Research in my group is aimed at understanding the principles that govern membrane lipid homeostasis and identifying the underlying sensor-effector modules. These topics are investigated in the reference eukaryote baker’s yeast (S. cerevisiae) using biochemical, genetic and chemical biological approaches, complemented by lipidome analysis. A novel regulatory mechanism maintaining the balance between bilayer and non-bilayer lipids was discovered that adapts lipid acyl chain composition in response to changes in lipid class composition and vice versa. Current research focuses on the identity and molecular mechanism of the gene products involved including the membrane sensor. Acyltransferases were found to determine acyl chain desaturation, providing new insight into the regulation of membrane fluidity and generating new tools for manipulating membrane lipid composition. Photoactivatable and clickable phospholipid probe molecules have been developed that were successfully used to discover new lipid-protein interactions in biological membranes. In flanking application-oriented research, we aim to improve the performance of yeast in production processes involving hydrophobic substances by engineering the membrane lipid composition.