Interacting Proteins of Olfactroy Receptor OR1and OR2 with Co-IP Approach Followed by Mass Spectrometry Analysis in Apis cerana cerana

  Objectives   Roles of the proteins interacting with the odorant receptors (ORs) in the highly sensitive olfactory system of Apis cerana cerana were investigated.

  Methods   The eukaryotic expression vectors pFastBac of OR1 and OR2 in A. cerana cerana were constructed and transfected into Sf9 cells to extract the proteins. The cellular interacting proteins were identified by co-immunoprecipitation (Co-IP) and mass spectrometry, and GO function annotation, KEGG signal pathway analysis, and protein interaction network determination.

  Results   The recombinant proteins of the IP and IgG groups were successfully expressed in the cells. There were 273 proteins interacting with OR1, and 204 with OR2. They were mainly tubulin, heat shock proteins, and ribosomal proteins involving in a variety of biological functions, such as RNA splicing and ribosome and energy transport. The KEGG analysis also showed their association with the regulation of several important intracellular pathways related to the ribosome, splicing body, RNA transport, pyruvate metabolism, thiamine metabolism, fatty acid biosynthesis, starch and sucrose metabolism, and FoxO and Hedgehog signals.

  Conclusion  A unique honey bee species in China, A. cerana ceranahas evolved with a highly sensitive olfactory system capable of recognizing chemical signals in the bee population and distinguishing molecules emitted from food sources. OR1 and OR2 in A. cerana cerana regulated the olfactory transduction through direct or indirect interaction with a variety of proteins.