1Centre Européen des Sciences du Goût, CNRS, 15 rue Hugues Picardet, 21000 Dijon, France.
2Unité de Recherches de Biochimie et Structure des Protéines, INRA-UR 477, Domaine de Vilvert, 78 352 Jouy-en-Josas Cedex, France.
3Neurobiologie Expérimentale et Théorie des Systèmes Complexes, CNRS-UPR 9081, 16 rue Claude Bernard, 75 231 Paris Cedex 05, France.
The dual property of the honeybee queen pheromone, which acts both as a sex attractant for drones and controls numerous activities of workers, allows investigation of how such an odor is specifically encoded by the olfactory system (see also abstract of S. Laurent and C. Masson). Odorant-binding proteins (OBPs) are small abundant extracellular proteins involved in perireceptor events of odor/pheromone detection by carrying, deactivating and/or selecting odor stimuli. Two honeybee putative OBPs, ASP1 and ASP2, have been identified (Danty et al, 1997, FEBS Lett. 414:595-598 ; 1998, Chem. Senses 23:83-91). Their transcripts are detected in antennal olfactory sensilla, in S. placodea and in S. trichodea, respectively. Recombinant ASP1r and ASP2r produced by the yeast Pichia pastoris present the exact characteristics of the native proteins (Briand et al, 1999, Protein Expr. Purif. 15:362-369). ASP1r is dimeric, suggesting that isobare ASP1a and ASP1b isoforms might originate from dimerization. While both isoforms are detected in concomitance with the functional maturation of worker olfactory neurons, ASP1b biosynthetic accumulation starts only at drone sexual maturity. Significative interaction of ASP1r with one or two major components of the queen pheromone indicates that ASP1 is a queen pheromone-binding protein (Danty et al, 1999, J. Neuroscience 19:7468-7475).