Structural basis for sugar perception by Drosophila gustatory receptors. (https://pubmed.ncbi.nlm.nih.gov/38305684/)

These scientists wanted to understand how insects taste different things like sweet and bitter. They focused on a special group of proteins called gustatory receptors (GRs) that help insects taste different flavors.

To study this, the scientists looked at two specific gustatory receptors called GR43a and GR64a in a type of fruit fly called Drosophila. They wanted to see what happens to these receptors when they are empty (apo state) and when they have sugar molecules attached to them (sugar-bound state).

They found that both GR43a and GR64a are made up of four parts called ligand-binding domains (LBDs) and one part called a pore domain (PD). These parts work together to form a channel that allows certain ions (positively charged particles) to pass through.

When they looked closely at GR43a, they discovered that it gets activated specifically by a type of sugar called fructose. Fructose binds to a small pocket in the ligand-binding domain. On the other hand, GR64a gets activated by two types of sugars called sucrose and maltose. These sugars bind to a larger and flatter pocket in the ligand-binding domain.

When the sugars bind to the ligand-binding domain, it causes some parts of the receptor to change shape. These changes are then passed on to the pore domain, which opens up the channel, allowing ions to flow through.

So, the scientists have figured out how these gustatory receptors recognize and get activated by sugars. This is important because it helps us understand how insects taste different things and could also help us develop better ways to control pests in the future.

Ma D., Hu M., Yang X., Liu Q., Ye F., Cai W., Wang Y., Xu X., Chang S., Wang R., Yang W., Ye S., Su N., Fan M., Xu H., Guo J. Structural basis for sugar perception by Drosophila gustatory receptors. Science. 2024 Feb 2:eadj2609. doi: 10.1126/science.adj2609.