title: Calmodulin interacts with the cytoplasmic tails of the parathyroid hormone 1 receptor and a sub-set of class b G-protein coupled receptors.
abstract: Parathyroid hormone (PTH) binds to its receptor (PTH 1 receptor, PTH1R) and activates multiple pathways. The PTH1R, a class b GPCR, contains consensus calmodulin-binding motifs. The PTH1R cytoplasmic tail interacts with calmodulin in a calcium-dependent manner via the basic 1-5-8-14 motif. Calcium-dependent calmodulin interactions with the cytoplasmic tails of receptors for PTH 2, vasoactive intestinal peptide, pituitary adenylate cyclase activating peptide, corticotropin releasing hormone, calcitonin, and the glucagon-like peptides 1 and 2 are demonstrated. The cytoplasmic tails of the secretin receptor and the growth hormone releasing hormone receptor either interact poorly or not at all with calmodulin, respectively. Fluphenazine, a calmodulin antagonist, enhances PTH-mediated accumulation of total inositol phosphates, suggesting that calmodulin regulates signaling via phospholipase C.
authors.affiliation: Endocrine Unit, Massachusetts General Hospital, 50 Blossom Street, Wellman 501, Boston, MA 02114-2696, USA. mahon@helix.mgh.harvard.edu
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Mahon
authors.forename: Masako
authors.initials: M
authors.lastname: Shimada
mesh_terms: D000595:Amino Acid Sequence; D002147:Calmodulin / Q000378:metabolism*; D002460:Cell Line; D003593:Cytoplasm / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008969:Molecular Sequence Data; D017354:Point Mutation; D044168:Receptor, Parathyroid Hormone, Type 1 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid
chemical_list: D002147:Calmodulin; D044168:Receptor, Parathyroid Hormone, Type 1; D043562:Receptors, G-Protein-Coupled