Protein transport in and out of plant peroxisomes

Abstract

Plant peroxisomes house conserved functions such as β-oxidation and hydrogen peroxide decomposition along with specialized tasks including hormone metabolism and photorespiration. Phenotypes stemming from defects in these pathways have been exploited to isolate and characterize peroxisome-defective mutants in the reference plant Arabidopsis thaliana. Because peroxisome function is essential for plant viability, partial loss-of-function alleles have been frequently recovered from forward genetic screens. Analysis of these mutants has revealed the broad outlines of matrix protein import in plants and that these processes may be more similar between plants and mammals than between plants and yeast. Here we review matrix protein import into plant peroxisomes and the emerging understanding of how these matrix proteins may be degraded when they are damaged or no longer needed.