| Arabidopsis peroxisomes carry out diverse functions, including fatty acid beta-oxidation and conversion of indole-3-butyric acid (IBA) to indole-3-acetic acid (IAA). Peroxins are proteins necessary for peroxisome biogenesis; most peroxins facilitate protein import into the peroxisome matrix from the cytoplasm. Although many peroxins involved in matrix protein import have been identified, the process remains incompletely understood, and not all yeast and mammalian peroxins have identified plant homologs. For example, the peroxin that tethers PEX6 to the peroxisome membrane, Pex15p in yeast and PEX26 in humans, is not apparent in the Arabidopsis genome. We hypothesize that components of the receptor recycling machinery that are conserved between yeast and mammals also have homologs in Arabidopsis. I have combined bioinformatic and functional yeast expression approaches to identify Arabidopsis PEX15/26 candidates. I also have used reverse genetic analysis to assess the role of peroxisomal small thioesterases in the conversion of IBA to IAA. |
