Proteins Involved in Biosynthesis of Phosphatidic Acid in the Yeast Saccharomyces cerevisiae (Firnberg Fellowship T113)

In yeast as in mammalian cells, two pathways leading to the formation of PtdOH are known: (i) the glycerol-3-phosphate (Gro3P) and (ii) the dihydroxyacetonephosphate (GrnP) pathway named after the respective precursors utilized. Two acyltransferases catalyze the conversion of Gro3P to PtdOH, whereas a third enzyme is required for the GrnP pathway to convert 1-acyl-GrnP to 1 acyl-Gro3P. In all types of cells, these enzymes occur in redundancy. The aim of the project is further identification and characterization of yeast genes and gene products involved in PtdOH formation. Methods of bioinformatics, molecular biology, cell biology and biochemistry are employed to address this problem. To study the subcellular distribution of these proteins fluorescence microscopy (green fluorescent protein approach or immunological methods) and cell fractionation techniques (Western blot and enzymatic analysis) are used. Species analysis of PtdOH formed in wild type or the respective mutants which will be constructed will show the contribution of each specific enzyme to the total amount of cellular PtdOH. not assigned KP: G. Balliano