Lipid Molecular Species in Yeast (FWF 13767)

The fact that each organellar membrane has a characteristic lipid composition raises the possibility that membranes contain inheritable structural information encoded in their membrane-specific protein/lipid composition. How this lipid composition is determined and maintained is subject of this project. Our approach to study this question is to follow the fate of selected and precisely defined lipid molecular species in different subcellular membranes. This is a new approach that is made possible by recent technical advances in rapidly and sensitively analyzing the lipid molecular species composition by nano-electrospray tandem mass spectroscopy (ESI-MS/MS). A lipid molecular species is a lipid of defined chemical structure, i.e. of known acyl chain- and head group substituents. In previous work, we performed a comprehensive characterization of the lipid molecular species composition of different subcellular membranes from yeast by ESI-MS/MS. This analysis identified certain lipid molecular species that appear to be characteristic for a particular subcellular membrane. The fate of these lipid species will be analyzed in more detail. The synthesis of an unusual very-long-chain fatty acid (C26) substituted phosphatidylinositol is characterized by biochemical and genetic methods. Furthermore, synthesis, transport, and turnover of one lipid molecular species that is typically found at the plasma membrane will be followed in a number of different yeast mutants. not assigned KP: F. Prestwich not assigned KP: F. Wieland not assigned KP: J. Cooper not assigned KP: J. Knudsen