Acyl-CoA metabolism - Projects

Fatty acid metabolism in Arabidopsis

Despite a wide variety of high-throughput molecular techniques and bioinformatics the understanding of the biological role of individual proteins is still far from being complete. The proposed project aims on contributing knowledge to such uncharacterized proteins involved in the fatty acid metabolism. Specifically, the role of certain long-chain-acyl-CoA synthetases (LACS) on the plant lipid metabolism will be evaluated. Changes in lipid composition provoked by certain LACS mutant alleles seem to impact plant morphology and plant development substantially. In this project we will focus on LACS genes with so far uncharacterized biological roles. By means of mutant analyses we will dissect the contribution of individual LACS to changes in lipid metabolism finally affecting plant development. Mutant phenotypes will be analyzed with respect to biochemical changes of the lipid composition and to the impact on structure on cellular and tissue level. The overall goal will be the establishment of a model explaining the molecular basis for the observed morphological phenotypes.

Import of fatty acids into the peroxisomal matrix

In this project we are analyzing the mechanism of the import of fatty acid into the peroxisomal matrix. Of particular interest is the role of the membrane bound ABC-transporter PXA1 and its interaction with the peroxisomal acyl-CoA synthetases (LACS). In Arabidopsis PXA1 as well as the peroxisomal LACS are essentially required for fatty acid degradation during seedling establishment. We are investigating LACS in terms of its contribution to the fatty acid transport across the peroxisomal membrane. In yeast a homologous ABC-transporter is required for the import of fatty acids into peroxisomes as well but peroxisomal LACS activity is not essential in this case. This might suggest a different transport mechanism of the proteins in yeast and Arabidopsis. By reciprocal complementation tests we are trying to elucidate if in some cases protein-protein interactions between ABC-transporter and LACS are required. In addition we are investigating if alternative import mechanisms are involved in Arabidopsis to deliver fatty acids to the â-oxidation machinery.


Fatty acid metabolism in cyanobacteria and yeast

Besides the fatty acid metabolism in plants we are working on fatty acid metabolism in cyanobacteria and yeast. A special focus is the impact of fatty acid activating enzymes on the im – and export of fatty acids. In addition, we are investigating the role of lipid remodeling and autophagy on the fatty acid metabolism in unicellular organisms.