Review An overview of odorant-binding protein functions in insect peripheral olfactory reception

Abstract

ABSTRACT. Insect olfactory perception involves many aspects of insect life, and can directly or indirectly evoke either individual or group behaviors. Insect olfactory receptors and odorant-binding proteins (OBPs) are considered to be crucial to insect-specific and -sensitive olfaction. Although the mechanisms of interaction between OBPs or OBP/ligand complex with olfactory receptors are still not well understood, it has been shown that many OBPs contribute to insect olfactory perception at various levels. Some of these are numerous and divergent members in OBP family; expression in the olfactory organ at high concentration; a variety of combinational patterns between different OBPs and ligands, but exclusive affinity for one OBP to specific binding ligands; complicated interactions between OBP/ligand complex and transmembrane proteins (olfactory receptors or sensory neuron membrane proteins). First, we review OBPs' ligand-binding property based on OBP structural research and ligandbinding test; then, we review current progress around the points cited above OBP functions in insect peripheral olfactory reception to show the role of such proteins in insect olfactory signal transmission; finally, we discuss applications based on insect OBP research.

Olfactory Disruption

“…4) range from testing behavioral responses of targeted insects to candidate compounds 196,197 to predicting repellents using complex algorithms. 193,198 Alternate approaches start with a desired phenotype (strong attraction or avoidance) and are followed by identification of the required elements, e.g., a genetic difference or component of an odorous blend.…”

“…2). While it is clear that OBPs influence olfactory driven behaviors of insects including mosquitoes, 31,47,[191][192][193] the usefulness of targeting OBPs for repellent prediction has not been confirmed.…”

Mechanisms of Development and Evolution of the Insect Olfactory System

“…The insect olfactory system has a very specific organization that mirrors that of vertebrates: odorants in the air first come into contact with odorant-binding proteins (OBPs) that are responsible for binding with and solubilizing odorants, bringing them into contact with olfactory receptors (ORs) that are expressed by olfactory receptor neurons (ORNs) [21]. Cell bodies of ORNs are themselves located within hair-like structures called sensilla that are found on the surface of the two olfactory appendages of the insect, the antennae and the maxillary palps [22].…”

Smell Sensors Based on Odorant Binding Proteins

“…How to detect and discriminate these semiochemicals is essential for animals, especially insects, to survive. Insects are known for their remarkable olfaction ability, which is crucial for them to distinguish, comprehend, and estimate the overall situation and even for their survival, reproduction, and social communication [26,45]. Therefore, semiochemicals of plants and animals can be detected by insects at low concentrations over a long distance, even dozens of meters away [46].…”

“…Differing from vertebrates, insects like honeybees are more dependent on olfaction to distinguish, comprehend, and estimate the overall situation, which is essential for their survival, reproduction, and social communication within the hive; whereas vertebrate animals use their highly developed vision to define the outer world [26,27]. While their behavior heavily relies on olfactory cues, insects have remarkable olfaction ability to recognize signals around the habitat environment.…”