title: Constitutive activity of muscarinic acetylcholine receptors.
abstract: We review the literature describing constitutive activity of the five muscarinic acetylcholine receptors in native and recombinant systems and discuss the effect of constitutive activity on muscarinic pharmacology in the context of modern models of receptor activation. We include a summary of mutations found to cause constitutive activity and discuss the implications of these data for the structure, function, and activation mechanism of muscarinic receptors. Finally, we discuss the possible physiological significance of constitutive activity of muscarinic receptors, incorporating information provided by targeted deletion of each of the muscarinic subtypes.
authors.affiliation: Genomics Institute of the Novartis Research Foundation, San Diego, California 92121, USA. tspalding@gnf.org
authors.forename: Tracy A
authors.initials: TA
authors.lastname: Spalding
authors.forename: Ethan S
authors.initials: ES
authors.lastname: Burstein
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D019204:GTP-Binding Proteins / Q000378:metabolism; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D011976:Receptors, Muscarinic / Q000502:physiology*
chemical_list: D011976:Receptors, Muscarinic; D019204:GTP-Binding Proteins