Phosphatidic Acid Phosphatase Domain Containing 2 (PPAPDC2)

Upon cell activation Presqualene diphosphate (PSDP)2, a bioactive lipid, rapidly remodels to presqualene monophosphate (PSMP). A newly identified and characterized phosphatase (phosphatidic acid phosphatase domain containing 2 (PPAPDC2)) has recent;y been shown to convert PSDP to PSMP. Also known as Phosphatidic acid phosphatase type 2 domain-containing protein 2. Unlike the related polyisoprenyl phosphate farnesyl diphosphate (FDP), PSDP has been shown not to be a substrate for type 2 lipid phosphate phosphohydrolases. PSDP phosphatase activity has been identified in activated human neutrophil (PMN) extracts. Recombinant PPAPDC2 displays diphosphate phosphatase activity with substrate preference for PSDP > FDP phosphatidic acid. PPAPDC2 activity is independent of Mg2+ and optimal at pH 7.0-8.0. PPAPDC2 mRNA has been detected in human PMN, and is widely expressed in human tissues. PPAPDC2 expressed in human PMN is first lipid phosphate phosphohydrolase identified for PSDP. The regulation of this enzymeÕs activity has important implications for PMN activation in innate immunity.