scholarly journals Constitutive G protein coupling profiles of understudied orphan GPCRs

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0247743
Author(s):  
Sumin Lu ◽  
Wonjo Jang ◽  
Asuka Inoue ◽  
Nevin A. Lambert
Keyword(s):  
G Protein ◽  
Drug Targets ◽  
Protein Complexes ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Receptor Ligands ◽  
Orphan Receptors ◽  
G Protein Coupling ◽  
Protein Coupling ◽  
Orphan Gpcrs

A large number of GPCRs are potentially valuable drug targets but remain understudied. Many of these lack well-validated activating ligands and are considered “orphan” receptors, and G protein coupling profiles have not been defined for many orphan GPCRs. Here we asked if constitutive receptor activity can be used to determine G protein coupling profiles of orphan GPCRs. We monitored nucleotide-sensitive interactions between 48 understudied orphan GPCRs and five G proteins (240 combinations) using bioluminescence resonance energy transfer (BRET). No receptor ligands were used, but GDP was used as a common G protein ligand to disrupt receptor-G protein complexes. Constitutive BRET between the same receptors and β-arrestins was also measured. We found sufficient GDP-sensitive BRET to generate G protein coupling profiles for 22 of the 48 receptors we studied. Altogether we identified 48 coupled receptor-G protein pairs, many of which have not been described previously. We conclude that receptor-G protein complexes that form spontaneously in the absence of guanine nucleotides can be used to profile G protein coupling of constitutively-active GPCRs. This approach may prove useful for studying G protein coupling of other GPCRs for which activating ligands are not available.

scholarly journals Constitutive G protein coupling profiles of understudied orphan GPCRs

2021 ◽  
Author(s):  
Sumin Lu ◽  
Wonjo Jang ◽  
Asuka Inoue ◽  
Nevin A. Lambert
Keyword(s):  
G Protein ◽  
Drug Targets ◽  
Protein Complexes ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Receptor Ligands ◽  
Orphan Receptors ◽  
G Protein Coupling ◽  
Protein Coupling ◽  
Orphan Gpcrs

AbstractA large number of GPCRs are potentially valuable drug targets but remain understudied. Many of these lack well-validated activating ligands and are considered “orphan” receptors, and G protein coupling profiles have not been defined for many orphan GPCRs. Here we asked if constitutive receptor activity can be used to determine G protein coupling profiles of orphan GPCRs. We monitored nucleotide-sensitive interactions between 48 understudied orphan GPCRs and five G proteins (240 combinations) using bioluminescence resonance energy transfer (BRET). No receptor ligands were used, but GDP was used as a common G protein ligand to disrupt receptor-G protein complexes. Constitutive BRET between the same receptors and β-arrestins was also measured. We found sufficient GDP-sensitive BRET to generate G protein coupling profiles for 22 of the 48 receptors we studied. Altogether we identified 48 coupled receptor-G protein pairs, many of which have not been described previously. We conclude that receptor-G protein complexes that form spontaneously in the absence of guanine nucleotides can be used to profile G protein coupling of constitutively active GPCRs. This approach may prove useful for studying G protein coupling of other GPCRs for which activating ligands are not available.

scholarly journals Monitoring the formation of dynamic G-protein-coupled receptor–protein complexes in living cells

2005 ◽  
Vol 385 (3) ◽  
pp. 625-637 ◽  
Author(s):  
Kevin D. G. PFLEGER ◽  
Karin A. EIDNE
Keyword(s):  
Energy Transfer ◽  
G Protein ◽  
Protein Complexes ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Living Cells ◽  
Receptor Protein ◽  
Specificity And Sensitivity ◽  
G Protein Coupled ◽  
Gpcr Protein

GPCRs (G-protein-coupled receptors) play an extremely important role in transducing extracellular signals across the cell membrane with high specificity and sensitivity. They are central to many of the body's endocrine and neurotransmitter pathways, and are consequently a major drug target. It is now clear that GPCRs interact with a range of proteins, including other GPCRs. Identifying and elucidating the function of such interactions will significantly enhance our understanding of cellular function, with the promise of new and improved pharmaceuticals. Biophysical techniques involving resonance energy transfer, namely FRET (fluorescence resonance energy transfer) and BRET (bioluminescence resonance energy transfer), now enable us to monitor the formation of dynamic GPCR–protein complexes in living cells, in real time. Their use has firmly established the concept of GPCR oligomerization, as well as demonstrating GPCR interactions with GPCR kinases, β-arrestins, adenylate cyclase and a subunit of an inwardly rectifying K+ channel. The present review examines recent technological advances and experimental applications of FRET and BRET, discussing particularly how they have been adapted to extract an ever-increasing amount of information about the nature, specificity, stoichiometry, kinetics and agonist-dependency of GPCR–protein interactions.

Divergent agonist selectivity in activating β1- and β2-adrenoceptors for G-protein and arrestin coupling

2011 ◽  
Vol 438 (1) ◽  
pp. 191-202 ◽  
Author(s):  
Ida Casella ◽  
Caterina Ambrosio ◽  
Maria Cristina Grò ◽  
Paola Molinari ◽  
Tommaso Costa
Keyword(s):  
G Protein ◽  
Protein A ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Signalling Pathways ◽  
Β Subunit ◽  
G Protein Coupling ◽  
Competitive Antagonist ◽  
Ligand Selectivity ◽  
The Relationship

The functional selectivity of adrenergic ligands for activation of β1- and β2-AR (adrenoceptor) subtypes has been extensively studied in cAMP signalling. Much less is known about ligand selectivity for arrestin-mediated signalling pathways. In the present study we used resonance energy transfer methods to compare the ability of β1- and β2-ARs to form a complex with the G-protein β-subunit or β-arrestin-2 in response to a variety of agonists with various degrees of efficacy. The profiles of β1-/β2-AR selectivity of the ligands for the two receptor–transducer interactions were sharply different. For G-protein coupling, the majority of ligands were more effective in activating the β2-AR, whereas for arrestin coupling the relationship was reversed. These data indicate that the β1-AR interacts more efficiently than β2-AR with arrestin, but less efficiently than β2-AR with G-protein. A group of ligands exhibited β1-AR-selective efficacy in driving the coupling to arrestin. Dobutamine, a member of this group, had 70% of the adrenaline (epinephrine) effect on arrestin via β1-AR, but acted as a competitive antagonist of adrenaline via β2-AR. Thus the structure of such ligands appears to induce an arrestin-interacting form of the receptor only when bound to the β1-AR subtype.

scholarly journals Ligand recognition, unconventional activation, and G protein coupling of the prostaglandin E2 receptor EP2 subtype

2021 ◽  
Vol 7 (14) ◽  
pp. eabf1268
Author(s):  
Changxiu Qu ◽  
Chunyou Mao ◽  
Peng Xiao ◽  
Qingya Shen ◽  
Ya-Ni Zhong ◽  
...  
Keyword(s):  
G Protein ◽  
Rational Design ◽  
Receptor Activation ◽  
Prostaglandin E ◽  
Toggle Switch ◽  
G Protein Coupling ◽  
Protein Coupling ◽  
Ligand Selectivity ◽  
Activation Mechanisms ◽  
Prostaglandin E2 Receptor

Selective modulation of the heterotrimeric G protein α S subunit–coupled prostaglandin E2 (PGE2) receptor EP2 subtype is a promising therapeutic strategy for osteoporosis, ocular hypertension, neurodegenerative diseases, and cardiovascular disorders. Here, we report the cryo–electron microscopy structure of the EP2-Gs complex with its endogenous agonist PGE2 and two synthesized agonists, taprenepag and evatanepag (CP-533536). These structures revealed distinct features of EP2 within the EP receptor family in terms of its unconventional receptor activation and G protein coupling mechanisms, including activation in the absence of a typical W6.48 “toggle switch” and coupling to Gs via helix 8. Moreover, inspection of the agonist-bound EP2 structures uncovered key motifs governing ligand selectivity. Our study provides important knowledge for agonist recognition and activation mechanisms of EP2 and will facilitate the rational design of drugs targeting the PGE2 signaling system.

Functional Domains of the Mouse β3-Adrenoceptor Associated with Differential G Protein Coupling

2005 ◽  
Vol 315 (3) ◽  
pp. 1354-1361 ◽  
Author(s):  
Masaaki Sato ◽  
Dana S. Hutchinson ◽  
Tore Bengtsson ◽  
Anders Floren ◽  
Ülo Langel ◽  
...  
Keyword(s):  
G Protein ◽  
Functional Domains ◽  
G Protein Coupling ◽  
Protein Coupling
Sign in / Sign up

Export Citation Format

Share Document