scholarly journals The Habenular Receptor GPR151 Regulates Addiction Vulnerability Across Drug Classes

2019 ◽  
Author(s):  
Beatriz Antolin-Fontes ◽  
Kun Li ◽  
Jessica L. Ables ◽  
Michael H. Riad ◽  
Andreas Görlich ◽  
...  
Keyword(s):  
G Protein ◽  
Cannabinoid Receptors ◽  
Behavioral Responses ◽  
G Protein Coupled Receptor ◽  
Inhibitory Protein ◽  
Vesicle Release ◽  
Release Probability ◽  
Drug Classes ◽  
G Protein Coupled ◽  
Camp Levels

SUMMARYThe habenula controls the addictive properties of nicotine but also densely expresses opioid and cannabinoid receptors. As such, identification of strategies to manipulate habenular activity may yield new approaches to treat substance use disorders. Here we show that GPR151, an orphan G protein-coupled receptor (GPCR) highly enriched in the habenula of humans and rodents plays a critical role in regulating habenular function and behavioral responses to addictive drugs. We show that GPR151 is expressed on axonal and presynaptic membranes and synaptic vesicles, and regulates synaptic fidelity and plasticity. We find that GPR151 associates with synaptic components controlling vesicle release and ion transport and couples to the G-alpha inhibitory protein Gαo1to reduce cAMP levels. Stable cell lines expressing GPR151 confirm that it signals via Gi/o and are amenable to ligand screens.Gpr151null mice show diminished behavioral responses to nicotine, and self-administer greater quantities of the drug, phenotypes rescued by viral re-expression ofGpr151in the habenula.Gpr151null mice are also insensitive to the behavioral actions of morphine and cannabinoids. These data identify GPR151 as a critical modulator of habenular function that controls addiction vulnerability across different drug classes.HighlightsHabenula neurons are enriched in nicotinic, opioid, cannabinoid and GPR151 receptorsGPR151 modulates synaptic fidelity and release probability at habenular terminals.Habenular GPR151 plays a role in drug abuse and food intake/weight controlGPR151 couples to the G-alpha inhibitory protein Gαo1to reduce cAMP levels.eTOC BlurbAntolin-Fontes at al. identify a G protein-coupled receptor, GPR151, which is highly enriched in human habenular neurons. These neurons are primarily enriched with nicotinic, opioid and cannabinoid receptors. We find that GPR151 modulates habenular synaptic vesicle release probability and behavioral responses to these drugs of abuse.

scholarly journals The Vertical and Horizontal Pathways in the Monkey Retina Are Modulated by Typical and Atypical Cannabinoid Receptors

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 3160
Author(s):  
Joseph Bouskila ◽  
Maxime Bleau ◽  
Catarina Micaelo-Fernandes ◽  
Jean-François Bouchard ◽  
Maurice Ptito
Keyword(s):  
G Protein ◽  
Visual Information ◽  
Cannabinoid Receptors ◽  
Transient Receptor Potential ◽  
Expression Patterns ◽  
Retinal Function ◽  
Age Related Macular Degeneration ◽  
Transient Receptor Potential Vanilloid ◽  
G Protein Coupled Receptor ◽  
G Protein Coupled

The endocannabinoid (eCB) system has been found in all visual parts of the central ner-vous system and plays a role in the processing of visual information in many species, including monkeys and humans. Using anatomical methods, cannabinoid receptors are present in the monkey retina, particularly in the vertical glutamatergic pathway, and also in the horizontal GABAergic pathway. Modulating the eCB system regulates normal retinal function as demonstrated by electrophysiological recordings. The characterization of the expression patterns of all types of cannabinoid receptors in the retina is progressing, and further research is needed to elucidate their exact role in processing visual information. Typical cannabinoid receptors include G-protein coupled receptor CB1R and CB2R, and atypical cannabinoid receptors include the G-protein coupled receptor 55 (GPR55) and the ion channel transient receptor potential vanilloid 1 (TRPV1). This review focuses on the expression and localization studies carried out in monkeys, but some data on other animal species and humans will also be reported. Furthermore, the role of the endogenous cannabinoid receptors in retinal function will also be presented using intraocular injections of known modulators (agonists and antagonists) on electroretinographic patterns in monkeys. The effects of the natural bioactive lipid lysophosphatidylglucoside and synthetic FAAH inhibitor URB597 on retinal function, will also be described. Finally, the potential of typical and atypical cannabinoid receptor acti-vity regulation in retinal diseases, such as age-related macular degeneration, diabetic retinopathy, glaucoma, and retinitis pigmentosa will be briefly explored.

scholarly journals Conserved salt-bridge competition triggered by phosphorylation regulates the protein interactome

2017 ◽  
Vol 114 (51) ◽  
pp. 13453-13458 ◽  
Author(s):  
John J. Skinner ◽  
Sheng Wang ◽  
Jiyoung Lee ◽  
Colin Ong ◽  
Ruth Sommese ◽  
...  
Keyword(s):  
G Protein ◽  
Protein Interactions ◽  
Salt Bridge ◽  
G Protein Coupled Receptor ◽  
Inhibitory Protein ◽  
Raf Kinase ◽  
Protein Interfaces ◽  
Partial Unfolding ◽  
Direct Recognition ◽  
G Protein Coupled

Phosphorylation is a major regulator of protein interactions; however, the mechanisms by which regulation occurs are not well understood. Here we identify a salt-bridge competition or “theft” mechanism that enables a phospho-triggered swap of protein partners by Raf Kinase Inhibitory Protein (RKIP). RKIP transitions from inhibiting Raf-1 to inhibiting G-protein–coupled receptor kinase 2 upon phosphorylation, thereby bridging MAP kinase and G-Protein–Coupled Receptor signaling. NMR and crystallography indicate that a phosphoserine, but not a phosphomimetic, competes for a lysine from a preexisting salt bridge, initiating a partial unfolding event and promoting new protein interactions. Structural elements underlying the theft occurred early in evolution and are found in 10% of homo-oligomers and 30% of hetero-oligomers including Bax, Troponin C, and Early Endosome Antigen 1. In contrast to a direct recognition of phosphorylated residues by binding partners, the salt-bridge theft mechanism represents a facile strategy for promoting or disrupting protein interactions using solvent-accessible residues, and it can provide additional specificity at protein interfaces through local unfolding or conformational change.

scholarly journals A Novel High Throughput Chemiluminescent Assay for the Measurement of Cellular Cyclic Adenosine Monophosphate Levels

2000 ◽  
Vol 5 (4) ◽  
pp. 239-247 ◽  
Author(s):  
Anthony C. Chiulli ◽  
Karen Trompeter ◽  
Michelle Palmer
Keyword(s):  
G Protein ◽  
High Throughput ◽  
High Throughput Screening ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Receptor Activation ◽  
G Protein Coupled Receptor ◽  
Wide Range ◽  
G Protein Coupled ◽  
Camp Levels

The second messenger 3′, 5′-cyclic AMP (cAMP) is a highly regulated molecule that is governed by G protein-coupled receptor activation and other cellular processes. Measurement of cAMP levels in cells is widely used as an indicator of receptor function in drug discovery applications. We have developed a nonradioactive ELISA for the accurate quantitation of cAMP levels produced in cell-based assays. This novel competitive assay utilizes chemiluminescent detection that affords both a sensitivity and a dynamic assay range that have not been previously reported with any other assay methodologies. The assay has been automated in 96- and 384-well formats, providing assay data that are equivalent to, if not better than, data generated by hand. This report demonstrates the application of this novel assay technology to the functional analysis of a specific G protein-coupled receptor, neuropeptide receptor Y1, on SK-N-MC cells. Our data indicate the feasibility of utilizing this assay methodology for monitoring cAMP levels in a wide range of functional cell-based assays for high throughput screening.

scholarly journals The habenular G-protein–coupled receptor 151 regulates synaptic plasticity and nicotine intake

2020 ◽  
Vol 117 (10) ◽  
pp. 5502-5509 ◽  
Author(s):  
Beatriz Antolin-Fontes ◽  
Kun Li ◽  
Jessica L. Ables ◽  
Michael H. Riad ◽  
Andreas Görlich ◽  
...  
Keyword(s):  
G Protein ◽  
Nicotinic Acetylcholine Receptors ◽  
Brain Area ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Nicotine Addiction ◽  
G Protein Coupled Receptor ◽  
Inhibitory Protein ◽  
Nicotine Intake ◽  
G Protein Coupled

The habenula, an ancient small brain area in the epithalamus, densely expresses nicotinic acetylcholine receptors and is critical for nicotine intake and aversion. As such, identification of strategies to manipulate habenular activity may yield approaches to treat nicotine addiction. Here we show that GPR151, an orphan G-protein–coupled receptor (GPCR) highly enriched in the habenula of humans and rodents, is expressed at presynaptic membranes and synaptic vesicles and associates with synaptic components controlling vesicle release and ion transport. Deletion of Gpr151 inhibits evoked neurotransmission but enhances spontaneous miniature synaptic currents and eliminates short-term plasticity induced by nicotine. We find that GPR151 couples to the G-alpha inhibitory protein Gαo1 to reduce cyclic adenosine monophosphate (cAMP) levels in mice and in GPR151-expressing cell lines that are amenable to ligand screens. Gpr151– knockout (KO) mice show diminished behavioral responses to nicotine and self-administer greater quantities of the drug, phenotypes rescued by viral reexpression of Gpr151 in the habenula. These data identify GPR151 as a critical modulator of habenular function that controls nicotine addiction vulnerability.

scholarly journals AMP010014A09 in Sus Scrofa Encodes an Analog of G Protein-Coupled Receptor 109A, Which Mediates the Anti-Inflammatory Effects of Beta-Hydroxybutyric Acid

2017 ◽  
Vol 42 (4) ◽  
pp. 1420-1430 ◽  
Author(s):  
Guangxin Chen ◽  
Shoupeng Fu ◽  
Wenqian Feng ◽  
Bingxu Huang ◽  
Shiyao Xu ◽  
...  
Keyword(s):  
G Protein ◽  
Inflammatory Cytokines ◽  
Sus Scrofa ◽  
Hydroxybutyric Acid ◽  
G Protein Coupled Receptor ◽  
Anti Inflammatory ◽  
High Level ◽  
G Protein Coupled ◽  
Camp Levels ◽  
Pro Inflammatory Cytokines

Background: Hydroxy-carboxylic acid receptor 2 (HCA2, also called GPR109A) belongs to the G protein-coupled receptor (GPCR) family and is found in humans, rats, mice, hamsters and guinea pigs, but there are almost no reports of this protein in other species. In this investigation, we speculated that AMP010014A09 (AMP+) is a homologue of GPR109A in swine. Methods: To test this hypothesis, the following experiments were designed: monocytes isolated from the peripheral blood of swine were treated with LPS after pretreating with or without β-hydroxybutyric acid (BHBA), and the levels of pro-inflammatory cytokines and inflammatory proteins were assessed. cAMP levels induced by Forskolin in swine testicular (ST) and IPEC-J2 cells were detected with or without BHBA treatment and following silencing or stable transfection of the AMP+ gene. Results: AMP+ in swine exhibited a high level of homology with HM74A in humans and PUMA-G in mice. BHBA inhibited the LPS-induced secretion of the pro-inflammatory cytokines TNF-α, IL-6 and IL-1β and the inflammatory protein COX-2 in monocytes of swine. BHBA suppressed the Forskolin-induced cAMP level increase in ST cells, but failed to inhibit the accumulation of cAMP after the AMP+ gene was silenced with shRNA by transfecting cells with the pGPU6-GFP-Neo-AMP+-sus-392 plasmid. BHBA had no effect on cAMP levels in IPEC-J2 cells, but significantly inhibited the increase in cAMP induced by Forskolin treatment following transfection of the AMP+ gene into IPEC-J2 cells by a lentivirus vector. Conclusion: Our results indicated that AMP+ encodes a G protein-coupled receptor in Sus scrofa that inhibits cAMP levels and mediates anti-inflammatory effects in swine monocytes.

scholarly journals GPR-4 Is a Predicted G-Protein-Coupled Receptor Required for Carbon Source-Dependent Asexual Growth and Development in Neurospora crassa

2006 ◽  
Vol 5 (8) ◽  
pp. 1287-1300 ◽  
Author(s):  
Liande Li ◽  
Katherine A. Borkovich
Keyword(s):  
Carbon Source ◽  
Neurospora Crassa ◽  
G Protein ◽  
Growth And Development ◽  
Carbon Sources ◽  
Wild Type ◽  
G Protein Coupled Receptor ◽  
G Protein Coupled ◽  
Camp Levels ◽  
Mass Accumulation

ABSTRACT The filamentous fungus Neurospora crassa is able to utilize a wide variety of carbon sources. Here, we examine the involvement of a predicted G-protein-coupled receptor (GPCR), GPR-4, during growth and development in the presence of different carbon sources in N. crassa. Δgpr-4 mutants have reduced mass accumulation compared to the wild type when cultured on high levels of glycerol, mannitol, or arabinose. The defect is most severe on glycerol and is cell density dependent. The genetic and physical relationship between GPR-4 and the three N. crassa Gα subunits (GNA-1, GNA-2, and GNA-3) was explored. All three Gα mutants are defective in mass accumulation when cultured on glycerol. However, the phenotypes of Δgna-1 and Δgpr-4 Δgna-1 mutants are identical, introduction of a constitutively activated gna-1 allele suppresses the defects of the Δgpr-4 mutation, and the carboxy terminus of GPR-4 interacts most strongly with GNA-1 in the yeast two-hybrid assay. Although steady-state cyclic AMP (cAMP) levels are normal in Δgpr-4 strains, exogenous cAMP partially remediates the dry mass defects of Δgpr-4 mutants on glycerol medium and Δgpr-4 strains lack the transient increase in cAMP levels observed in the wild type after addition of glucose to glycerol-grown liquid cultures. Our results support the hypothesis that GPR-4 is coupled to GNA-1 in a cAMP signaling pathway that regulates the response to carbon source in N. crassa. GPR-4-related GPCRs are present in the genomes of several filamentous ascomycete fungal pathogens, raising the possibility that a similar pathway regulates carbon sensing in these organisms.

scholarly journals Identification of Surrogate Agonists and Antagonists for Orphan G-Protein-Coupled Receptor GPR139

2009 ◽  
Vol 14 (7) ◽  
pp. 789-797 ◽  
Author(s):  
Liaoyuan A. Hu ◽  
Pauline M. Tang ◽  
Nima K. Eslahi ◽  
Tian Zhou ◽  
Joseph Barbosa ◽  
...  
Keyword(s):  
G Protein ◽  
Signal Transduction Pathway ◽  
Intracellular Camp ◽  
G Protein Coupled Receptor ◽  
The Central Nervous System ◽  
G Protein Coupled ◽  
Camp Levels ◽  
Orphan Gpcr ◽  
In Cells

GPR139 is an orphan G-protein-coupled receptor (GPCR) that is expressed nearly exclusively in the central nervous system and may play a role in the control of locomotor activity. The signal transduction pathway and pharmacological function of GPR139, however, are still controversial due to the lack of natural or synthetic ligands. The authors report the characterization of human GPR139 signaling pathway and identification of surrogate agonists and antagonists. In both transient and stable transfections of HEK293F cells, overexpression of GPR139 increased basal intracellular cAMP concentrations compared to control cells. Furthermore, forskolin and isoproterenol-stimulated cAMP responses were enhanced in GPR139-expressing cells, suggesting that GPR139 is predominantly coupled to Gαs. The authors screened a large library of small molecules for compounds that increase cAMP levels in GPR139-expressing cells and identified a compound with GPR139 agonist activity. This compound increased cAMP production specifically in cells expressing GPR139 but not in cells expressing its highly homologous receptor GPR142. Furthermore, this compound did not induce calcium mobilization in GPR139 cells, indicating no Gαq-mediated response. In addition, antagonist screening with the identified agonist yielded 2 classes of compounds as antagonists. The identification of surrogate agonists and antagonists of human GPR139 provides important tools for further study of this orphan GPCR. ( Journal of Biomolecular Screening 2009:789-797)

scholarly journals Morphine-induced physiological and behavioral responses in mice lacking G protein-coupled receptor kinase 6

2009 ◽  
Vol 104 (3) ◽  
pp. 187-196 ◽  
Author(s):  
Kirsten M. Raehal ◽  
Cullen L. Schmid ◽  
Ivan O. Medvedev ◽  
Raul R. Gainetdinov ◽  
Richard T. Premont ◽  
...  
Keyword(s):  
G Protein ◽  
Behavioral Responses ◽  
Receptor Kinase ◽  
G Protein Coupled Receptor ◽  
G Protein Coupled
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