A Pheromone-Binding Protein Mediates the Bombykol-Induced Activation of a Pheromone Receptor In Vitro

Institute of Physiology (230), University of Hohenheim, Garbenstrasse 30, 70599 Stuttgart, Germany.
Chemical Senses (Impact Factor: 3.16). 08/2006; 31(6):547-55. DOI: 10.1093/chemse/bjj059
Source: PubMed


The enormous capacity of the male silkmoth Bombyx mori in recognizing and discriminating bombykol and bombykal is based on distinct sensory neurons in the antennal sensilla hairs.
The hydrophobic pheromonal compounds are supposed to be ferried by soluble pheromone-binding proteins (PBPs) through the sensillum
lymph toward the receptors in the dendritic membrane. We have generated stable cell lines expressing the candidate pheromone
receptors of B. mori, BmOR-1 or BmOR-3, and assessed their responses to hydrophobic pheromone compounds dissolved by means of dimethyl sulfoxide.
BmOR-1–expressing cells were activated by bombykol but also responded to bombykal, whereas cells expressing BmOR-3 responded
to bombykal only. In experiments employing the B. mori PBP, no organic solvent was necessary to mediate an activation of BmOR-1 by bombykol, indicating that the PBP solubilizes
the hydrophobic compound. Furthermore, the employed PBP selectively mediated a response to bombykol but not to bombykal, supporting
a ligand specificity of PBPs. This study provides evidence that both distinct pheromone receptors and PBPs play an important
role in insect pheromone recognition.

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    • "Both protein classes reversibly bind small ligands with dissociation constants in the micromolar range (Pelosi et al. 2006). OBPs are likely involved in chemosensory perception, participating in the solubilization and transfer of odorants through the sensillum lymph (Vogt et al. 1991; Pelosi 1994; Prestwich et al. 1995; Pophof 2004; Tsuchihara et al. 2005; Grosse-Wilde et al. 2006). Additionally, they are supposed to contribute to the sensitivity of the olfactory system (Gomez-Diaz et al. 2013) and could protect odors from enzymatic degradation (Chertemps et al. 2012; Gomez-Diaz et al. 2013). "
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    ABSTRACT: Chemosensory protein (CSP) and gustatory receptor genes have been identified in all major arthropod groups. However, odorant binding proteins (OBP) and olfactory receptor genes are insect specific, suggesting that both gene families originated after the Hexapoda–Crustacea split (~470 million years ago). The seemingly parallel diversification of OBP and olfactory receptors has been suggested as coevolution between these genes after insect terrestrialization. To test this hypothesis we used the recently published transcriptomes of the jumping bristletail Lepismachilis y-signata and the firebrat Thermobia domestica to search for putative OBP and CSP sequences and analyzed their relationship to binding proteins of other insects and crustaceans. Our results suggest an evolution and expansion of OBPs as an adaptation to a terrestrial insect lifestyle, independently from the emergence of olfactory receptors.
    Full-text · Article · Sep 2015 · Chemical Senses
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    • "Based on the fact that MsexOR-4 is the OR with the highest expression level, we conclude that it is likely the bombykal receptor. The B. mori bomkykal receptor, BmorOR-3 (Grosse-Wilde et al., 2006; Nakagawa et al., 2005), is orthologous to MsexOR-1 (Fig. 1), and the putative bombykal receptor, MsexOR- 4, is orthologous to the B. mori bombykol receptor, BmorOR-1 (Grosse-Wilde et al., 2006; Nakagawa et al., 2005). Thus, it would seem likely for the orthologous genes MsexOR-4 and BmorOR-1 to detect the major compound of the pheromone blend. "
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    ABSTRACT: The order of Lepidoptera has historically been crucial for chemosensory research, with many important advances coming from the analysis of species like Bombyx mori or the tobacco hornworm, Manduca sexta. Specifically M. sexta has long been a major model species in the field, especially regarding the importance of olfaction in an ecological context, mainly the interaction with its host plants. In recent years transcriptomic data has led to the discovery of members of all major chemosensory receptor families in the species, but the data was fragmentary and incomplete. Here we present the analysis of the newly available high-quality genome data for the species, supplemented by additional transcriptome data to generate a high quality reference gene set for the three major chemosensory receptor gene families, the gustatory (GR), olfactory (OR) and antennal ionotropic receptors (IR). Coupled with gene expression analysis our approach allows association of specific receptor types and behaviors, like pheromone and host detection. The dataset will provide valuable support for future analysis of these essential chemosensory modalities in this species and in Lepidoptera in general.
    Full-text · Article · Sep 2015 · Insect biochemistry and molecular biology
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    • "These six cysteines form three disulfide bridges, which play important roles in maintaining the protein tertiary structure. Experimental evidence has demonstrated that OBPs could selectively bind odorants or pheromones (Vogt and Riddiford, 1981; Plettner et al., 2000; Pophof, 2004; Grosse-Wilde et al., 2006; Syed et al., 2006; Gong et al., 2009b; Zhou et al., 2009). "
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    ABSTRACT: In this study, we constructed a high-quality cDNA library from the antennae of the Chilo suppressalis (Walker) (Lepidoptera: Pyralidae). A total of 1,235 colonies with inserts greater than 0.7 kb were sequenced and analyzed. Homology searching coupled with bioinformatics analysis identified 15 and 7 cDNA sequences, respectively, encoding putative odorant-binding proteins (OBPs) and chemosensory proteins (CSPs). A phylogenetic tree of CsupCSPs showed that each CsupCSP has orthologs in Manduca sexta and Bombyx mori with strong bootstrapping support. One CSP was either very specific or more related to the CSPs of another species than to conspecific CSP. The expression profiles of the OBPs and CSPs in different tissues were measured by real-time quantitative PCR. The results revealed that of the 11 OBP genes, the transcript levels of CsupOBP1, CsupOBP5, and CsupOBP7 were higher in both male and female antennae than those in other tissues. And CsupCSP7 was highly expressed in both male and female antennae. Based on these results, the possible physiological functions of CsupOBPs and CsupCSPs were discussed. © 2015 Wiley Periodicals, Inc.
    Full-text · Article · Feb 2015 · Archives of Insect Biochemistry and Physiology
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