G Protein Coupled Receptor 123 (GPR123)

Using bioinformatic analysis to identify genes encoding G protein-coupled receptors with long N termini, Fredriksson et al. (2003) identified GPR123. The deduced 1,281 amino acid protein contains a long serine- and threonine-rich region predicted to form a mucin-like stalk, and 7 C-terminal transmembrane domains with conserved cysteines between extracellular loops 2 and 3 that were predicted to form disulfide bridges.

The deduced protein shared significant similarity with the 7-transmembrane secretin receptor. RT-PCR ELISA detected highest expression in adult and fetal brain, in adult spinal cord, and in all specific adult brain regions examined. Expression was very low in kidney and was not detected in other tissues.