Long reach of the NAAG family tree

The last common ancestor of humans and fruit flies lived about 800 million years ago, yet both of us have nervous systems that share a number of common important features, for example the use of glutamate as a neurotransmitter. We can now possibly add another common feature to the neural tissue of humans and fruit flies which is that of N-acetylaspartylglutamate (NAAG) peptides. This Editorial highlights an article by Kozik and coworkers in the current issue of the Journal of Neurochemistry, in which the authors report the discovery, in Drosophila melanogaster nervous system, of NAA-glutamylglutamate (NAAG2).