Pheromone biosynthesis activating neuropeptides: Functions and chemistry

Sex pheromones are critical for reproductive success in most species of Lepidoptera and their production is regulated by the action of pheromone biosynthesis activating neuropeptides (PBAN). These peptides, composed of 33-34 amino acids, have approximately 80% sequence homology and share the C-terminal sequence FSPRL-NH₂, which has been shown to be the minimum sequence required for pheromonotropic activity. This pentamer is structurally similar to the active core (FXPRL-NH₂, X = V, T, or G) of the insect myotropic pyrokinins. Structure-activity studies have shown that all of the pyrokinins have various degrees of pheromonotropic activity and that some have a superagonistic effect. Peptides that only have sequence homology with PBAN in the C-terminal pentapeptide region, but that are pheromonotropic, also have been identified from moths. These findings suggest that induction of pheromone biosynthesis may be regulated by more than one peptide, that PBAN may have a number of physiological functions, and that these peptides regulate induction of pheromone production in a variety of ways.