Structural basis for ligand recognition of the neuropeptide Y Y₂ receptor

The human neuropeptide Y (NPY) Y₂ receptor (Y₂R) plays essential roles in food intake, bone formation and mood regulation, and has been considered an important drug target for obesity and anxiety. However, development of drugs targeting Y₂R remains challenging with no success in clinical application yet. Here, we report the crystal structure of Y₂R bound to a selective antagonist JNJ-31020028 at 2.8 Å resolution. The structure reveals molecular details of the ligand-binding mode of Y₂R. Combined with mutagenesis studies, the Y₂R structure provides insights into key factors that define antagonistic activity of diverse antagonists. Comparison with the previously determined antagonist-bound Y₁R structures identified receptor-ligand interactions that play different roles in modulating receptor activation and mediating ligand selectivity. These findings deepen our understanding about molecular mechanisms of ligand recognition and subtype specificity of NPY receptors, and would enable structure-based drug design.