Dynamics and modulation of metabotropic glutamate receptors

•ECD dimers oscillate between resting and active states on a sub-millisecond time scale.•Agonists shift the ECD dimers equilibrium towards the activated state.•The mGluR 7TM crystal structures reveal the molecular basis of allosteric modulators.•Major change in the 7TM dimer interface during receptor activation.•Time-resolved FRET sensors are powerful tools to study mGluR activation in cells.

The metabotropic glutamate receptors (mGluRs) are glutamate-activated G protein-coupled receptors widely expressed in the central nervous system. The eight mGluRs subtypes modulate transmission at many synapses, and are interesting therapeutic targets for the treatment of many neurological and psychiatric diseases. In particular, their organization in multiple domains and subunits offers various possibilities for the development of drugs that modulate mGluRs activity with different efficacies. Recent structural, biophysical and functional analyses have provided new insights into the mechanism of mGluR activation and dynamics. They also revealed the structural bases of ligand efficacy then providing possible mechanism of action of partial agonists and allosteric modulators. These new findings are of great interest for the development of novel mGluR subtype-selective compounds.