Structural basis for activation of G-protein-coupled receptors
TLDR
Using the beta2-adrenergic receptor as a model system, evidence is obtained for an evolutionary conserved activation mechanism where disruption of intramolecular interactions between TM3 and TM6 leads to a major conformational change of TM6 relative to the rest of the receptor.Abstract:
Our understanding of how G-protein-coupled receptors (GPCRs) operate at the molecular level has been considerably improved over the last few years. The application of advanced biophysical techniques as well as the availability of high-resolution structural information has allowed insight both into conformational changes accompanying GPCR activation and the underlying molecular mechanism governing transition of the receptor between its active and inactive states. Using the beta2-adrenergic receptor as a model system we have obtained evidence for an evolutionary conserved activation mechanism where disruption of intramolecular interactions between TM3 and TM6 leads to a major conformational change of TM6 relative to the rest of the receptor. This conclusion was based on experiments in which environmentally sensitive, sulfhydryl-reactive fluorophores were site-selectively incorporated into wild-type and mutant beta2-adrenergic receptors purified from Sf-9 insect cells. Our studies have also raised important questions regarding kinetics of receptors activation. These questions should be addressed in the future by application of techniques that will allow for simultaneous measurement of conformational changes and receptor activation. At the current stage we are exploring the possibility of reaching this goal by direct in situ labeling of the beta2-adrenergic receptor in Xenopus laevis oocytes with conformationally sensitive fluorescent probes and parallel detection of receptor activation by co-expression with the cAMP sensitive Cl- channel CFTR (cystic fibrosis transmembrane conductance regulator) and electrophysiological measurements.read more
Citations
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Journal ArticleDOI
Mammalian G proteins and their cell type specific functions
TL;DR: In this review, some of the functions of heterotrimeric G proteins in defined cells and tissues are described.
Journal ArticleDOI
Heterotrimeric G protein activation by G-protein-coupled receptors
William M. Oldham,Heidi E. Hamm +1 more
TL;DR: The complex series of interactions and conformational changes that connect agonist binding to G protein activation raise various interesting questions about the structure, biomechanics, kinetics and specificity of signal transduction across the plasma membrane.
Journal ArticleDOI
Molecular mechanisms of ligand binding, signaling, and regulation within the superfamily of G-protein-coupled receptors: molecular modeling and mutagenesis approaches to receptor structure and function
TL;DR: The combined use of site-directed mutagenesis and molecular modeling approaches have provided detailed insight into molecular mechanisms of ligand binding, receptor folding, receptor activation, G-protein coupling, and regulation of GPCRs.
Journal ArticleDOI
Activation of the novel estrogen receptor G protein-coupled receptor 30 (GPR30) at the plasma membrane.
Edward J. Filardo,Jeffrey A. Quinn,Yefei Pang,Carl T. Graeber,S. Shaw,Jing Dong,Peter Thomas +6 more
TL;DR: It is shown that detectable expression of GPR30 on the surface of transfected HEK-293 cells can be selected by fluorescence-activated cell sorting, and results suggest that G PR30, like other 7TMRs, functions as a plasma membrane receptor.
Journal ArticleDOI
Direct G Protein Modulation of Cav2 Calcium Channels
TL;DR: Twenty-five years after this mode of physiological regulation was first described, the investigations that have led to the current understanding of its molecular mechanisms are reviewed.
References
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Journal ArticleDOI
Crystal Structure of Rhodopsin: A G Protein-Coupled Receptor
Krzysztof Palczewski,Takashi Kumasaka,Tetsuya Hori,Craig A. Behnke,H. Motoshima,Brian A. Fox,I. Le Trong,David C. Teller,Tetsuji Okada,Ronald E. Stenkamp,Masaki Yamamoto,Masashi Miyano +11 more
TL;DR: This article determined the structure of rhodopsin from diffraction data extending to 2.8 angstroms resolution and found that the highly organized structure in the extracellular region, including a conserved disulfide bridge, forms a basis for the arrangement of the sevenhelix transmembrane motif.
Book ChapterDOI
[19] Integrated methods for the construction of three-dimensional models and computational probing of structure-function relations in G protein-coupled receptors
TL;DR: This chapter discusses the integrated methods for the construction of three-dimensional models and computational probing of structure–function relations in G protein-coupled receptors (GPCR) and expects increased rate of success achieved by molecular modeling and computational simulation methods in providing structural insights relevant to the functions of biological molecules.
Journal ArticleDOI
G Protein-coupled Receptors I. DIVERSITY OF RECEPTOR-LIGAND INTERACTIONS
TL;DR: The most striking difference has been observed in the sites and modes of ligand binding and signal generation, which not only manifests the diversity but also indicates the availability of numerous alternative approaches to clinical and industrial applications.
Journal ArticleDOI
Uncovering Molecular Mechanisms Involved in Activation of G Protein-Coupled Receptors
TL;DR: The goal of the present review is to specifically address the physical changes linking agonist binding to receptor activation and subsequent transduction of the signal to the associated G protein on the cytoplasmic side of the membrane and to other putative signaling pathways.
Journal ArticleDOI
A mutation-induced activated state of the beta 2-adrenergic receptor. Extending the ternary complex model.
TL;DR: The experimental findings with the mutant receptor cannot be adequately rationalized within the theoretical framework of the Ternary Complex Model, and an extended version of this model that includes an explicit isomerization of the receptor to an active state closely models all the findings for both the mutant and the wild-type receptors.