Proteomic Analysis of Peroxisomal Proteins

Peroxisome is a ubiquitous eukaryotic organelle with a single-layer membrane. It maintains various functions that differ depending on the species and cell types, as well as the environmental or developmental conditions. In the first part of this thesis, the peroxisomal protein content was systematically analyzed in different organs in mouse from different ages using proteomic approaches. Thirty-one peroxisomal proteins were identified and ten putative peroxisomal proteins were suggested. The results indicate that peroxisomal proteins show a tissue-specific functional response to the aging process that is probably dependent on their differential regeneration capacity. Besides, alteration in the fatty acid metabolism could alter membrane protein functions; decrease in catalase expression in kidney may contribute to oxidative stress and isoprenoid biosynthesis could contribute to decline in bile salt synthesis. The ability to detect changes in the peroxisomal proteome associated with organ impairment during the course of aging would provide a conceptual framework to understand the role of peroxisome in aging. In the second part, peroxisome proteomics was used as a novel approach in marine pollution assessment. The peroxisomal protein expression profiles were obtained and identified from mussel Mytilus sp. exposed to different pollutants, in both laboratory and field experiments. The identified proteins were involved in α- and β–oxidation pathways, xenobiotics and amino acid metabolism, cell signalling, oxyradical metabolism, peroxisomal assembly, respiration and cytoskeleton pathway, etc. Generally, these findings suggest that protein expression signatures could become a valuable tool to monitor the presence of pollutants in marine environment