A review of phosphatidate phosphatase assays

Phosphatidate phosphatase catalyzes the penultimate step in the synthesis of triacylglycerol and regulates the synthesis of membrane phospholipids. There is much interest in this enzyme because it controls the cellular levels of its substrate phosphatidate and product diacylglycerol; defects in the metabolism of these lipid intermediates are the basis for lipid-based diseases such as obesity, lipodystrophy, and inflammation. The measurement of phosphatidate phosphatase activity is required for studies aimed at understanding its mechanisms of action, how it is regulated, and for screening its activators and/or inhibitors. Enzyme activity is determined through the use of radioactive and nonradioactive assays that measure the product diacylglycerol or Pi. However, sensitivity and ease of use are variable across these methods. This review summarizes approaches to synthesize radioactive phosphatidate, to analyze radioactive and nonradioactive products diacylglycerol and Pi and discusses the advantages and disadvantages of each phosphatidate phosphatase assay.

Keywords: Diacylglycerol; Lipids; PA phosphatase; Pah1; Phosphatases/Lipid; Phospholipids; Phospholipids/Phosphatidate; Triacylglycerol; enzyme assays; lipin.