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Karl K, Del Piccolo N, Light T, Roy T, Dudeja P, Ursachi VC, Fafilek B, Krejci P, Hristova K. Ligand bias underlies differential signaling of multiple FGFs via FGFR1. eLife 2024; 12:RP88144. [PMID: 38568193 PMCID: PMC10990489 DOI: 10.7554/elife.88144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2024] Open
Abstract
The differential signaling of multiple FGF ligands through a single fibroblast growth factor (FGF) receptor (FGFR) plays an important role in embryonic development. Here, we use quantitative biophysical tools to uncover the mechanism behind differences in FGFR1c signaling in response to FGF4, FGF8, and FGF9, a process which is relevant for limb bud outgrowth. We find that FGF8 preferentially induces FRS2 phosphorylation and extracellular matrix loss, while FGF4 and FGF9 preferentially induce FGFR1c phosphorylation and cell growth arrest. Thus, we demonstrate that FGF8 is a biased FGFR1c ligand, as compared to FGF4 and FGF9. Förster resonance energy transfer experiments reveal a correlation between biased signaling and the conformation of the FGFR1c transmembrane domain dimer. Our findings expand the mechanistic understanding of FGF signaling during development and bring the poorly understood concept of receptor tyrosine kinase ligand bias into the spotlight.
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Affiliation(s)
- Kelly Karl
- Department of Materials Science and Engineering, Institute for NanoBioTechnology, and Program in Molecular Biophysics, Johns Hopkins UniversityBaltimoreUnited States
| | - Nuala Del Piccolo
- Department of Materials Science and Engineering, Institute for NanoBioTechnology, and Program in Molecular Biophysics, Johns Hopkins UniversityBaltimoreUnited States
| | - Taylor Light
- Department of Materials Science and Engineering, Institute for NanoBioTechnology, and Program in Molecular Biophysics, Johns Hopkins UniversityBaltimoreUnited States
| | - Tanaya Roy
- Department of Materials Science and Engineering, Institute for NanoBioTechnology, and Program in Molecular Biophysics, Johns Hopkins UniversityBaltimoreUnited States
| | - Pooja Dudeja
- Department of Biology, Faculty of Medicine, Masaryk UniversityBrnoCzech Republic
- Institute of Animal Physiology and Genetics of the CASBrnoCzech Republic
| | - Vlad-Constantin Ursachi
- Department of Biology, Faculty of Medicine, Masaryk UniversityBrnoCzech Republic
- International Clinical Research Center, St. Anne's University HospitalBrnoCzech Republic
| | - Bohumil Fafilek
- Department of Biology, Faculty of Medicine, Masaryk UniversityBrnoCzech Republic
- Institute of Animal Physiology and Genetics of the CASBrnoCzech Republic
- International Clinical Research Center, St. Anne's University HospitalBrnoCzech Republic
| | - Pavel Krejci
- Department of Biology, Faculty of Medicine, Masaryk UniversityBrnoCzech Republic
- Institute of Animal Physiology and Genetics of the CASBrnoCzech Republic
- International Clinical Research Center, St. Anne's University HospitalBrnoCzech Republic
| | - Kalina Hristova
- Department of Materials Science and Engineering, Institute for NanoBioTechnology, and Program in Molecular Biophysics, Johns Hopkins UniversityBaltimoreUnited States
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2
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Buchwald P. Quantitative receptor model for responses that are left- or right-shifted versus occupancy (are more or less concentration sensitive): the SABRE approach. Front Pharmacol 2023; 14:1274065. [PMID: 38161688 PMCID: PMC10755021 DOI: 10.3389/fphar.2023.1274065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 12/05/2023] [Indexed: 01/03/2024] Open
Abstract
Simple one-to three-parameter models routinely used to fit typical dose-response curves and calculate EC50 values using the Hill or Clark equation cannot provide the full picture connecting measured response to receptor occupancy, which can be quite complex due to the interplay between partial agonism and (pathway-dependent) signal amplification. The recently introduced SABRE quantitative receptor model is the first one that explicitly includes a parameter for signal amplification (γ) in addition to those for binding affinity (K d), receptor-activation efficacy (ε), constitutive activity (ε R0), and steepness of response (Hill slope, n). It can provide a unified framework to fit complex cases, where fractional response and occupancy do not match, as well as simple ones, where parameters constrained to specific values can be used (e.g., ε R0 = 0, γ = 1, or n = 1). Here, it is shown for the first time that SABRE can fit not only typical cases where response curves are left-shifted compared to occupancy (κ = K d/EC50 > 1) due to signal amplification (γ > 1), but also less common ones where they are right-shifted (i.e., less concentration-sensitive; κ = K d/EC50 < 1) by modeling them as apparent signal attenuation/loss (γ < 1). Illustrations are provided with μ-opioid receptor (MOPr) data from three different experiments with one left- and one right-shifted response (G protein activation and β-arrestin2 recruitment, respectively; EC50,Gprt < K d < EC50,βArr). For such cases of diverging pathways with differently shifted responses, partial agonists can cause very weak responses in the less concentration-sensitive pathway without having to be biased ligands due to the combination of low ligand efficacy and signal attenuation/loss-an illustration with SABRE-fitted oliceridine data is included.
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Affiliation(s)
- Peter Buchwald
- Department of Molecular and Cellular Pharmacology, Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, FL, United States
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3
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Hill R, Sanchez J, Lemel L, Antonijevic M, Hosking Y, Mistry SN, Kruegel AC, Javitch JA, Lane JR, Canals M. Assessment of the potential of novel and classical opioids to induce respiratory depression in mice. Br J Pharmacol 2023; 180:3160-3174. [PMID: 37489013 PMCID: PMC10952895 DOI: 10.1111/bph.16199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 06/08/2023] [Accepted: 07/15/2023] [Indexed: 07/26/2023] Open
Abstract
BACKGROUND AND PURPOSE Opioid-induced respiratory depression limits the use of μ-opioid receptor agonists in clinical settings and is the main cause of opioid overdose fatalities. The relative potential of different opioid agonists to induce respiratory depression at doses exceeding those producing analgesia is understudied despite its relevance to assessments of opioid safety. Here we evaluated the respiratory depressant and anti-nociceptive effects of three novel opioids and relate these measurements to their in vitro efficacy. EXPERIMENTAL APPROACH Respiration was measured in awake, freely moving male CD-1 mice using whole body plethysmography. Anti-nociception was measured using the hot plate test. Morphine, oliceridine and tianeptine were administered intraperitoneally, whereas methadone, oxycodone and SR-17018 were administered orally. Receptor activation and arrestin-3 recruitment were measured in HEK293 cells using BRET assays. KEY RESULTS Across the dose ranges examined, all opioids studied depressed respiration in a dose-dependent manner, with similar effects at the highest doses, and with tianeptine and oliceridine showing reduced duration of effect, when compared with morphine, oxycodone, methadone and SR-17018. When administered at doses that induced similar respiratory depression, all opioids induced similar anti-nociception, with tianeptine and oliceridine again showing reduced duration of effect. These data were consistent with the in vitro agonist activity of the tested compounds. CONCLUSION AND IMPLICATIONS In addition to providing effective anti-nociception, the novel opioids, oliceridine, tianeptine and SR-17018 depress respiration in male mice. However, the different potencies and kinetics of effect between these novel opioids may be relevant to their therapeutic application in different clinical settings.
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Affiliation(s)
- Rob Hill
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical CentreUniversity of NottinghamNottinghamUK
- Centre of Membrane Proteins and Receptors, Universities of Nottingham and BirminghamMidlandsUK
| | - Julie Sanchez
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical CentreUniversity of NottinghamNottinghamUK
- Centre of Membrane Proteins and Receptors, Universities of Nottingham and BirminghamMidlandsUK
| | - Laura Lemel
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical CentreUniversity of NottinghamNottinghamUK
- Centre of Membrane Proteins and Receptors, Universities of Nottingham and BirminghamMidlandsUK
| | - Mirjana Antonijevic
- Division of Biomolecular Science and Medicinal Chemistry, School of Pharmacy, University of Nottingham Biodiscovery InstituteUniversity ParkNottinghamUK
| | - Yselkla Hosking
- Division of Biomolecular Science and Medicinal Chemistry, School of Pharmacy, University of Nottingham Biodiscovery InstituteUniversity ParkNottinghamUK
| | - Shailesh N. Mistry
- Division of Biomolecular Science and Medicinal Chemistry, School of Pharmacy, University of Nottingham Biodiscovery InstituteUniversity ParkNottinghamUK
| | | | - Jonathan A. Javitch
- Departments of Psychiatry and Molecular Pharmacology and TherapeuticsColumbia University Vagelos College of Physicians & SurgeonsNew YorkNew YorkUSA
- Division of Molecular TherapeuticsNew York State Psychiatric InstituteNew YorkNew YorkUSA
| | - J. Robert Lane
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical CentreUniversity of NottinghamNottinghamUK
- Centre of Membrane Proteins and Receptors, Universities of Nottingham and BirminghamMidlandsUK
| | - Meritxell Canals
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical CentreUniversity of NottinghamNottinghamUK
- Centre of Membrane Proteins and Receptors, Universities of Nottingham and BirminghamMidlandsUK
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Karl K, Rajagopal S, Hristova K. Quantitative assessment of ligand bias from bias plots: The bias coefficient "kappa". Biochim Biophys Acta Gen Subj 2023; 1867:130428. [PMID: 37488010 PMCID: PMC10528940 DOI: 10.1016/j.bbagen.2023.130428] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 06/15/2023] [Accepted: 07/16/2023] [Indexed: 07/26/2023]
Abstract
The current methods for quantifying ligand bias involve the construction of bias plots and the calculations of bias coefficients that can be compared using statistical methods. However, widely used bias coefficients can diverge in their abilities to identify ligand bias and can give false positives. As the empirical bias plots are considered the most reliable tools in bias identification, here we develop an analytical description of bias plot trajectories and introduce a bias coefficient, kappa, which is calculated from these trajectories. The new bias coefficient complements the tool-set in ligand bias identification in cell signaling research.
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Affiliation(s)
- Kelly Karl
- Institute for NanoBioTechnology, Department of Materials Science and Engineering, and Program in Molecular Biophysics, Johns Hopkins University, Baltimore, MD 21218, United States of America
| | - Sudarshan Rajagopal
- Division of Cardiology, Department of Medicine, Duke University School of Medicine, Durham, NC 27710, United States of America
| | - Kalina Hristova
- Institute for NanoBioTechnology, Department of Materials Science and Engineering, and Program in Molecular Biophysics, Johns Hopkins University, Baltimore, MD 21218, United States of America.
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5
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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.
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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
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6
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Kurose H. [Biased Signaling through G Protein-coupled Receptors]. YAKUGAKU ZASSHI 2022; 142:1091-1101. [PMID: 36184444 DOI: 10.1248/yakushi.22-00087] [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: 11/22/2022]
Abstract
It is well-established that G protein-coupled receptors (GPCRs) transduce signals into cells using G proteins as intermediary molecules. β-Arrestins are molecules involved in regulating GPCRs; however, it has recently been reported that β-arrestins can also mediate signaling through GPCRs. Signaling through G proteins or β-arrestins can be activated selectively using specific agonists; of the latter, those that can selectively activate either G proteins or β-arrestins are called biased agonists. The clinical use of biased agonists could potentially induce fewer side effects. However, partial agonists can also explain the mechanism of G protein-biased agonists; thus, appropriate assay systems must be considered. Endogenous agonists are known to bind to orthosteric and allosteric sites in the agonist binding site, and the allosteric site is associated with the activity of biased agonists. This current review presents a detailed discussion of biased agonists.
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Affiliation(s)
- Hitoshi Kurose
- Department of Pharmacology and Toxicology, Graduate School of Pharmaceutical Sciences, Kyushu University
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7
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Hammad MM, Mohammad A, Alam-Eldin N, Madhu D, Al-Mulla F, Abu-Farha M, Abubaker J. Structural analysis of setmelanotide binding to MC4R variants in comparison to wild-type receptor. Life Sci 2022; 307:120857. [PMID: 35931197 DOI: 10.1016/j.lfs.2022.120857] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 07/18/2022] [Accepted: 07/30/2022] [Indexed: 11/27/2022]
Abstract
AIMS Melanocortin 4 receptor (MC4R) has a well-established role in regulating appetite, food intake and energy homeostasis. Setmelanotide is an MC4R agonist currently approved for weight loss in obese adults and children with mutations in components of the leptin-melanocortin pathway. This study aims to compare structural and functional aspects of the physiological MC4R agonist α-melanocyte-stimulating hormone (α-MSH) with setmelanotide. We also aim to show the binding affinity of setmelanotide to known MC4R human missense mutations associated with obesity. MAIN METHODS AutoDock Vina was used in the structural analysis to calculate induced fit docking scores of ligand binding to MC4R wild type or the selected variants. HEK293-MC4R were utilized in the functional analysis of MC4R-actiavted pathways upon stimulating with α-MSH or setmelanotide. KEY FINDINGS Our data shows that setmelanotide has a higher potency for cAMP formation and a weaker effect on ERK1/2 phosphorylation when compared to α-MSH indicating functional selectivity otherwise known as biased agonism. We also present structural data showing that setmelanotide has a higher binding affinity to MC4R compared to α-MSH. Lastly, we show that two loss-of-function and two gain-of-function MC4R variants change the conformation not only of the ligand binding pocket of the receptor but also of the peptide when bound to the receptor because the interaction network and the residues involved in the binding are altered. SIGNIFICANCE Taken together, our study provides important insights into the diversity of MC4R signaling pathways which will facilitate the development of personalized anti-obesity drugs via refining MC4R agonists.
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Affiliation(s)
- Maha M Hammad
- Biochemistry and Molecular Biology Department, Dasman Diabetes Institute, Kuwait
| | - Anwar Mohammad
- Biochemistry and Molecular Biology Department, Dasman Diabetes Institute, Kuwait
| | - Nada Alam-Eldin
- Biochemistry and Molecular Biology Department, Dasman Diabetes Institute, Kuwait
| | - Dhanya Madhu
- Biochemistry and Molecular Biology Department, Dasman Diabetes Institute, Kuwait
| | - Fahd Al-Mulla
- Genetics and Bioinformatics Department, Dasman Diabetes Institute, Kuwait
| | - Mohamed Abu-Farha
- Biochemistry and Molecular Biology Department, Dasman Diabetes Institute, Kuwait.
| | - Jehad Abubaker
- Biochemistry and Molecular Biology Department, Dasman Diabetes Institute, Kuwait.
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8
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Portales‐Castillo I, Dean T, Khatri A, Jüppner H, Gardella TJ. Functional Properties of Two Distinct PTH1R Mutants Associated With Either Skeletal Defects or Pseudohypoparathyroidism. JBMR Plus 2022; 6:e10604. [PMID: 35720667 PMCID: PMC9189904 DOI: 10.1002/jbm4.10604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 01/11/2022] [Indexed: 12/03/2022] Open
Abstract
Consistent with a vital role of parathyroid hormone (PTH) receptor type 1 (PTH1R) in skeletal development, homozygous loss-of-function PTH1R mutations in humans results in neonatal lethality (Blomstrand chondrodysplasia), whereas such heterozygous mutations cause a primary failure of tooth eruption (PFE). Despite a key role of PTH1R in calcium and phosphate homeostasis, blood mineral ion levels are not altered in such cases of PFE. Recently, two nonlethal homozygous PTH1R mutations were identified in two unrelated families in which affected members exhibit either dental and skeletal abnormalities (PTH1R-V204E) or hypocalcemia and hyperphosphatemia (PTH1R-R186H). Arg186 and Val204 map to the first transmembrane helix of the PTH1R, and thus to a critical region of this class B G protein-coupled receptor. We used cell-based assays and PTH and PTH-related protein (PTHrP) ligand analogs to assess the impact of the R186H and V204E mutations on PTH1R function in vitro. In transiently transfected HEK293 cells, PTH1R-R186H mediated cyclic adenosine monophosphate (cAMP) responses to PTH(1-34) and PTHrP(1-36) that were of comparable potency to those observed on wild-type PTH1R (PTH1R-WT) (half maximal effective concentrations [EC50s] = 0.4nM to 1.2nM), whereas the response-maxima were significantly reduced for the PTH1R-V204E mutant (maximum effect [Emax] = 81%-77% of PTH1R-WT, p ≤ 0.004). Antibody binding to an extracellular hemagglutinin (HA) tag was comparable for PTH1R-R186H and PTH1R-WT, but was significantly reduced for PTH1R-V204E (maximum binding level [Bmax] = 44% ± 11% of PTH1R-WT, p = 0.002). The potency of cAMP signaling induced by a PTH(1-11) analog was reduced by ninefold and threefold, respectively, for PTH1R-R186H and PTH1R-V204E, relative to PTH1R-WT, and a PTH(1-15) radioligand analog that bound adequately to PTH1R-WT exhibited little or no specific binding to either mutant receptor. The data support a general decrease in PTH1R surface expression and/or function as a mechanism for PFE and a selective impairment in PTH ligand affinity as a potential PTH1R-mutation-based mechanism for pseudohypoparathyroidism. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.
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Affiliation(s)
- Ignacio Portales‐Castillo
- Department of Medicine, Division of NephrologyMassachusetts General Hospital, and Harvard Medical SchoolBostonMAUSA
| | - Thomas Dean
- Endocrine UnitMassachusetts General Hospital, and Harvard Medical SchoolBostonMAUSA
| | - Ashok Khatri
- Endocrine UnitMassachusetts General Hospital, and Harvard Medical SchoolBostonMAUSA
| | - Harald Jüppner
- Endocrine UnitMassachusetts General Hospital, and Harvard Medical SchoolBostonMAUSA
- Pediatric Nephrology UnitMassachusetts General Hospital, and Harvard Medical SchoolBostonMAUSA
| | - Thomas J Gardella
- Endocrine UnitMassachusetts General Hospital, and Harvard Medical SchoolBostonMAUSA
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9
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Pathological AT1R-B2R Protein Aggregation and Preeclampsia. Cells 2021; 10:cells10102609. [PMID: 34685589 PMCID: PMC8533718 DOI: 10.3390/cells10102609] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 09/22/2021] [Accepted: 09/27/2021] [Indexed: 01/07/2023] Open
Abstract
Preeclampsia is one of the most frequent and severe complications of pregnancy. Symptoms of preeclampsia usually occur after 20 weeks of pregnancy and include hypertension and kidney dysfunction with proteinuria. Up to now, delivery of the infant has been the most effective and life-saving treatment to alleviate symptoms of preeclampsia because a causative treatment does not exist, which could prolong a pregnancy complicated with preeclampsia. Preeclampsia is a complex medical condition, which is attributed to a variety of different risk factors and causes. Risk factors account for insufficient placentation and impaired vasculogenesis and finally culminate in this life-threatening condition of pregnancy. Despite progress, many pathomechanisms and causes of preeclampsia are still incompletely understood. In recent years, it was found that excessive protein complex formation between G-protein-coupled receptors is a common sign of preeclampsia. Specifically, the aberrant heteromerization of two vasoactive G-protein-coupled receptors (GPCRs), the angiotensin II AT1 receptor and the bradykinin B2 receptor, is a causative factor of preeclampsia symptoms. Based on this knowledge, inhibition of abnormal GPCR protein complex formation is an experimental treatment approach of preeclampsia. This review summarizes the impact of pathological GPCR protein aggregation on symptoms of preeclampsia and delineates potential new therapeutic targets.
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10
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De Neve J, Barlow TMA, Tourwé D, Bihel F, Simonin F, Ballet S. Comprehensive overview of biased pharmacology at the opioid receptors: biased ligands and bias factors. RSC Med Chem 2021; 12:828-870. [PMID: 34223156 PMCID: PMC8221262 DOI: 10.1039/d1md00041a] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 03/30/2021] [Indexed: 12/19/2022] Open
Abstract
One of the main challenges in contemporary medicinal chemistry is the development of safer analgesics, used in the treatment of pain. Currently, moderate to severe pain is still treated with the "gold standard" opioids whose long-term often leads to severe side effects. With the discovery of biased agonism, the importance of this area of pharmacology has grown exponentially over the past decade. Of these side effects, tolerance, opioid misuse, physical dependence and substance use disorder (SUD) stand out, since these have led to many deaths over the past decades in both USA and Europe. New therapeutic molecules that induce a biased response at the opioid receptors (MOR, DOR, KOR and NOP receptor) are able to circumvent these side effects and, consequently, serve as more advantageous therapies with great promise. The concept of biased signaling extends far beyond the already sizeable field of GPCR pharmacology and covering everything would be vastly outside the scope of this review which consequently covers the biased ligands acting at the opioid family of receptors. The limitation of quantifying bias, however, makes this a controversial subject, where it is dependent on the reference ligand, the equation or the assay used for the quantification. Hence, the major issue in the field of biased ligands remains the translation of the in vitro profiles of biased signaling, with corresponding bias factors to in vivo profiles showing the presence or the lack of specific side effects. This review comprises a comprehensive overview of biased ligands in addition to their bias factors at individual members of the opioid family of receptors, as well as bifunctional ligands.
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Affiliation(s)
- Jolien De Neve
- Research Group of Organic Chemistry, Departments of Chemistry and Bioengineering Sciences, Vrije Universiteit Brussel Brussels Belgium
| | - Thomas M A Barlow
- Research Group of Organic Chemistry, Departments of Chemistry and Bioengineering Sciences, Vrije Universiteit Brussel Brussels Belgium
| | - Dirk Tourwé
- Research Group of Organic Chemistry, Departments of Chemistry and Bioengineering Sciences, Vrije Universiteit Brussel Brussels Belgium
| | - Frédéric Bihel
- Laboratoire d'Innovation Thérapeutique, Faculté de Pharmacie, UMR 7200, CNRS Université de Strasbourg Illkirch France
| | - Frédéric Simonin
- Biotechnologie et Signalisation Cellulaire, UMR 7242, CNRS, Université de Strasbourg Illkirch France
| | - Steven Ballet
- Research Group of Organic Chemistry, Departments of Chemistry and Bioengineering Sciences, Vrije Universiteit Brussel Brussels Belgium
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11
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Abstract
There is increasing appreciation that G-protein-coupled receptors (GPCRs) can initiate diverse cellular responses by activating multiple G proteins, arrestins, and other biochemical effectors. Structurally different ligands targeting the same receptor are thought to stabilize the receptor in multiple distinct active conformations such that specific subsets of signaling effectors are engaged at the exclusion of others, creating a bias toward a particular outcome, which has been referred to as ligand-induced selective signaling, biased agonism, ligand-directed signaling, and functional selectivity, among others. The potential involvement of functional selectivity in mammalian olfactory signal transduction has received little attention, notwithstanding the fact that mammalian olfactory receptors comprise the largest family of mammalian GPCRs. This position review considers the possibility that, although such complexity in G-protein function may have been lost in the specialization of olfactory receptors to serve as sensory receptors, the ability of olfactory receptor neurons (ORNs) to function as signal integrators and growing appreciation that this functionality is widespread in the receptor population suggest otherwise. We pose that functional selectivity driving 2 opponent inputs have the potential to generate an output that reflects the balance of ligand-dependent signaling, the direction of which could be either suppressive or synergistic and, as such, needs to be considered as a mechanistic basis for signal integration in mammalian ORNs.
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Affiliation(s)
- Barry W Ache
- Whitney Laboratory, Departments of Biology and Neuroscience, and Center for Smell and Taste, University of Florida, Gainesville, FL, USA
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12
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Slosky LM, Caron MG, Barak LS. Biased Allosteric Modulators: New Frontiers in GPCR Drug Discovery. Trends Pharmacol Sci 2021; 42:283-299. [PMID: 33581873 PMCID: PMC9797227 DOI: 10.1016/j.tips.2020.12.005] [Citation(s) in RCA: 82] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 12/21/2020] [Accepted: 12/22/2020] [Indexed: 12/31/2022]
Abstract
G protein-coupled receptors (GPCRs) are the largest class of cell surface receptors in the genome and the most successful family of targets of FDA-approved drugs. New frontiers in GPCR drug discovery remain, however, as achieving receptor subtype selectivity and controlling off- and on-target side effects are not always possible with classic agonist and antagonist ligands. These challenges may be overcome by focusing development efforts on allosteric ligands that confer signaling bias. Biased allosteric modulators (BAMs) are an emerging class of GPCR ligands that engage less well-conserved regulatory motifs outside the orthosteric pocket and exert pathway-specific effects on receptor signaling. The unique ways that BAMs texturize receptor signaling present opportunities to fine-tune physiology and develop safer, more selective therapeutics. Here, we provide a conceptual framework for understanding the pharmacology of BAMs, explore their therapeutic potential, and discuss strategies for their discovery.
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Affiliation(s)
- Lauren M. Slosky
- Department of Cell Biology, Duke University, Durham, NC 27710, USA
| | - Marc G. Caron
- Departments of Cell Biology, Neurobiology and Medicine, Duke University, Durham, NC 27710, USA,Correspondence: (L.S.B.); (M.G.C.)
| | - Lawrence S. Barak
- Department of Cell Biology, Duke University, Durham, NC 27710, USA,Correspondence: (L.S.B.); (M.G.C.)
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13
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Lymperopoulos A, Cora N, Maning J, Brill AR, Sizova A. Signaling and function of cardiac autonomic nervous system receptors: Insights from the GPCR signalling universe. FEBS J 2021; 288:2645-2659. [DOI: 10.1111/febs.15771] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 02/02/2021] [Accepted: 02/16/2021] [Indexed: 12/16/2022]
Affiliation(s)
- Anastasios Lymperopoulos
- Laboratory for the Study of Neurohormonal Control of the Circulation Department of Pharmaceutical Sciences Nova Southeastern University Fort Lauderdale FL USA
| | - Natalie Cora
- Laboratory for the Study of Neurohormonal Control of the Circulation Department of Pharmaceutical Sciences Nova Southeastern University Fort Lauderdale FL USA
| | - Jennifer Maning
- Laboratory for the Study of Neurohormonal Control of the Circulation Department of Pharmaceutical Sciences Nova Southeastern University Fort Lauderdale FL USA
| | - Ava R. Brill
- Laboratory for the Study of Neurohormonal Control of the Circulation Department of Pharmaceutical Sciences Nova Southeastern University Fort Lauderdale FL USA
| | - Anastasiya Sizova
- Laboratory for the Study of Neurohormonal Control of the Circulation Department of Pharmaceutical Sciences Nova Southeastern University Fort Lauderdale FL USA
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14
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Corey EA, Ukhanov K, Bobkov YV, McIntyre JC, Martens JR, Ache BW. Inhibitory signaling in mammalian olfactory transduction potentially mediated by Gα o. Mol Cell Neurosci 2020; 110:103585. [PMID: 33358996 DOI: 10.1016/j.mcn.2020.103585] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 11/27/2020] [Accepted: 12/09/2020] [Indexed: 01/12/2023] Open
Abstract
Olfactory GPCRs (ORs) in mammalian olfactory receptor neurons (ORNs) mediate excitation through the Gαs family member Gαolf. Here we tentatively associate a second G protein, Gαo, with inhibitory signaling in mammalian olfactory transduction by first showing that odor evoked phosphoinositide 3-kinase (PI3K)-dependent inhibition of signal transduction is absent in the native ORNs of mice carrying a conditional OMP-Cre based knockout of Gαo. We then identify an OR from native rat ORNs that are activated by octanol through cyclic nucleotide signaling and inhibited by citral in a PI3K-dependent manner. We show that the OR activates cyclic nucleotide signaling and PI3K signaling in a manner that reflects its functionality in native ORNs. Our findings lay the groundwork to explore the interesting possibility that ORs can interact with two different G proteins in a functionally identified, ligand-dependent manner to mediate opponent signaling in mature mammalian ORNs.
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Affiliation(s)
- Elizabeth A Corey
- Whitney Laboratory, Center for Smell and Taste, University of Florida, Gainesville, FL 32610, United States of America
| | - Kirill Ukhanov
- Dept. of Pharmacology and Therapeutics, Center for Smell and Taste, University of Florida, Gainesville, FL 32610, United States of America
| | - Yuriy V Bobkov
- Whitney Laboratory, Center for Smell and Taste, University of Florida, Gainesville, FL 32610, United States of America
| | - Jeremy C McIntyre
- Dept. of Neuroscience, Center for Smell and Taste, University of Florida, Gainesville, FL 32610, United States of America
| | - Jeffrey R Martens
- Dept. of Pharmacology and Therapeutics, Center for Smell and Taste, University of Florida, Gainesville, FL 32610, United States of America
| | - Barry W Ache
- Whitney Laboratory, Dept. of Biology, Center for Smell and Taste, University of Florida, Gainesville, FL 32610, United States of America; Whitney Laboratory, Dept. of Neuroscience, Center for Smell and Taste, University of Florida, Gainesville, FL 32610, United States of America.
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15
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Karl K, Paul MD, Pasquale EB, Hristova K. Ligand bias in receptor tyrosine kinase signaling. J Biol Chem 2020; 295:18494-18507. [PMID: 33122191 PMCID: PMC7939482 DOI: 10.1074/jbc.rev120.015190] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 10/28/2020] [Indexed: 12/14/2022] Open
Abstract
Ligand bias is the ability of ligands to differentially activate certain receptor signaling responses compared with others. It reflects differences in the responses of a receptor to specific ligands and has implications for the development of highly specific therapeutics. Whereas ligand bias has been studied primarily for G protein-coupled receptors (GPCRs), there are also reports of ligand bias for receptor tyrosine kinases (RTKs). However, the understanding of RTK ligand bias is lagging behind the knowledge of GPCR ligand bias. In this review, we highlight how protocols that were developed to study GPCR signaling can be used to identify and quantify RTK ligand bias. We also introduce an operational model that can provide insights into the biophysical basis of RTK activation and ligand bias. Finally, we discuss possible mechanisms underpinning RTK ligand bias. Thus, this review serves as a primer for researchers interested in investigating ligand bias in RTK signaling.
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Affiliation(s)
- Kelly Karl
- Department of Materials Science and Engineering, Institute for NanoBioTechnology, and Program in Molecular Biophysics, Johns Hopkins University, Baltimore, Maryland, USA
| | - Michael D Paul
- Department of Materials Science and Engineering, Institute for NanoBioTechnology, and Program in Molecular Biophysics, Johns Hopkins University, Baltimore, Maryland, USA
| | - Elena B Pasquale
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, USA.
| | - Kalina Hristova
- Department of Materials Science and Engineering, Institute for NanoBioTechnology, and Program in Molecular Biophysics, Johns Hopkins University, Baltimore, Maryland, USA.
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16
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Ahmed F, Zapata-Mercado E, Rahman S, Hristova K. The Biased Ligands NGF and NT-3 Differentially Stabilize Trk-A Dimers. Biophys J 2020; 120:55-63. [PMID: 33285113 DOI: 10.1016/j.bpj.2020.11.2262] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 11/14/2020] [Accepted: 11/23/2020] [Indexed: 12/23/2022] Open
Abstract
Trk-A is a receptor tyrosine kinase (RTK) that plays an essential role in the development and functioning of the nervous system. Trk-A is expressed in neurons and signals in response to two ligands, NGF and neurotrophin-3 (NT-3), with very different functional consequences. Thus, NGF and NT-3 are "biased" ligands for Trk-A. Because it has been hypothesized that biased RTK ligands induce differential stabilization of RTK dimers, here, we seek to test this hypothesis for NGF and NT-3. In particular, we use Förster resonance energy transfer (FRET) and fluorescence intensity fluctuation spectroscopy to assess the strength of Trk-A interactions and Trk-A oligomer size in the presence of the two ligands. Although the difference in Trk-A behavior in response to the two ligands has been previously attributed to differences in their binding to Trk-A in the endosomes at low pH, here, we further show differences in the stabilities of the NGF- and NT-3-bound Trk-A dimers in the plasma membrane and at neutral pH. We discuss the biological significance of these new findings and their implications for the design of Trk-A ligands with novel functionalities.
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Affiliation(s)
- Fozia Ahmed
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland; Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, Maryland
| | - Elmer Zapata-Mercado
- Program in Molecular Biophysics, Johns Hopkins University, Baltimore, Maryland; Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, Maryland
| | - Sanim Rahman
- Program in Molecular Biophysics, Johns Hopkins University, Baltimore, Maryland
| | - Kalina Hristova
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland; Program in Molecular Biophysics, Johns Hopkins University, Baltimore, Maryland; Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, Maryland.
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17
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Alexander RA, Lot I, Saha K, Abadie G, Lambert M, Decosta E, Kobayashi H, Beautrait A, Borrull A, Asnacios A, Bouvier M, Scott MGH, Marullo S, Enslen H. Beta-arrestins operate an on/off control switch for focal adhesion kinase activity. Cell Mol Life Sci 2020; 77:5259-5279. [PMID: 32040695 PMCID: PMC11104786 DOI: 10.1007/s00018-020-03471-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 01/13/2020] [Accepted: 01/24/2020] [Indexed: 12/20/2022]
Abstract
Focal adhesion kinase (FAK) regulates key biological processes downstream of G protein-coupled receptors (GPCRs) in normal and cancer cells, but the modes of kinase activation by these receptors remain unclear. We report that after GPCR stimulation, FAK activation is controlled by a sequence of events depending on the scaffolding proteins β-arrestins and G proteins. Depletion of β-arrestins results in a marked increase in FAK autophosphorylation and focal adhesion number. We demonstrate that β-arrestins interact directly with FAK and inhibit its autophosphorylation in resting cells. Both FAK-β-arrestin interaction and FAK inhibition require the FERM domain of FAK. Following the stimulation of the angiotensin receptor AT1AR and subsequent translocation of the FAK-β-arrestin complex to the plasma membrane, β-arrestin interaction with the adaptor AP-2 releases inactive FAK from the inhibitory complex, allowing its activation by receptor-stimulated G proteins and activation of downstream FAK effectors. Release and activation of FAK in response to angiotensin are prevented by an AP-2-binding deficient β-arrestin and by a specific inhibitor of β-arrestin/AP-2 interaction; this inhibitor also prevents FAK activation in response to vasopressin. This previously unrecognized mechanism of FAK regulation involving a dual role of β-arrestins, which inhibit FAK in resting cells while driving its activation at the plasma membrane by GPCR-stimulated G proteins, opens new potential therapeutic perspectives in cancers with up-regulated FAK.
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Affiliation(s)
- Revu Ann Alexander
- Institut Cochin, Inserm U 1016, CNRS UMR8104, Université de Paris, 27 rue du Faubourg Saint-Jacques, 75014, Paris, France
| | - Isaure Lot
- Institut Cochin, Inserm U 1016, CNRS UMR8104, Université de Paris, 27 rue du Faubourg Saint-Jacques, 75014, Paris, France
| | - Kusumika Saha
- Institut Cochin, Inserm U 1016, CNRS UMR8104, Université de Paris, 27 rue du Faubourg Saint-Jacques, 75014, Paris, France
| | - Guillaume Abadie
- Institut Cochin, Inserm U 1016, CNRS UMR8104, Université de Paris, 27 rue du Faubourg Saint-Jacques, 75014, Paris, France
| | - Mireille Lambert
- Institut Cochin, Inserm U 1016, CNRS UMR8104, Université de Paris, 27 rue du Faubourg Saint-Jacques, 75014, Paris, France
| | - Eleonore Decosta
- Institut Cochin, Inserm U 1016, CNRS UMR8104, Université de Paris, 27 rue du Faubourg Saint-Jacques, 75014, Paris, France
| | - Hiroyuki Kobayashi
- Department of Biochemistry and the Institute for Research in Immunology and Cancer, Université de Montréal, Montreal, QC, H3C 3J7, Canada
| | - Alexandre Beautrait
- Department of Biochemistry and the Institute for Research in Immunology and Cancer, Université de Montréal, Montreal, QC, H3C 3J7, Canada
| | - Aurélie Borrull
- Institut Cochin, Inserm U 1016, CNRS UMR8104, Université de Paris, 27 rue du Faubourg Saint-Jacques, 75014, Paris, France
| | - Atef Asnacios
- Laboratoire Matière et Systèmes Complexes, CNRS UMR 7057, Université de Paris, Paris, France
| | - Michel Bouvier
- Department of Biochemistry and the Institute for Research in Immunology and Cancer, Université de Montréal, Montreal, QC, H3C 3J7, Canada
| | - Mark G H Scott
- Institut Cochin, Inserm U 1016, CNRS UMR8104, Université de Paris, 27 rue du Faubourg Saint-Jacques, 75014, Paris, France
| | - Stefano Marullo
- Institut Cochin, Inserm U 1016, CNRS UMR8104, Université de Paris, 27 rue du Faubourg Saint-Jacques, 75014, Paris, France
| | - Hervé Enslen
- Institut Cochin, Inserm U 1016, CNRS UMR8104, Université de Paris, 27 rue du Faubourg Saint-Jacques, 75014, Paris, France.
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18
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Buchwald P. A single unified model for fitting simple to complex receptor response data. Sci Rep 2020; 10:13386. [PMID: 32770075 PMCID: PMC7414914 DOI: 10.1038/s41598-020-70220-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 07/27/2020] [Indexed: 12/17/2022] Open
Abstract
The fitting of complex receptor-response data where fractional response and occupancy do not match is challenging. They encompass important cases including (a) the presence of "receptor reserve" and/or partial agonism, (b) multiple responses assessed at different vantage points along a pathway, (c) responses that are different along diverging downstream pathways (biased agonism), and (d) constitutive activity. For these, simple models such as the well-known Clark or Hill equations cannot be used. Those that can, such as the operational (Black&Leff) model, do not provide a unified approach, have multiple nonintuitive parameters that are challenging to fit in well-defined manner, have difficulties incorporating binding data, and cannot be reduced or connected to simpler forms. We have recently introduced a quantitative receptor model (SABRE) that includes parameters for Signal Amplification (γ), Binding affinity (Kd), Receptor activation Efficacy (ε), and constitutive activity (εR0). It provides a single equation to fit complex cases within a full two-state framework with the possibility of incorporating receptor occupancy data (i.e., experimental Kds). Simpler cases can be fit by using consecutively reduced forms obtained by constraining parameters to specific values, e.g., εR0 = 0: no constitutive activity, γ = 1: no amplification (Emax-type fitting), and ε = 1: no partial agonism (Clark equation). Here, a Hill-type extension is introduced (n ≠ 1), and simulated and experimental receptor-response data from simple to increasingly complex cases are fitted within the unified framework of SABRE with differently constrained parameters.
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Affiliation(s)
- Peter Buchwald
- Department of Molecular and Cellular Pharmacology and Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, FL, 33136, USA.
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19
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Fernandez TJ, De Maria M, Lobingier BT. A cellular perspective of bias at G protein-coupled receptors. Protein Sci 2020; 29:1345-1354. [PMID: 32297394 DOI: 10.1002/pro.3872] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 04/10/2020] [Accepted: 04/10/2020] [Indexed: 12/17/2022]
Abstract
G protein-coupled receptors (GPCRs) modulate cell function over short- and long-term timescales. GPCR signaling depends on biochemical parameters that define the what, when, and where of receptor function: what proteins mediate and regulate receptor signaling, where within the cell these interactions occur, and how long these interactions persist. These parameters can vary significantly depending on the activating ligand. Collectivity, differential agonist activity at a GPCR is called bias or functional selectivity. Here we review agonist bias at GPCRs with a focus on ligands that show dramatically different cellular responses from their unbiased counterparts.
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Affiliation(s)
- Thomas J Fernandez
- Department of Chemical Physiology and Biochemistry, Oregon Health and Sciences University, Portland, Oregon, USA
| | - Monica De Maria
- Department of Chemical Physiology and Biochemistry, Oregon Health and Sciences University, Portland, Oregon, USA
| | - Braden T Lobingier
- Department of Chemical Physiology and Biochemistry, Oregon Health and Sciences University, Portland, Oregon, USA
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20
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Rouault AAJ, Rosselli-Murai LK, Hernandez CC, Gimenez LE, Tall GG, Sebag JA. The GPCR accessory protein MRAP2 regulates both biased signaling and constitutive activity of the ghrelin receptor GHSR1a. Sci Signal 2020; 13:13/613/eaax4569. [PMID: 31911434 DOI: 10.1126/scisignal.aax4569] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Ghrelin is a hormone secreted by the stomach during fasting periods and acts through its receptor, the growth hormone secretagogue 1a (GHSR1a), to promote food intake and prevent hypoglycemia. As such, GHSR1a is an important regulator of energy and glucose homeostasis and a target for the treatment of obesity. Here, we showed that the accessory protein MRAP2 altered GHSR1a signaling by inhibiting its constitutive activity, as well as by enhancing its G protein-dependent signaling and blocking the recruitment and signaling of β-arrestin in response to ghrelin. In addition, the effects of MRAP2 on the Gαq and β-arrestin pathways were independent and involved distinct regions of MRAP2. These findings may have implications for the regulation of ghrelin function in vivo and the role of MRAP2 in energy homeostasis. They also show that accessory proteins can bias signaling downstream of GPCRs in response to their endogenous agonist.
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Affiliation(s)
- Alix A J Rouault
- Department of Molecular Physiology and Biophysics, Fraternal Order of Eagles Diabetes Research Center, Iowa Neuroscience Institute, Pappajohn Biomedical Institute, University of Iowa, Iowa City, IA 52242, USA
| | | | - Ciria C Hernandez
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Luis E Gimenez
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Gregory G Tall
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Julien A Sebag
- Department of Molecular Physiology and Biophysics, Fraternal Order of Eagles Diabetes Research Center, Iowa Neuroscience Institute, Pappajohn Biomedical Institute, University of Iowa, Iowa City, IA 52242, USA.
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21
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Schurman LD, Lu D, Kendall DA, Howlett AC, Lichtman AH. Molecular Mechanism and Cannabinoid Pharmacology. Handb Exp Pharmacol 2020; 258:323-353. [PMID: 32236882 PMCID: PMC8637936 DOI: 10.1007/164_2019_298] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Since antiquity, Cannabis has provoked enormous intrigue for its potential medicinal properties as well as for its unique pharmacological effects. The elucidation of its major cannabinoid constituents, Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD), led to the synthesis of new cannabinoids (termed synthetic cannabinoids) to understand the mechanisms underlying the pharmacology of Cannabis. These pharmacological tools were instrumental in the ultimate discovery of the endogenous cannabinoid system, which consists of CB1 and CB2 cannabinoid receptors and endogenously produced ligands (endocannabinoids), which bind and activate both cannabinoid receptors. CB1 receptors mediate the cannabimimetic effects of THC and are highly expressed on presynaptic neurons in the nervous system, where they modulate neurotransmitter release. In contrast, CB2 receptors are primarily expressed on immune cells. The endocannabinoids are tightly regulated by biosynthetic and hydrolytic enzymes. Accordingly, the endocannabinoid system plays a modulatory role in many physiological processes, thereby generating many promising therapeutic targets. An unintended consequence of this research was the emergence of synthetic cannabinoids sold for human consumption to circumvent federal laws banning Cannabis use. Here, we describe research that led to the discovery of the endogenous cannabinoid system and show how knowledge of this system benefitted as well as unintentionally harmed human health.
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Affiliation(s)
- Lesley D Schurman
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, USA
| | - Dai Lu
- Rangel College of Pharmacy, Health Science Center, Texas A&M University, Kingsville, TX, USA
| | - Debra A Kendall
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, CT, USA
| | - Allyn C Howlett
- Department of Physiology and Pharmacology and Center for Research on Substance Use and Addiction, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Aron H Lichtman
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, USA.
- Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond, VA, USA.
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22
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Louw A. GR Dimerization and the Impact of GR Dimerization on GR Protein Stability and Half-Life. Front Immunol 2019; 10:1693. [PMID: 31379877 PMCID: PMC6653659 DOI: 10.3389/fimmu.2019.01693] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 07/08/2019] [Indexed: 12/14/2022] Open
Abstract
Pharmacologically, glucocorticoids, which mediate their effects via the glucocorticoid receptor (GR), are a most effective therapy for inflammatory diseases despite the fact that chronic use causes side-effects and acquired GC resistance. The design of drugs with fewer side-effects and less potential for the development of resistance is therefore considered crucial for improved therapy. Dimerization of the GR is an integral step in glucocorticoid signaling and has been identified as a possible molecular site to target for drug development of anti-inflammatory drugs with an improved therapeutic index. Most of the current understanding regarding the role of GR dimerization in GC signaling derives for dimerization deficient mutants, although the role of ligands biased toward monomerization has also been described. Even though designing for loss of dimerization has mostly been applied for reduction of side-effect profile, designing for loss of dimerization may also be a fruitful strategy for the development of GC drugs with less potential to develop GC resistance. GC-induced resistance affects up to 30% of users and is due to a reduction in the GR functional pool. Several molecular mechanisms of GC-mediated reductions in GR pool have been described, one of which is the autologous down-regulation of GR density by the ubiquitin-proteasome-system (UPS). Loss of GR dimerization prevents autologous down-regulation of the receptor through modulation of interactions with components of the UPS and post-translational modifications (PTMs), such as phosphorylation, which prime the GR for degradation. Rational design of conformationally biased ligands that select for a monomeric GR conformation, which increases GC sensitivity through improving GR protein stability and increasing half-life, may be a productive avenue to explore. However, potential drawbacks to this approach should be considered as well as the advantages and disadvantages in chronic vs. acute treatment regimes.
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Affiliation(s)
- Ann Louw
- Department of Biochemistry, Stellenbosch University, Stellenbosch, South Africa
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23
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Mahmod Al-Qattan MN, Mordi MN. Molecular Basis of Modulating Adenosine Receptors Activities. Curr Pharm Des 2019; 25:817-831. [DOI: 10.2174/1381612825666190304122624] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Accepted: 02/26/2019] [Indexed: 01/04/2023]
Abstract
Modulating cellular processes through extracellular chemical stimuli is medicinally an attractive approach to control disease conditions. GPCRs are the most important group of transmembranal receptors that produce different patterns of activations using intracellular mediators (such as G-proteins and Beta-arrestins). Adenosine receptors (ARs) belong to GPCR class and are divided into A1AR, A2AAR, A2BAR and A3AR. ARs control different physiological activities thus considered valuable target to control neural, heart, inflammatory and other metabolic disorders. Targeting ARs using small molecules essentially works by binding orthosteric and/or allosteric sites of the receptors. Although targeting orthosteric site is considered typical to modulate receptor activity, allosteric sites provide better subtype selectivity, saturable modulation of activity and variable activation patterns. Each receptor exists in dynamical equilibrium between conformational ensembles. The equilibrium is affected by receptor interaction with other molecules. Changing the population of conformational ensembles of the receptor is the method by which orthosteric, allosteric and other cellular components control receptor signaling. Herein, the interactions of ARs with orthosteric, allosteric ligands as well as intracellular mediators are described. A quinary interaction model for the receptor is proposed and energy wells for major conformational ensembles are retrieved.
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Affiliation(s)
| | - Mohd Nizam Mordi
- Centre For Drug Research, Universiti Sains Malaysia, 11800 Gelugor, Penang, Malaysia
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25
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Wilkinson L, Verhoog NJD, Louw A. Disease- and treatment-associated acquired glucocorticoid resistance. Endocr Connect 2018; 7:R328-R349. [PMID: 30352419 PMCID: PMC6280593 DOI: 10.1530/ec-18-0421] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 10/11/2018] [Indexed: 12/16/2022]
Abstract
The development of resistance to glucocorticoids (GCs) in therapeutic regimens poses a major threat. Generally, GC resistance is congenital or acquired over time as a result of disease progression, prolonged GC treatment or, in some cases, both. Essentially, disruptions in the function and/or pool of the glucocorticoid receptor α (GRα) underlie this resistance. Many studies have detailed how alterations in GRα function lead to diminished GC sensitivity; however, the current review highlights the wealth of data concerning reductions in the GRα pool, mediated by disease-associated and treatment-associated effects, which contribute to a significant decrease in GC sensitivity. Additionally, the current understanding of the molecular mechanisms involved in driving reductions in the GRα pool is discussed. After highlighting the importance of maintaining the level of the GRα pool to combat GC resistance, we present current strategies and argue that future strategies to prevent GC resistance should involve biased ligands with a predisposition for reduced GR dimerization, a strategy originally proposed as the SEMOGRAM-SEDIGRAM concept to reduce the side-effect profile of GCs.
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Affiliation(s)
- Legh Wilkinson
- Department of Biochemistry, Stellenbosch University, Stellenbosch, South Africa
| | | | - Ann Louw
- Department of Biochemistry, Stellenbosch University, Stellenbosch, South Africa
- Correspondence should be addressed to A Louw:
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26
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Oyagawa CRM, de la Harpe SM, Saroz Y, Glass M, Vernall AJ, Grimsey NL. Cannabinoid Receptor 2 Signalling Bias Elicited by 2,4,6-Trisubstituted 1,3,5-Triazines. Front Pharmacol 2018; 9:1202. [PMID: 30524271 PMCID: PMC6256112 DOI: 10.3389/fphar.2018.01202] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 10/01/2018] [Indexed: 12/17/2022] Open
Abstract
Cannabinoid receptor 2 (CB2) is predominantly distributed in immune tissues and cells and is a promising therapeutic target for modulating inflammation. In this study we designed and synthesised a series of 2,4,6-trisubstituted 1,3,5-triazines with piperazinylalkyl or 1,2-diethoxyethane (PEG2) chains as CB2 agonists, all of which were predicted to be considerably more polar than typical cannabinoid ligands. In this series, we found that triazines containing an adamantanyl group were conducive to CB2 binding whereas those with a cyclopentyl group were not. Although the covalent attachment of a PEG2 linker to the adamantyl triazines resulted in a decrease in binding affinity, some of the ligands produced very interesting hCB2 signalling profiles. Six compounds with notable hCB2 orthosteric binding were functionally characterised in three pathways; internalisation, cyclic adenosine monophosphate (cAMP) and ERK phosphorylation (pERK). These were predominantly confirmed to be hCB2 agonists, and upon comparison to a reference ligand (CP 55,940), four compounds exhibited signalling bias. Triazines 14 (UOSD017) and 15 were biased towards internalisation over cAMP and pERK, and 7 was biased away from pERK activation relative to cAMP and internalisation. Intriguingly, the triazine with an amino-PEG2-piperazinyl linker (13 [UOSD008]) was identified to be a mixed agonist/inverse agonist, exhibiting apparent neutral antagonism in the internalisation pathway, transient inverse agonism in the cAMP pathway and weak partial agonism in the pERK pathway. Both the cAMP and pERK signalling were pertussis toxin (PTX) sensitive, implying that 13 is acting as both a weak agonist and inverse agonist at CB2 via Gαi/o. Compound 10 (UOSD015) acted as a balanced high intrinsic efficacy agonist with the potential to produce greater hCB2-mediated efficacy than reference ligand CP 55,940. As 10 includes a Boc-protected PEG2 moiety it is also a promising candidate for further modification, for example with a secondary reporter or fluorophore. The highest affinity compound in this set of relatively polar hCB2 ligands was compound 16, which acted as a slightly partial balanced agonist in comparison with CP 55,940. The ligands characterised here may therefore exhibit unique functional properties in vivo and have the potential to be valuable in the future development of CB2-directed therapeutics.
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Affiliation(s)
- Caitlin R. M. Oyagawa
- Department of Pharmacology and Clinical Pharmacology, School of Medical Sciences, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
- Centre for Brain Research, School of Medical Sciences, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | | | - Yurii Saroz
- Department of Pharmacology and Clinical Pharmacology, School of Medical Sciences, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
- Centre for Brain Research, School of Medical Sciences, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Michelle Glass
- Department of Pharmacology and Clinical Pharmacology, School of Medical Sciences, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
- Centre for Brain Research, School of Medical Sciences, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | | | - Natasha Lillia Grimsey
- Department of Pharmacology and Clinical Pharmacology, School of Medical Sciences, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
- Centre for Brain Research, School of Medical Sciences, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
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Leysen H, van Gastel J, Hendrickx JO, Santos-Otte P, Martin B, Maudsley S. G Protein-Coupled Receptor Systems as Crucial Regulators of DNA Damage Response Processes. Int J Mol Sci 2018; 19:E2919. [PMID: 30261591 PMCID: PMC6213947 DOI: 10.3390/ijms19102919] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 09/14/2018] [Accepted: 09/15/2018] [Indexed: 12/11/2022] Open
Abstract
G protein-coupled receptors (GPCRs) and their associated proteins represent one of the most diverse cellular signaling systems involved in both physiological and pathophysiological processes. Aging represents perhaps the most complex biological process in humans and involves a progressive degradation of systemic integrity and physiological resilience. This is in part mediated by age-related aberrations in energy metabolism, mitochondrial function, protein folding and sorting, inflammatory activity and genomic stability. Indeed, an increased rate of unrepaired DNA damage is considered to be one of the 'hallmarks' of aging. Over the last two decades our appreciation of the complexity of GPCR signaling systems has expanded their functional signaling repertoire. One such example of this is the incipient role of GPCRs and GPCR-interacting proteins in DNA damage and repair mechanisms. Emerging data now suggest that GPCRs could function as stress sensors for intracellular damage, e.g., oxidative stress. Given this role of GPCRs in the DNA damage response process, coupled to the effective history of drug targeting of these receptors, this suggests that one important future activity of GPCR therapeutics is the rational control of DNA damage repair systems.
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Affiliation(s)
- Hanne Leysen
- Department of Biomedical Sciences, University of Antwerp, 2610 Antwerp, Belgium.
| | - Jaana van Gastel
- Department of Biomedical Sciences, University of Antwerp, 2610 Antwerp, Belgium.
- Translational Neurobiology Group, Center of Molecular Neurology, VIB, 2610 Antwerp, Belgium.
| | - Jhana O Hendrickx
- Department of Biomedical Sciences, University of Antwerp, 2610 Antwerp, Belgium.
- Translational Neurobiology Group, Center of Molecular Neurology, VIB, 2610 Antwerp, Belgium.
| | - Paula Santos-Otte
- Institute of Biophysics, Humboldt-Universität zu Berlin, 10115 Berlin, Germany.
| | - Bronwen Martin
- Department of Biomedical Sciences, University of Antwerp, 2610 Antwerp, Belgium.
| | - Stuart Maudsley
- Department of Biomedical Sciences, University of Antwerp, 2610 Antwerp, Belgium.
- Translational Neurobiology Group, Center of Molecular Neurology, VIB, 2610 Antwerp, Belgium.
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28
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Luttrell LM, Wang J, Plouffe B, Smith JS, Yamani L, Kaur S, Jean-Charles PY, Gauthier C, Lee MH, Pani B, Kim J, Ahn S, Rajagopal S, Reiter E, Bouvier M, Shenoy SK, Laporte SA, Rockman HA, Lefkowitz RJ. Manifold roles of β-arrestins in GPCR signaling elucidated with siRNA and CRISPR/Cas9. Sci Signal 2018; 11:11/549/eaat7650. [PMID: 30254056 DOI: 10.1126/scisignal.aat7650] [Citation(s) in RCA: 132] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
G protein-coupled receptors (GPCRs) use diverse mechanisms to regulate the mitogen-activated protein kinases ERK1/2. β-Arrestins (βArr1/2) are ubiquitous inhibitors of G protein signaling, promoting GPCR desensitization and internalization and serving as scaffolds for ERK1/2 activation. Studies using CRISPR/Cas9 to delete βArr1/2 and G proteins have cast doubt on the role of β-arrestins in activating specific pools of ERK1/2. We compared the effects of siRNA-mediated knockdown of βArr1/2 and reconstitution with βArr1/2 in three different parental and CRISPR-derived βArr1/2 knockout HEK293 cell pairs to assess the effect of βArr1/2 deletion on ERK1/2 activation by four Gs-coupled GPCRs. In all parental lines with all receptors, ERK1/2 stimulation was reduced by siRNAs specific for βArr2 or βArr1/2. In contrast, variable effects were observed with CRISPR-derived cell lines both between different lines and with activation of different receptors. For β2 adrenergic receptors (β2ARs) and β1ARs, βArr1/2 deletion increased, decreased, or had no effect on isoproterenol-stimulated ERK1/2 activation in different CRISPR clones. ERK1/2 activation by the vasopressin V2 and follicle-stimulating hormone receptors was reduced in these cells but was enhanced by reconstitution with βArr1/2. Loss of desensitization and receptor internalization in CRISPR βArr1/2 knockout cells caused β2AR-mediated stimulation of ERK1/2 to become more dependent on G proteins, which was reversed by reintroducing βArr1/2. These data suggest that βArr1/2 function as a regulatory hub, determining the balance between mechanistically different pathways that result in activation of ERK1/2, and caution against extrapolating results obtained from βArr1/2- or G protein-deleted cells to GPCR behavior in native systems.
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Affiliation(s)
- Louis M Luttrell
- Department of Medicine, Medical University of South Carolina, Charleston, SC 29425, USA.,Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA.,Research Service of the Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC 29401, USA
| | - Jialu Wang
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
| | - Bianca Plouffe
- Department of Biochemistry and Molecular Medicine, Institute for Research in Immunology and Cancer, University of Montreal, Montreal, Quebec H3C IJ4, Canada
| | - Jeffrey S Smith
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA.,Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA
| | - Lama Yamani
- Department of Medicine, Research Institute of the McGill University Health Center, McGill University, Montreal, Quebec H4A 3J1, Canada
| | - Suneet Kaur
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
| | | | - Christophe Gauthier
- Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique, CNRS, Université de Tours, 37380 Nouzilly, France
| | - Mi-Hye Lee
- Department of Medicine, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Biswaranjan Pani
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
| | - Jihee Kim
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
| | - Seungkirl Ahn
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
| | - Sudarshan Rajagopal
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA.,Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA
| | - Eric Reiter
- Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique, CNRS, Université de Tours, 37380 Nouzilly, France
| | - Michel Bouvier
- Department of Biochemistry and Molecular Medicine, Institute for Research in Immunology and Cancer, University of Montreal, Montreal, Quebec H3C IJ4, Canada
| | - Sudha K Shenoy
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA.,Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Stéphane A Laporte
- Department of Medicine, Research Institute of the McGill University Health Center, McGill University, Montreal, Quebec H4A 3J1, Canada
| | - Howard A Rockman
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA.,Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA.,Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Robert J Lefkowitz
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA. .,Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA.,Howard Hughes Medical Institute, Duke University Medical Center, Durham, NC 27710, USA
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29
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Berg KA, Clarke WP. Making Sense of Pharmacology: Inverse Agonism and Functional Selectivity. Int J Neuropsychopharmacol 2018; 21:962-977. [PMID: 30085126 PMCID: PMC6165953 DOI: 10.1093/ijnp/pyy071] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 08/04/2018] [Indexed: 12/12/2022] Open
Abstract
Constitutive receptor activity/inverse agonism and functional selectivity/biased agonism are 2 concepts in contemporary pharmacology that have major implications for the use of drugs in medicine and research as well as for the processes of new drug development. Traditional receptor theory postulated that receptors in a population are quiescent unless activated by a ligand. Within this framework ligands could act as agonists with various degrees of intrinsic efficacy, or as antagonists with zero intrinsic efficacy. We now know that receptors can be active without an activating ligand and thus display "constitutive" activity. As a result, a new class of ligand was discovered that can reduce the constitutive activity of a receptor. These ligands produce the opposite effect of an agonist and are called inverse agonists. The second topic discussed is functional selectivity, also commonly referred to as biased agonism. Traditional receptor theory also posited that intrinsic efficacy is a single drug property independent of the system in which the drug acts. However, we now know that a drug, acting at a single receptor subtype, can have multiple intrinsic efficacies that differ depending on which of the multiple responses coupled to a receptor is measured. Thus, a drug can be simultaneously an agonist, an antagonist, and an inverse agonist acting at the same receptor. This means that drugs have an additional level of selectivity (signaling selectivity or "functional selectivity") beyond the traditional receptor selectivity. Both inverse agonism and functional selectivity need to be considered when drugs are used as medicines or as research tools.
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Affiliation(s)
- Kelly A Berg
- Department of Pharmacology, University of Texas Health, San Antonio, Texas
| | - William P Clarke
- Department of Pharmacology, University of Texas Health, San Antonio, Texas,Correspondence: William P. Clarke, PhD, Department of Pharmacology, Mail Stop 7764, UT Health at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229 ()
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30
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Abstract
β-arrestin1 (or arrestin2) and β-arrestin2 (or arrestin3) are ubiquitously expressed cytosolic adaptor proteins that were originally discovered for their inhibitory role in G protein-coupled receptor (GPCR) signaling through heterotrimeric G proteins. However, further biochemical characterization revealed that β-arrestins do not just "block" the activated GPCRs, but trigger endocytosis and kinase activation leading to specific signaling pathways that can be localized on endosomes. The signaling pathways initiated by β-arrestins were also found to be independent of G protein activation by GPCRs. The discovery of ligands that blocked G protein activation but promoted β-arrestin binding, or vice-versa, suggested the exciting possibility of selectively activating intracellular signaling pathways. In addition, it is becoming increasingly evident that β-arrestin-dependent signaling is extremely diverse and provokes distinct cellular responses through different GPCRs even when the same effector kinase is involved. In this review, we summarize various signaling pathways mediated by β-arrestins and highlight the physiologic effects of β-arrestin-dependent signaling.
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31
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The EphA2 receptor is activated through induction of distinct, ligand-dependent oligomeric structures. Commun Biol 2018; 1:15. [PMID: 30271902 PMCID: PMC6123813 DOI: 10.1038/s42003-018-0017-7] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 01/28/2018] [Indexed: 01/19/2023] Open
Abstract
The EphA2 receptor tyrosine kinase is capable of activating multiple diverse signaling pathways with roles in processes such as tissue homeostasis and cancer. EphA2 is known to form activated oligomers in the presence of ephrin-A ligands. Here, we characterize the lateral interactions between full-length EphA2 molecules in the plasma membrane in the presence of three types of ligands (dimeric ephrinA1-Fc, monomeric ephrinA1, and an engineered peptide ligand) as well as in the absence of ligand, using a quantitative FRET technique. The data show that EphA2 forms higher-order oligomers and two different types of dimers that all lead to increased EphA2 tyrosine phosphorylation, which is indicative of increased kinase-dependent signaling. We find that different ligands stabilize conformationally distinct oligomers that are assembled through two different interfaces. Our results suggest that these different oligomeric assemblies could have distinct signaling properties, contributing to the diverse activities of the EphA2 receptor. Deo Singh et al. use Fully Quantified Spectral Imaging-FRET to show that the EphA2 receptor forms dimers or higher order oligomers depending on the type of ligand, and that different ligands stabilize EphA2 dimers through distinct interfaces. These findings may explain how EphA2 activates diverse signaling pathways.
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32
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Abstract
G protein-coupled receptors (GPCRs) are the largest class of receptors in the human genome and some of the most common drug targets. It is now well established that GPCRs can signal through multiple transducers, including heterotrimeric G proteins, GPCR kinases and β-arrestins. While these signalling pathways can be activated or blocked by 'balanced' agonists or antagonists, they can also be selectively activated in a 'biased' response. Biased responses can be induced by biased ligands, biased receptors or system bias, any of which can result in preferential signalling through G proteins or β-arrestins. At many GPCRs, signalling events mediated by G proteins and β-arrestins have been shown to have distinct biochemical and physiological actions from one another, and an accurate evaluation of biased signalling from pharmacology through physiology is crucial for preclinical drug development. Recent structural studies have provided snapshots of GPCR-transducer complexes, which should aid in the structure-based design of novel biased therapies. Our understanding of GPCRs has evolved from that of two-state, on-and-off switches to that of multistate allosteric microprocessors, in which biased ligands transmit distinct structural information that is processed into distinct biological outputs. The development of biased ligands as therapeutics heralds an era of increased drug efficacy with reduced drug side effects.
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33
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Mouillac B, Mendre C. Pharmacological Chaperones as Potential Therapeutic Strategies for Misfolded Mutant Vasopressin Receptors. Handb Exp Pharmacol 2018; 245:63-83. [PMID: 28939971 DOI: 10.1007/164_2017_50] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Pharmacological chaperones recently opened new possibilities in G protein-coupled receptor drug discovery. Even more interestingly, some unique ligands combine pharmacological chaperoning and biased agonism properties, boosting their therapeutic interest in many human diseases resulting from G protein-coupled receptor mutation and misfolding. These compounds displaying dual characteristics would constitute a perfect treatment for congenital Nephrogenic Diabetes Insipidus, a typical conformational disease. This X-linked genetic pathology is mostly associated with inactivating mutations of the renal arginine-vasopressin V2 receptor leading to misfolding and intracellular retention of the receptor, causing the inability of patients to concentrate their urine in response to the antidiuretic hormone. Cell-permeable pharmacological chaperones have been successfully challenged to restore plasma membrane localization of many V2 receptor mutants. In addition, different classes of specific ligands such as antagonists, agonists as well as biased agonists of the V2 receptor have proven their usefulness in rescuing mutant receptor function. This is particularly relevant for small-molecule biased agonists which only trigger Gs protein activation and cyclic adenosine monophosphate production, the V2-induced signaling pathway responsible for water reabsorption. In parallel, high-throughput screening assays based on receptor trafficking rescue approaches have been developed to discover novel V2 pharmacological chaperone molecules from different chemical libraries. These new hit compounds, which still need to be pharmacologically characterized and functionally tested in vivo, represent promising candidates for the treatment of congenital Nephrogenic Diabetes Insipidus.
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Affiliation(s)
- Bernard Mouillac
- Institut de Génomique Fonctionnelle, CNRS, INSERM, Université de Montpellier, 141 rue de la cardonille, 34094, Montpellier Cedex 05, France.
| | - Christiane Mendre
- Institut de Génomique Fonctionnelle, CNRS, INSERM, Université de Montpellier, 141 rue de la cardonille, 34094, Montpellier Cedex 05, France
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34
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Bousfield GR, May JV, Davis JS, Dias JA, Kumar TR. In Vivo and In Vitro Impact of Carbohydrate Variation on Human Follicle-Stimulating Hormone Function. Front Endocrinol (Lausanne) 2018; 9:216. [PMID: 29867757 PMCID: PMC5960776 DOI: 10.3389/fendo.2018.00216] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 04/17/2018] [Indexed: 12/11/2022] Open
Abstract
Human follicle-stimulating hormone (FSH) exhibits both macro- and microheterogeneity in its carbohydrate moieties. Macroheterogeneity results in three physiologically relevant FSHβ subunit variants, two that possess a single N-linked glycan at either one of the two βL1 loop glycosylation sites or one with both glycans. Microheterogeneity is characterized by 80 to over 100 unique oligosaccharide structures attached to each of the 3 to 4 occupied N-glycosylation sites. With respect to its receptor, partially glycosylated (hypo-glycosylated) FSH variants exhibit higher association rates, greater apparent affinity, and greater occupancy than fully glycosylated FSH. Higher receptor binding-activity is reflected by greater in vitro bioactivity and, in some cases, greater in vivo bioactivity. Partially glycosylated pituitary FSH shows an age-related decline in abundance that may be associated with decreased fertility. In this review, we describe an integrated approach involving genetic models, in vitro signaling studies, FSH biochemistry, relevance of physiological changes in FSH glycoform abundance, and characterize the impact of FSH macroheterogeneity on fertility and reproductive aging. We will also address the controversy with regard to claims of a direct action of FSH in mediating bone loss especially at the peri- and postmenopausal stages.
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Affiliation(s)
- George R. Bousfield
- Department of Biological Sciences, Wichita State University, Wichita, KS, United States
- *Correspondence: George R. Bousfield,
| | - Jeffrey V. May
- Department of Biological Sciences, Wichita State University, Wichita, KS, United States
| | - John S. Davis
- Department of Obstetrics and Gynecology, University of Nebraska Medical Center, Omaha, NE, United States
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, United States
- Nebraska-Western Iowa Health Care System, Omaha, NE, United States
| | - James A. Dias
- Department of Biomedical Sciences, School of Public Health, University at Albany, Albany, NY, United States
| | - T. Rajendra Kumar
- Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
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35
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Peterson YK, Luttrell LM. The Diverse Roles of Arrestin Scaffolds in G Protein-Coupled Receptor Signaling. Pharmacol Rev 2017. [PMID: 28626043 DOI: 10.1124/pr.116.013367] [Citation(s) in RCA: 299] [Impact Index Per Article: 42.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The visual/β-arrestins, a small family of proteins originally described for their role in the desensitization and intracellular trafficking of G protein-coupled receptors (GPCRs), have emerged as key regulators of multiple signaling pathways. Evolutionarily related to a larger group of regulatory scaffolds that share a common arrestin fold, the visual/β-arrestins acquired the capacity to detect and bind activated GPCRs on the plasma membrane, which enables them to control GPCR desensitization, internalization, and intracellular trafficking. By acting as scaffolds that bind key pathway intermediates, visual/β-arrestins both influence the tonic level of pathway activity in cells and, in some cases, serve as ligand-regulated scaffolds for GPCR-mediated signaling. Growing evidence supports the physiologic and pathophysiologic roles of arrestins and underscores their potential as therapeutic targets. Circumventing arrestin-dependent GPCR desensitization may alleviate the problem of tachyphylaxis to drugs that target GPCRs, and find application in the management of chronic pain, asthma, and psychiatric illness. As signaling scaffolds, arrestins are also central regulators of pathways controlling cell growth, migration, and survival, suggesting that manipulating their scaffolding functions may be beneficial in inflammatory diseases, fibrosis, and cancer. In this review we examine the structure-function relationships that enable arrestins to perform their diverse roles, addressing arrestin structure at the molecular level, the relationship between arrestin conformation and function, and sites of interaction between arrestins, GPCRs, and nonreceptor-binding partners. We conclude with a discussion of arrestins as therapeutic targets and the settings in which manipulating arrestin function might be of clinical benefit.
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Affiliation(s)
- Yuri K Peterson
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy (Y.K.P.), and Departments of Medicine and Biochemistry and Molecular Biology (L.M.L.), Medical University of South Carolina, Charleston, South Carolina; and Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina (L.M.L.)
| | - Louis M Luttrell
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy (Y.K.P.), and Departments of Medicine and Biochemistry and Molecular Biology (L.M.L.), Medical University of South Carolina, Charleston, South Carolina; and Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina (L.M.L.)
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36
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Khurana L, Mackie K, Piomelli D, Kendall DA. Modulation of CB1 cannabinoid receptor by allosteric ligands: Pharmacology and therapeutic opportunities. Neuropharmacology 2017; 124:3-12. [PMID: 28527758 PMCID: PMC5540789 DOI: 10.1016/j.neuropharm.2017.05.018] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 04/12/2017] [Accepted: 05/16/2017] [Indexed: 02/03/2023]
Abstract
Cannabinoid pharmacology has been intensely studied because of cannabis' pervasive medicinal and non-medicinal uses as well as for the therapeutic potential of cannabinoid-based drugs for the treatment of pain, anxiety, substance abuse, obesity, cancer and neurodegenerative disorders. The identification of allosteric modulators of the cannabinoid receptor 1 (CB1) has given a new direction to the development of cannabinoid-based therapeutics due to the many advantages offered by targeting allosteric site(s). Allosteric receptor modulators hold potential to develop subtype-specific and pathway-specific therapeutics. Here we briefly discuss the first-generation of allosteric modulators of CB1 receptor, their structure-activity relationships, signaling pathways and the allosteric binding site(s) on the CB1 receptor. This article is part of the Special Issue entitled "A New Dawn in Cannabinoid Neurobiology".
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Affiliation(s)
- Leepakshi Khurana
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, CT 06269, United States
| | - Ken Mackie
- Gill Center and Departmental of Psychological and Brain Sciences, Indiana University, Bloomington, IN 47405, United States
| | - Daniele Piomelli
- Department of Anatomy and Neurobiology, University of California, Irvine, CA 92697, United States; Department of Biological Chemistry, University of California, Irvine, CA 92697, United States
| | - Debra A Kendall
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, CT 06269, United States.
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37
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Liebick M, Henze S, Vogt V, Oppermann M. Functional consequences of chemically-induced β-arrestin binding to chemokine receptors CXCR4 and CCR5 in the absence of ligand stimulation. Cell Signal 2017; 38:201-211. [PMID: 28733085 DOI: 10.1016/j.cellsig.2017.07.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 06/26/2017] [Accepted: 07/15/2017] [Indexed: 01/14/2023]
Abstract
Chemokine receptor signaling is a tightly regulated process which was for a long time exclusively attributed to heterotrimeric G proteins. β-Arrestins constitute a separable signaling arm from classical heterotrimeric G proteins, in addition to their well-established roles in receptor desensitization and endocytosis. In order to clearly dissect β-arrestin- from G protein-dependent effects we forced the recruitment of β-arrestin to CXCR4 and CCR5 independently of agonist-promoted receptor activation through chemically-induced dimerization. Targeting β-arrestins to receptors at the plasma membrane prior to chemokine stimulation attenuated G protein-mediated calcium release. Association of β-arrestins to the receptors was sufficient to induce their internalization in the absence of ligand and this effect could be further enhanced by translocation of a constitutively active β-arrestin 1 variant. CXCR4 and CCR5 were targeted to different intracellular compartments upon chemical-induced dimerization with β-arrestins and reproduced the intracellular distribution of receptors after activation with their respective ligands. Our data further provide evidence for direct β-arrestin-mediated signaling via MAP kinases ERK 1/2. These results provide clear evidence that CXCR4- or CCR5-β-arrestin complexes induce receptor endocytosis and signaling in the absence of G protein coupling and ligand-induced conformational changes of the receptor.
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Affiliation(s)
- Marcel Liebick
- Department of Cellular and Molecular Immunology, University of Göttingen, Göttingen, Niedersachsen, Germany.
| | - Sarah Henze
- Department of Cellular and Molecular Immunology, University of Göttingen, Göttingen, Niedersachsen, Germany
| | - Viola Vogt
- Department of Cellular and Molecular Immunology, University of Göttingen, Göttingen, Niedersachsen, Germany
| | - Martin Oppermann
- Department of Cellular and Molecular Immunology, University of Göttingen, Göttingen, Niedersachsen, Germany
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38
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Abstract
G protein-coupled receptors, such as the cannabinoid type 1 receptor (CB1R), have been shown to interact with multiple binding partners to transmit signals. In both transfected cell systems and in endogenously expressing cell lines, CB1R signaling has been described as multifaceted. The question remains as to how this highly widely expressed receptor signals in a given cell at a given time in vivo. The concept of functional selectivity, or biased agonism, describes the ability of an agonist to engage the receptor in a manner that preferentially engages certain signaling interactions (e.g., G proteins) over others (e.g., β-arrestins), presumably by stabilizing certain receptor conformations. There is growing interest in using such properties of ligands to direct signaling downstream of CB1R toward desirable therapeutic outcomes and to avoid adverse side effects. While it is not currently clear what pathways should be engaged and which should be avoided, the development of biased agonist tool compounds will aid in answering these questions. In this chapter, we discuss the approaches and caveats to assessing biased agonism at the CB1R.
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Affiliation(s)
| | - Edward L Stahl
- The Scripps Research Institute, Jupiter, FL, United States
| | - Laura M Bohn
- The Scripps Research Institute, Jupiter, FL, United States.
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Woolley MJ, Conner AC. Understanding the common themes and diverse roles of the second extracellular loop (ECL2) of the GPCR super-family. Mol Cell Endocrinol 2017; 449:3-11. [PMID: 27899324 DOI: 10.1016/j.mce.2016.11.023] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 11/02/2016] [Accepted: 11/24/2016] [Indexed: 11/16/2022]
Abstract
The extracellular loops (ECLs) of G protein-coupled receptors (GPCRs) can bind directly to docked orthosteric or allosteric ligands, they can contain transient contact points for ligand entry into the transmembrane (TM) bundle and they can regulate the activation of the receptor signalling pathways. Of the three ECLs, ECL2 is the largest and most structurally diverse reflecting its functional importance. This has been shown through biochemical techniques and has been supported by the many subsequent crystal structures of GPCRs bound to both agonists and antagonists. ECL2 shares common structural features between (and sometimes across) receptor sub-families and can facilitate ligand entry to the TM core or act directly as a surface of the ligand-binding pocket. Structural similarities seem to underpin common binding mechanisms; however, where these exist, variations in primary sequence ensure ligand-binding specificity. This review will compare current understanding of the structural themes and main functional roles of ECL2 in ligand binding, activation and regulation of the major families of GPCRs.
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Affiliation(s)
- Michael J Woolley
- Institute of Clinical Sciences, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, UK
| | - Alex C Conner
- Institute of Clinical Sciences, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, UK.
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40
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Takezako T, Unal H, Karnik SS, Node K. Current topics in angiotensin II type 1 receptor research: Focus on inverse agonism, receptor dimerization and biased agonism. Pharmacol Res 2017. [PMID: 28648738 DOI: 10.1016/j.phrs.2017.06.013] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Although the octapeptide hormone angiotensin II (Ang II) regulates cardiovascular and renal homeostasis through the Ang II type 1 receptor (AT1R), overstimulation of AT1R causes various human diseases, such as hypertension and cardiac hypertrophy. Therefore, AT1R blockers (ARBs) have been widely used as therapeutic drugs for these diseases. Recent basic research and clinical studies have resulted in the discovery of interesting phenomena associated with AT1R function. For example, ligand-independent activation of AT1R by mechanical stress and agonistic autoantibodies, as well as via receptor mutations, has been shown to decrease the inverse agonistic efficacy of ARBs, though the molecular mechanisms of such phenomena had remained elusive until recently. Furthermore, although AT1R is believed to exist as a monomer, recent studies have demonstrated that AT1R can homodimerize and heterodimerize with other G-protein coupled receptors (GPCR), altering the receptor signaling properties. Therefore, formation of both AT1R homodimers and AT1R-GPCR heterodimer may be involved in the pathogenesis of human disease states, such as atherosclerosis and preeclampsia. Finally, biased AT1R ligands that can preferentially activate the β-arrestin-mediated signaling pathway have been discovered. Such β-arrestin-biased AT1R ligands may be better therapeutic drugs for cardiovascular diseases. New findings on AT1R described herein could provide a conceptual framework for application of ARBs in the treatment of diseases, as well as for novel drug development. Since AT1R is an extensively studied member of the GPCR superfamily encoded in the human genome, this review is relevant for understanding the functions of other members of this superfamily.
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Affiliation(s)
- Takanobu Takezako
- Department of Advanced Heart Research, Saga University, Saga, Japan; Medical Center for Student Health, Kobe University, Kobe, Japan.
| | - Hamiyet Unal
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Sadashiva S Karnik
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Koichi Node
- Department of Cardiovascular Medicine, Saga University, Japan
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Regulation of G Protein-Coupled Receptors by Ubiquitination. Int J Mol Sci 2017; 18:ijms18050923. [PMID: 28448471 PMCID: PMC5454836 DOI: 10.3390/ijms18050923] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 04/20/2017] [Accepted: 04/23/2017] [Indexed: 02/07/2023] Open
Abstract
G protein-coupled receptors (GPCRs) comprise the largest family of membrane receptors that control many cellular processes and consequently often serve as drug targets. These receptors undergo a strict regulation by mechanisms such as internalization and desensitization, which are strongly influenced by posttranslational modifications. Ubiquitination is a posttranslational modification with a broad range of functions that is currently gaining increased appreciation as a regulator of GPCR activity. The role of ubiquitination in directing GPCRs for lysosomal degradation has already been well-established. Furthermore, this modification can also play a role in targeting membrane and endoplasmic reticulum-associated receptors to the proteasome. Most recently, ubiquitination was also shown to be involved in GPCR signaling. In this review, we present current knowledge on the molecular basis of GPCR regulation by ubiquitination, and highlight the importance of E3 ubiquitin ligases, deubiquitinating enzymes and β-arrestins. Finally, we discuss classical and newly-discovered functions of ubiquitination in controlling GPCR activity.
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42
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Cairns EA, Toguri JT, Porter RF, Szczesniak AM, Kelly MEM. Seeing over the horizon - targeting the endocannabinoid system for the treatment of ocular disease. J Basic Clin Physiol Pharmacol 2017; 27:253-65. [PMID: 26565550 DOI: 10.1515/jbcpp-2015-0065] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 09/25/2015] [Indexed: 01/09/2023]
Abstract
The observation that marijuana reduces intraocular pressure was made by Hepler and Frank in the 1970s. Since then, there has been a significant body of work investigating cannabinoids for their potential use as therapeutics. To date, no endocannabinoid system (ECS)-modulating drug has been approved for clinical use in the eye; however, recent advances in our understanding of the ECS, as well as new pharmacological tools, has renewed interest in the development of ocular ECS-based therapeutics. This review summarizes the current state-of-affairs for the use of ECS-modulating drugs for the treatment of glaucoma and ocular inflammatory and ischemic disease.
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Human Luteinizing Hormone and Chorionic Gonadotropin Display Biased Agonism at the LH and LH/CG Receptors. Sci Rep 2017; 7:940. [PMID: 28424471 PMCID: PMC5430435 DOI: 10.1038/s41598-017-01078-8] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 03/27/2017] [Indexed: 12/12/2022] Open
Abstract
Human luteinizing hormone (LH) and chorionic gonadotropin (hCG) have been considered biologically equivalent because of their structural similarities and their binding to the same receptor; the LH/CGR. However, accumulating evidence suggest that LH/CGR differentially responds to the two hormones triggering differential intracellular signaling and steroidogenesis. The mechanistic basis of such differential responses remains mostly unknown. Here, we compared the abilities of recombinant rhLH and rhCG to elicit cAMP, β-arrestin 2 activation, and steroidogenesis in HEK293 cells and mouse Leydig tumor cells (mLTC-1). For this, BRET and FRET technologies were used allowing quantitative analyses of hormone activities in real-time and in living cells. Our data indicate that rhLH and rhCG differentially promote cell responses mediated by LH/CGR revealing interesting divergences in their potencies, efficacies and kinetics: rhCG was more potent than rhLH in both HEK293 and mLTC-1 cells. Interestingly, partial effects of rhLH were found on β-arrestin recruitment and on progesterone production compared to rhCG. Such a link was further supported by knockdown experiments. These pharmacological differences demonstrate that rhLH and rhCG act as natural biased agonists. The discovery of novel mechanisms associated with gonadotropin-specific action may ultimately help improve and personalize assisted reproduction technologies.
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44
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Truong PM, Hassan SA, Lee YS, Kopajtic TA, Katz JL, Chadderdon AM, Traynor JR, Deschamps JR, Jacobson AE, Rice KC. Modulation of opioid receptor affinity and efficacy via N-substitution of 9β-hydroxy-5-(3-hydroxyphenyl)morphan: Synthesis and computer simulation study. Bioorg Med Chem 2017; 25:2406-2422. [PMID: 28314512 PMCID: PMC5407189 DOI: 10.1016/j.bmc.2017.02.064] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 02/27/2017] [Indexed: 10/20/2022]
Abstract
The enantiomers of a variety of N-alkyl-, N-aralkyl-, and N-cyclopropylalkyl-9β-hydroxy-5-(3-hydroxyphenyl)morphans were synthesized employing cyanogen bromide and K2CO3 to improve the original N-demethylation procedure. Their binding affinity to the μ-, δ-, and κ-opioid receptors (ORs) was determined and functional (GTPγ35S) assays were carried out on those with reasonable affinity. The 1R,5R,9S-enantiomers (1R,5R,9S)-(-)-5-(3-hydroxyphenyl)-2-(4-nitrophenethyl)-2-azabicyclo[3.3.1]nonan-9-ol (1R,5R,9S-16), (1R,5R,9S)-(-) 2-cinnamyl-5-(3-hydroxyphenyl)-2-azabicyclo[3.3.1]nonan-9-ol (1R,5R,9S-20), and (1R,5R,9S)-(-)-5-(3-hydroxyphenyl)-2-(4-(trifluoromethyl)phenethyl)-2-azabicyclo[3.3.1]nonan-9-ol (1R,5R,9S-15), had high affinity for the μ-opioid receptor (e.g., 1R,5R,9S-16: Ki=0.073, 0.74, and 1.99nM, respectively). The 1R,5R,9S-16 and 1R,5R,9S-15 were full, high efficacy μ-agonists (EC50=0.74 and 18.5nM, respectively) and the former was found to be a partial agonist at δ-OR and an antagonist at κ-OR, while the latter was a partial agonist at δ-OR and κ-OR in the GTPγ35S assay. The enantiomer of 1R,5R,9S-16, (+)-1S,5S,9R-16 was unusual, it had good affinity for the μ-OR (Ki=26.5nM) and was an efficacious μ-antagonist (Ke=29.1nM). Molecular dynamics simulations of the μ-OR were carried out with the 1R,5R,9S-16 μ-agonist and the previously synthesized (1R,5R,9S)-(-)-5-(9-hydroxy-5-(3-hydroxyphenyl-2-phenylethyl)-2-azabicyclo[3.3.1]nonane (1R,5R,9S-(-)-NIH 11289) to provide a structural basis for the observed high affinities and efficacies. The critical roles of both the 9β-OH and the p-nitro group are elucidated, with the latter forming direct, persistent hydrogen bonds with residues deep in the binding cavity, and the former interacting with specific residues via highly structured water bridges.
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Affiliation(s)
- Phong M Truong
- Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse and the National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Department of Health and Human Services, 9800 Medical Center Drive, Bethesda, MD 20892-3373, United States
| | - Sergio A Hassan
- Center for Molecular Modeling, Office of Intramural Research, Center for Information Technology, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892, United States
| | - Yong-Sok Lee
- Center for Molecular Modeling, Office of Intramural Research, Center for Information Technology, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892, United States
| | - Theresa A Kopajtic
- Psychobiology Section, Molecular Neuropsychiatry Research Branch, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Department of Health and Human Services, Baltimore, MD 21224, United States
| | - Jonathan L Katz
- Psychobiology Section, Molecular Neuropsychiatry Research Branch, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Department of Health and Human Services, Baltimore, MD 21224, United States
| | - Aaron M Chadderdon
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI 48109, United States
| | - John R Traynor
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI 48109, United States
| | - Jeffrey R Deschamps
- Center for Biomolecular Science and Engineering, Naval Research Laboratory, Washington DC 20375, United States
| | - Arthur E Jacobson
- Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse and the National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Department of Health and Human Services, 9800 Medical Center Drive, Bethesda, MD 20892-3373, United States
| | - Kenner C Rice
- Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse and the National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Department of Health and Human Services, 9800 Medical Center Drive, Bethesda, MD 20892-3373, United States.
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45
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Dyckman AJ. Modulators of Sphingosine-1-phosphate Pathway Biology: Recent Advances of Sphingosine-1-phosphate Receptor 1 (S1P 1) Agonists and Future Perspectives. J Med Chem 2017; 60:5267-5289. [PMID: 28291340 DOI: 10.1021/acs.jmedchem.6b01575] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The sphingoid base derived class of lipids (sphingolipids) is a family of interconverting molecules that play key roles in numerous structural and signaling processes. The biosynthetic pathway of the sphingolipids affords many opportunities for therapeutic intervention: targeting the ligands directly, targeting the various proteins involved in the interconversion of the ligands, or targeting the receptors that respond to the ligands. The focus of this article is on the most advanced of the sphingosine-related therapeutics, agonists of sphingosine-1-phosphate receptor 1 (S1P1). The diverse structural classes of S1P1 agonists will be discussed and the status of compounds of clinical relevance will be detailed. An examination of how potential safety concerns are being navigated with compounds currently under clinical evaluation is followed by a discussion of the novel methods being explored to identify next-generation S1P1 agonists with improved safety profiles. Finally, therapeutic opportunities for sphingosine-related targets outside of S1P1 are touched upon.
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Affiliation(s)
- Alaric J Dyckman
- Research and Development, Bristol-Myers Squibb Company , P.O. Box 4000, Princeton, New Jersey 08543-4000, United States
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46
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Mallipeddi S, Janero DR, Zvonok N, Makriyannis A. Functional selectivity at G-protein coupled receptors: Advancing cannabinoid receptors as drug targets. Biochem Pharmacol 2017; 128:1-11. [PMID: 27890725 PMCID: PMC5470118 DOI: 10.1016/j.bcp.2016.11.014] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 11/14/2016] [Indexed: 12/11/2022]
Abstract
The phenomenon of functional selectivity, whereby a ligand preferentially directs the information output of a G-protein coupled receptor (GPCR) along (a) particular effector pathway(s) and away from others, has redefined traditional GPCR signaling paradigms to provide a new approach to structure-based drug design. The two principal cannabinoid receptors (CBRs) 1 and 2 belong to the class-A GPCR subfamily and are considered tenable therapeutic targets for several indications. Yet conventional orthosteric ligands (agonists, antagonists/inverse agonists) for these receptors have had very limited clinical utility due to their propensity to incite on-target adverse events. Chemically distinct classes of cannabinergic ligands exhibit signaling bias at CBRs towards individual subsets of signal transduction pathways. In this review, we discuss the known signaling pathways regulated by CBRs and examine the current evidence for functional selectivity at CBRs in response to endogenous and exogenous cannabinergic ligands as biased agonists. We further discuss the receptor and ligand structural features allowing for selective activation of CBR-dependent functional responses. The design and development of biased ligands may offer a pathway to therapeutic success for novel CBR-targeted drugs.
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Affiliation(s)
- Srikrishnan Mallipeddi
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02115, United States; Center for Drug Discovery, Northeastern University, Boston, MA 02115, United States
| | - David R Janero
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02115, United States; Center for Drug Discovery, Northeastern University, Boston, MA 02115, United States
| | - Nikolai Zvonok
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02115, United States; Center for Drug Discovery, Northeastern University, Boston, MA 02115, United States
| | - Alexandros Makriyannis
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02115, United States; Center for Drug Discovery, Northeastern University, Boston, MA 02115, United States; Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115, United States.
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47
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Yang Z, Yang F, Zhang D, Liu Z, Lin A, Liu C, Xiao P, Yu X, Sun JP. Phosphorylation of G Protein-Coupled Receptors: From the Barcode Hypothesis to the Flute Model. Mol Pharmacol 2017; 92:201-210. [DOI: 10.1124/mol.116.107839] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2016] [Accepted: 02/23/2017] [Indexed: 12/21/2022] Open
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48
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Halls ML, Cooper DMF. Adenylyl cyclase signalling complexes - Pharmacological challenges and opportunities. Pharmacol Ther 2017; 172:171-180. [PMID: 28132906 DOI: 10.1016/j.pharmthera.2017.01.001] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Signalling pathways involving the vital second messanger, cAMP, impact on most significant physiological processes. Unsurprisingly therefore, the activation and regulation of cAMP signalling is tightly controlled within the cell by processes including phosphorylation, the scaffolding of protein signalling complexes and sub-cellular compartmentalisation. This inherent complexity, along with the highly conserved structure of the catalytic sites among the nine membrane-bound adenylyl cyclases, presents significant challenges for efficient inhibition of cAMP signalling. Here, we will describe the biochemistry and cell biology of the family of membrane-bound adenylyl cyclases, their organisation within the cell, and the nature of the cAMP signals that they produce, as a prelude to considering how cAMP signalling might be perturbed. We describe the limitations associated with direct inhibition of adenylyl cyclase activity, and evaluate alternative strategies for more specific targeting of adenylyl cyclase signalling. The inherent complexity in the activation and organisation of adenylyl cyclase activity may actually provide unique opportunities for selectively targeting discrete adenylyl cyclase functions in disease.
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Affiliation(s)
- Michelle L Halls
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052, Victoria, Australia
| | - Dermot M F Cooper
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK.
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49
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Nogueras-Ortiz C, Yudowski GA. The Multiple Waves of Cannabinoid 1 Receptor Signaling. Mol Pharmacol 2016; 90:620-626. [PMID: 27338082 PMCID: PMC11037448 DOI: 10.1124/mol.116.104539] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 06/22/2016] [Indexed: 12/15/2022] Open
Abstract
The cannabinoid 1 receptor (CB1R) is one of the most abundant G protein-coupled receptors (GPCRs) in the central nervous system, with key roles during neurotransmitter release and synaptic plasticity. Upon ligand activation, CB1Rs may signal in three different spatiotemporal waves. The first wave, which is transient (<10 minutes) and initiated by heterotrimeric G proteins, is followed by a second wave (>5 minutes) that is mediated by β-arrestins. The third and final wave occurs at intracellular compartments and could be elicited by G proteins or β-arrestins. This complexity presents multiple challenges, including the correct classification of receptor ligands, the identification of the signaling pathways regulated by each wave, and the underlying molecular mechanisms and physiologic impacts of these waves. Simultaneously, it provides new opportunities to harness the therapeutic potential of the cannabinoid system and other GPCRs. Over the last several years, we have significantly expanded our understanding of the mechanisms and pathways downstream from the CB1R. The identification of receptor mutations that can bias signaling to specific pathways and the use of siRNA technology have been key tools to identifying which signaling cascades are controlled by G proteins or β-arrestins. Here, we review our current knowledge on CB1R signaling, with particular emphasis on the mechanisms and cascades mediated by β-arrestins downstream from the CB1R.
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Affiliation(s)
- Carlos Nogueras-Ortiz
- Institute of Neurobiology(C.N.-O., G.A.Y.) and Department of Anatomy and Neurobiology (G.A.Y.), University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico
| | - Guillermo A Yudowski
- Institute of Neurobiology(C.N.-O., G.A.Y.) and Department of Anatomy and Neurobiology (G.A.Y.), University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico
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50
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Roy I, Getschman AE, Volkman BF, Dwinell MB. Exploiting agonist biased signaling of chemokines to target cancer. Mol Carcinog 2016; 56:804-813. [PMID: 27648825 DOI: 10.1002/mc.22571] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 09/12/2016] [Accepted: 09/16/2016] [Indexed: 12/20/2022]
Abstract
As knowledge of growth-independent functions of cancer cells is expanding, exploration into the role of chemokines in modulating cancer pathogenesis, particularly metastasis, continues to develop. However, more study into the mechanisms whereby chemokines direct the migration of cancer cells is needed before specific therapies can be generated to target metastasis. Herein, we draw attention to the longstanding conundrum in the field of chemokine biology that chemokines stimulate migration in a biphasic manner; and explore this phenomenon's impact on chemokine function in the context of cancer. Typically, low concentrations of chemokines lead to chemotactic migration and higher concentrations halt migration. The signaling mechanisms that govern this phenomenon remain unclear. Over the last decade, we have defined a novel signaling mechanism for regulation of chemokine migration through ligand oligomerization and biased agonist signaling. We provide insight into this new paradigm for chemokine signaling and discuss how it will impact future exploration into chemokine function and biology. In the pursuit of producing more novel cancer therapies, we suggest a framework for pharmaceutical application of the principles of chemokine oligomerization and biased agonist signaling in cancer. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Ishan Roy
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Anthony E Getschman
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Brian F Volkman
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Michael B Dwinell
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin.,MCW Cancer Center, Medical College of Wisconsin, Milwaukee, Wisconsin
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