title: Structure of β-adrenergic receptors.
abstract: β-Adrenergic receptors (βARs) control key physiological functions by transducing signals encoded in catecholamine hormones and neurotransmitters to activate intracellular signaling pathways. As members of the large family of G protein-coupled receptors (GPCRs), βARs have a seven-transmembrane helix topology and signal via G protein- and arrestin-dependent pathways. Until 2007, three-dimensional structural information of GPCRs activated by diffusible ligands, including βARs, was limited to homology models that used the related photoreceptor rhodopsin as a template. Over many years, several labs have developed strategies that have finally allowed the structures of the turkey β(1)AR and the human β(2)AR to be determined experimentally. The challenges to overcome included heterologous receptor overexpression, design of stabilized and crystallizable modified receptor constructs, ligand-affinity purification of active receptor and the development of novel techniques in crystallization and microcrystallography. The structures of βARs in complex with inverse agonists, antagonists, and agonists have revealed the binding mode of ligands with different efficacies, have allowed to obtain insights into ligand selectivity, and have provided better templates for drug design. Also, the structures of β(2)AR in complex with a G protein and a G protein-mimicking nanobody have provided important insights into the mechanism of receptor activation and G protein coupling. This chapter summarizes the strategies and methods that have been successfully applied to the structural studies of βARs. These are exemplified with detailed protocols toward the structure determination of stabilized turkey β(1)AR-ligand complexes. We also discuss the spectacular insights into adrenergic receptor function that were obtained from the structures.
authors: Laboratory of Biomolecular Research, Paul Scherrer Institut, Villigen PSI, Switzerland.
authors: Florian
authors: F
authors: Brueckner
authors: Chayne L
authors: CL
authors: Piscitelli
authors: Ching-Ju
authors: CJ
authors: Tsai
authors: Jörg
authors: J
authors: Standfuss
authors: Xavier
authors: X
authors: Deupi
authors: Gebhard F X
authors: GF
authors: Schertler
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D018360:Crystallography, X-Ray; D006801:Humans; D008969:Molecular Sequence Data; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D011943:Receptors, Adrenergic, beta / Q000737:chemistry* / Q000378:metabolism; D043562:Receptors, G-Protein-Coupled / Q000737:chemistry / Q000378:metabolism
chemical_list: D011943:Receptors, Adrenergic, beta; D043562:Receptors, G-Protein-Coupled