The yeast TGL3‐encoded triacylglycerol (TAG) lipase catalyzes the hydrolytic reaction of TAG to generate fatty acid and diacylglycerol. The reaction products not only can be used as building blocks for the synthesis of phospholipids, but also serve ...
The yeast TGL3‐encoded triacylglycerol (TAG) lipase catalyzes the hydrolytic reaction of TAG to generate fatty acid and diacylglycerol. The reaction products not only can be used as building blocks for the synthesis of phospholipids, but also serve as lipid signaling molecules involving many cellular functions. Moreover, fatty acid can be broken down to generate ATP via peroxisomal b‐oxidation. However, excessed fatty acid and DAG is detrimental to cell growth as they exhibit detergent‐like properties and can disrupt membrane structure. Thus, Tgl3 lipase activity must be tightly controlled to maintain lipid homeostasis and cell physiology.Phosphoproteome studies showed that Tgl3 TAG lipase is subject to phosphorylation regulation. In this study, we showed that the purified Tgl3 TAG lipase and its synthetic peptide RKTQRSSSQSPIK containing Ser‐478 were phosphorylated by the TPK1‐encoded protein kinase A. The phosphorylation‐deficient mutant S478A, which exhibited a 55.9% decrease in Tgl3 phosphorylation, caused a 76% reduction in the protein level of Tgl3 TAG lipase. The effects of Tgl3 phosphorylation on the lipid metabolism and cell growth are currently under investigation. Supported by MOST grant 108‐2311‐B‐259 ‐001.