1
|
Saha S, Gonzalez-Maeso J. Translation-independent association of mRNAs encoding protomers of the 5-HT 2A -mGlu2 receptor complex in living cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.17.599432. [PMID: 38948858 PMCID: PMC11212926 DOI: 10.1101/2024.06.17.599432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
The serotonin 2A receptor (5-HT 2A R) and the metabotropic glutamate 2 receptor (mGluR2) form heteromeric G protein-coupled receptor (GPCR) complexes through a direct physical interaction. Co-translational association of mRNAs encoding subunits of heteromeric ion channels has been reported, but whether complex assembly of GPCRs occurs during translation remains unknown. Our in vitro data reveal evidence of co-translational modulation in 5-HT 2A R and mGluR2 mRNAs following siRNA-mediated knockdown. Interestingly, immunoprecipitation of either 5-HT 2A R or mGluR2, using an antibody targeting epitope tags at their N-terminus, results in detection of both transcripts associated with ribonucleoprotein complexes containing RPS24. Additionally, we demonstrate that the mRNA transcripts of 5-HT 2A R and mGluR2 associate autonomously of their respective encoded proteins. Validation of this translation-independent association is extended ex vivo using mouse frontal cortex samples. Together, these findings provide mechanistic insights into the co-translational assembly of GPCR heteromeric complexes, unraveling regulatory processes governing protein-protein interactions and complex formation.
Collapse
|
2
|
Saha S, González-Maeso J. The crosstalk between 5-HT 2AR and mGluR2 in schizophrenia. Neuropharmacology 2023; 230:109489. [PMID: 36889432 PMCID: PMC10103009 DOI: 10.1016/j.neuropharm.2023.109489] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 02/26/2023] [Accepted: 03/05/2023] [Indexed: 03/08/2023]
Abstract
Schizophrenia is a severe brain disorder that usually produces a lifetime of disability. First generation or typical antipsychotics such as haloperidol and second generation or atypical antipsychotics such as clozapine and risperidone remain the current standard for schizophrenia treatment. In some patients with schizophrenia, antipsychotics produce complete remission of positive symptoms, such as hallucinations and delusions. However, antipsychotic drugs are ineffective against cognitive deficits and indeed treated schizophrenia patients have small improvements or even deterioration in several cognitive domains. This underlines the need for novel and more efficient therapeutic targets for schizophrenia treatment. Serotonin and glutamate have been identified as key parts of two neurotransmitter systems involved in fundamental brain processes. Serotonin (or 5-hydroxytryptamine) 5-HT2A receptor (5-HT2AR) and metabotropic glutamate 2 receptor (mGluR2) are G protein-coupled receptors (GPCRs) that interact at epigenetic and functional levels. These two receptors can form GPCR heteromeric complexes through which their pharmacology, function and trafficking becomes affected. Here we review past and current research on the 5-HT2AR-mGluR2 heterocomplex and its potential implication in schizophrenia and antipsychotic drug action. This article is part of the Special Issue on "The receptor-receptor interaction as a new target for therapy".
Collapse
Affiliation(s)
- Somdatta Saha
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
| | - Javier González-Maeso
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA.
| |
Collapse
|
3
|
Murali S, Aradhyam GK. Structure-function relationship and physiological role of apelin and its G protein coupled receptor. Biophys Rev 2023; 15:127-143. [PMID: 36919024 PMCID: PMC9995629 DOI: 10.1007/s12551-023-01044-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/19/2023] [Indexed: 02/19/2023] Open
Abstract
Apelin receptor (APJR) is a class A peptide (apelin) binding G protein-coupled receptor (GPCR) that plays a significant role in regulating blood pressure, cardiac output, and maintenance of fluid homeostasis. It is activated by a wide range of endogenous peptide isoforms of apelin and elabela. The apelin peptide isoforms contain distinct structural features that aid in ligand recognition and activation of the receptor. Site-directed mutagenesis and structure-based studies have revealed the involvement of extracellular and transmembrane regions of the receptor in binding to the peptide isoforms. The structural features of APJR activation of the receptor as well as mediating G-protein and β-arrestin-mediated signaling are delineated by multiple mutagenesis studies. There is increasing evidence that the structural requirements of APJR to activate G-proteins and β-arrestins are different, leading to biased signaling. APJR also responds to mechanical stimuli in a ligand-independent manner. A multitude of studies has focused on developing both peptide and non-peptide agonists and antagonists specific to APJR. Apelin/elabela-activated APJR orchestrates major signaling pathways such as extracellular signal-regulated kinase (ERKs), protein kinase B (PKB/Akt), and p70S. This review focuses on the structural and functional characteristics of apelin, elabela, APJR, and their interactions involved in the binding and activation of the downstream signaling cascade. We also focus on the diverse signaling profile of APJR and its ligands and their involvement in various physiological systems.
Collapse
Affiliation(s)
- Subhashree Murali
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biological Sciences, Indian Institute of Technology Madras, Chennai, India
| | - Gopala Krishna Aradhyam
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biological Sciences, Indian Institute of Technology Madras, Chennai, India
| |
Collapse
|
4
|
Kim H, Baek IY, Seong J. Genetically encoded fluorescent biosensors for GPCR research. Front Cell Dev Biol 2022; 10:1007893. [PMID: 36247000 PMCID: PMC9559200 DOI: 10.3389/fcell.2022.1007893] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Accepted: 09/09/2022] [Indexed: 11/13/2022] Open
Abstract
G protein-coupled receptors (GPCRs) regulate a wide range of physiological and pathophysiological cellular processes, thus it is important to understand how GPCRs are activated and function in various cellular contexts. In particular, the activation process of GPCRs is dynamically regulated upon various extracellular stimuli, and emerging evidence suggests the subcellular functions of GPCRs at endosomes and other organelles. Therefore, precise monitoring of the GPCR activation process with high spatiotemporal resolution is required to investigate the underlying molecular mechanisms of GPCR functions. In this review, we will introduce genetically encoded fluorescent biosensors that can precisely monitor the real-time GPCR activation process in live cells. The process includes the binding of extracellular GPCR ligands, conformational change of GPCR, recruitment of G proteins or β-arrestin, GPCR internalization and trafficking, and the GPCR-related downstream signaling events. We will introduce fluorescent GPCR biosensors based on a variety of strategies such as fluorescent resonance energy transfer (FRET), bioluminescence resonance energy transfer (BRET), circular permuted fluorescent protein (cpFP), and nanobody. We will discuss the pros and cons of these GPCR biosensors as well as their applications in GPCR research.
Collapse
Affiliation(s)
- Hyunbin Kim
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, South Korea
- Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology, Seoul, South Korea
| | - In-Yeop Baek
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, South Korea
- Department of Converging Science and Technology, Kyung Hee University, Seoul, South Korea
| | - Jihye Seong
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, South Korea
- Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology, Seoul, South Korea
- Department of Converging Science and Technology, Kyung Hee University, Seoul, South Korea
- *Correspondence: Jihye Seong,
| |
Collapse
|
5
|
Mantas I, Saarinen M, Xu ZQD, Svenningsson P. Update on GPCR-based targets for the development of novel antidepressants. Mol Psychiatry 2022; 27:534-558. [PMID: 33589739 PMCID: PMC8960420 DOI: 10.1038/s41380-021-01040-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 01/22/2021] [Accepted: 01/25/2021] [Indexed: 01/31/2023]
Abstract
Traditional antidepressants largely interfere with monoaminergic transport or degradation systems, taking several weeks to have their therapeutic actions. Moreover, a large proportion of depressed patients are resistant to these therapies. Several atypical antidepressants have been developed which interact with G protein coupled receptors (GPCRs) instead, as direct targeting of receptors may achieve more efficacious and faster antidepressant actions. The focus of this review is to provide an update on how distinct GPCRs mediate antidepressant actions and discuss recent insights into how GPCRs regulate the pathophysiology of Major Depressive Disorder (MDD). We also discuss the therapeutic potential of novel GPCR targets, which are appealing due to their ligand selectivity, expression pattern, or pharmacological profiles. Finally, we highlight recent advances in understanding GPCR pharmacology and structure, and how they may provide new avenues for drug development.
Collapse
Affiliation(s)
- Ioannis Mantas
- grid.4714.60000 0004 1937 0626Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - Marcus Saarinen
- grid.4714.60000 0004 1937 0626Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - Zhi-Qing David Xu
- grid.24696.3f0000 0004 0369 153XDepartment of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China
| | - Per Svenningsson
- Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden.
| |
Collapse
|
6
|
Strategies for targeting cell surface proteins using multivalent conjugates and chemical biology. Methods Cell Biol 2021. [PMID: 34752333 DOI: 10.1016/bs.mcb.2021.06.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/30/2023]
Abstract
Proper function of receptors on the cell surface is essential for homeostasis. Compounds that target cell surface receptors to address dysregulation have proven exceptionally successful as therapeutic agents; however, the development of compounds with the desired specificity for receptors, cells, and tissues of choice has proven difficult in some cases. The use of compounds that can engage more than one binding site at the cell surface offers a path toward improving biological specificity or pharmacological properties. In this chapter we summarize historical context for the development of such bivalent compounds. We focus on developments in chemical methods and biological engineering to provide bivalent compounds in which the high affinity and specificity of antibodies are leveraged to create multifunctional conjugates with new and useful properties. The development of methods to meld biological macromolecules with synthetic compounds will facilitate modulation of receptor biology in ways not previously possible.
Collapse
|
7
|
Fonseca-Barriendos D, Frías-Soria CL, Pérez-Pérez D, Gómez-López R, Borroto Escuela DO, Rocha L. Drug-resistant epilepsy: Drug target hypothesis and beyond the receptors. Epilepsia Open 2021; 7 Suppl 1:S23-S33. [PMID: 34542940 PMCID: PMC9340308 DOI: 10.1002/epi4.12539] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 08/21/2021] [Accepted: 08/27/2021] [Indexed: 12/28/2022] Open
Abstract
Epilepsy is a chronic neurological disorder that affects more than 50 million people worldwide. Despite a recent introduction of antiseizure drugs for the treatment of epileptic seizures, one-third of these patients suffer from drug-resistant epilepsy (DRE). The therapeutic target hypothesis is a cited theory to explain DRE. According to the target hypothesis, the failure to achieve seizure freedom leads to alteration of the structure and/or function of the antiseizure medication (ASM) target. However, this hypothesis fails to explain why patients with DRE do not respond to antiseizure medications of different targets. This review presents different conditions, such as epigenetic mechanisms and protein-protein interactions that may result in alterations of diverse drug targets using different mechanisms. These novel conditions represent new targets to control DRE.
Collapse
Affiliation(s)
| | | | - Daniel Pérez-Pérez
- Plan of Combined Studies in Medicine (PECEM), Faculty of Medicine, UNAM, México City, Mexico
| | - Rosenda Gómez-López
- Escuela Nacional de Medicina y Homeopatía, Instituto Politécnico Nacional, Mexico City, México
| | | | - Luisa Rocha
- Pharmacobiology Department, Center for Research and Advanced Studies, México City, México
| |
Collapse
|
8
|
Cevheroğlu O, Murat M, Mingu-Akmete S, Son ÇD. Ste2p Under the Microscope: the Investigation of Oligomeric States of a Yeast G Protein-Coupled Receptor. J Phys Chem B 2021; 125:9526-9536. [PMID: 34433281 DOI: 10.1021/acs.jpcb.1c05872] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Oligomerization of G protein-coupled receptors (GPCRs) may play important roles in maturation, internalization, signaling, and pharmacology of these receptors. However, the nature and extent of their oligomerization is still under debate. In our study, Ste2p, a yeast mating pheromone GPCR, was tagged with enhanced green fluorescent protein (EGFP), mCherry, and with split florescent protein fragments at the receptor C-terminus. The Förster resonance energy transfer (FRET) technique was used to detect receptors' oligomerization by calculating the energy transfer from EGFP to mCherry. Stimulation of Ste2p oligomers with the receptor ligand did not result in any significant change on observed FRET values. The bimolecular fluorescence complementation (BiFC) assay was combined with FRET to further investigate the tetrameric complexes of Ste2p. Our results suggest that in its quiescent (nonligand-activated) state, Ste2p is found at least as a tetrameric complex on the plasma membrane. Intriguingly, receptor tetramers in their active form showed a significant increase in FRET. This study provides a direct in vivo visualization of Ste2p tetramers and the pheromone effect on the extent of the receptor oligomerization.
Collapse
Affiliation(s)
- Orkun Cevheroğlu
- Stem Cell Institute, Ankara University, Cankaya, 06520 Ankara, Turkey
| | - Merve Murat
- Stem Cell Institute, Ankara University, Cankaya, 06520 Ankara, Turkey.,Department of Biological Sciences, Middle East Technical University, Cankaya, 06800 Ankara, Turkey
| | - Sara Mingu-Akmete
- Stem Cell Institute, Ankara University, Cankaya, 06520 Ankara, Turkey.,Department of Biological Sciences, Middle East Technical University, Cankaya, 06800 Ankara, Turkey
| | - Çağdaş D Son
- Department of Biological Sciences, Middle East Technical University, Cankaya, 06800 Ankara, Turkey
| |
Collapse
|
9
|
Laitakari A, Liu L, Frimurer TM, Holst B. The Zinc-Sensing Receptor GPR39 in Physiology and as a Pharmacological Target. Int J Mol Sci 2021; 22:ijms22083872. [PMID: 33918078 PMCID: PMC8070507 DOI: 10.3390/ijms22083872] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 03/31/2021] [Accepted: 04/06/2021] [Indexed: 12/16/2022] Open
Abstract
The G-protein coupled receptor GPR39 is abundantly expressed in various tissues and can be activated by changes in extracellular Zn2+ in physiological concentrations. Previously, genetically modified rodent models have been able to shed some light on the physiological functions of GPR39, and more recently the utilization of novel synthetic agonists has led to the unraveling of several new functions in the variety of tissues GPR39 is expressed. Indeed, GPR39 seems to be involved in many important metabolic and endocrine functions, but also to play a part in inflammation, cardiovascular diseases, saliva secretion, bone formation, male fertility, addictive and depression disorders and cancer. These new discoveries offer opportunities for the development of novel therapeutic approaches against many diseases where efficient therapeutics are still lacking. This review focuses on Zn2+ as an endogenous ligand as well as on the novel synthetic agonists of GPR39, placing special emphasis on the recently discovered physiological functions and discusses their pharmacological potential.
Collapse
Affiliation(s)
- Anna Laitakari
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark; (A.L.); (L.L.); (T.M.F.)
| | - Lingzhi Liu
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark; (A.L.); (L.L.); (T.M.F.)
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Thomas M. Frimurer
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark; (A.L.); (L.L.); (T.M.F.)
| | - Birgitte Holst
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark; (A.L.); (L.L.); (T.M.F.)
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
- Correspondence:
| |
Collapse
|
10
|
Toneatti R, Shin JM, Shah UH, Mayer CR, Saunders JM, Fribourg M, Arsenovic PT, Janssen WG, Sealfon SC, López-Giménez JF, Benson DL, Conway DE, González-Maeso J. Interclass GPCR heteromerization affects localization and trafficking. Sci Signal 2020; 13:eaaw3122. [PMID: 33082287 PMCID: PMC7717648 DOI: 10.1126/scisignal.aaw3122] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Membrane trafficking processes regulate G protein-coupled receptor (GPCR) activity. Although class A GPCRs are capable of activating G proteins in a monomeric form, they can also potentially assemble into functional GPCR heteromers. Here, we showed that the class A serotonin 5-HT2A receptors (5-HT2ARs) affected the localization and trafficking of class C metabotropic glutamate receptor 2 (mGluR2) through a mechanism that required their assembly as heteromers in mammalian cells. In the absence of agonists, 5-HT2AR was primarily localized within intracellular compartments, and coexpression of 5-HT2AR with mGluR2 increased the intracellular distribution of the otherwise plasma membrane-localized mGluR2. Agonists for either 5-HT2AR or mGluR2 differentially affected trafficking through Rab5-positive endosomes in cells expressing each component of the 5-HT2AR-mGluR2 heterocomplex alone, or together. In addition, overnight pharmacological 5-HT2AR blockade with clozapine, but not with M100907, decreased mGluR2 density through a mechanism that involved heteromerization between 5-HT2AR and mGluR2. Using TAT-tagged peptides and chimeric constructs that are unable to form the interclass 5-HT2AR-mGluR2 complex, we demonstrated that heteromerization was necessary for the 5-HT2AR-dependent effects on mGluR2 subcellular distribution. The expression of 5-HT2AR also augmented intracellular localization of mGluR2 in mouse frontal cortex pyramidal neurons. Together, our data suggest that GPCR heteromerization may itself represent a mechanism of receptor trafficking and sorting.
Collapse
MESH Headings
- Amino Acids/pharmacology
- Animals
- Bridged Bicyclo Compounds, Heterocyclic/pharmacology
- Cell Membrane/metabolism
- Clozapine/pharmacology
- Endosomes/metabolism
- HEK293 Cells
- Humans
- Mice, 129 Strain
- Mice, Knockout
- Microscopy, Confocal
- Multiprotein Complexes/chemistry
- Multiprotein Complexes/metabolism
- Protein Multimerization
- Protein Transport/drug effects
- Receptor, Serotonin, 5-HT2A/chemistry
- Receptor, Serotonin, 5-HT2A/genetics
- Receptor, Serotonin, 5-HT2A/metabolism
- Receptors, Metabotropic Glutamate/chemistry
- Receptors, Metabotropic Glutamate/genetics
- Receptors, Metabotropic Glutamate/metabolism
- Serotonin Antagonists/pharmacology
- Signal Transduction
Collapse
Affiliation(s)
- Rudy Toneatti
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Jong M Shin
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Urjita H Shah
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Carl R Mayer
- Department of Biomedical Engineering, College of Engineering, Virginia Commonwealth University, Richmond, VA 23220, USA
| | - Justin M Saunders
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Miguel Fribourg
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Translational Transplant Research Center, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Paul T Arsenovic
- Department of Biomedical Engineering, College of Engineering, Virginia Commonwealth University, Richmond, VA 23220, USA
| | - William G Janssen
- Department Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Stuart C Sealfon
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Juan F López-Giménez
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, VA 23298, USA
- Instituto de Parasitología y Biomedicina "López-Neyra", CSIC, E-18016 Granada, Spain
| | - Deanna L Benson
- Department Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Daniel E Conway
- Department of Biomedical Engineering, College of Engineering, Virginia Commonwealth University, Richmond, VA 23220, USA
| | - Javier González-Maeso
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, VA 23298, USA.
| |
Collapse
|
11
|
Conradi Smith GD. Allostery in oligomeric receptor models. MATHEMATICAL MEDICINE AND BIOLOGY : A JOURNAL OF THE IMA 2020; 37:313-333. [PMID: 31822901 DOI: 10.1093/imammb/dqz016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 10/03/2019] [Accepted: 10/22/2019] [Indexed: 06/10/2023]
Abstract
We show how equilibrium binding curves of receptor homodimers can be expressed as rational polynomial functions of the equilibrium binding curves of the constituent monomers, without approximation and without assuming independence of receptor monomers. Using a distinguished spanning tree construction for reduced graph powers, the method properly accounts for thermodynamic constraints and allosteric interactions between receptor monomers (i.e. conformational coupling). The method is completely general; it begins with an arbitrary undirected graph representing the topology of a monomer state-transition diagram and ends with an algebraic expression for the equilibrium binding curve of a receptor oligomer composed of two or more identical and indistinguishable monomers. Several specific examples are analysed, including guanine nucleotide-binding protein-coupled receptor dimers and tetramers composed of multiple 'ternary complex' monomers.
Collapse
|
12
|
Shah UH, Toneatti R, Gaitonde SA, Shin JM, González-Maeso J. Site-Specific Incorporation of Genetically Encoded Photo-Crosslinkers Locates the Heteromeric Interface of a GPCR Complex in Living Cells. Cell Chem Biol 2020; 27:1308-1317.e4. [PMID: 32726588 DOI: 10.1016/j.chembiol.2020.07.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 05/04/2020] [Accepted: 07/08/2020] [Indexed: 01/02/2023]
Abstract
G protein-coupled receptors (GPCRs) are critical mediators of cell signaling. Although capable of activating G proteins in a monomeric form, numerous studies reveal a possible association of class A GPCRs into dimers/oligomers. The relative location of individual protomers within these GPCR complexes remains a topic of intense debate. We previously reported that class A serotonin 5-HT2A receptor (5-HT2AR) and class C metabotropic glutamate 2 receptor (mGluR2) are able to form a GPCR heterocomplex. By introducing the photoactivatable unnatural amino acid p-azido-L-phenylalanine (azF) at selected individual positions along the transmembrane (TM) segments of mGluR2, we delineate the residues that physically interact at the heteromeric interface of the 5-HT2AR-mGluR2 complex. We show that 5-HT2AR crosslinked with azF incorporated at the intracellular end of mGluR2's TM4, while no crosslinking was observed at other positions along TM1 and TM4. Together, these findings provide important insights into the structural arrangement of the 5-HT2AR-mGluR2 complex.
Collapse
Affiliation(s)
- Urjita H Shah
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA
| | - Rudy Toneatti
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA
| | - Supriya A Gaitonde
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA
| | - Jong M Shin
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA
| | - Javier González-Maeso
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA.
| |
Collapse
|
13
|
Sierra S, Lippold KM, Stevens DL, Poklis JL, Dewey WL, González-Maeso J. Adjunctive effect of the serotonin 5-HT 2C receptor agonist lorcaserin on opioid-induced antinociception in mice. Neuropharmacology 2020; 167:107949. [PMID: 31987863 DOI: 10.1016/j.neuropharm.2020.107949] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 12/11/2019] [Accepted: 01/08/2020] [Indexed: 12/25/2022]
Abstract
Opioid-sparing adjuncts are treatments that aim to reduce the overall dose of opioids needed to achieve analgesia, hence decreasing the burden of side effects through alternative mechanisms of action. Lorcaserin is a serotonin 5-HT2C receptor (5-HT2CR) agonist that has recently been reported to reduce abuse-related effects of the opioid analgesic oxycodone. The goal of our studies was to evaluate the effects of adjunctive lorcaserin on opioid-induced analgesic-like behavior using the tail-flick reflex (TFR) test as a mouse model of acute thermal nociception. We show that whereas subcutaneous (s.c.) administration of lorcaserin alone was inactive on the TFR test, adjunctive lorcaserin (s.c.) significantly increased the potency of oxycodone as an antinociceptive drug. This effect was prevented by the 5-HT2CR antagonist SB242084. A similar lorcaserin (s.c.)-induced adjunctive phenotype was observed upon administration of the opioid analgesics morphine and fentanyl. Remarkably, we also show that, opposite to the effects observed via s.c. administration, intrathecal (i.t.) administration of lorcaserin alone induced antinociceptive TFR behavior, an effect that was not prevented by the opioid receptor antagonist naloxone. This route of administration (i.t.) also led to a significant augmentation of oxycodone-induced antinociception. Lorcaserin (s.c.) did not alter the brain or blood concentrations of oxycodone, which suggests that its adjunctive effects on opioid-induced antinociception do not depend upon changes in opioid metabolism. Together, these data indicate that lorcaserin-mediated activation of the 5-HT2CR may represent a new pharmacological approach to augment opioid-induced antinociception. This article is part of the special issue entitled 'Serotonin Research: Crossing Scales and Boundaries'.
Collapse
Affiliation(s)
- Salvador Sierra
- Department of Physiology & Biophysics Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
| | - Kumiko M Lippold
- Department of Pharmacology & Toxicology Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
| | - David L Stevens
- Department of Pharmacology & Toxicology Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
| | - Justin L Poklis
- Department of Pharmacology & Toxicology Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
| | - William L Dewey
- Department of Pharmacology & Toxicology Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
| | - Javier González-Maeso
- Department of Physiology & Biophysics Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA.
| |
Collapse
|
14
|
Newman AH, Battiti FO, Bonifazi A. 2016 Philip S. Portoghese Medicinal Chemistry Lectureship: Designing Bivalent or Bitopic Molecules for G-Protein Coupled Receptors. The Whole Is Greater Than the Sum of Its Parts. J Med Chem 2019; 63:1779-1797. [PMID: 31499001 DOI: 10.1021/acs.jmedchem.9b01105] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The genesis of designing bivalent or bitopic molecules that engender unique pharmacological properties began with Portoghese's work directed toward opioid receptors, in the early 1980s. This strategy has evolved as an attractive way to engineer highly selective compounds for targeted G-protein coupled receptors (GPCRs) with optimized efficacies and/or signaling bias. The emergence of X-ray crystal structures of many GPCRs and the identification of both orthosteric and allosteric binding sites have provided further guidance to ligand drug design that includes a primary pharmacophore (PP), a secondary pharmacophore (SP), and a linker between them. It is critical to note the synergistic relationship among all three of these components as they contribute to the overall interaction of these molecules with their receptor proteins and that strategically designed combinations have and will continue to provide the GPCR molecular tools of the future.
Collapse
Affiliation(s)
- Amy Hauck Newman
- Medicinal Chemistry Section, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse-Intramural Research Program, National Institutes of Health, 333 Cassell Drive, Baltimore, Maryland 21224, United States
| | - Francisco O Battiti
- Medicinal Chemistry Section, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse-Intramural Research Program, National Institutes of Health, 333 Cassell Drive, Baltimore, Maryland 21224, United States
| | - Alessandro Bonifazi
- Medicinal Chemistry Section, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse-Intramural Research Program, National Institutes of Health, 333 Cassell Drive, Baltimore, Maryland 21224, United States
| |
Collapse
|
15
|
Rasineni K, Kubik JL, Casey CA, Kharbanda KK. Inhibition of Ghrelin Activity by Receptor Antagonist [d-Lys-3] GHRP-6 Attenuates Alcohol-Induced Hepatic Steatosis by Regulating Hepatic Lipid Metabolism. Biomolecules 2019; 9:biom9100517. [PMID: 31546643 PMCID: PMC6843513 DOI: 10.3390/biom9100517] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 09/18/2019] [Accepted: 09/19/2019] [Indexed: 01/13/2023] Open
Abstract
Alcoholic steatosis, characterized by an accumulation of triglycerides in hepatocytes, is one of the earliest pathological changes in the progression of alcoholic liver disease. In our previous study, we showed that alcohol-induced increase in serum ghrelin levels impair insulin secretion from pancreatic β-cells. The consequent reduction in the circulating insulin levels promote adipose-derived fatty acid mobilization to ultimately contribute to hepatic steatosis. In this study, we determined whether inhibition of ghrelin activity in chronic alcohol-fed rats could improve hepatic lipid homeostasis at the pancreas-adipose-liver axis. Adult Wistar rats were fed Lieber-DeCarli control or an ethanol liquid diet for 7 weeks. At 6 weeks, a subset of rats in each group were injected with either saline or ghrelin receptor antagonist, [d-Lys-3] GHRP-6 (DLys; 9 mg/kg body weight) for 5 days and all rats were sacrificed 2 days later. DLys treatment of ethanol rats improved pancreatic insulin secretion, normalized serum insulin levels, and the adipose lipid metabolism, as evidenced by the decreased serum free fatty acids (FFA). DLys treatment of ethanol rats also significantly decreased the circulating FFA uptake, de novo hepatic fatty acid synthesis ultimately attenuating alcoholic steatosis. To summarize, inhibition of ghrelin activity reduced alcoholic steatosis by improving insulin secretion, normalizing serum insulin levels, inhibiting adipose lipolysis, and preventing fatty acid uptake and synthesis in the liver. Our studies provided new insights on the important role of ghrelin in modulating the pancreas-adipose-liver, and promoting adipocyte lipolysis and hepatic steatosis. The findings offer a therapeutic approach of not only preventing alcoholic liver injury but also treating it.
Collapse
Affiliation(s)
- Karuna Rasineni
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA.
- Research Service, Veterans' Affairs Nebraska-Western Iowa Health Care System, Omaha, NE 68105, USA.
| | - Jacy L Kubik
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA.
- Research Service, Veterans' Affairs Nebraska-Western Iowa Health Care System, Omaha, NE 68105, USA.
| | - Carol A Casey
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA.
- Research Service, Veterans' Affairs Nebraska-Western Iowa Health Care System, Omaha, NE 68105, USA.
| | - Kusum K Kharbanda
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA.
- Research Service, Veterans' Affairs Nebraska-Western Iowa Health Care System, Omaha, NE 68105, USA.
| |
Collapse
|
16
|
Casadó-Anguera V, Cortés A, Casadó V, Moreno E. Targeting the receptor-based interactome of the dopamine D1 receptor: looking for heteromer-selective drugs. Expert Opin Drug Discov 2019; 14:1297-1312. [DOI: 10.1080/17460441.2019.1664469] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Verònica Casadó-Anguera
- Laboratory of Molecular Neurobiology, Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, University of Barcelona, (IBUB), Barcelona, Spain
- Institute of Biomedicine of the University of Barcelona (IBUB), Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Antoni Cortés
- Laboratory of Molecular Neurobiology, Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, University of Barcelona, (IBUB), Barcelona, Spain
- Institute of Biomedicine of the University of Barcelona (IBUB), Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Vicent Casadó
- Laboratory of Molecular Neurobiology, Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, University of Barcelona, (IBUB), Barcelona, Spain
- Institute of Biomedicine of the University of Barcelona (IBUB), Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Estefanía Moreno
- Laboratory of Molecular Neurobiology, Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, University of Barcelona, (IBUB), Barcelona, Spain
- Institute of Biomedicine of the University of Barcelona (IBUB), Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| |
Collapse
|
17
|
Rasineni K, Casey CA, Kharbanda KK. Reply to "Letter to Editor: Chronic alcohol exposure alters circulating insulin and ghrelin levels in hepatic steatosis: a translational research perspective". Am J Physiol Gastrointest Liver Physiol 2019; 317:G361-G362. [PMID: 31461305 PMCID: PMC6774088 DOI: 10.1152/ajpgi.00143.2019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 06/03/2019] [Indexed: 01/31/2023]
Affiliation(s)
- Karuna Rasineni
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Nebraska
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, Nebraska
| | - Carol A Casey
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Nebraska
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, Nebraska
| | - Kusum K Kharbanda
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Nebraska
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, Nebraska
| |
Collapse
|
18
|
Srinivasan S, Guixà-González R, Cordomí A, Garriga P. Ligand Binding Mechanisms in Human Cone Visual Pigments. Trends Biochem Sci 2019; 44:629-639. [PMID: 30853245 DOI: 10.1016/j.tibs.2019.02.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 02/04/2019] [Accepted: 02/07/2019] [Indexed: 12/13/2022]
Abstract
Vertebrate vision starts with light absorption by visual pigments in rod and cone photoreceptor cells of the retina. Rhodopsin, in rod cells, responds to dim light, whereas three types of cone opsins (red, green, and blue) function under bright light and mediate color vision. Cone opsins regenerate with retinal much faster than rhodopsin, but the molecular mechanism of regeneration is still unclear. Recent advances in the area pinpoint transient intermediate opsin conformations, and a possible secondary retinal-binding site, as determinant factors for regeneration. In this Review, we compile previous and recent findings to discuss possible mechanisms of ligand entry in cone opsins, involving a secondary binding site, which may have relevant functional and evolutionary implications.
Collapse
Affiliation(s)
- Sundaramoorthy Srinivasan
- Grup de Biotecnologia Molecular i Industrial, Centre de Biotecnologia Molecular, Departament d'Enginyeria Química, Universitat Politècnica de Catalunya-Barcelona Tech, Rambla de Sant Nebridi 22, 08222 Terrassa, Spain
| | - Ramon Guixà-González
- Laboratori de Medicina Computational, Universitat Autonòma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Arnau Cordomí
- Laboratori de Medicina Computational, Universitat Autonòma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Pere Garriga
- Grup de Biotecnologia Molecular i Industrial, Centre de Biotecnologia Molecular, Departament d'Enginyeria Química, Universitat Politècnica de Catalunya-Barcelona Tech, Rambla de Sant Nebridi 22, 08222 Terrassa, Spain.
| |
Collapse
|
19
|
Kaczor AA, Bartuzi D, Stępniewski TM, Matosiuk D, Selent J. Protein-Protein Docking in Drug Design and Discovery. Methods Mol Biol 2019; 1762:285-305. [PMID: 29594778 DOI: 10.1007/978-1-4939-7756-7_15] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Protein-protein interactions (PPIs) are responsible for a number of key physiological processes in the living cells and underlie the pathomechanism of many diseases. Nowadays, along with the concept of so-called "hot spots" in protein-protein interactions, which are well-defined interface regions responsible for most of the binding energy, these interfaces can be targeted with modulators. In order to apply structure-based design techniques to design PPIs modulators, a three-dimensional structure of protein complex has to be available. In this context in silico approaches, in particular protein-protein docking, are a valuable complement to experimental methods for elucidating 3D structure of protein complexes. Protein-protein docking is easy to use and does not require significant computer resources and time (in contrast to molecular dynamics) and it results in 3D structure of a protein complex (in contrast to sequence-based methods of predicting binding interfaces). However, protein-protein docking cannot address all the aspects of protein dynamics, in particular the global conformational changes during protein complex formation. In spite of this fact, protein-protein docking is widely used to model complexes of water-soluble proteins and less commonly to predict structures of transmembrane protein assemblies, including dimers and oligomers of G protein-coupled receptors (GPCRs). In this chapter we review the principles of protein-protein docking, available algorithms and software and discuss the recent examples, benefits, and drawbacks of protein-protein docking application to water-soluble proteins, membrane anchoring and transmembrane proteins, including GPCRs.
Collapse
Affiliation(s)
- Agnieszka A Kaczor
- Department of Synthesis and Chemical Technology of Pharmaceutical Substances with Computer Modelling Lab, Medical University of Lublin, Lublin, Poland. .,School of Pharmacy, University of Eastern Finland, Kuopio, Finland.
| | - Damian Bartuzi
- Department of Synthesis and Chemical Technology of Pharmaceutical Substances with Computer Modelling Lab, Medical University of Lublin, Lublin, Poland
| | - Tomasz Maciej Stępniewski
- GPCR Drug Discovery Group, Research Programme on Biomedical Informatics (GRIB), Universitat Pompeu Fabra (UPF)-Hospital del Mar Medical Research Institute (IMIM), Parc de Recerca Biomèdica de Barcelona (PRBB), Barcelona, Spain
| | - Dariusz Matosiuk
- Department of Synthesis and Chemical Technology of Pharmaceutical Substances with Computer Modelling Lab, Medical University of Lublin, Lublin, Poland
| | - Jana Selent
- GPCR Drug Discovery Group, Research Programme on Biomedical Informatics (GRIB), Universitat Pompeu Fabra (UPF)-Hospital del Mar Medical Research Institute (IMIM), Parc de Recerca Biomèdica de Barcelona (PRBB), Barcelona, Spain
| |
Collapse
|
20
|
Koelle MR. Neurotransmitter signaling through heterotrimeric G proteins: insights from studies in C. elegans. WORMBOOK : THE ONLINE REVIEW OF C. ELEGANS BIOLOGY 2018; 2018:1-52. [PMID: 26937633 PMCID: PMC5010795 DOI: 10.1895/wormbook.1.75.2] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Neurotransmitters signal via G protein coupled receptors (GPCRs) to modulate activity of neurons and muscles. C. elegans has ∼150 G protein coupled neuropeptide receptor homologs and 28 additional GPCRs for small-molecule neurotransmitters. Genetic studies in C. elegans demonstrate that neurotransmitters diffuse far from their release sites to activate GPCRs on distant cells. Individual receptor types are expressed on limited numbers of cells and thus can provide very specific regulation of an individual neural circuit and behavior. G protein coupled neurotransmitter receptors signal principally via the three types of heterotrimeric G proteins defined by the G alpha subunits Gαo, Gαq, and Gαs. Each of these G alpha proteins is found in all neurons plus some muscles. Gαo and Gαq signaling inhibit and activate neurotransmitter release, respectively. Gαs signaling, like Gαq signaling, promotes neurotransmitter release. Many details of the signaling mechanisms downstream of Gαq and Gαs have been delineated and are consistent with those of their mammalian orthologs. The details of the signaling mechanism downstream of Gαo remain a mystery. Forward genetic screens in C. elegans have identified new molecular components of neural G protein signaling mechanisms, including Regulators of G protein Signaling (RGS proteins) that inhibit signaling, a new Gαq effector (the Trio RhoGEF domain), and the RIC-8 protein that is required for neuronal Gα signaling. A model is presented in which G proteins sum up the variety of neuromodulator signals that impinge on a neuron to calculate its appropriate output level.
Collapse
Affiliation(s)
- Michael R Koelle
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven CT 06520 USA
| |
Collapse
|
21
|
Role of mGlu2 in the 5-HT 2A receptor-dependent antipsychotic activity of clozapine in mice. Psychopharmacology (Berl) 2018; 235:3149-3165. [PMID: 30209534 PMCID: PMC6408231 DOI: 10.1007/s00213-018-5015-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 08/29/2018] [Indexed: 02/05/2023]
Abstract
BACKGROUND Serotonin 5-HT2A and metabotropic glutamate 2 (mGlu2) are neurotransmitter G protein-coupled receptors (GPCRs) involved in the signaling mechanisms underlying psychosis and schizophrenia treatment. Previous findings in mGlu2 knockout (KO) mice suggested that mGlu2 is necessary for head-twitch behavior, a rodent phenotype characteristic of hallucinogenic 5-HT2A receptor agonists. However, the role of mGlu2 in the behavioral effects induced by antipsychotic drugs remains poorly understood. Here, we tested antipsychotic-like behavioral phenotypes induced by the atypical antipsychotic clozapine in mGlu2-KO mice and wild-type control littermates. METHODS Locomotor activity was tested in mGlu2-KO mice and control littermates injected (i.p.) with clozapine (1.5 mg/kg) or vehicle followed by MK801 (0.5 mg/kg), PCP (7.5 mg/kg), amphetamine (6 mg/kg), scopolamine (2 mg/kg), or vehicle. Using a virally (HSV) mediated transgene expression approach, the role of frontal cortex mGlu2 in the modulation of MK801-induced locomotor activity by clozapine treatment was also evaluated. RESULTS The effect of clozapine on hyperlocomotor activity induced by the dissociative drugs MK801 and phencyclidine (PCP) was decreased in mGlu2-KO mice as compared to controls. Clozapine treatment, however, reduced hyperlocomotor activity induced by the stimulant drug amphetamine and the deliriant drug scopolamine in both wild-type and mGlu2-KO mice. Virally mediated over-expression of mGlu2 in the frontal cortex of mGlu2-KO mice rescued the ability of clozapine to reduce MK801-induced hyperlocomotion. CONCLUSION These findings further support the existence of a functionally relevant crosstalk between 5-HT2A and mGlu2 receptors in different preclinical models of antipsychotic activity.
Collapse
|
22
|
Formosa-Dague C, Castelain M, Martin-Yken H, Dunker K, Dague E, Sletmoen M. The Role of Glycans in Bacterial Adhesion to Mucosal Surfaces: How Can Single-Molecule Techniques Advance Our Understanding? Microorganisms 2018; 6:E39. [PMID: 29734645 PMCID: PMC6027152 DOI: 10.3390/microorganisms6020039] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 04/24/2018] [Accepted: 04/26/2018] [Indexed: 12/14/2022] Open
Abstract
Bacterial adhesion is currently the subject of increased interest from the research community, leading to fast progress in our understanding of this complex phenomenon. Resent research within this field has documented the important roles played by glycans for bacterial surface adhesion, either through interaction with lectins or with other glycans. In parallel with this increased interest for and understanding of bacterial adhesion, there has been a growth in the sophistication and use of sensitive force probes for single-molecule and single cell studies. In this review, we highlight how the sensitive force probes atomic force microscopy (AFM) and optical tweezers (OT) have contributed to clarifying the mechanisms underlying bacterial adhesion to glycosylated surfaces in general and mucosal surfaces in particular. We also describe research areas where these techniques have not yet been applied, but where their capabilities appear appropriate to advance our understanding.
Collapse
Affiliation(s)
| | - Mickaël Castelain
- LISBP, Université de Toulouse, CNRS, INRA, INSA, 31400 Toulouse, France.
| | - Hélène Martin-Yken
- LISBP, Université de Toulouse, CNRS, INRA, INSA, 31400 Toulouse, France.
| | - Karen Dunker
- Department of Biotechnology and Food Science, NTNU the Norwegian University of Science and Technology, NO-7491 Trondheim, Norway.
| | - Etienne Dague
- LAAS-CNRS, Université de Toulouse, CNRS, 31400 Toulouse, France.
| | - Marit Sletmoen
- Department of Biotechnology and Food Science, NTNU the Norwegian University of Science and Technology, NO-7491 Trondheim, Norway.
| |
Collapse
|
23
|
Paroxetine and Low-dose Risperidone Induce Serotonin 5-HT1A and Dopamine D2 Receptor Heteromerization in the Mouse Prefrontal Cortex. Neuroscience 2018; 377:184-196. [DOI: 10.1016/j.neuroscience.2018.03.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 02/12/2018] [Accepted: 03/04/2018] [Indexed: 01/10/2023]
|
24
|
Song Y, Ge B, Lao J, Wang Z, Yang B, Wang X, He H, Li J, Huang F. Regulation of the Oligomeric Status of CCR3 with Binding Ligands Revealed by Single-Molecule Fluorescence Imaging. Biochemistry 2017; 57:852-860. [PMID: 28994588 DOI: 10.1021/acs.biochem.7b00676] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The relationship between the oligomeric status and functions of chemokine receptor CCR3 is still controversial. We use total internal reflection fluorescence microscopy at the single-molecule level to visualize the oligomeric status of CCR3 and its regulation of the membrane of stably transfected T-REx-293 cells. We find that the population of the dimers and oligomers of CCR3 can be modulated by the binding of ligands. Natural agonists can induce an increase in the level of dimers and oligomers at high concentrations, whereas antagonists do not have a significant influence on the oligomeric status. Moreover, monomeric CCR3 exhibits a stronger chemotactic response in the migration assay of stably transfected CCR3 cells. Together, these data support the notion that CCR3 exists as a mixture of monomers and dimers under nearly physiological conditions and the monomeric CCR3 receptor is the minimal functional unit in cellular signaling transduction. To the best of our knowledge, these results constitute the first report of the oligomeric status of CCR3 and its regulation.
Collapse
Affiliation(s)
- Yanzhuo Song
- State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology, China University of Petroleum (East China) , Qingdao 266580, P. R. China
| | - Baosheng Ge
- State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology, China University of Petroleum (East China) , Qingdao 266580, P. R. China
| | - Jun Lao
- State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology, China University of Petroleum (East China) , Qingdao 266580, P. R. China
| | - Zhencai Wang
- State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology, China University of Petroleum (East China) , Qingdao 266580, P. R. China
| | - Bin Yang
- State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology, China University of Petroleum (East China) , Qingdao 266580, P. R. China
| | - Xiaojuan Wang
- State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology, China University of Petroleum (East China) , Qingdao 266580, P. R. China
| | - Hua He
- State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology, China University of Petroleum (East China) , Qingdao 266580, P. R. China
| | - Jiqiang Li
- State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology, China University of Petroleum (East China) , Qingdao 266580, P. R. China
| | - Fang Huang
- State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology, China University of Petroleum (East China) , Qingdao 266580, P. R. China
| |
Collapse
|
25
|
Cevheroğlu O, Becker JM, Son ÇD. GPCR-Gα protein precoupling: Interaction between Ste2p, a yeast GPCR, and Gpa1p, its Gα protein, is formed before ligand binding via the Ste2p C-terminal domain and the Gpa1p N-terminal domain. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:2435-2446. [PMID: 28958779 DOI: 10.1016/j.bbamem.2017.09.022] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 09/20/2017] [Accepted: 09/22/2017] [Indexed: 01/19/2023]
Abstract
G protein coupled receptors bind ligands that initiate intracellular signaling cascades via heterotrimeric G proteins. In this study, involvement of the N-terminal residues of yeast G-alpha (Gpa1p) with the C-terminal residues of a full-length or C-terminally truncated Ste2p were investigated using bioluminescence resonance energy transfer (BRET), a non-radiative energy transfer phenomenon where protein-protein interactions can be quantified between a donor bioluminescent molecule and a suitable acceptor fluorophore. Constitutive and position-dependent BRET signal was observed in the absence of agonist (α-factor). Upon the activation of the receptors with α-factor, no significant change in BRET signal was observed. The location of Ste2p-Gpa1p heterodimer was investigated using confocal fluorescence microscopy and bimolecular fluorescence complementation (BiFC) assay, a technique where two non-fluorescent fragments of a fluorescent protein reassemble in vivo to restore fluorescence property thereby directly reporting a protein-protein interaction. BiFC experiments resulted in a dimerization signal intracellularly during biosynthesis on the endoplasmic reticulum (ER) and on the plasma membrane (PM). The constitutive BRET and BiFC signals observed on ER between Ste2p and Gpa1p in their quiescent and activated states are indicative of pre-coupling between these two proteins. This study is the first to show that the extreme N-terminus of yeast G protein alpha subunit is in close proximity to its receptor. The data suggests a pre-coupled heterodimer prior to receptor activation. The images presented in this study are the first direct in vivo evidence showing the localization of receptor - G protein heterodimers during biosynthesis and before reaching the plasma membrane.
Collapse
Affiliation(s)
- Orkun Cevheroğlu
- Department of Microbiology, University of Tennessee, Knoxville, TN 37996-0845, United States; Department of Biological Sciences, Middle East Technical University, Universiteler Mah. Dumlupinar Blv. No: 1, Çankaya, Ankara, 06800, Turkey
| | - Jeffrey M Becker
- Department of Microbiology, University of Tennessee, Knoxville, TN 37996-0845, United States
| | - Çağdaş D Son
- Department of Biological Sciences, Middle East Technical University, Universiteler Mah. Dumlupinar Blv. No: 1, Çankaya, Ankara, 06800, Turkey.
| |
Collapse
|
26
|
Rodrigues RS, Ribeiro FF, Ferreira F, Vaz SH, Sebastião AM, Xapelli S. Interaction between Cannabinoid Type 1 and Type 2 Receptors in the Modulation of Subventricular Zone and Dentate Gyrus Neurogenesis. Front Pharmacol 2017; 8:516. [PMID: 28848435 PMCID: PMC5554396 DOI: 10.3389/fphar.2017.00516] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 07/24/2017] [Indexed: 01/13/2023] Open
Abstract
Neurogenesis in the adult mammalian brain occurs mainly in two neurogenic niches, the subventricular zone (SVZ) and the subgranular zone (SGZ) of the dentate gyrus (DG). Cannabinoid type 1 and 2 receptors (CB1R and CB2R) have been shown to differently modulate neurogenesis. However, low attention has been given to the interaction between CB1R and CB2R in modulating postnatal neurogenesis (proliferation, neuronal differentiation and maturation). We focused on a putative crosstalk between CB1R and CB2R to modulate neurogenesis and cultured SVZ and DG stem/progenitor cells from early postnatal (P1-3) Sprague-Dawley rats. Data showed that the non-selective cannabinoid receptor agonist WIN55,212-2 promotes DG cell proliferation (measured by BrdU staining), an effect blocked by either CB1R or CB2R selective antagonists. Experiments with selective agonists showed that facilitation of DG cell proliferation requires co-activation of both CB1R and CB2R. Cell proliferation in the SVZ was not affected by the non-selective receptor agonist, but it was enhanced by CB1R selective activation. However, either CB1R or CB2R selective antagonists abolished the effect of the CB1R agonist in SVZ cell proliferation. Neuronal differentiation (measured by immunocytochemistry against neuronal markers of different stages and calcium imaging) was facilitated by WIN55,212-2 at both SVZ and DG. This effect was mimicked by either CB1R or CB2R selective agonists and blocked by either CB1R or CB2R selective antagonists, cross-antagonism being evident. In summary, our findings indicate a tight interaction between CB1R and CB2R to modulate neurogenesis in the two major neurogenic niches, thus contributing to further unraveling the mechanisms behind the action of endocannabinoids in the brain.
Collapse
Affiliation(s)
- Rui S Rodrigues
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de LisboaLisboa, Portugal.,Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de LisboaLisboa, Portugal
| | - Filipa F Ribeiro
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de LisboaLisboa, Portugal.,Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de LisboaLisboa, Portugal
| | - Filipa Ferreira
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de LisboaLisboa, Portugal.,Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de LisboaLisboa, Portugal
| | - Sandra H Vaz
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de LisboaLisboa, Portugal.,Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de LisboaLisboa, Portugal
| | - Ana M Sebastião
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de LisboaLisboa, Portugal.,Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de LisboaLisboa, Portugal
| | - Sara Xapelli
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de LisboaLisboa, Portugal.,Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de LisboaLisboa, Portugal
| |
Collapse
|
27
|
|
28
|
Fribourg M, Logothetis DE, González-Maeso J, Sealfon SC, Galocha-Iragüen B, Las-Heras Andrés F, Brezina V. Elucidation of molecular kinetic schemes from macroscopic traces using system identification. PLoS Comput Biol 2017; 13:e1005376. [PMID: 28192423 PMCID: PMC5330533 DOI: 10.1371/journal.pcbi.1005376] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 02/28/2017] [Accepted: 01/21/2017] [Indexed: 12/28/2022] Open
Abstract
Overall cellular responses to biologically-relevant stimuli are mediated by networks of simpler lower-level processes. Although information about some of these processes can now be obtained by visualizing and recording events at the molecular level, this is still possible only in especially favorable cases. Therefore the development of methods to extract the dynamics and relationships between the different lower-level (microscopic) processes from the overall (macroscopic) response remains a crucial challenge in the understanding of many aspects of physiology. Here we have devised a hybrid computational-analytical method to accomplish this task, the SYStems-based MOLecular kinetic scheme Extractor (SYSMOLE). SYSMOLE utilizes system-identification input-output analysis to obtain a transfer function between the stimulus and the overall cellular response in the Laplace-transformed domain. It then derives a Markov-chain state molecular kinetic scheme uniquely associated with the transfer function by means of a classification procedure and an analytical step that imposes general biological constraints. We first tested SYSMOLE with synthetic data and evaluated its performance in terms of its rate of convergence to the correct molecular kinetic scheme and its robustness to noise. We then examined its performance on real experimental traces by analyzing macroscopic calcium-current traces elicited by membrane depolarization. SYSMOLE derived the correct, previously known molecular kinetic scheme describing the activation and inactivation of the underlying calcium channels and correctly identified the accepted mechanism of action of nifedipine, a calcium-channel blocker clinically used in patients with cardiovascular disease. Finally, we applied SYSMOLE to study the pharmacology of a new class of glutamate antipsychotic drugs and their crosstalk mechanism through a heteromeric complex of G protein-coupled receptors. Our results indicate that our methodology can be successfully applied to accurately derive molecular kinetic schemes from experimental macroscopic traces, and we anticipate that it may be useful in the study of a wide variety of biological systems. Unraveling the lower-level (microscopic) processes underlying the overall (macroscopic) cell response to a given stimulus is a challenging problem in cell physiology. This has been a classic problem in biophysics, where the ability to record the activity of single ion channels that generate a macroscopic ion current has allowed a measure of direct access to the underlying microscopic processes. These classic studies have demonstrated that very different groupings of the microscopic processes can yield extremely similar macroscopic responses. Biologists in fields other than biophysics are frequently confronted with the same macroscopic-to-microscopic problem, usually, however, without any direct access to the microscopic processes. Thus, the development of computational methods to deduce from the available macroscopic measurements the nature of the underlying microscopic processes can be expected to substantially advance the study of many areas of cell physiology. Toward that aim, here we have derived and tested a hybrid computational-analytical method to extract information about the microscopic processes that is hidden in macroscopic experimental traces. Our method is independent of the particular system under study, and thus can be applied to new as well as previously-recorded macroscopic traces obtained in a wide variety of biological systems.
Collapse
Affiliation(s)
- Miguel Fribourg
- Department of Neurology and Center for Translational Systems Biology, Icahn School Of Medicine at Mount Sinai, New York, New York, United States of America
- * E-mail:
| | - Diomedes E. Logothetis
- Department of Pharmaceutical Sciences, Northeastern University, Boston, Massachusetts, United States of America
| | - Javier González-Maeso
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, Virginia, United States of America
| | - Stuart C. Sealfon
- Department of Neurology and Center for Translational Systems Biology, Icahn School Of Medicine at Mount Sinai, New York, New York, United States of America
| | - Belén Galocha-Iragüen
- Department of Signals Systems and Radiocommunications, Universidad Politécnica de Madrid, Madrid, Spain
| | | | - Vladimir Brezina
- Department of Neuroscience, Icahn School of Medicine, New York, New York, United States of America
| |
Collapse
|
29
|
Abstract
The neuropsychological effects of naturally occurring psychoactive chemicals have been recognized for millennia. Hallucinogens, which include naturally occurring chemicals such as mescaline and psilocybin, as well as synthetic compounds, such as lysergic acid diethylamide (LSD), induce profound alterations of human consciousness, emotion, and cognition. The discovery of the hallucinogenic effects of LSD and the observations that LSD and the endogenous ligand serotonin share chemical and pharmacological profiles led to the suggestion that biogenic amines like serotonin were involved in the psychosis of mental disorders such as schizophrenia. Although they bind other G protein-coupled receptor (GPCR) subtypes, studies indicate that several effects of hallucinogens involve agonist activity at the serotonin 5-HT2A receptor. In this chapter, we review recent advances in understanding hallucinogen drug action through characterization of structure, neuroanatomical location, and function of the 5-HT2A receptor.
Collapse
|
30
|
Gaitonde SA, González-Maeso J. Contribution of heteromerization to G protein-coupled receptor function. Curr Opin Pharmacol 2016; 32:23-31. [PMID: 27835800 DOI: 10.1016/j.coph.2016.10.006] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 10/22/2016] [Accepted: 10/24/2016] [Indexed: 12/22/2022]
Abstract
G protein-coupled receptors (GPCRs) are a remarkably multifaceted family of transmembrane proteins that exert a variety of physiological effects. Although family A GPCRs are able to operate as monomers, there is increasing evidence that heteromerization represents a fundamental aspect of receptor function, trafficking and pharmacology. Most recently, it has been suggested that GPCR heteromers may play a crucial role as new molecular targets of heteromer-selective and bivalent ligands. The current review summarizes key recent developments in these topics.
Collapse
Affiliation(s)
- Supriya A Gaitonde
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, United States
| | - Javier González-Maeso
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, United States.
| |
Collapse
|
31
|
Ross CL. The use of electric, magnetic, and electromagnetic field for directed cell migration and adhesion in regenerative medicine. Biotechnol Prog 2016; 33:5-16. [PMID: 27797153 DOI: 10.1002/btpr.2371] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 10/10/2016] [Indexed: 01/01/2023]
Abstract
Directed cell migration and adhesion is essential to embryonic development, tissue formation and wound healing. For decades it has been reported that electric field (EF), magnetic field (MF) and electromagnetic field (EMF) can play important roles in determining cell differentiation, migration, adhesion, and evenwound healing. Combinations of these techniques have revealed new and exciting explanations for how cells move and adhere to surfaces; how the migration of multiple cells are coordinated and regulated; how cellsinteract with neighboring cells, and also to changes in their microenvironment. In some cells, speed and direction are voltage dependent. Data suggests that the use of EF, MF and EMF could advance techniques in regenerative medicine, tissue engineering and wound healing. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 33:5-16, 2017.
Collapse
Affiliation(s)
- Christina L Ross
- The Wake Forest Institute for Regenerative Medicine, Wake Forest Center for Integrative Medicine, Medical Center Blvd, Winston-Salem, NC
| |
Collapse
|
32
|
Lu M, Wu B. Structural studies of G protein-coupled receptors. IUBMB Life 2016; 68:894-903. [PMID: 27766738 DOI: 10.1002/iub.1578] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 10/08/2016] [Indexed: 11/08/2022]
Abstract
G protein-coupled receptors (GPCRs) comprise the largest membrane protein family. These receptors sense a variety of signaling molecules, activate multiple intracellular signal pathways, and act as the targets of over 40% of marketed drugs. Recent progress on GPCR structural studies provides invaluable insights into the structure-function relationship of the GPCR superfamily, deepening our understanding about the molecular mechanisms of GPCR signal transduction. Here, we review recent breakthroughs on GPCR structure determination and the structural features of GPCRs, and take the structures of chemokine receptor CCR5 and purinergic receptors P2Y1 R and P2Y12 R as examples to discuss the importance of GPCR structures on functional studies and drug discovery. In addition, we discuss the prospect of GPCR structure-based drug discovery. © 2016 IUBMB Life, 68(11):894-903, 2016.
Collapse
Affiliation(s)
- Mengjie Lu
- CAS Key laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Beili Wu
- CAS Key laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China. .,School of Life Science and Technology, ShanghaiTech University, Pudong, Shanghai, China.
| |
Collapse
|
33
|
Hopkins MM, Liu Z, Meier KE. Positive and Negative Cross-Talk between Lysophosphatidic Acid Receptor 1, Free Fatty Acid Receptor 4, and Epidermal Growth Factor Receptor in Human Prostate Cancer Cells. J Pharmacol Exp Ther 2016; 359:124-33. [PMID: 27474750 PMCID: PMC5034703 DOI: 10.1124/jpet.116.233379] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 07/22/2016] [Indexed: 12/22/2022] Open
Abstract
Lysophosphatidic acid (LPA) is a lipid mediator that mediates cellular effects via G protein-coupled receptors (GPCRs). Epidermal growth factor (EGF) is a peptide that acts via a receptor tyrosine kinase. LPA and EGF both induce proliferation of prostate cancer cells and can transactivate each other's receptors. The LPA receptor LPA1 is particularly important for LPA response in human prostate cancer cells. Previous work in our laboratory has demonstrated that free fatty acid 4 (FFA4), a GPCR activated by ω-3 fatty acids, inhibits responses to both LPA and EGF in these cells. One potential mechanism for the inhibition involves negative interactions between FFA4 and LPA1, thereby suppressing responses to EGF that require LPA1 In the current study, we examined the role of LPA1 in mediating EGF and FFA4 agonist responses in two human prostate cancer cell lines, DU145 and PC-3. The results show that an LPA1-selective antagonist inhibits proliferation and migration to both LPA and EGF. Knockdown of LPA1 expression, using silencing RNA, blocks responses to LPA and significantly inhibits responses to EGF. The partial response to EGF that is observed after LPA1 knockdown is not inhibited by FFA4 agonists. Finally, the role of arrestin-3, a GPCR-binding protein that mediates many actions of activated GPCRs, was tested. Knockdown of arrestin-3 completely inhibits responses to both LPA and EGF in prostate cancer cells. Taken together, these results suggest that LPA1 plays a critical role in EGF responses and that FFA4 agonists inhibit proliferation by suppressing positive cross-talk between LPA1 and the EGF receptor.
Collapse
Affiliation(s)
- Mandi M Hopkins
- Department of Pharmaceutical Sciences, College of Pharmacy, Washington State University, Spokane, Washington
| | - Ze Liu
- Department of Pharmaceutical Sciences, College of Pharmacy, Washington State University, Spokane, Washington
| | - Kathryn E Meier
- Department of Pharmaceutical Sciences, College of Pharmacy, Washington State University, Spokane, Washington
| |
Collapse
|
34
|
Holloway T, Moreno JL, González-Maeso J. HSV-Mediated Transgene Expression of Chimeric Constructs to Study Behavioral Function of GPCR Heteromers in Mice. J Vis Exp 2016. [PMID: 27501227 DOI: 10.3791/53717] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
The heteromeric receptor complex between 5-HT2A and mGlu2 has been implicated in some of the behavioral phenotypes in mouse models of psychosis(1,2). Consequently, investigation of structural details of the interaction between 5-HT2A and mGlu2 affecting schizophrenia-related behaviors represents a powerful translational tool. As previously shown, the head-twitch response (HTR) in mice is elicited by hallucinogenic drugs and this behavioral response is absent in 5-HT2A knockout (KO) mice(3,4). Additionally, by conditionally expressing the 5-HT2A receptor only in cortex, it was demonstrated that 5-HT2A receptor-dependent signaling pathways on cortical pyramidal neurons are sufficient to elicit head-twitch behavior in response to hallucinogenic drugs(3). Finally, it has been shown that the head-twitch behavioral response induced by the hallucinogens DOI and lysergic acid diethylamide (LSD) is significantly decreased in mGlu2-KO mice(5). These findings suggest that mGlu2 is at least in part necessary for the 5-HT2A receptor-dependent psychosis-like behavioral effects induced by LSD-like drugs. However, this does not provide evidence as to whether the 5-HT2A-mGlu2 receptor complex is necessary for this behavioral phenotype. To address this question, herpes simplex virus (HSV) constructs to express either mGlu2 or mGlu2ΔTM4N (mGlu2/mGlu3 chimeric construct that does not form the 5-HT2A-mGlu2 receptor complex) in the frontal cortex of mGlu2-KO mice were used to examine whether this GPCR heteromeric complex is needed for the behavioral effects induced by LSD-like drugs(6).
Collapse
Affiliation(s)
- Terrell Holloway
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai
| | - Jose L Moreno
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai
| | - Javier González-Maeso
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai; Department of Neurology, Icahn School of Medicine at Mount Sinai; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai; Department of Physiology and Biophysics, Virginia Commonwealth University Medical School;
| |
Collapse
|
35
|
Muguruza C, Meana JJ, Callado LF. Group II Metabotropic Glutamate Receptors as Targets for Novel Antipsychotic Drugs. Front Pharmacol 2016; 7:130. [PMID: 27242534 PMCID: PMC4873505 DOI: 10.3389/fphar.2016.00130] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 05/05/2016] [Indexed: 11/13/2022] Open
Abstract
Schizophrenia is a chronic psychiatric disorder which substantially impairs patients' quality of life. Despite the extensive research in this field, the pathophysiology and etiology of schizophrenia remain unknown. Different neurotransmitter systems and functional networks have been found to be affected in the brain of patients with schizophrenia. In this context, postmortem brain studies as well as genetic assays have suggested alterations in Group II metabotropic glutamate receptors (mGluRs) in schizophrenia. Despite many years of drug research, several needs in the treatment of schizophrenia have not been addressed sufficiently. In fact, only 5-10% of patients with schizophrenia successfully achieve a full recovery after treatment. In recent years mGluRs have turned up as novel targets for the design of new antipsychotic medications for schizophrenia. Concretely, Group II mGluRs are of particular interest due to their regulatory role in neurotransmission modulating glutamatergic activity in brain synapses. Preclinical studies have demonstrated that orthosteric Group II mGluR agonists exhibit antipsychotic-like properties in animal models of schizophrenia. However, when these compounds have been tested in human clinical studies with schizophrenic patients results have been inconclusive. Nevertheless, it has been recently suggested that this apparent lack of efficacy in schizophrenic patients may be related to previous exposure to atypical antipsychotics. Moreover, the role of the functional heterocomplex formed by 5-HT2A and mGlu2 receptors in the clinical response to Group II mGluR agonists is currently under study.
Collapse
Affiliation(s)
- Carolina Muguruza
- Department of Pharmacology, University of the Basque Country, UPV/EHULeioa, Spain
- Centro de Investigación Biomédica en Red de Salud MentalMadrid, Spain
| | - J. Javier Meana
- Department of Pharmacology, University of the Basque Country, UPV/EHULeioa, Spain
- Centro de Investigación Biomédica en Red de Salud MentalMadrid, Spain
| | - Luis F. Callado
- Department of Pharmacology, University of the Basque Country, UPV/EHULeioa, Spain
- Centro de Investigación Biomédica en Red de Salud MentalMadrid, Spain
| |
Collapse
|
36
|
Huang YH, Su YS, Chang CJ, Sun WH. Heteromerization of G2A and OGR1 enhances proton sensitivity and proton-induced calcium signals. J Recept Signal Transduct Res 2016; 36:633-644. [PMID: 27049592 DOI: 10.3109/10799893.2016.1155064] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Proton-sensing G-protein-coupled receptors (GPCRs; OGR1, GPR4, G2A, TDAG8), with full activation at pH 6.4 ∼ 6.8, are important to pH homeostasis, immune responses and acid-induced pain. Although G2A mediates the G13-Rho pathway in response to acid, whether G2A activates Gs, Gi or Gq proteins remains debated. In this study, we examined the response of this fluorescence protein-tagged OGR1 family to acid stimulation in HEK293T cells. G2A did not generate detectable intracellular calcium or cAMP signals or show apparent receptor redistribution with moderate acid (pH ≥ 6.0) stimulation but reduced cAMP accumulation under strong acid stimulation (pH ≤ 5.5). Surprisingly, coexpression of OGR1- and G2A-enhanced proton sensitivity and proton-induced calcium signals. This alteration is attributed to oligomerization of OGR1 and G2A. The oligomeric potential locates receptors at a specific site, which leads to enhanced proton-induced calcium signals through channels.
Collapse
Affiliation(s)
- Ya-Han Huang
- a Department of Life Sciences , National Central University , Jhongli , Taiwan and
| | - Yeu-Shiuan Su
- a Department of Life Sciences , National Central University , Jhongli , Taiwan and
| | - Chung-Jen Chang
- a Department of Life Sciences , National Central University , Jhongli , Taiwan and
| | - Wei-Hsin Sun
- a Department of Life Sciences , National Central University , Jhongli , Taiwan and.,b Center for Biotechnology and Biomedical Engineering, National Central University , Jhongli , Taiwan
| |
Collapse
|
37
|
|
38
|
Moreno JL, Miranda-Azpiazu P, García-Bea A, Younkin J, Cui M, Kozlenkov A, Ben-Ezra A, Voloudakis G, Fakira AK, Baki L, Ge Y, Georgakopoulos A, Morón JA, Milligan G, López-Giménez JF, Robakis NK, Logothetis DE, Meana JJ, González-Maeso J. Allosteric signaling through an mGlu2 and 5-HT2A heteromeric receptor complex and its potential contribution to schizophrenia. Sci Signal 2016; 9:ra5. [PMID: 26758213 DOI: 10.1126/scisignal.aab0467] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Heterotrimeric guanine nucleotide-binding protein (G protein)-coupled receptors (GPCRs) can form multiprotein complexes (heteromers), which can alter the pharmacology and functions of the constituent receptors. Previous findings demonstrated that the Gq/11-coupled serotonin 5-HT2A receptor and the Gi/o-coupled metabotropic glutamate 2 (mGlu2) receptor-GPCRs that are involved in signaling alterations associated with psychosis-assemble into a heteromeric complex in the mammalian brain. In single-cell experiments with various mutant versions of the mGlu2 receptor, we showed that stimulation of cells expressing mGlu2-5-HT2A heteromers with an mGlu2 agonist led to activation of Gq/11 proteins by the 5-HT2A receptors. For this crosstalk to occur, one of the mGlu2 subunits had to couple to Gi/o proteins, and we determined the relative location of the Gi/o-contacting subunit within the mGlu2 homodimer of the heteromeric complex. Additionally, mGlu2-dependent activation of Gq/11, but not Gi/o, was reduced in the frontal cortex of 5-HT2A knockout mice and was reduced in the frontal cortex of postmortem brains from schizophrenic patients. These findings offer structural insights into this important target in molecular psychiatry.
Collapse
Affiliation(s)
- José L Moreno
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA. Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Patricia Miranda-Azpiazu
- Department of Pharmacology, University of the Basque Country UPV/EHU, E-48940 Leioa, Bizkaia, Spain. Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), University of the Basque Country UPV/EHU, E-48940 Leioa, Bizkaia, Spain
| | - Aintzane García-Bea
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA. Department of Pharmacology, University of the Basque Country UPV/EHU, E-48940 Leioa, Bizkaia, Spain. Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), University of the Basque Country UPV/EHU, E-48940 Leioa, Bizkaia, Spain
| | - Jason Younkin
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA
| | - Meng Cui
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA
| | - Alexey Kozlenkov
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Ariel Ben-Ezra
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Georgios Voloudakis
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Amanda K Fakira
- Department of Anesthesiology, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
| | - Lia Baki
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA
| | - Yongchao Ge
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | | | - José A Morón
- Department of Anesthesiology, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
| | - Graeme Milligan
- Molecular Pharmacology Group, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, UK
| | - Juan F López-Giménez
- Molecular Pharmacology Group, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, UK. Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC-CSIC-UC), E-39011 Santander, Cantabria, Spain
| | - Nikolaos K Robakis
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA. Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA. Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Diomedes E Logothetis
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA
| | - J Javier Meana
- Department of Pharmacology, University of the Basque Country UPV/EHU, E-48940 Leioa, Bizkaia, Spain. Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), University of the Basque Country UPV/EHU, E-48940 Leioa, Bizkaia, Spain. BioCruces Health Research Institute, E-48903 Barakaldo, Bizkaia, Spain.
| | - Javier González-Maeso
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA. Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA. Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA. Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
| |
Collapse
|
39
|
Bourque M, Morissette M, Di Paolo T. Neuroprotection in Parkinsonian-treated mice via estrogen receptor α activation requires G protein-coupled estrogen receptor 1. Neuropharmacology 2015; 95:343-52. [DOI: 10.1016/j.neuropharm.2015.04.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Revised: 03/16/2015] [Accepted: 04/07/2015] [Indexed: 10/23/2022]
|
40
|
Low dosage of rimonabant leads to anxiolytic-like behavior via inhibiting expression levels and G-protein activity of kappa opioid receptors in a cannabinoid receptor independent manner. Neuropharmacology 2015; 89:298-307. [DOI: 10.1016/j.neuropharm.2014.10.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 09/19/2014] [Accepted: 10/04/2014] [Indexed: 12/15/2022]
|
41
|
Hattori M, Ozawa T. Bioluminescent tools for the analysis of G-protein-coupled receptor and arrestin interactions. RSC Adv 2015. [DOI: 10.1039/c4ra14979c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
New protein-based bioluminescent probes for monitoring GPCR interaction with β-arrestin are presented.
Collapse
Affiliation(s)
- Mitsuru Hattori
- Department of Chemistry
- School of Science
- The University of Tokyo
- Bunkyo-ku
- Japan
| | - Takeaki Ozawa
- Department of Chemistry
- School of Science
- The University of Tokyo
- Bunkyo-ku
- Japan
| |
Collapse
|
42
|
Edwards D, Huber T, Hussain S, Stone K, Kinnebrew M, Kaminker I, Matalon E, Sherwin M, Goldfarb D, Han S. Determining the Oligomeric Structure of Proteorhodopsin by Gd3+-Based Pulsed Dipolar Spectroscopy of Multiple Distances. Structure 2014; 22:1677-86. [DOI: 10.1016/j.str.2014.09.008] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Revised: 08/15/2014] [Accepted: 09/04/2014] [Indexed: 12/30/2022]
|
43
|
González-Maeso J. Family a GPCR heteromers in animal models. Front Pharmacol 2014; 5:226. [PMID: 25346690 PMCID: PMC4191056 DOI: 10.3389/fphar.2014.00226] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 09/21/2014] [Indexed: 11/30/2022] Open
Affiliation(s)
- Javier González-Maeso
- Departments of Psychiatry and Neurology, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai New York, NY, USA
| |
Collapse
|
44
|
Fujita W, Gomes I, Devi LA. Heteromers of μ-δ opioid receptors: new pharmacology and novel therapeutic possibilities. Br J Pharmacol 2014; 172:375-87. [PMID: 24571499 DOI: 10.1111/bph.12663] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Revised: 02/05/2014] [Accepted: 02/17/2014] [Indexed: 12/22/2022] Open
Abstract
UNLABELLED Several studies suggest that heteromerization between μ (MOP) and δ (DOP) opioid receptors modulates the signalling properties of the individual receptors. For example, whereas activation of MOP receptors by an agonist induces G protein-mediated signalling, the same agonist induces β-arrestin-mediated signalling in the context of the MOP-DOP receptor heteromer. Moreover, heteromer-mediated signalling is allosterically modulated by a combination of MOP and DOP receptor ligands. This has implications in analgesia given that morphine-induced antinociception can be potentiated by DOP receptor ligands. Recently reagents selectively targeting the MOP-DOP receptor heteromer such as bivalent ligands, antibodies or membrane permeable peptides have been generated; these reagents are enabling studies to elucidate the contribution of endogenously expressed heteromers to analgesia as well as to the development of side-effects associated with chronic opioid use. Recent advances in drug screening technology have led to the identification of a MOP-DOP receptor heteromer-biased agonist that activates both G protein-mediated and β-arrestin-mediated signalling. Moreover, this heteromer-biased agonist exhibits potent antinociceptive activity but with reduced side-effects, suggesting that ligands targeting the MOP-DOP receptor heteromer form a basis for the development of novel therapeutics for the treatment of pain. In this review, we summarize findings regarding the biological and functional characteristics of the MOP-DOP receptor heteromer and the in vitro and in vivo properties of heteromer-selective ligands. LINKED ARTICLES This article is part of a themed section on Opioids: New Pathways to Functional Selectivity. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-2.
Collapse
Affiliation(s)
- Wakako Fujita
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | | | | |
Collapse
|
45
|
Zádor F, Kocsis D, Borsodi A, Benyhe S. Micromolar concentrations of rimonabant directly inhibits delta opioid receptor specific ligand binding and agonist-induced G-protein activity. Neurochem Int 2014; 67:14-22. [PMID: 24508403 DOI: 10.1016/j.neuint.2013.12.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 11/26/2013] [Accepted: 12/17/2013] [Indexed: 12/16/2022]
Abstract
WHAT IS KNOWN There is a growing number of evidence showing, that the cannabinoid receptor 1 (CB1) antagonist rimonabant has many non-cannabimimetic actions, such as affecting the opioid system. The direct effect of rimonabant on opioid receptors has been studied so far mainly on μ-opioid receptors. However recently the δ-opioid receptor (DOR) receives much more attention as before, due to its potential therapeutic applications, such as nociception or treatment for psychiatric disorders. OBJECTIVES To investigate the direct effect of rimonabant on DOR specific ligand binding and on the DOR mediated G-protein activation. RESULTS Micromolar concentrations of rimonabant directly inhibited the DOR specific agonist binding in radioligand competition binding experiments using Chinese hamster ovary cells stably transfected with mouse DOR (CHO-mDOR). However the inhibition occurred also in the subnanomolar range during DOR specific antagonist binding in similar experimental conditions. In functional [(35)S]GTPγS binding assays rimonabant significantly decreased the basal receptor activity in CHO-mDOR but also in parental CHO cell membranes. During DOR agonist stimulation, micromolar concentration of rimonabant attenuated the DOR G-protein activation and the potency of the activator ligand in [(35)S]GTPγS binding assays performed in CHO-mDOR, in wild type and also in CB1/CB2 double knock-out mouse forebrain membranes. Yet again this inhibitory action was DOR specific, since it did not occur during other specific GPCR agonist mediated G-protein activation. CONCLUSION Rimonabant directly inhibited DOR function in the micromolar concentrations. The inhibitory actions indicate an antagonistic behavior towards DOR which was established by the followings: (i) rimonabant inhibited DOR antagonist binding more effectively than agonist binding, (ii) the inverse agonistic, agonistic effect of the compound can be excluded, and (iii) additionally according to previous findings the allosteric mechanism can also be foreclosed.
Collapse
MESH Headings
- Animals
- CHO Cells
- Cricetinae
- Cricetulus
- GTP-Binding Proteins/metabolism
- Guanosine 5'-O-(3-Thiotriphosphate)/metabolism
- Ligands
- Mice
- Piperidines/pharmacology
- Protein Binding
- Pyrazoles/pharmacology
- Receptor, Cannabinoid, CB1/genetics
- Receptor, Cannabinoid, CB2/genetics
- Receptors, Opioid, delta/agonists
- Receptors, Opioid, delta/antagonists & inhibitors
- Receptors, Opioid, delta/metabolism
- Rimonabant
Collapse
Affiliation(s)
- Ferenc Zádor
- Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, H-6726 Szeged, Hungary.
| | - Dóra Kocsis
- Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, H-6726 Szeged, Hungary
| | - Anna Borsodi
- Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, H-6726 Szeged, Hungary
| | - Sándor Benyhe
- Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, H-6726 Szeged, Hungary
| |
Collapse
|
46
|
Jaeger WC, Armstrong SP, Hill SJ, Pfleger KDG. Biophysical Detection of Diversity and Bias in GPCR Function. Front Endocrinol (Lausanne) 2014; 5:26. [PMID: 24634666 PMCID: PMC3943086 DOI: 10.3389/fendo.2014.00026] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Accepted: 02/19/2014] [Indexed: 12/27/2022] Open
Abstract
Guanine nucleotide binding protein (G protein)-coupled receptors (GPCRs) function in complexes with a range of molecules and proteins including ligands, G proteins, arrestins, ubiquitin, and other receptors. Elements of these complexes may interact constitutively or dynamically, dependent upon factors such as ligand binding, phosphorylation, and dephosphorylation. They may also be allosterically modulated by other proteins in a manner that changes temporally and spatially within the cell. Elucidating how these complexes function has been greatly enhanced by biophysical technologies that are able to monitor proximity and/or binding, often in real time and in live cells. These include resonance energy transfer approaches such as bioluminescence resonance energy transfer (BRET) and fluorescence resonance energy transfer (FRET). Furthermore, the use of fluorescent ligands has enabled novel insights into allosteric interactions between GPCRs. Consequently, biophysical approaches are helping to unlock the amazing diversity and bias in G protein-coupled receptor signaling.
Collapse
Affiliation(s)
- Werner C. Jaeger
- Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, Perth, WA, Australia
| | - Stephen P. Armstrong
- Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, Perth, WA, Australia
| | - Stephen J. Hill
- Cell Signalling Research Group, School of Life Sciences, Queen’s Medical Centre, University of Nottingham Medical School, Nottingham, UK
| | - Kevin D. G. Pfleger
- Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, Perth, WA, Australia
- Dimerix Bioscience Pty Ltd, Perth, WA, Australia
- *Correspondence: Kevin D. G. Pfleger, Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, QEII Medical Centre, QQ Block, 6 Verdun Street, Nedlands, Perth, WA 6009, Australia e-mail:
| |
Collapse
|
47
|
Gomes I, Fujita W, Chandrakala MV, Devi LA. Disease-specific heteromerization of G-protein-coupled receptors that target drugs of abuse. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2013; 117:207-65. [PMID: 23663971 DOI: 10.1016/b978-0-12-386931-9.00009-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Drugs of abuse such as morphine or marijuana exert their effects through the activation of G-protein-coupled receptors (GPCRs), the opioid and cannabinoid receptors, respectively. Moreover, interactions between either of these receptors have been shown to be involved in the rewarding effects of drugs of abuse. Recent advances in the field, using a variety of approaches, have demonstrated that many GPCRs, including opioid, cannabinoid, and dopamine receptors, can form associations between different receptor subtypes or with other GPCRs to form heteromeric complexes. The formation of these complexes, in turn, leads to the modulation of the properties of individual protomers. The development of tools that can selectively disrupt GPCR heteromers as well as monoclonal antibodies that can selectively block signaling by specific heteromer pairs has indicated that heteromers involving opioid, cannabinoid, or dopamine receptors may play a role in various disease states. In this review, we describe evidence for opioid, cannabinoid, and dopamine receptor heteromerization and the potential role of GPCR heteromers in pathophysiological conditions.
Collapse
Affiliation(s)
- Ivone Gomes
- Department of Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine, New York, USA
| | | | | | | |
Collapse
|
48
|
Wilson B, Tavakoli H, DeCecchis D, Mahadev V. Synthetic Cannabinoids, Synthetic Cathinones, and Other Emerging Drugs of Abuse. Psychiatr Ann 2013. [DOI: 10.3928/00485713-20131206-08] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
|
49
|
Present and future approaches to screening of G-protein-coupled receptors. Future Med Chem 2013; 5:523-38. [PMID: 23573971 DOI: 10.4155/fmc.13.9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
As G-protein-coupled receptors (GPCRs) mediate a multitude of cellular signal transduction events, affecting more or less all human disease areas, it is, therefore, no surprise that they comprise the largest family of current drug targets. Screening of compounds interacting with GPCRs has developed during the past decade from receptor binding assays, to various functional determination of coupling to G-proteins, and, more recently, G-protein-independent signal transduction events. Additional opportunities have been presented in drug discovery through novel pharmacological properties obtained for receptor dimers and by identification of ligands for orphan GPCRs. Furthermore, high-throughput formats and automation has substantially facilitated and accelerated the screening process providing powerful tools in improving modern drug discovery.
Collapse
|
50
|
Schellekens H, Dinan TG, Cryan JF. Taking two to tango: a role for ghrelin receptor heterodimerization in stress and reward. Front Neurosci 2013; 7:148. [PMID: 24009547 PMCID: PMC3757321 DOI: 10.3389/fnins.2013.00148] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Accepted: 08/01/2013] [Indexed: 12/25/2022] Open
Abstract
The gut hormone, ghrelin, is the only known peripherally derived orexigenic signal. It activates its centrally expressed receptor, the growth hormone secretagogue receptor (GHS-R1a), to stimulate food intake. The ghrelin signaling system has recently been suggested to play a key role at the interface of homeostatic control of appetite and the hedonic aspects of food intake, as a critical role for ghrelin in dopaminergic mesolimbic circuits involved in reward signaling has emerged. Moreover, enhanced plasma ghrelin levels are associated with conditions of physiological stress, which may underline the drive to eat calorie-dense "comfort-foods" and signifies a role for ghrelin in stress-induced food reward behaviors. These complex and diverse functionalities of the ghrelinergic system are not yet fully elucidated and likely involve crosstalk with additional signaling systems. Interestingly, accumulating data over the last few years has shown the GHS-R1a receptor to dimerize with several additional G-protein coupled receptors (GPCRs) involved in appetite signaling and reward, including the GHS-R1b receptor, the melanocortin 3 receptor (MC3), dopamine receptors (D1 and D2), and more recently, the serotonin 2C receptor (5-HT2C). GHS-R1a dimerization was shown to affect downstream signaling and receptor trafficking suggesting a potential novel mechanism for fine-tuning GHS-R1a receptor mediated activity. This review summarizes ghrelin's role in food reward and stress and outlines the GHS-R1a dimer pairs identified to date. In addition, the downstream signaling and potential functional consequences of dimerization of the GHS-R1a receptor in appetite and stress-induced food reward behavior are discussed. The existence of multiple GHS-R1a heterodimers has important consequences for future pharmacotherapies as it significantly increases the pharmacological diversity of the GHS-R1a receptor and has the potential to enhance specificity of novel ghrelin-targeted drugs.
Collapse
|