The secret work of olfactory receptors is finally revealed

The group’s observations may explain why insect receptors in general can evolve so rapidly and differ so much between species. All insect species have developed “a unique repertoire of receptors that are very well adapted to their particular chemical receptor,” Rota said.

“It tells us that it’s more than just the idea that receptors interact freely with a bunch of ligands,” Datta said. A receptor built around a single binding pocket, with a response profile that can be adapted to the smallest response, can accelerate evolution by exploring the broad spectrum of chemical repertoires.

The architecture of the recipient also supported this view. Ruta and her colleagues found that four protein subunits were bound to the central pore of the canal, like the petals of a flower. Only the central region had to be preserved as the recipient diversified and evolved; the genetic sequences governing the remaining recipient units were not so limited. This structural arrangement allows the recipient to take on a wide range of diversification.

Mild evolutionary limits at the receptor level probably impose high selective pressure on olfactory circuits for olfactory: Nervous systems need good mechanisms to decode disturbed patterns of receptor activity. “Effectively, olfactory systems have taken arbitrary patterns of receptor activation and made sense through learning and experience,” Rota said.

Oddly enough, it doesn’t seem like the nervous system makes the problem itself easier. The scientists strongly believed that all the receptors on an individual olfactory neuron were of the same class, and that neurons of different classes went to different regions of brain processing. In one prepress pair published last NovemberHowever, the researchers reported that individual olfactory neurons in flies and mosquitoes represent multiple classes of receptors. “It’s really amazing, and it would increase the diversity of sensory perception even more,” Barber said.

The findings of the route group are far from the final word on the functioning of olfactory receptors. Insects use many other classes of ion channel olfactory receptors, including those that are much more complex and accurate than the jumping stem. In mammals, the olfactory receptor is not even an ion channel; the protein family is completely different.

“It’s the first odor recognition structure for any recipient of any species. But it’s probably not the only mechanism for odor recognition,” Rota said. “This is just a solution to the problem. It would be very difficult to have a single solution.”

However, he and other researchers believe that there are many more general lessons to be learned from jumping the tail of the bristle tail. It is tempting, for example, to imagine how this mechanism can be applied to other receptors in the animal brain — from those that detect neuromodulators like dopamine to those affected by different types of anesthetics — and how accurately they leave them. be, “Barber said.” It provides a fascinating model for continuing to explore specific binding interactions. “

Perhaps this flexible link approach should also be considered in other contexts, he added. Published research in Proceedings of the National Academy of Sciences in March, for example, the suggested ion-channel receptors also suggested not being as selective as scientists thought.

If many types of proteins bind to receptors through flexible and weak interactions between certain types of pockets, this principle can guide the rational design of drugs for a variety of diseases, particularly neurological conditions. At the very least, the work that Ruta associates with a DEET insect odor receptor may serve to shed light on how to develop targeted scarers. “The mosquito is still the deadliest animal on Earth” because of the diseases it carries, Rota said.