| Title: | Specificity determinants of the silkworm moth sex pheromone |
| Author(s): | Xu P; Hooper AM; Pickett JA; Leal WS; |
| Address: | "Honorary Maeda-Duffey Laboratory, University of California Davis, Davis, California, United States of America" |
| DOI: | 10.1371/journal.pone.0044190 |
| ISSN/ISBN: | 1932-6203 (Electronic) 1932-6203 (Linking) |
| Abstract: | "The insect olfactory system, particularly the peripheral sensory system for sex pheromone reception in male moths, is highly selective, but specificity determinants at the receptor level are hitherto unknown. Using the Xenopus oocyte recording system, we conducted a thorough structure-activity relationship study with the sex pheromone receptor of the silkworm moth, Bombyx mori, BmorOR1. When co-expressed with the obligatory odorant receptor co-receptor (BmorOrco), BmorOR1 responded in a dose-dependent fashion to both bombykol and its related aldehyde, bombykal, but the threshold of the latter was about one order of magnitude higher. Solubilizing these ligands with a pheromone-binding protein (BmorPBP1) did not enhance selectivity. By contrast, both ligands were trapped by BmorPBP1 leading to dramatically reduced responses. The silkworm moth pheromone receptor was highly selective towards the stereochemistry of the conjugated diene, with robust response to the natural (10E,12Z)-isomer and very little or no response to the other three isomers. Shifting the conjugated diene towards the functional group or elongating the carbon chain rendered these molecules completely inactive. In contrast, an analogue shortened by two omega carbons elicited the same or slightly higher responses than bombykol. Flexibility of the saturated C1-C9 moiety is important for function as addition of a double or triple bond in position 4 led to reduced responses. The ligand is hypothesized to be accommodated by a large hydrophobic cavity within the helical bundle of transmembrane domains" |
| Keywords: | "Alkadienes/pharmacology Animals Bombyx/*physiology Carrier Proteins/metabolism Cloning, Molecular Dose-Response Relationship, Drug Fatty Alcohols/pharmacology Insect Proteins/metabolism Intercellular Signaling Peptides and Proteins Ligands Magnetic Resona;" |
| Notes: | "MedlineXu, Pingxi Hooper, Antony M Pickett, John A Leal, Walter S eng R01 AI095514/AI/NIAID NIH HHS/ 1R01AI095514-01A1/AI/NIAID NIH HHS/ BB_/Biotechnology and Biological Sciences Research Council/United Kingdom Research Support, N.I.H., Extramural Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. 2012/09/08 PLoS One. 2012; 7(9):e44190. doi: 10.1371/journal.pone.0044190. Epub 2012 Sep 5" |
