AMPylation, the covalent addition of adenosine 5'-monophosphate (AMP) to hydroxyl groups, is a recently appreciated post-translational modification by which bacterial Fic domain proteins regulate small GTPases. To explore the function of eukaryotic Fic domains we generated fic null mutants. We discovered a role of AMPylation in the Drosophila visual system: Fic-mediated AMPylation in glia is necessary for normal recycling of the histamine neurotransmitter. How AMPylation of glial proteins contributes to neurotransmitter recycling is a focus of our investigations.
