Induction of peroxisomal Lon protease in rat liver after di-(2-ethylhexyl)phthalate treatment.

Previously, we identified a peroxisome-specific isoform of Lon protease using subcellular proteomics. In the present study, we investigated changes in the level of the Lon protease in peroxisomes during recovery from peroxisomal proliferation induced by di-(2-ethylhexyl)phthalate (DEHP) to elucidate the function of peroxisomal Lon protease (PSLP). Following a 2-week treatment with DEHP, the level of PSLP was monitored for 15 days. The amount of protease was greatly increased after the 2-week treatment, followed by a further increase 3 days after cessation of the treatment. Afterward, it decreased and reached the control level on day 15. On the other hand, level peroxisomal beta-oxidation enzymes induced to express by DEHP started to decrease soon after discontinuation of treatment. The results suggest that PSLP functions to degrade beta-oxidation enzymes induced by DEHP during recovery from perxisomal proliferation.