Figure 1.

Graphical representation of the serotonin 2C receptor (5-HT2c) receptor and its editing sites. The five editing sites, named A, B, C, D and E, are mapped in the RNA sequence that encodes for the second intracellular loop of the receptor. At the protein level, they induce one to three amino acids changes that can result in twenty-four different protein isoforms with different G-protein-coupling activity. In particular, it has been reported that the edited isoforms have a decreased G-protein-coupling activity and in turn a lower serotonin affinity. Thanks to its ability of modulating serotonin signaling, dysregulation in 5-HT2c receptor RNA editing might be involved in the etiology of major depressive disorder (MDD).