Wednesday 4 January 2012
Definition: Phosphatidic acids (PAs) are the acid forms of phosphatidates, a part of common phospholipids, major constituents of cell membranes.
Phosphatidic acids are the simplest diacyl-glycerophospholipids.
Phosphatidic acid consists of a glycerol backbone, with, in general, a saturated fatty acid bonded to carbon-1, an unsaturated fatty acid bonded to carbon-2, and a phosphate group bonded to carbon-3.
Formation and degradation
Besides de novo synthesis, PA can be formed in three ways:
By phospholipase D (PLD), via the hydrolysis of the P-O bond of phosphatidylcholine (PC) to produce PA and choline.
By the phosphorylation of diacylglycerol (DAG) by DAG kinase (DAGK)
By the acylation of lysophosphatidic acid by lysoPA-acyltransferase (LPAAT); this is the most common pathway.
PA is degraded by conversion into DAG by lipid phosphate phosphohydrolases (LPPs) or into lyso-PA by phospholipase A (PLA).