We are interested in fundamental aspects of cellular membrane biogenesis. Our work covers a number of areas concerned with lipid biosynthesis, propagation of the phospholipid bilayer of biological membranes, translocation (flip-flop) of lipids across bilayers, and intracellular lipid transport. We approach these problems through biochemical, biophysical, genetic and chemical methods. Current projects are to [1] identify flippase proteins responsible for transbilayer flip-flop of phospholipids and glycolipids in biogenic membranes, [2] determine the molecular mechanism of sterol transport from the endoplasmic reticulum to the plasma membrane in yeast, [3] analyze the membrane trafficking of retinal derivatives that is necessary for the regeneration of the visual pigment in mammalian retina, and [4] elucidate structure-function relationships of the multi-subunit, membrane-bound enzyme complex responsible for the last step in the assembly of glycosylphosphatidylinositol (GPI)-anchored proteins in the endoplasmic reticulum.
