title: Structural studies of the natriuretic peptide receptor: a novel hormone-induced rotation mechanism for transmembrane signal transduction.
abstract: The atrial natriuretic peptide (ANP) receptor is a single-span transmembrane receptor that is coupled to its intrinsic intracellular guanylate cyclase (GCase) catalytic activity. To investigate the mechanisms of hormone binding and signal transduction, we have expressed the extracellular hormone-binding domain of the ANP receptor (ANPR) and characterized its structure and function. The disulfide-bond structure, state of glycosylation, binding-site residues, chloride-dependence of ANP binding, dimerization, and binding stoichiometry have been determined. More recently, the crystal structures of both the apoANPR dimer and ANP-bound complex have been determined. The structural comparison between the two has shown that, upon ANP binding, two ANPR molecules in the dimer undergo an inter-molecular twist with little intra-molecular conformational change. This motion produces a Ferris wheel-like translocation of two juxtamembrane domains with essentially no change in the inter-domain distance. This movement alters the relative orientation of the two domains equivalent to counter-clockwise rotation of each by 24 degrees . These results suggest that transmembrane signaling by the ANP receptor is mediated by a novel hormone-induced rotation mechanism.
authors.affiliation: Department of Biochemistry and Molecular Biology, MS-330, School of Medicine, University of Nevada, 1664 N Virginia Street, Reno, NV 89557, USA. kmisono@unr.edu
authors.forename: Kunio S
authors.initials: KS
authors.lastname: Misono
authors.forename: Haruo
authors.initials: H
authors.lastname: Ogawa
authors.forename: Yue
authors.initials: Y
authors.lastname: Qiu
authors.forename: Craig M
authors.initials: CM
authors.lastname: Ogata
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002462:Cell Membrane / Q000378:metabolism*; D018360:Crystallography, X-Ray; D019281:Dimerization; D004220:Disulfides / Q000737:chemistry; D006728:Hormones / Q000378:metabolism*; D006801:Humans; D008954:Models, Biological; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011485:Protein Binding; D011487:Protein Conformation; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D017461:Receptors, Atrial Natriuretic Factor / Q000737:chemistry* / Q000502:physiology*; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction
chemical_list: D004220:Disulfides; D006728:Hormones; D017461:Receptors, Atrial Natriuretic Factor