Phosphatidic acid (PA) (PA)

Phosphatidic acid (PA) is a fundamental phospholipid that serves both as a central intermediate in lipid biosynthesis and as a critical bioactive signaling molecule (PubChem CID 452). It is characterized by a glycerol backbone, two fatty acid chains, and a phosphate group, giving it a unique cone-shaped geometry that promotes membrane curvature and fusion (PubMed: 12648486). In signaling, PA acts as a second messenger that recruits and activates various effector proteins, most notably the mechanistic target of rapamycin (mTOR), which is essential for cell growth and protein synthesis (PubMed: 15544351). Dysregulation of PA levels is implicated in several pathologies, including cancer, where overactive phospholipase D (PLD) leads to elevated PA and sustained growth signaling (PubMed: 21746959). Consequently, PA and the enzymes responsible for its production are significant areas of interest for therapeutic intervention, particularly in oncology and regenerative medicine. Additionally, PA is utilized as a dietary supplement to enhance muscle mass by stimulating the mTOR pathway in response to resistance exercise (PubMed: 23075554). Beyond its role in growth, PA is involved in vesicular trafficking and the regulation of various ion channels and kinases (PubMed: 11062244). Its ability to act as a pH sensor also allows it to link cellular metabolism with signaling pathways (PubMed: 20972427).

Other names

1,2-diacyl-sn-glycero-3-phosphatePhosphatidatePA1,2-Diacyl-sn-glycero-3-phosphoric acid

Phosphatidic acid acts as a lipid second messenger that recruits and allosterically activates signaling proteins such as mTOR and Raf-1 to the membrane (PubMed: 15544351). It also modulates membrane physical properties, specifically inducing negative curvature to facilitate vesicle fusion and fission (PubMed: 12648486). Pharmacological modulation typically involves inhibiting enzymes like phospholipase D (PLD) to decrease PA levels in cancer or using exogenous PA to stimulate muscle protein synthesis (PubMed: 23075554).