PHOSPHATIDATE PHOSPHATASES OF MAMMALS, YEAST, AND HIGHER-PLANTS

Phosphatidate phosphatase (EC 3.1.3.4) catalyzes the hydrolysis of pho sphatidate to yield sn-1,2-diacylglycerol and inorganic phosphate. In mammalian systems, forms of phosphatidate phosphatase involved in glyc erolipid synthesis and signal transduction have been identified. Forms of the enzyme involved in signal transduction have been purified and partially characterized. In yeast, phosphatidate phosphatases associat ed with the endoplasmic reticulum and mitochondria have also been puri fied and partially characterized. Information on phosphatidate phospha tases from mammals and yeast is useful in characterizing the enzyme fr om plant systems, This review examines progress on the characterizatio n of phosphatidate phosphatases from mammals, yeast, and higher plants . The purification and characterization of the phosphatidate phosphata se involved in glycerolipid synthesis in developing oilseeds may lead to the identification of the encoding gene. Increasing our understandi ng of the enzymes of lipid synthesis in developing seeds will aid in t he development of biotechnological strategies for seed oil modificatio n.