The path to the G protein-coupled receptor structural landscape: Major milestones and future directions.

G protein-coupled receptors (GPCRs) play a crucial role in cell function by transducing signals from the extracellular environment to the inside of the cell. They mediate the effects of various stimuli, including hormones, neurotransmitters, ions, photons, food tastants and odorants, and are renowned drug targets. Advancements in structural biology techniques, including X-ray crystallography and cryo-electron microscopy (cryo-EM), have driven the elucidation of an increasing number of GPCR structures.

Nanobody GPS by PCS: An Efficient New NMR Analysis Method for G Protein Coupled Receptors and Other Large Proteins.

NMR chemical shift changes can report on the functional dynamics of biomacromolecules in solution with sizes >1 MDa. However, their interpretation requires chemical shift assignments to individual nuclei, which for large molecules often can only be obtained by tedious point mutations that may interfere with function. We present here an efficient pseudocontact shift NMR method to assign biomacromolecules using bound antibodies tagged with lanthanoid DOTA chelators.

Filling of a water-free void explains the allosteric regulation of the β-adrenergic receptor by cholesterol.

Recent high-pressure NMR results indicate that the preactive conformation of the β-adrenergic receptor (βAR) harbours completely empty cavities of ~100 Å volume, which disappear in the active conformation of the receptor. Here we have localized these cavities using X-ray crystallography of xenon-derivatized βAR crystals. One of the cavities is in direct contact with the cholesterol-binding pocket.

Efficient production of a functional G protein-coupled receptor in E. coli for structural studies.

G protein-coupled receptors (GPCRs) are transmembrane signal transducers which regulate many key physiological process. Since their discovery, their analysis has been limited by difficulties in obtaining sufficient amounts of the receptors in high-quality, functional form from heterologous expression hosts. Albeit highly attractive because of its simplicity and the ease of isotope labeling for NMR studies, heterologous expression of functional GPCRs in E.

A high-resolution description of β-adrenergic receptor functional dynamics and allosteric coupling from backbone NMR.

Signal transmission and regulation of G-protein-coupled receptors (GPCRs) by extra- and intracellular ligands occurs via modulation of complex conformational equilibria, but their exact kinetic details and underlying atomic mechanisms are unknown. Here we quantified these dynamic equilibria in the β-adrenergic receptor in its apo form and seven ligand complexes using H/N NMR spectroscopy. We observe three major exchanging conformations: an inactive conformation (C), a preactive conformation (C) and an active conformation (C), which becomes fully populated in a ternary complex with a G protein mimicking nanobody.

High Pressure Shifts the β-Adrenergic Receptor to the Active Conformation in the Absence of G Protein.

G protein-coupled receptors (GPCRs) are versatile chemical sensors, which transmit the signal of an extracellular binding event across the plasma membrane to the intracellular side. This function is achieved via the modulation of highly dynamical equilibria of various conformational receptor states. Here we have probed the effect of pressure on the conformational equilibria of a functional thermostabilized β-adrenergic GPCR (βAR) by solution NMR.

Model for the allosteric regulation of the Na+/Ca2+ exchanger NCX.

The Na(+) /Ca(2+) exchanger provides a major Ca(2+) extrusion pathway in excitable cells and plays a key role in the control of intracellular Ca(2+) concentrations. In Canis familiaris, Na(+) /Ca(2+) exchanger (NCX) activity is regulated by the binding of Ca(2+) to two cytosolic Ca(2+) -binding domains, CBD1 and CBD2, such that Ca(2+) -binding activates the exchanger. Despite its physiological importance, little is known about the exchanger's global structure, and the mechanism of allosteric Ca(2+) -regulation remains unclear.

Molecular docking and panicolytic effect of 8-prenylnaringenin in the elevated T-maze.

The purpose of this study was to investigate the effects of the chronic administration of a racemic mixture of 8-prenylnaringenin (8-PN) on rats submitted to the elevated T-maze (ETM) model of generalized anxiety and panic disorders. The selective serotonin (SERT) reuptake inhibitor fluoxetine was used as a positive control. Rat locomotion was assessed in a circular arena following each drug treatment.