Location: Corn Insects and Crop Genetics ResearchTitle: Binding affinity of five PBPs to Ostrinia sex pheromones Author
|Zhang, Tian-tao - Chinese Academy Of Agricultural Sciences|
|Yaqi, Sun - Chinese Academy Of Agricultural Sciences|
|Wanner, Kevin - Montana State University|
|He, Kang-lai - Chinese Academy Of Agricultural Sciences|
|Wang, Zhenying - Chinese Academy Of Agricultural Sciences|
Submitted to: BioMed Central (BMC) Molecular Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/16/2017
Publication Date: 2/7/2017
Citation: Zhang, T., Yaqi, S., Wanner, K., Coates, B.S., He, K., Wang, Z. 2017. Binding affinity of five PBPs to Ostrinia sex pheromones. BioMed Central (BMC) Molecular Biology. 18(1):4. doi: 10.1186/s12867-017-0079-y.
Interpretive Summary: Species of corn borer are highly destructive insect pests of corn in North America, Europe, China and Southeast Asia. Many species have recently evolved in this group of insects, and mechanisms by which species become differentiated are important for understanding adaptation to crop production practices. An ARS scientist and collaborators showed that female-emitted pheromones are bound by specific types of a protein, called pheromone binding protein, in male moths of corn borer in a species specific manor. A subset of pheromone binding proteins specifically interact with pheromones of different species, and are hypothesized to stimulate repulsive behaviors in male moths. These finding are important in understanding the molecular mechanisms by which males become attracted to mates, and may lead to novel methods for mating disruption as a means to control corn borer populations.
Technical Abstract: Pheromone binding proteins (PBPs) of Lepidoptera function in chemical communication, mate attraction and recognition, and may be involved in reinforcement of sexual isolation between recently diverged species. Directional selection was previously predicted between PBP3 orthologs of the corn borer sister species Ostrinia furnacalis and O. nubilalis. Five PBP gene family members were cloned from male antennae of O. furnacalis and proteins were expressed in Escherichia coli. Protein-ligand binding assays show that female O. furnacalis sex pheromones Z12-14: tetradecanl acetate (Z12-14:OAc) and E12-14: tetradecanl acetate (E12-14: OAc) have estimated dissociation constants (KD) = 4.12±0.08 when bound to OfPBP1 and OfPBP2, and KD = 6.64±0.66 for OfPBP4 and OfPBP5 at pH 7.4,. Z- and E-12-14:OAc bound most strongly to O. furnacalis PBP3, OfPBP3, with respective KD of 2.86±0.04 and 2.85±0.01, but also bound strongly to female European corn borer (ECB), O. nubilalis, pheromone blends components Z-11-14:OAc (KD = 2.44±0.18) and E-11-14:OAc (KD=1.97±0.11). 3-dimensional modeling of PBP3 structure and computational predictions suggest that hydrophobic interactions may allow interspecific binding of sex pheromones, and suggests that directional selection between O. furnacalis and O. nubilalis PBP3 may not affect the corresponding ligand-binding specificity. Binding of OfPBP4 and 5 only with O. nubilalis Z- and E-11-14:OAc and Z- and E-12-14:OAc suggest that these paralogs have derived an antagonist-specific binding capacity, and are important in understanding signal transduction involved in species-specific response of male Lepidoptera to cognate female pheromones.