My laboratory for the past 40 years has carried out studies on the two major components of cell membranes–Phospholipids and Proteins. Early studies in Escherichia coli focused on purification and characterization of membrane-associated enzymes responsible for synthesis of the major phospholipid classes. Molecular genetic approaches are currently used to construct strains of E. coli and Saccharomyces cerevisiae in which membrane phospholipid composition can be regulated in a dose-dependent and temporal manner to define the role of specific phospholipids in cell function.
Through variation of phospholipid composition and expression of foreign lipids in E. coli, the following roles for phospholipids have been defined: structure, topological organization and function of membrane proteins; organization and function of the cell division and DNA replication machinery; organization and function of lipid domains in the membrane; export of proteins across the inner membrane; control of regulated membrane permeability. In yeast mitochondria important roles have been delineated for the phospholipid cardiolipin in organization and function of the respiratory chain.