An intracellular amino acid scarcity sensor tunes protein hunger

Most animals, including Drosophila, display compensatory preference for amino acid-rich food following dietary protein scarcity. In the CNS, peptidergic cells play an important role in adaptive feeding behaviour, by mediating the satiating effects of protein consumption.

We demonstrate that protein appetite and compensatory feeding following amino acid deprivation are also under peptidergic control. Using single-nucleus RNA-sequencing, we identified gene expression changes in peptidergic neurons from amino acid-deprived flies and sated controls. One of the strongly regulated genes is Lsp2, which encodes an amino acid storage protein essential for larval development and pupation.