PC (Phosphatidylcholine) is the most abundant Phospholipid in the yeast S. cerevisiae (Saccharomyces cerevisiae) and the major Phospholipid present in eucaryotic cell membranes. It serves as a major structural component of cellular membranes and as a source of several lipid messengers. There are two pathways for PC synthesis in yeast, the CDP-Choline (Cytidine Diphosphate-Choline) pathway (a part of Kennedy Pathway) and the CDP-DAG (Cytidine Diphosphate-Diacylglycerol). Both pathways function to synthesize PC in wild-type cells (Ref.1). The CDP-DAG pathway is used primarily by cells in the absence of exogenous Choline. The PC synthesized by this pathway is constantly metabolized to free Choline and PA (Phosphatidate/Phosphatidic Acid) via the reaction catalyzed by PLD1 (Phospholipase-D1). The free Choline is then incorporated back into [...]