title: Cloning and characterization of an extracellular Ca(2+)-sensing receptor from bovine parathyroid.
abstract: Maintenance of a stable internal environment within complex organisms requires specialized cells that sense changes in the extracellular concentration of specific ions (such as Ca2+). Although the molecular nature of such ion sensors is unknown, parathyroid cells possess a cell surface Ca(2+)-sensing mechanism that also recognizes trivalent and polyvalent cations (such as neomycin) and couples by changes in phosphoinositide turnover and cytosolic Ca2+ to regulation of parathyroid hormone secretion. The latter restores normocalcaemia by acting on kidney and bone. We now report the cloning of complementary DNA encoding an extracellular Ca(2+)-sensing receptor from bovine parathyroid with pharmacological and functional properties nearly identical to those of the native receptor. The novel approximately 120K receptor shares limited similarity with the metabotropic glutamate receptors and features a large extracellular domain, containing clusters of acidic amino-acid residues possibly involved in calcium binding, coupled to a seven-membrane-spanning domain like those in the G-protein-coupled receptor superfamily.
authors.affiliation: Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: E M
authors.initials: EM
authors.lastname: Brown
authors.forename: G
authors.initials: G
authors.lastname: Gamba
authors.forename: D
authors.initials: D
authors.lastname: Riccardi
authors.forename: M
authors.initials: M
authors.lastname: Lombardi
authors.forename: R
authors.initials: R
authors.lastname: Butters
authors.forename: O
authors.initials: O
authors.lastname: Kifor
authors.forename: A
authors.initials: A
authors.lastname: Sun
authors.forename: M A
authors.initials: MA
authors.lastname: Hediger
authors.forename: J
authors.initials: J
authors.lastname: Lytton
authors.forename: S C
authors.initials: SC
authors.lastname: Hebert
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D002413:Cations, Divalent / Q000494:pharmacology; D002417:Cattle; D003001:Cloning, Molecular; D016384:Consensus Sequence; D017124:Conserved Sequence; D004533:Egtazic Acid / Q000494:pharmacology; D005682:Gadolinium / Q000494:pharmacology; D006031:Glycosylation; D008969:Molecular Sequence Data; D009355:Neomycin / Q000494:pharmacology; D009865:Oocytes / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D010280:Parathyroid Glands / Q000378:metabolism*; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D044169:Receptors, Calcium-Sensing; D011956:Receptors, Cell Surface / Q000096:biosynthesis / Q000187:drug effects / Q000378:metabolism*; D014982:Xenopus laevis
chemical_list: D002413:Cations, Divalent; D044169:Receptors, Calcium-Sensing; D011956:Receptors, Cell Surface; D004533:Egtazic Acid; D005682:Gadolinium; D009355:Neomycin; D002118:Calcium