Our research interest focuses on plant peroxisomes. Plant peroxisomes are well-known for their important physiological functions in photorespiration, fatty acid beta-oxidation and ROS metabolism. However, many enzymes and metabolic pathways of plant peroxisomes have remained largely uncharacterized to date. Also, we are only in the beginning to understand inter-organellar metabolic and signaling networks between peroxisomes, mitochondria and chloroplasts. Plant peroxisomes are significant for plants, humans, and the global climate: Plant photorespiration releases large quantities of CO2 into the atmosphere, thereby reducing plant biomass production. Intensive international efforts are now undertaken to understand and optimize photorespiration to ultimately improve plant CO2 fixation and biomass production (see research consortium PROMICS below).
To identify novel proteins of plant peroxisomes we established proteome analysis of Arabidopsis leaf peroxisomes. Proteome analysis of senescent leaf peroxisomes (gerontosomes) and glyoxysomes is covered incollaboration with the Arabidopsis 2010 Peroxisome Project (see below). Stress and phosphoproteomics have been initiated in our group.
In a complementary approach we are developing algorithms to predict matrix proteins of plant peroxisomes with high accuracy from genome sequences. Arabidopsis proteins predicted to be targeted to peroxisomes have been assembled in the database AraPerox 1.2. A new relational format of the database is currently being developed.
At the molecular level we currently focus on ROS metabolism including novel detoxification mechanisms and chaperones that are likely to be involved in renaturation of oxidatively damaged matrix proteins. Furthermore, we study how photorespiration and ROS metabolism are regulated at the post-translational level, for instance by reversible phosphorylation.
