Researchers redefine the classification of glutamate receptors, essentials in the central nervous system

Evolution of glutamate recepors. Circle colors show the four main types of receptors. Image: A. Bayés
Evolution of glutamate recepors. Circle colors show the four main types of receptors. Image: A. Bayés
Research
(28/11/2018)

Researchers from the research group Molecular Physiology of the Synapse at the Sant Pau Biomedical Research Institute (IIB Sant Pau), Universitat Autònoma de Barcelona(UAB), the University of Barcelona and the French National Center for Scientific Research (CNRS) have proved that two families of the neurotransmitter glutamate receptor -essential for the transfer in the nervous impulse between neurons- show a more complex organization than what was originally thought. The study, published in the journal eLife, states that the current classification, accepted by the scientific community for more than twenty years, is not enough and is dominated by an overly enthropocentric view of evolution.

Evolution of glutamate recepors. Circle colors show the four main types of receptors. Image: A. Bayés
Evolution of glutamate recepors. Circle colors show the four main types of receptors. Image: A. Bayés
Research
28/11/2018

Researchers from the research group Molecular Physiology of the Synapse at the Sant Pau Biomedical Research Institute (IIB Sant Pau), Universitat Autònoma de Barcelona(UAB), the University of Barcelona and the French National Center for Scientific Research (CNRS) have proved that two families of the neurotransmitter glutamate receptor -essential for the transfer in the nervous impulse between neurons- show a more complex organization than what was originally thought. The study, published in the journal eLife, states that the current classification, accepted by the scientific community for more than twenty years, is not enough and is dominated by an overly enthropocentric view of evolution.

The study is led by researcher Àlex Bayés, from IIB Sant Pau, with the participation of the researchers Jordi Garcia Fernàndez, Enrique Navas Pérez and Demián Bruguera, from the Evo-Devo-Genomics Group from the Department of Genetics, Microbiology and Statistics of the Faculty of Biology of the UB. Other collaborators are David Soto and Esther Gratacós Batlle, from the Department of Biomedicine of the Faculty of Medicine and Health Sciences, who carried out the electrophysiological characterization of one of the ion channel type receptors, discovered in this study. This enabled proving these new receptors are functional and therefore, used by certain bodies in nature.

The study analyses the evolutionary history of both families of neurotransmitter glutamate receptors. These proteins are one of the fundamental pillars of the nervous system, since they allow the formation of the impulses and modulate its power.

This study shows that the classification of these two families is incomplete, especially regarding the receptors that form ionic channels. Over the nearly billion years of evolution of animals, the diversity of glutamate receptors appears to be much higher than those seen in vertebrate genomes.

Previous studies that focused on vertebrates which appear about four hundred million years ago and therefore could not identify all kinds of receptors that exist beyond these species. The study of representative species of all the animal kingdom lineages has allowed to significantly expand the classification of these families. This study represents, therefore, a fundamental change in the understanding of the diversity that exists within these receptor families.

The study of the properties of these new receptors could result in the identification of receptors with new properties that could have applications in the field of neurosciences. It is interesting to think what would happen if similar studies were conducted in other protein families that have been studied mainly in vertebrates, which are, on the other hand, the vast majority.

Article reference
D. Ramos Vicente, J. Ji, E. Gratacós Batlle, G. Gou, R. Reig Viader, J. Luis, D. Burguera, E. Navas-Perez, J. Garcia Fernàndez, P. Fuentes Prior, H. Escrivà, N. Roher, D. Soto, À. Bayés. "Metazoan evolution of glutamate receptors reveals unreported phylogenetic groups and divergent lineage-specific events". eLife, November, 2018. Doi: 10.7554/eLife.35774