco cells and analyzed binding of Pex5p to Cat1 by yeast two-hybrid system. These results suggested that Cat1 is transported to peroxisomes by the PTS1 system. In this study, we focused on Pex10p and Pex12p. We isolated the cDNAs for tobacco peroxins and generated transgenic tobacco BY-2 cells lacking these peroxins. Furthermore, we analyzed the cellular localization of catalase in these transgenic tobacco cells.
