Members of family C of the G protein-coupled receptor (GPCR) superfamily, such as GPRC6A, are characterized by an evolutionarily conserved amino acid-sensing motif linked to an intramembranous 7-transmembrane loop region. Several members of GPCR family C, including GPRC6A, also have a long N-terminal domain (summary by Pi et al., 2005 [PubMed 16199532]).[supplied by OMIM, Nov 2010].