Molecular cloning and characterization of a lipase from the honeybee Apis mellifera

Lipids perform essential and important functions, such as serving as an energy source for growth, development, reproduction, flight, starvation, and diapause in insects. Lipases are key enzymes involving in lipid metabolism and have been reported in several insect species. However, the molecular characterization of the pancreatic triacylglycerol lipase-like genes in honeybees has not been elucidated. Here, we describe the cDNA cloning and characterization of lipase from the honeybee Apis mellifera (Am-Lipase). Am-Lipase consists of 321 amino acids, including a Ser-Glu-His catalytic triad and a consensus active site motif GXSXG. Recombinant Am-Lipase protein degrades triglycerides, preferentially catalyzing the hydrolysis of long-chain fatty acids. Furthermore, the expression pattern of Am-Lipase seems to be a fat body-specific lipase, shows higher expression in forager bees, and is decreased under starvation conditions. Thus, our results suggest that Am-Lipase plays a role in the utilization of lipids stored in the fat body for lipid metabolism.