Abstract 1662 Mammalian PHOSPHO1 and PHOSPHO2 exhibit phospholipase C and lipid phosphate phosphatase activities in vitro, respectively

Introduction Phosphatase orphan 1 and 2 (PHOSPHO1 and PHOSPHO2) are cytosolic proteins containing three catalytic motifs, conserved within the haloacid dehalogenase (HAD) superfamily. It has been demonstrated that PHOSPHO1 exhibits phosphohydrolase activity toward phosphoethanolamine (PEA) and phosphocholine (PCho), and that PHOSPHO2 shows phosphohydrolase activity toward pyridoxal-5-phosphate (P5P). Mammalian lipin isoforms contain HAD-like domain and exhibit phosphatase activity toward phosphatidic acid (PA), a phospholipid (PA phosphatase (PAP) activity).