Phospholipids degradation (Saccharomyces cerevisiae)

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In addition to being a primary structural components of cell membranes, phospholipids may also be thought of as a reservoir of signaling molecules. Hydrolysis of phosphatidylinositol 4,5-biphosphate (PIP2) by phospholipase C, for instance, generates the signaling molecules inositol triphosphate (IP3) and diacylglycerol (DAG). S. cerevisiae catalyzes this reaction via Plc1p, a phosphatidylinositol-specific phospholipase C involved in a variety of biological processes including nutrient sensing and filamentous growth. On the other hand, degradation of phosphatidylcholine (PC) by phospholipase D (Spo14p) yields phosphatidic acid and choline; this activity generates PA required for sporulation in S. cerevisiae. A phospholipase C specific for PC has yet to be identified in S. cerevisiae, however PC may also serve as substrate for phospholipases B (Plb1-3p and Nte1p), which hydrolyze PC to yield glycerophosphocholine (GPC) and two fatty acids. Both phospholipases B and D are thought to mediate PC turnover in yeast, and phospholipase B (as Plb1p) has also been implicated in acyl chain remodeling. Source: https://pathway.yeastgenome.org/