title: Structural Insights into the Dynamic Process of β2-Adrenergic Receptor Signaling.
abstract: G-protein-coupled receptors (GPCRs) transduce signals from the extracellular environment to intracellular proteins. To gain structural insight into the regulation of receptor cytoplasmic conformations by extracellular ligands during signaling, we examine the structural dynamics of the cytoplasmic domain of the β2-adrenergic receptor (β2AR) using (19)F-fluorine NMR and double electron-electron resonance spectroscopy. These studies show that unliganded and inverse-agonist-bound β2AR exists predominantly in two inactive conformations that exchange within hundreds of microseconds. Although agonists shift the equilibrium toward a conformation capable of engaging cytoplasmic G proteins, they do so incompletely, resulting in increased conformational heterogeneity and the coexistence of inactive, intermediate, and active states. Complete transition to the active conformation requires subsequent interaction with a G protein or an intracellular G protein mimetic. These studies demonstrate a loose allosteric coupling of the agonist-binding site and G-protein-coupling interface that may generally be responsible for the complex signaling behavior observed for many GPCRs.
authors.affiliation: Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305, USA.
authors.forename: Aashish
authors.initials: A
authors.lastname: Manglik
authors.affiliation: Department of Chemistry, University of Toronto, UTM, 3359 Mississauga Road North, Mississauga, Ontario L5L 1C6, Canada.
authors.forename: Tae Hun
authors.initials: TH
authors.lastname: Kim
authors.affiliation: Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305, USA.
authors.forename: Matthieu
authors.initials: M
authors.lastname: Masureel
authors.affiliation: Jules Stein Eye Institute and Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095-7008, USA.
authors.forename: Christian
authors.initials: C
authors.lastname: Altenbach
authors.affiliation: Jules Stein Eye Institute and Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095-7008, USA.
authors.forename: Zhongyu
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Hilger
authors.affiliation: Jules Stein Eye Institute and Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095-7008, USA.
authors.forename: Michael T
authors.initials: MT
authors.lastname: Lerch
authors.affiliation: Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305, USA.
authors.forename: Tong Sun
authors.initials: TS
authors.lastname: Kobilka
authors.affiliation: Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305, USA.
authors.forename: Foon Sun
authors.initials: FS
authors.lastname: Thian
authors.affiliation: Jules Stein Eye Institute and Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095-7008, USA.
authors.forename: Wayne L
authors.initials: WL
authors.lastname: Hubbell
authors.affiliation: Department of Chemistry, University of Toronto, UTM, 3359 Mississauga Road North, Mississauga, Ontario L5L 1C6, Canada.
authors.forename: R Scott
authors.initials: RS
authors.lastname: Prosser
authors.affiliation: Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305, USA. Electronic address: kobilka@stanford.edu.
authors.forename: Brian K
authors.initials: BK
authors.lastname: Kobilka
mesh_terms: D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000595:Amino Acid Sequence; D048588:Benzoxazines / Q000494:pharmacology; D006801:Humans; D007545:Isoproterenol / Q000378:metabolism / Q000494:pharmacology; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D018343:Receptors, Adrenergic, beta-2 / Q000737:chemistry / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D000318:Adrenergic beta-Agonists; C584569:BI167107; D048588:Benzoxazines; D018343:Receptors, Adrenergic, beta-2; D007545:Isoproterenol