title: Pheromonotropic and melanotropic PK/PBAN receptors: differential ligand-receptor interactions.
abstract: The aim of the present study was to further characterize the PK/PBAN receptors and their interaction with various PK/PBAN peptides in order to get a better understanding of their ubiquitous and multifunctional nature. Two cloned receptors stably expressed in Spodoptera frugiperda (Sf9) cells were used in this study: a Heliothis peltigera pheromone gland receptor (Hep-PK/PBAN-R) (which stimulates sex pheromone biosynthesis) and Spodoptera littoralis larval receptor (Spl-PK/PBAN-R) (which mediates cuticular melanization in moth larvae) and their ability to respond to several native PK/PBAN peptides: β-subesophageal neuropeptide (β-SGNP), myotropin (MT) and Leucophaea maderae pyrokinin (LPK), as well as linear and cyclic analogs was tested by monitoring their ability to stimulate Ca(2+) release. The receptors exhibited a differential response to β-SGNP, which activated the Hep-PK/PBAN-R but not the Spl-PK/PBAN-R - a response opposite to that previously demonstrated with diapause hormone (DH). MT was somewhat more active on Spl-PK/PBAN-R than on Hep-PK/PBAN-R. LPK elicited similar positive responses in both receptors (like that with PBAN). A differential response toward both receptors was also noticed with the PBAN-derived backbone cyclic (BBC) conformationally constrained peptide BBC-5. The peptides BBC-7 and BBC-8 activated both receptors. The results correlate between two PK/PBAN mediated function (cuticular melanization and sex pheromone biosynthesis) and the peptides that activate them and thus advance our understanding of the mode of action of the PK/PBAN family, and might help in exploring novel high-affinity receptor-specific antagonists that could serve as a basis for development of new families of insect-control agents.
authors.affiliation: Department of Entomology, The Volcani Center, Bet Dagan 50250, Israel.
authors.forename: Aliza Hariton
authors.initials: AH
authors.lastname: Shalev
authors.affiliation: Department of Entomology, The Volcani Center, Bet Dagan 50250, Israel. Electronic address: vinnie2@agri.gov.il.
authors.forename: Miriam
authors.initials: M
authors.lastname: Altstein
mesh_terms: D000818:Animals; D020013:Calcium Signaling; D020128:Inhibitory Concentration 50; D019476:Insect Proteins / Q000502:physiology*; D009036:Moths; D009479:Neuropeptides / Q000494:pharmacology / Q000502:physiology*; D010675:Pheromones / Q000502:physiology; D018013:Receptors, Neuropeptide / Q000819:agonists / Q000502:physiology*; D061987:Sf9 Cells; D018411:Spodoptera
chemical_list: D019476:Insect Proteins; D009479:Neuropeptides; D010675:Pheromones; D018013:Receptors, Neuropeptide
keywords: Heliothis peltigera; Insect neuropeptides; PBAN; PK/PBAN-receptor; Spodoptera littoralis