C-terminal motif of human neuropeptide Y receptor determines internalization and arrestin recruitment.

The human neuropeptide Y receptor is a rhodopsin-like G protein-coupled receptor (GPCR), which contributes to anorexigenic signals. Thus, this receptor is a highly interesting target for metabolic diseases. As GPCR internalization and trafficking affect receptor signaling and vice versa, we aimed to investigate the molecular mechanism of hYR desensitization and endocytosis. The role of distinct segments of the hYR carboxyl terminus was investigated by fluorescence microscopy, binding assays, inositol turnover experiments and bioluminescence resonance energy transfer assays to examine the internalization behavior of hYR and its interaction with arrestin-3. Based on results of C-terminal deletion mutants and substitution of single amino acids, the motif EESEHLPLSTVHTEVSKGS was identified, with glutamate, threonine and serine residues playing key roles, based on site-directed mutagenesis. Thus, we identified the internalization motif for the human neuropeptide Y receptor, which regulates arrestin-3 recruitment and receptor endocytosis.