The lipolysis of TAGs was also studied in impressive detail in B. mori. PBAN activates the calcium influx upon binding to its receptor (i.e. a G-protein coupled receptor)14. Ca2+/calmodulin-dependent protein kinase II (BmCaMKII), activated by PBAN-mediated calcium influx, phosphorylates lipid storage droplet protein-1 (Lsd-1), a homologue of perilipin in mammalians. The phosphorylation of Lsd-1 facilitates and promotes the release of the lipase activator complex to activate TAG lipase for the generation of bombykol precursors10. In addition, several key proteins involved in B. mori sex pheromone biosynthesis were identified, such as fatty acid transport protein, which facilitates the uptake of extracellular long-chain fatty acids across the plasma membrane15, Acyl-CoA binding proteins (ACBPs), which protect fatty acyl-CoA esters from hydrolysis and ensure enough fatty acid precursors for bombykol biosynthesis, stromal interaction molecule I (STIMl) and store-operated channel protein (Orail: including OrailA and OrailB), which are essential components of the signal transduction cascade regulating bombykol production516. Despite previous efforts, the essential components involved in biosynthesis of bombykol precursor and activation of lipases for TAG lipolysis have yet to be identified. In the present study, quantitative proteomics, molecular biology and behavior analysis were combined to investigate the molecular mechanism regarding the synthesis of sex pheromone precursor. The results showed that glycerol-3-phosphate O-acyltransferase (GPAT) is required for TAG biosynthesis and subsequent bombykol production in B. mori, thus, providing insights into the PBAN-regulated pheromone biosynthesis in B. mori.