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Agonist-Specific Recruitment of Arrestin Isoforms Differentially Modify Delta Opioid Receptor Function. J Neurosci 2016; 36:3541-51. [PMID: 27013682 DOI: 10.1523/jneurosci.4124-15.2016] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 02/11/2016] [Indexed: 12/28/2022] Open
Abstract
UNLABELLED Ligand-specific recruitment of arrestins facilitates functional selectivity of G-protein-coupled receptor signaling. Here, we describe agonist-selective recruitment of different arrestin isoforms to the delta opioid receptor in mice. A high-internalizing delta opioid receptor agonist (SNC80) preferentially recruited arrestin 2 and, in arrestin 2 knock-outs (KOs), we observed a significant increase in the potency of SNC80 to inhibit mechanical hyperalgesia and decreased acute tolerance. In contrast, the low-internalizing delta agonists (ARM390, JNJ20788560) preferentially recruited arrestin 3 with unaltered behavioral effects in arrestin 2 KOs. Surprisingly, arrestin 3 KO revealed an acute tolerance to these low-internalizing agonists, an effect never observed in wild-type animals. Furthermore, we examined delta opioid receptor-Ca(2+)channel coupling in dorsal root ganglia desensitized by ARM390 and the rate of resensitization was correspondingly decreased in arrestin 3 KOs. Live-cell imaging in HEK293 cells revealed that delta opioid receptors are in pre-engaged complexes with arrestin 3 at the cell membrane and that ARM390 strengthens this membrane interaction. The disruption of these complexes in arrestin 3 KOs likely accounts for the altered responses to low-internalizing agonists. Together, our results show agonist-selective recruitment of arrestin isoforms and reveal a novel endogenous role of arrestin 3 as a facilitator of resensitization and an inhibitor of tolerance mechanisms. SIGNIFICANCE STATEMENT Agonists that bind to the same receptor can produce highly distinct signaling events and arrestins are a major mediator of this ligand bias. Here, we demonstrate that delta opioid receptor agonists differentially recruit arrestin isoforms. We found that the high-internalizing agonist SNC80 preferentially recruits arrestin 2 and knock-out (KO) of this protein results in increased efficacy of SNC80. In contrast, low-internalizing agonists (ARM390 and JNJ20788560) preferentially recruit arrestin 3 and, surprisingly, KO of arrestin 3 produces acute tolerance and impaired receptor resensitization to these agonists. Arrestin 3 is in pre-engaged complexes with the delta opioid receptor at the cell membrane and low-internalizing agonists promote this interaction. This study reveals a novel role for arrestin 3 as a facilitator of receptor resensitization.
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52
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Characterization of the interaction between the dopamine D4 receptor, KLHL12 and β-arrestins. Cell Signal 2016; 28:1001-14. [DOI: 10.1016/j.cellsig.2016.05.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2016] [Revised: 04/27/2016] [Accepted: 05/02/2016] [Indexed: 01/11/2023]
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β-arrestin-biased signaling through the β2-adrenergic receptor promotes cardiomyocyte contraction. Proc Natl Acad Sci U S A 2016; 113:E4107-16. [PMID: 27354517 DOI: 10.1073/pnas.1606267113] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
β-adrenergic receptors (βARs) are critical regulators of acute cardiovascular physiology. In response to elevated catecholamine stimulation during development of congestive heart failure (CHF), chronic activation of Gs-dependent β1AR and Gi-dependent β2AR pathways leads to enhanced cardiomyocyte death, reduced β1AR expression, and decreased inotropic reserve. β-blockers act to block excessive catecholamine stimulation of βARs to decrease cellular apoptotic signaling and normalize β1AR expression and inotropy. Whereas these actions reduce cardiac remodeling and mortality outcomes, the effects are not sustained. Converse to G-protein-dependent signaling, β-arrestin-dependent signaling promotes cardiomyocyte survival. Given that β2AR expression is unaltered in CHF, a β-arrestin-biased agonist that operates through the β2AR represents a potentially useful therapeutic approach. Carvedilol, a currently prescribed nonselective β-blocker, has been classified as a β-arrestin-biased agonist that can inhibit basal signaling from βARs and also stimulate cell survival signaling pathways. To understand the relative contribution of β-arrestin bias to the efficacy of select β-blockers, a specific β-arrestin-biased pepducin for the β2AR, intracellular loop (ICL)1-9, was used to decouple β-arrestin-biased signaling from occupation of the orthosteric ligand-binding pocket. With similar efficacy to carvedilol, ICL1-9 was able to promote β2AR phosphorylation, β-arrestin recruitment, β2AR internalization, and β-arrestin-biased signaling. Interestingly, ICL1-9 was also able to induce β2AR- and β-arrestin-dependent and Ca(2+)-independent contractility in primary adult murine cardiomyocytes, whereas carvedilol had no efficacy. Thus, ICL1-9 is an effective tool to access a pharmacological profile stimulating cardioprotective signaling and inotropic effects through the β2AR and serves as a model for the next generation of cardiovascular drug development.
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From biased signalling to polypharmacology: unlocking unique intracellular signalling using pepducins. Biochem Soc Trans 2016; 44:555-61. [DOI: 10.1042/bst20150230] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Indexed: 01/06/2023]
Abstract
For over a decade, pepducins have been utilized to develop unique pharmacological profiles that have been particularly challenging for traditional drug discovery methods. It is becoming increasingly clear that these cell-penetrating lipopeptides can access receptor conformations that are currently not accessible through orthosteric targeting. This review addresses the emerging concepts in the development of pepducins including the elicitation of biased signalling, pepducin polypharmacology and recent insight into their mechanism of action.
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55
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Lee MH, Appleton KM, Strungs EG, Kwon JY, Morinelli TA, Peterson YK, Laporte SA, Luttrell LM. The conformational signature of β-arrestin2 predicts its trafficking and signalling functions. Nature 2016; 531:665-8. [PMID: 27007854 PMCID: PMC4973468 DOI: 10.1038/nature17154] [Citation(s) in RCA: 156] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 01/19/2016] [Indexed: 12/11/2022]
Abstract
Arrestins are cytosolic proteins that regulate G-protein-coupled receptor (GPCR) desensitization, internalization, trafficking and signalling. Arrestin recruitment uncouples GPCRs from heterotrimeric G proteins, and targets the proteins for internalization via clathrin-coated pits. Arrestins also function as ligand-regulated scaffolds that recruit multiple non-G-protein effectors into GPCR-based 'signalsomes'. Although the dominant function(s) of arrestins vary between receptors, the mechanism whereby different GPCRs specify these divergent functions is unclear. Using a panel of intramolecular fluorescein arsenical hairpin (FlAsH) bioluminescence resonance energy transfer (BRET) reporters to monitor conformational changes in β-arrestin2, here we show that GPCRs impose distinctive arrestin 'conformational signatures' that reflect the stability of the receptor-arrestin complex and role of β-arrestin2 in activating or dampening downstream signalling events. The predictive value of these signatures extends to structurally distinct ligands activating the same GPCR, such that the innate properties of the ligand are reflected as changes in β-arrestin2 conformation. Our findings demonstrate that information about ligand-receptor conformation is encoded within the population average β-arrestin2 conformation, and provide insight into how different GPCRs can use a common effector for different purposes. This approach may have application in the characterization and development of functionally selective GPCR ligands and in identifying factors that dictate arrestin conformation and function.
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Affiliation(s)
- Mi-Hye Lee
- Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, USA 29425
| | - Kathryn M. Appleton
- Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, USA 29425
| | - Erik G. Strungs
- Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, USA 29425
| | - Joshua Y. Kwon
- Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, USA 29425
| | - Thomas A. Morinelli
- Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, USA 29425
| | - Yuri K. Peterson
- Department of Pharmaceutical & Biomedical Sciences, College of Pharmacy, Medical University of South Carolina, Charleston, SC, USA 29425
| | - Stephane A. Laporte
- Departments of Medicine, Pharmacology and Therapeutics, and Anatomy and Cell Biology, McGill University Health Center Research Institute, McGill University, Quebec, CANADA H4A 3J1
| | - Louis M. Luttrell
- Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, USA 29425
- Research Service of the Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC, USA 29401
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56
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Delgado-Peraza F, Ahn KH, Nogueras-Ortiz C, Mungrue IN, Mackie K, Kendall DA, Yudowski GA. Mechanisms of Biased β-Arrestin-Mediated Signaling Downstream from the Cannabinoid 1 Receptor. Mol Pharmacol 2016; 89:618-29. [PMID: 27009233 PMCID: PMC4885504 DOI: 10.1124/mol.115.103176] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Accepted: 03/22/2016] [Indexed: 12/23/2022] Open
Abstract
Activation of G protein-coupled receptors results in multiple waves of signaling that are mediated by heterotrimeric G proteins and the scaffolding proteins β-arrestin 1/2. Ligands can elicit full or subsets of cellular responses, a concept defined as ligand bias or functional selectivity. However, our current understanding of β-arrestin-mediated signaling is still very limited. Here we provide a comprehensive view of β-arrestin-mediated signaling from the cannabinoid 1 receptor (CB1R). By using a signaling biased receptor, we define the cascades, specific receptor kinases, and molecular mechanism underlying β-arrestin-mediated signaling: We identify the interaction kinetics of CB1R and β-arrestin 1 during their endocytic trafficking as directly proportional to its efficacy. Finally, we demonstrate that signaling results in the control of genes clustered around prosurvival and proapoptotic functions among others. Together, these studies constitute a comprehensive description of β-arrestin-mediated signaling from CB1Rs and suggest modulation of receptor endocytic trafficking as a therapeutic approach to control β-arrestin-mediated signaling.
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Affiliation(s)
- Francheska Delgado-Peraza
- Department of Anatomy and Neurobiology (F.D.-P., G.A.Y.) and Institute of Neurobiology (F.D.-P., C.N.-O., G.A.Y.), University of Puerto Rico - Medical Sciences Campus, San Juan, Puerto Rico; Department of Pharmaceutical Sciences, University of Connecticut, Storrs, Connecticut (K.H.A., D.A.K.); Department of Pharmacology & Experimental Therapeutics, Louisiana State University Health Sciences Center, New Orleans, Louisiana (I.N.M.); and Department of Psychological & Brain Sciences, Gill Center for Biomedical Sciences, Indiana University, Bloomington, Indiana (K.M.)
| | - Kwang H Ahn
- Department of Anatomy and Neurobiology (F.D.-P., G.A.Y.) and Institute of Neurobiology (F.D.-P., C.N.-O., G.A.Y.), University of Puerto Rico - Medical Sciences Campus, San Juan, Puerto Rico; Department of Pharmaceutical Sciences, University of Connecticut, Storrs, Connecticut (K.H.A., D.A.K.); Department of Pharmacology & Experimental Therapeutics, Louisiana State University Health Sciences Center, New Orleans, Louisiana (I.N.M.); and Department of Psychological & Brain Sciences, Gill Center for Biomedical Sciences, Indiana University, Bloomington, Indiana (K.M.)
| | - Carlos Nogueras-Ortiz
- Department of Anatomy and Neurobiology (F.D.-P., G.A.Y.) and Institute of Neurobiology (F.D.-P., C.N.-O., G.A.Y.), University of Puerto Rico - Medical Sciences Campus, San Juan, Puerto Rico; Department of Pharmaceutical Sciences, University of Connecticut, Storrs, Connecticut (K.H.A., D.A.K.); Department of Pharmacology & Experimental Therapeutics, Louisiana State University Health Sciences Center, New Orleans, Louisiana (I.N.M.); and Department of Psychological & Brain Sciences, Gill Center for Biomedical Sciences, Indiana University, Bloomington, Indiana (K.M.)
| | - Imran N Mungrue
- Department of Anatomy and Neurobiology (F.D.-P., G.A.Y.) and Institute of Neurobiology (F.D.-P., C.N.-O., G.A.Y.), University of Puerto Rico - Medical Sciences Campus, San Juan, Puerto Rico; Department of Pharmaceutical Sciences, University of Connecticut, Storrs, Connecticut (K.H.A., D.A.K.); Department of Pharmacology & Experimental Therapeutics, Louisiana State University Health Sciences Center, New Orleans, Louisiana (I.N.M.); and Department of Psychological & Brain Sciences, Gill Center for Biomedical Sciences, Indiana University, Bloomington, Indiana (K.M.)
| | - Ken Mackie
- Department of Anatomy and Neurobiology (F.D.-P., G.A.Y.) and Institute of Neurobiology (F.D.-P., C.N.-O., G.A.Y.), University of Puerto Rico - Medical Sciences Campus, San Juan, Puerto Rico; Department of Pharmaceutical Sciences, University of Connecticut, Storrs, Connecticut (K.H.A., D.A.K.); Department of Pharmacology & Experimental Therapeutics, Louisiana State University Health Sciences Center, New Orleans, Louisiana (I.N.M.); and Department of Psychological & Brain Sciences, Gill Center for Biomedical Sciences, Indiana University, Bloomington, Indiana (K.M.)
| | - Debra A Kendall
- Department of Anatomy and Neurobiology (F.D.-P., G.A.Y.) and Institute of Neurobiology (F.D.-P., C.N.-O., G.A.Y.), University of Puerto Rico - Medical Sciences Campus, San Juan, Puerto Rico; Department of Pharmaceutical Sciences, University of Connecticut, Storrs, Connecticut (K.H.A., D.A.K.); Department of Pharmacology & Experimental Therapeutics, Louisiana State University Health Sciences Center, New Orleans, Louisiana (I.N.M.); and Department of Psychological & Brain Sciences, Gill Center for Biomedical Sciences, Indiana University, Bloomington, Indiana (K.M.)
| | - Guillermo A Yudowski
- Department of Anatomy and Neurobiology (F.D.-P., G.A.Y.) and Institute of Neurobiology (F.D.-P., C.N.-O., G.A.Y.), University of Puerto Rico - Medical Sciences Campus, San Juan, Puerto Rico; Department of Pharmaceutical Sciences, University of Connecticut, Storrs, Connecticut (K.H.A., D.A.K.); Department of Pharmacology & Experimental Therapeutics, Louisiana State University Health Sciences Center, New Orleans, Louisiana (I.N.M.); and Department of Psychological & Brain Sciences, Gill Center for Biomedical Sciences, Indiana University, Bloomington, Indiana (K.M.)
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57
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Bitter taste receptors: Novel insights into the biochemistry and pharmacology. Int J Biochem Cell Biol 2016; 77:184-96. [PMID: 26995065 DOI: 10.1016/j.biocel.2016.03.005] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Revised: 03/14/2016] [Accepted: 03/15/2016] [Indexed: 01/14/2023]
Abstract
Bitter taste receptors (T2Rs) belong to the super family of G protein-coupled receptors (GPCRs). There are 25 T2Rs expressed in humans, and these interact with a large and diverse group of bitter ligands. T2Rs are expressed in many extra-oral tissues and can perform diverse physiological roles. Structure-function studies led to the identification of similarities and dissimilarities between T2Rs and Class A GPCRs including amino acid conservation and novel motifs. However, the efficacy of most of the T2R ligands is not yet elucidated and the biochemical pharmacology of T2Rs is poorly understood. Recent studies on T2Rs characterized novel ligands including blockers for these receptors that include inverse agonist and antagonists. In this review we discuss the techniques used for elucidating bitter blockers, concept of ligand bias, generic amino acid numbering, the role of cholesterol, and conserved water molecules in the biochemistry and pharmacology of T2Rs.
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58
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Pupo AS, Duarte DA, Lima V, Teixeira LB, Parreiras-E-Silva LT, Costa-Neto CM. Recent updates on GPCR biased agonism. Pharmacol Res 2016; 112:49-57. [PMID: 26836887 DOI: 10.1016/j.phrs.2016.01.031] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Revised: 01/27/2016] [Accepted: 01/28/2016] [Indexed: 12/20/2022]
Abstract
G protein-coupled receptors (GPCRs) are the most important targets for drug discovery and not surprisingly ∼40% of all drugs currently in the market act on these receptors. Currently, one of the most active areas in GPCRs signaling is biased agonism, a phenomenon that occurs when a given ligand is able to preferentially activate one (or some) of the possible signaling pathways. In this review, we highlight the most recent findings about biased agonism, including an extension of this concept to intracellular signaling, allosterism, strategies for assessment and interpretation, and perspectives of therapeutic applications for biased agonists.
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Affiliation(s)
- André S Pupo
- Department of Pharmacology, Instituto de Biociências, UNESP, Botucatu, SP, Brazil.
| | - Diego A Duarte
- Department of Biochemistry and Immunology, Faculty of Medicine at Ribeirão Preto, University of São Paulo, 14049-900 Ribeirão Preto, SP, Brazil
| | - Vanessa Lima
- Department of Pharmacology, Instituto de Biociências, UNESP, Botucatu, SP, Brazil; Department of Biochemistry and Immunology, Faculty of Medicine at Ribeirão Preto, University of São Paulo, 14049-900 Ribeirão Preto, SP, Brazil
| | - Larissa B Teixeira
- Department of Biochemistry and Immunology, Faculty of Medicine at Ribeirão Preto, University of São Paulo, 14049-900 Ribeirão Preto, SP, Brazil
| | - Lucas T Parreiras-E-Silva
- Department of Biochemistry and Immunology, Faculty of Medicine at Ribeirão Preto, University of São Paulo, 14049-900 Ribeirão Preto, SP, Brazil
| | - Claudio M Costa-Neto
- Department of Biochemistry and Immunology, Faculty of Medicine at Ribeirão Preto, University of São Paulo, 14049-900 Ribeirão Preto, SP, Brazil.
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59
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Devost D, Audet N, Zhou C, Kobayashi H, Bonin H, Lukashova V, Le Gouill C, Bouvier M, Hébert TE. Cellular and subcellular context determine outputs from signaling biosensors. Methods Cell Biol 2016; 132:319-37. [DOI: 10.1016/bs.mcb.2015.11.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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60
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Hattersley G, Dean T, Corbin BA, Bahar H, Gardella TJ. Binding Selectivity of Abaloparatide for PTH-Type-1-Receptor Conformations and Effects on Downstream Signaling. Endocrinology 2016; 157:141-9. [PMID: 26562265 PMCID: PMC4701881 DOI: 10.1210/en.2015-1726] [Citation(s) in RCA: 186] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The PTH receptor type 1 (PTHR1) mediates the actions of two endogenous polypeptide ligands, PTH and PTHrP, and thereby plays key roles in bone biology. Based on its capacity to stimulate bone formation, the peptide fragment PTH (1-34) is currently in use as therapy for osteoporosis. Abaloparatide (ABL) is a novel synthetic analog of human PTHrP (1-34) that holds promise as a new osteoporosis therapy, as studies in animals suggest that it can stimulate bone formation with less of the accompanying bone resorption and hypercalcemic effects that can occur with PTH (1-34). Recent studies in vitro suggest that certain PTH or PTHrP ligand analogs can distinguish between two high-affinity PTHR1 conformations, R(0) and RG, and that efficient binding to R(0) results in prolonged signaling responses in cells and prolonged calcemic responses in animals, whereas selective binding to RG results in more transient responses. As intermittent PTH ligand action is known to favor the bone-formation response, whereas continuous ligand action favors the net bone-resorption/calcemic response, we hypothesized that ABL binds more selectively to the RG vs the R(0) PTHR1 conformation than does PTH (1-34), and thus induces more transient signaling responses in cells. We show that ABL indeed binds with greater selectivity to the RG conformation than does PTH (1-34), and as a result of this RG bias, ABL mediates more transient cAMP responses in PTHR1-expressing cells. The findings provide a plausible mechanism (ie, transient signaling via RG-selective binding) that can help account for the favorable anabolic effects that ABL has on bone.
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Affiliation(s)
- Gary Hattersley
- Radius Health Inc (G.H., H.B.), Waltham, Massachusetts 02451; and Endocrine Unit (T.D., B.A.C., T.J.G.), Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
| | - Thomas Dean
- Radius Health Inc (G.H., H.B.), Waltham, Massachusetts 02451; and Endocrine Unit (T.D., B.A.C., T.J.G.), Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
| | - Braden A Corbin
- Radius Health Inc (G.H., H.B.), Waltham, Massachusetts 02451; and Endocrine Unit (T.D., B.A.C., T.J.G.), Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
| | - Hila Bahar
- Radius Health Inc (G.H., H.B.), Waltham, Massachusetts 02451; and Endocrine Unit (T.D., B.A.C., T.J.G.), Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
| | - Thomas J Gardella
- Radius Health Inc (G.H., H.B.), Waltham, Massachusetts 02451; and Endocrine Unit (T.D., B.A.C., T.J.G.), Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
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61
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Comparing Class A GPCRs to bitter taste receptors: Structural motifs, ligand interactions and agonist-to-antagonist ratios. Methods Cell Biol 2015; 132:401-27. [PMID: 26928553 DOI: 10.1016/bs.mcb.2015.10.005] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
G protein-coupled receptors (GPCRs) are seven transmembrane (TM) proteins that play a key role in human physiology. The GPCR superfamily comprises about 800 members, classified into several classes, with rhodopsin-like Class A being the largest and most studied thus far. A huge component of the human repertoire consists of the chemosensory GPCRs, including ∼400 odorant receptors, 25 bitter taste receptors (TAS2Rs), which are thought to guard the organism from consuming poisons, and sweet and umami TAS1R heteromers, which indicate the nutritive value of food. The location of the binding site of TAS2Rs is similar to that of Class A GPCRs. However, most of the known bitter ligands are agonists, with only a few antagonists documented thus far. The agonist-to-antagonist ratios of Class A GPCRs vary, but in general are much lower than for TAS2Rs. For a set of well-studied GPCRs, a gradual change in agonists-to-antagonists ratios is observed when comparing low (10 μM)- and high (10 nM)-affinity ligand sets from ChEMBL and the DrugBank set of drugs. This shift reflects pharmaceutical bias toward the therapeutically desirable pharmacology for each of these GPCRs, while the 10 μM sets possibly represent the native tendency of the receptors toward either agonists or antagonists. Analyzing ligand-GPCR interactions in 56 X-ray structures representative of currently available structural data, we find that the N-terminus, TM1 and TM2 are more involved in binding of antagonists than of agonists. On the other hand, ECL2 tends to be more involved in binding of agonists. This is of interest, since TAS2Rs harbor variations on the typical Class A sequence motifs, including the absence of the ECL2-TM3 disulfide bridge. This suggests an alternative mode of regulation of conformational states for TAS2Rs, with potentially less stabilized inactive state. The comparison of TAS2Rs and Class A GPCRs structural features and the pharmacology of the their ligands highlights the intricacies of GPCR architecture and provides a framework for rational design of new ligands.
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62
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Cheloha RW, Gellman SH, Vilardaga JP, Gardella TJ. PTH receptor-1 signalling-mechanistic insights and therapeutic prospects. Nat Rev Endocrinol 2015; 11:712-24. [PMID: 26303600 PMCID: PMC4651712 DOI: 10.1038/nrendo.2015.139] [Citation(s) in RCA: 145] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Parathyroid hormone/parathyroid hormone-related protein receptor (PTH/PTHrP type 1 receptor; commonly known as PTHR1) is a family B G-protein-coupled receptor (GPCR) that regulates skeletal development, bone turnover and mineral ion homeostasis. PTHR1 transduces stimuli from PTH and PTHrP into the interior of target cells to promote diverse biochemical responses. Evaluation of the signalling properties of structurally modified PTHR1 ligands has helped to elucidate determinants of receptor function and mechanisms of downstream cellular and physiological responses. Analysis of PTHR1 responses induced by structurally modified ligands suggests that PTHR1 can continue to signal through a G-protein-mediated pathway within endosomes. Such findings challenge the longstanding paradigm in GPCR biology that the receptor is transiently activated at the cell membrane, followed by rapid deactivation and receptor internalization. Evaluation of structurally modified PTHR1 ligands has further led to the identification of ligand analogues that differ from PTH or PTHrP in the type, strength and duration of responses induced at the receptor, cellular and organism levels. These modified ligands, and the biochemical principles revealed through their use, might facilitate an improved understanding of PTHR1 function in vivo and enable the treatment of disorders resulting from defects in PTHR1 signalling. This Review discusses current understanding of PTHR1 modes of action and how these findings might be applied in future therapeutic agents.
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Affiliation(s)
- Ross W Cheloha
- Department of Chemistry, 1101 University Avenue, University of Wisconsin, Madison, WI 53706, USA
| | - Samuel H Gellman
- Department of Chemistry, 1101 University Avenue, University of Wisconsin, Madison, WI 53706, USA
| | - Jean-Pierre Vilardaga
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, 200 Lothrop Street, Pittsburgh, PA 15213, USA
| | - Thomas J Gardella
- Endocrine Unit, Massachusetts General Hospital, 50 Blossom Street, Boston, MA 02114, USA
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63
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Bartuzi D, Kaczor AA, Matosiuk D. Activation and Allosteric Modulation of Human μ Opioid Receptor in Molecular Dynamics. J Chem Inf Model 2015; 55:2421-34. [DOI: 10.1021/acs.jcim.5b00280] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Damian Bartuzi
- Department
of Synthesis and Chemical Technology of Pharmaceutical Substances
with Computer Modeling Lab, Faculty of Pharmacy with Division of Medical
Analytics, Medical University of Lublin, 4A Chodźki St., PL-20093 Lublin, Poland
| | - Agnieszka A. Kaczor
- Department
of Synthesis and Chemical Technology of Pharmaceutical Substances
with Computer Modeling Lab, Faculty of Pharmacy with Division of Medical
Analytics, Medical University of Lublin, 4A Chodźki St., PL-20093 Lublin, Poland
- School
of Pharmacy, University of Eastern Finland, Yliopistonranta 1, P.O. Box 1627, FI-70211 Kuopio, Finland
| | - Dariusz Matosiuk
- Department
of Synthesis and Chemical Technology of Pharmaceutical Substances
with Computer Modeling Lab, Faculty of Pharmacy with Division of Medical
Analytics, Medical University of Lublin, 4A Chodźki St., PL-20093 Lublin, Poland
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64
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Emerging Approaches to GPCR Ligand Screening for Drug Discovery. Trends Mol Med 2015; 21:687-701. [DOI: 10.1016/j.molmed.2015.09.002] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 09/02/2015] [Accepted: 09/04/2015] [Indexed: 01/07/2023]
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65
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Gardella TJ, Vilardaga JP. International Union of Basic and Clinical Pharmacology. XCIII. The parathyroid hormone receptors--family B G protein-coupled receptors. Pharmacol Rev 2015; 67:310-37. [PMID: 25713287 DOI: 10.1124/pr.114.009464] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The type-1 parathyroid hormone receptor (PTHR1) is a family B G protein-coupled receptor (GPCR) that mediates the actions of two polypeptide ligands; parathyroid hormone (PTH), an endocrine hormone that regulates the levels of calcium and inorganic phosphate in the blood by acting on bone and kidney, and PTH-related protein (PTHrP), a paracrine-factor that regulates cell differentiation and proliferation programs in developing bone and other tissues. The type-2 parathyroid hormone receptor (PTHR2) binds a peptide ligand, called tuberoinfundibular peptide-39 (TIP39), and while the biologic role of the PTHR2/TIP39 system is not as defined as that of the PTHR1, it likely plays a role in the central nervous system as well as in spermatogenesis. Mechanisms of action at these receptors have been explored through a variety of pharmacological and biochemical approaches, and the data obtained support a basic "two-site" mode of ligand binding now thought to be used by each of the family B peptide hormone GPCRs. Recent crystallographic studies on the family B GPCRs are providing new insights that help to further refine the specifics of the overall receptor architecture and modes of ligand docking. One intriguing pharmacological finding for the PTHR1 is that it can form surprisingly stable complexes with certain PTH/PTHrP ligand analogs and thereby mediate markedly prolonged cell signaling responses that persist even when the bulk of the complexes are found in internalized vesicles. The PTHR1 thus appears to be able to activate the Gα(s)/cAMP pathway not only from the plasma membrane but also from the endosomal domain. The cumulative findings could have an impact on efforts to develop new drug therapies for the PTH receptors.
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Affiliation(s)
- Thomas J Gardella
- Endocrine Unit, Massachusetts General Hospital, Boston, Massachusetts (T.J.G.); and Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania (J.-P.V.)
| | - Jean-Pierre Vilardaga
- Endocrine Unit, Massachusetts General Hospital, Boston, Massachusetts (T.J.G.); and Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania (J.-P.V.)
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66
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Optodynamic simulation of β-adrenergic receptor signalling. Nat Commun 2015; 6:8480. [PMID: 26412387 PMCID: PMC4588095 DOI: 10.1038/ncomms9480] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 08/27/2015] [Indexed: 02/08/2023] Open
Abstract
Optogenetics has provided a revolutionary approach to dissecting biological phenomena. However, the generation and use of optically active GPCRs in these contexts is limited and it is unclear how well an opsin-chimera GPCR might mimic endogenous receptor activity. Here we show that a chimeric rhodopsin/β2 adrenergic receptor (opto-β2AR) is similar in dynamics to endogenous β2AR in terms of: cAMP generation, MAP kinase activation and receptor internalization. In addition, we develop and characterize a novel toolset of optically active, functionally selective GPCRs that can bias intracellular signalling cascades towards either G-protein or arrestin-mediated cAMP and MAP kinase pathways. Finally, we show how photoactivation of opto-β2AR in vivo modulates neuronal activity and induces anxiety-like behavioural states in both fiber-tethered and wireless, freely moving animals when expressed in brain regions known to contain β2ARs. These new GPCR approaches enhance the utility of optogenetics and allow for discrete spatiotemporal control of GPCR signalling in vitro and in vivo. Optogenetic activation of β2-adrenergic receptors (β2-AR) has been achieved, but not characterized in detail. Here, Siuda et al. show that light-controlled opto-β2AR mimics endogenous β2AR activity in vitro and in vivo, and develop novel, optically active, functionally selective receptors to bias β2AR intracellular signaling mechanisms.
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67
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Hébert TE. Biasing the odds: Approaches to capturing, understanding and exploiting functional selectivity in GPCRs. Methods 2015; 92:1-4. [PMID: 26416495 DOI: 10.1016/j.ymeth.2015.09.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 09/23/2015] [Accepted: 09/24/2015] [Indexed: 02/07/2023] Open
Abstract
There is significant expectation in the pharmacological community that an understanding of biased signalling will lead to the development of new drugs and a better understanding of molecular targets in the in vivo context. I think it is safe to say that Pharma is withholding judgment on the promise and potential of what they view as an interesting pharmacological curiosity. That said, beyond successes of biased ligands in clinical trials and their appearance on the market, what it is need is a clear plan and the right tools and analytical methods to characterize functional selectivity from in cellulo to in vivo. In this issue of Methods, we have put together a series of articles that help lay out a methodological and analytical framework to help get us there.
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Affiliation(s)
- Terence E Hébert
- Department of Pharmacology and Therapeutics, McGill University, Canada.
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68
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Dysregulated Inflammatory Signaling upon Charcot-Marie-Tooth Type 1C Mutation of SIMPLE Protein. Mol Cell Biol 2015; 35:2464-78. [PMID: 25963657 DOI: 10.1128/mcb.00300-15] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Endosomal trafficking is a key mechanism to modulate signal propagation and cross talk. Ubiquitin adaptors, along with endosomal sorting complex required for transport (ESCRT) complexes, are also integrated to terminate ligand-receptor activation in late endosomes and multivesicular bodies (MVBs). Within these pathways, we recently demonstrated that the protein SIMPLE is a novel player in MVB regulation. SIMPLE is also clinically important and its mutation accounts for the Charcot-Marie-Tooth type 1C (CMT1C) disease. MVB defects of mutation and deletion of SIMPLE, however, are distinct. Here, we show that MVB defects found in mutation but not deletion of SIMPLE lead to impaired turnover and accumulation of ESCRT-0 protein Hrs punctain late endosomes. We further uncover increased colocalization of ubiquitin ligase TRAF6 and Hrs in late endosomes. Upon stimulation with interkeukin-1 or transforming growth factor , prolonged activation of p38 kinase/JNK is detected, while nuclear accumulation of NF-κB and phosphorylation of SMAD2 is reduced with CMT1C mutation. The aberrant kinetics we observed in inflammatory signaling may contribute to increased tumor susceptibility and changes in the levels of chemokines/cytokines that result from CMT1C mutation. We propose that altered endosomal trafficking due to malformations of MVBs and subsequent atypical signaling kinetic may account for a toxic gain of function in CMT1C pathogenesis.
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69
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Valentin-Hansen L, Frimurer TM, Mokrosinski J, Holliday ND, Schwartz TW. Biased Gs versus Gq proteins and β-arrestin signaling in the NK1 receptor determined by interactions in the water hydrogen bond network. J Biol Chem 2015; 290:24495-508. [PMID: 26269596 DOI: 10.1074/jbc.m115.641944] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Indexed: 11/06/2022] Open
Abstract
X-ray structures, molecular dynamics simulations, and mutational analysis have previously indicated that an extended water hydrogen bond network between trans-membranes I-III, VI, and VII constitutes an allosteric interface essential for stabilizing different active and inactive helical constellations during the seven-trans-membrane receptor activation. The neurokinin-1 receptor signals efficiently through Gq, Gs, and β-arrestin when stimulated by substance P, but it lacks any sign of constitutive activity. In the water hydrogen bond network the neurokinin-1 has a unique Glu residue instead of the highly conserved AspII:10 (2.50). Here, we find that this GluII:10 occupies the space of a putative allosteric modulating Na(+) ion and makes direct inter-helical interactions in particular with SerIII:15 (3.39) and AsnVII:16 (7.49) of the NPXXY motif. Mutational changes in the interface between GluII:10 and AsnVII:16 created receptors that selectively signaled through the following: 1) Gq only; 2) β-arrestin only; and 3) Gq and β-arrestin but not through Gs. Interestingly, increased constitutive Gs but not Gq signaling was observed by Ala substitution of four out of the six core polar residues of the network, in particular SerIII:15. Three residues were essential for all three signaling pathways, i.e. the water-gating micro-switch residues TrpVI:13 (6.48) of the CWXP motif and TyrVII:20 (7.53) of the NPXXY motif plus the totally conserved AsnI:18 (1.50) stabilizing the kink in trans-membrane VII. It is concluded that the interface between position II:10 (2.50), III:15 (3.39), and VII:16 (7.49) in the center of the water hydrogen bond network constitutes a focal point for fine-tuning seven trans-membrane receptor conformations activating different signal transduction pathways.
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Affiliation(s)
- Louise Valentin-Hansen
- From the Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, The Panum Institute, Novo Nordisk Foundation Center for Basic Metabolic Research, and
| | - Thomas M Frimurer
- Novo Nordisk Foundation Center for Protein Research,University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen, Denmark and
| | - Jacek Mokrosinski
- From the Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, The Panum Institute, Novo Nordisk Foundation Center for Basic Metabolic Research, and
| | - Nicholas D Holliday
- the Cell Signaling Research Group, School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham NG7 2UH, United Kingdom
| | - Thue W Schwartz
- From the Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, The Panum Institute, Novo Nordisk Foundation Center for Basic Metabolic Research, and
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Manfra O, Van Craenenbroeck K, Skieterska K, Frimurer T, Schwartz TW, Levy FO, Andressen KW. Downregulation of 5-HT7 Serotonin Receptors by the Atypical Antipsychotics Clozapine and Olanzapine. Role of Motifs in the C-Terminal Domain and Interaction with GASP-1. ACS Chem Neurosci 2015; 6:1206-18. [PMID: 25706089 DOI: 10.1021/cn500339p] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The human 5-HT7 serotonin receptor, a G-protein-coupled receptor (GPCR), activates adenylyl cyclase constitutively and upon agonist activation. Biased ligands differentially activate 5-HT7 serotonin receptor desensitization, internalization and degradation in addition to G protein activation. We have previously found that the atypical antipsychotics clozapine and olanzapine inhibited G protein activation and, surprisingly, induced both internalization and lysosomal degradation of 5-HT7 receptors. Here, we aimed to determine the mechanism of clozapine- and olanzapine-mediated degradation of 5-HT7 receptors. In the C-terminus of the 5-HT7 receptor, we identified two YXXΦ motifs, LR residues, and a palmitoylated cysteine anchor as potential sites involved in receptor trafficking to lysosomes followed by receptor degradation. Mutating either of these sites inhibited clozapine- and olanzapine-mediated degradation of 5-HT7 receptors and also interfered with G protein activation. In addition, we tested whether receptor degradation was mediated by the GPCR-associated sorting protein-1 (GASP-1). We show that GASP-1 binds the 5-HT7 receptor and regulates the clozapine-mediated degradation. Mutations of the identified motifs and residues, located in or close to Helix-VIII of the 5-HT7 receptor, modified antipsychotic-stimulated binding of proteins (such as GASP-1), possibly by altering the flexibility of Helix-VIII, and also interfered with G protein activation. Taken together, our data demonstrate that binding of clozapine or olanzapine to the 5-HT7 receptor leads to antagonist-mediated lysosomal degradation by exposing key residues in the C-terminal tail that interact with GASP-1.
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Affiliation(s)
- Ornella Manfra
- Department of Pharmacology,
Institute of Clinical Medicine, University of Oslo and Oslo University Hospital,
P.O. Box 1057 Blindern, 0316 Oslo, Norway
- K.G.
Jebsen Cardiac Research Centre and Center for Heart Failure Research,
Institute of Clinical Medicine, University of Oslo, 0316 Oslo, Norway
| | - Kathleen Van Craenenbroeck
- Laboratory of GPCR
Expression and Signal Transduction (LEGEST), Ghent University-Ghent, 9000 Ghent, Belgium
| | - Kamila Skieterska
- Laboratory of GPCR
Expression and Signal Transduction (LEGEST), Ghent University-Ghent, 9000 Ghent, Belgium
| | - Thomas Frimurer
- The Novo Nordisk Foundation Center for Basic Metabolic Research,
Faculty of Health and Medical Sciences, University of Copenhagen, DK-1165 Copenhagen, Denmark
| | - Thue W. Schwartz
- The Novo Nordisk Foundation Center for Basic Metabolic Research,
Faculty of Health and Medical Sciences, University of Copenhagen, DK-1165 Copenhagen, Denmark
- Laboratory for Molecular Pharmacology, Department of Pharmacology,
Panum Institute, University of Copenhagen, DK-22 00 Copenhagen, Denmark
| | - Finn Olav Levy
- Department of Pharmacology,
Institute of Clinical Medicine, University of Oslo and Oslo University Hospital,
P.O. Box 1057 Blindern, 0316 Oslo, Norway
- K.G.
Jebsen Cardiac Research Centre and Center for Heart Failure Research,
Institute of Clinical Medicine, University of Oslo, 0316 Oslo, Norway
| | - Kjetil Wessel Andressen
- Department of Pharmacology,
Institute of Clinical Medicine, University of Oslo and Oslo University Hospital,
P.O. Box 1057 Blindern, 0316 Oslo, Norway
- K.G.
Jebsen Cardiac Research Centre and Center for Heart Failure Research,
Institute of Clinical Medicine, University of Oslo, 0316 Oslo, Norway
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71
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Williams GR, Bethard JR, Berkaw MN, Nagel AK, Luttrell LM, Ball LE. Exploring G protein-coupled receptor signaling networks using SILAC-based phosphoproteomics. Methods 2015; 92:36-50. [PMID: 26160508 DOI: 10.1016/j.ymeth.2015.06.022] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Revised: 06/29/2015] [Accepted: 06/30/2015] [Indexed: 12/21/2022] Open
Abstract
The type 1 parathyroid hormone receptor (PTH1R) is a key regulator of calcium homeostasis and bone turnover. Here, we employed SILAC-based quantitative mass spectrometry and bioinformatic pathways analysis to examine global changes in protein phosphorylation following short-term stimulation of endogenously expressed PTH1R in osteoblastic cells in vitro. Following 5min exposure to the conventional agonist, PTH(1-34), we detected significant changes in the phosphorylation of 224 distinct proteins. Kinase substrate motif enrichment demonstrated that consensus motifs for PKA and CAMK2 were the most heavily upregulated within the phosphoproteome, while consensus motifs for mitogen-activated protein kinases were strongly downregulated. Signaling pathways analysis identified ERK1/2 and AKT as important nodal kinases in the downstream network and revealed strong regulation of small GTPases involved in cytoskeletal rearrangement, cell motility, and focal adhesion complex signaling. Our data illustrate the utility of quantitative mass spectrometry in measuring dynamic changes in protein phosphorylation following GPCR activation.
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Affiliation(s)
- Grace R Williams
- Department of Molecular and Cellular Pharmacology, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Jennifer R Bethard
- Department of Molecular and Cellular Pharmacology, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Mary N Berkaw
- Department of Molecular and Cellular Pharmacology, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Alexis K Nagel
- Department of Molecular and Cellular Pharmacology, Medical University of South Carolina, Charleston, SC 29425, USA; Department of Oral Health Sciences, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Louis M Luttrell
- Department of Medicine, Medical University of South Carolina, Charleston, SC 29425, USA; Research Service of the Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC 29401, USA
| | - Lauren E Ball
- Department of Molecular and Cellular Pharmacology, Medical University of South Carolina, Charleston, SC 29425, USA; Department of Oral Health Sciences, Medical University of South Carolina, Charleston, SC 29425, USA.
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72
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Andressen KW, Manfra O, Brevik CH, Ulsund AH, Vanhoenacker P, Levy FO, Krobert KA. The atypical antipsychotics clozapine and olanzapine promote down-regulation and display functional selectivity at human 5-HT7 receptors. Br J Pharmacol 2015; 172:3846-60. [PMID: 25884989 PMCID: PMC4523340 DOI: 10.1111/bph.13169] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Revised: 04/01/2015] [Accepted: 04/14/2015] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND AND PURPOSE Classically, ligands of GPCRs have been classified primarily upon their affinity and efficacy to activate a signal transduction pathway. Recent reports indicate that the efficacy of a particular ligand can vary depending on the receptor-mediated response measured (e.g. activating G proteins, other downstream responses, internalization). Previously, we reported that inverse agonists induce both homo- and heterologous desensitization, similar to agonist stimulation, at the Gs -coupled 5-HT7 receptor. The primary objective of this study was to determine whether different inverse agonists at the 5-HT7 receptor also induce internalization and/or degradation of 5-HT7 receptors. EXPERIMENTAL APPROACH HEK293 cells expressing 5-HT7(a, b or d) receptors were pre-incubated with 5-HT, clozapine, olanzapine, mesulergine or SB269970 and their effects upon receptor density, AC activity, internalization, recruitment of β-arrestins and lysosomal trafficking were measured. KEY RESULTS The agonist 5-HT and three out of four inverse agonists tested increased internalization independently of β-arrestin recruitment. Among these, only the atypical antipsychotics clozapine and olanzapine promoted lysosomal sorting and reduced 5-HT7 receptor density (∼60% reduction within 24 h). Inhibition of lysosomal degradation with chloroquine blocked the clozapine- and olanzapine-induced down-regulation of 5-HT7 receptors. Incubation with SB269970 decreased both 5-HT7(b) constitutive internalization and receptor density but increased 5-HT7(d) receptor density, indicating differential ligand regulation among the 5-HT7 splice variants. CONCLUSIONS AND IMPLICATIONS Taken together, we found that various ligands differentially activate regulatory processes governing receptor internalization and degradation in addition to signal transduction. Thus, these data extend our understanding of functional selectivity at the 5-HT7 receptor.
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Affiliation(s)
- K W Andressen
- Department of Pharmacology, Institute of Clinical Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway.,K.G. Jebsen Cardiac Research Centre and Center for Heart Failure Research, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - O Manfra
- Department of Pharmacology, Institute of Clinical Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway.,K.G. Jebsen Cardiac Research Centre and Center for Heart Failure Research, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - C H Brevik
- Department of Pharmacology, Institute of Clinical Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - A H Ulsund
- Department of Pharmacology, Institute of Clinical Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway.,K.G. Jebsen Cardiac Research Centre and Center for Heart Failure Research, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - P Vanhoenacker
- Laboratory of Eukaryotic Gene Expression and Signal Transduction, Ghent University, Ghent, Belgium.,Intrexon ActoBiotics N.V., Technologiepark 4, Zwijnaarde, Belgium
| | - F O Levy
- Department of Pharmacology, Institute of Clinical Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway.,K.G. Jebsen Cardiac Research Centre and Center for Heart Failure Research, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - K A Krobert
- Department of Pharmacology, Institute of Clinical Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway.,K.G. Jebsen Cardiac Research Centre and Center for Heart Failure Research, Faculty of Medicine, University of Oslo, Oslo, Norway
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73
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Shang Y, Filizola M. Opioid receptors: Structural and mechanistic insights into pharmacology and signaling. Eur J Pharmacol 2015; 763:206-13. [PMID: 25981301 DOI: 10.1016/j.ejphar.2015.05.012] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2015] [Revised: 03/02/2015] [Accepted: 05/11/2015] [Indexed: 01/18/2023]
Abstract
Opioid receptors are important drug targets for pain management, addiction, and mood disorders. Although substantial research on these important subtypes of G protein-coupled receptors has been conducted over the past two decades to discover ligands with higher specificity and diminished side effects, currently used opioid therapeutics remain suboptimal. Luckily, recent advances in structural biology of opioid receptors provide unprecedented insights into opioid receptor pharmacology and signaling. We review here a few recent studies that have used the crystal structures of opioid receptors as a basis for revealing mechanistic details of signal transduction mediated by these receptors, and for the purpose of drug discovery.
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Affiliation(s)
- Yi Shang
- Icahn School of Medicine at Mount Sinai, Department of Structural and Chemical Biology, One Gustave, L. Levy Place, Box 1677, New York, NY 10029, USA
| | - Marta Filizola
- Icahn School of Medicine at Mount Sinai, Department of Structural and Chemical Biology, One Gustave, L. Levy Place, Box 1677, New York, NY 10029, USA.
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74
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Walther C, Ferguson SSG. Minireview: Role of intracellular scaffolding proteins in the regulation of endocrine G protein-coupled receptor signaling. Mol Endocrinol 2015; 29:814-30. [PMID: 25942107 DOI: 10.1210/me.2015-1091] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The majority of hormones stimulates and mediates their signal transduction via G protein-coupled receptors (GPCRs). The signal is transmitted into the cell due to the association of the GPCRs with heterotrimeric G proteins, which in turn activates an extensive array of signaling pathways to regulate cell physiology. However, GPCRs also function as scaffolds for the recruitment of a variety of cytoplasmic protein-interacting proteins that bind to both the intracellular face and protein interaction motifs encoded by GPCRs. The structural scaffolding of these proteins allows GPCRs to recruit large functional complexes that serve to modulate both G protein-dependent and -independent cellular signaling pathways and modulate GPCR intracellular trafficking. This review focuses on GPCR interacting PSD95-disc large-zona occludens domain containing scaffolds in the regulation of endocrine receptor signaling as well as their potential role as therapeutic targets for the treatment of endocrinopathies.
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Affiliation(s)
- Cornelia Walther
- J. Allyn Taylor Centre for Cell Biology (C.W., S.S.G.F.), Robarts Research Institute, and Department of Physiology and Pharmacology (S.S.G.F.), University of Western Ontario, London, Ontario, Canada N6A 5K8
| | - Stephen S G Ferguson
- J. Allyn Taylor Centre for Cell Biology (C.W., S.S.G.F.), Robarts Research Institute, and Department of Physiology and Pharmacology (S.S.G.F.), University of Western Ontario, London, Ontario, Canada N6A 5K8
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75
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Picone RP, Kendall DA. Minireview: From the bench, toward the clinic: therapeutic opportunities for cannabinoid receptor modulation. Mol Endocrinol 2015; 29:801-13. [PMID: 25866875 DOI: 10.1210/me.2015-1062] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The effects of cannabinoids have been known for centuries and over the past several decades two G protein-coupled receptors, CB1 and CB2, that are responsible for their activity have been identified. Endogenous lipid-derived cannabinergic agents have been found, biosynthetic and catabolic machinery has been characterized, and synthetic agents have been designed to modulate these receptors. Selective agents including agonists, antagonists, inverse agonists, and novel allosteric modulators targeting either CB1 or CB2 have been developed to inhibit or augment their basal tone. As a result, the role these receptors play in human physiology and their potential therapeutic applications in disease states are being elucidated. The CB1 receptor, although ubiquitous, is densely expressed in the brain, and CB2 is largely found on cells of immune origin. This minireview highlights the role of CB1 in excitotoxic assaults in the brain and its potential to limit addiction liability. In addition, it will examine the relationship between receptor activity and stimulation of insulin release from pancreatic β-cells, insulin resistance, and feeding behavior leading toward obesity. The roles of CB2 in the neuropathology of amyotrophic lateral sclerosis and in the central manifestations of chronic HIV infection potentially converge at inflammatory cell activation, thereby providing an opportunity for intervention. Last, CB2 modulation is discussed in the context of an experimental model of postmenopausal osteoporosis. Achieving exquisite receptor selectivity and elucidating the mechanisms underlying receptor inhibition and activation will be essential for the development of the next generation of cannabinergic-based therapeutic agents.
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Affiliation(s)
- Robert P Picone
- Clinical Development (R.P.P.), Medical and Regulatory Affairs, Novo Nordisk Inc, Plainsboro, New Jersey 08536; and Department of Pharmaceutical Sciences (D.A.K.), University of Connecticut, Storrs, Connecticut 06269-3092
| | - Debra A Kendall
- Clinical Development (R.P.P.), Medical and Regulatory Affairs, Novo Nordisk Inc, Plainsboro, New Jersey 08536; and Department of Pharmaceutical Sciences (D.A.K.), University of Connecticut, Storrs, Connecticut 06269-3092
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Konoura K, Fujii H, Imaide S, Gouda H, Hirayama S, Hirono S, Nagase H. Transformation of naltrexone into mesembrane and investigation of the binding properties of its intermediate derivatives to opioid receptors. Bioorg Med Chem 2015; 23:439-48. [DOI: 10.1016/j.bmc.2014.12.032] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Revised: 12/15/2014] [Accepted: 12/15/2014] [Indexed: 11/28/2022]
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77
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Mueller A, Starobova H, Inserra MC, Jin AH, Deuis JR, Dutertre S, Lewis RJ, Alewood PF, Daly NL, Vetter I. α-Conotoxin MrIC is a biased agonist at α7 nicotinic acetylcholine receptors. Biochem Pharmacol 2015; 94:155-63. [PMID: 25646788 DOI: 10.1016/j.bcp.2015.01.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 01/20/2015] [Accepted: 01/20/2015] [Indexed: 12/23/2022]
Abstract
MrIC is a recently described selective agonist of endogenously expressed α7 nAChR. In this study, we further characterize the pharmacological activity of MrIC using Ca(2+) imaging approaches in SH-SY5Y cells endogenously expressing α7 nAChR and demonstrate that MrIC exclusively activates α7 nAChR modulated by type II positive allosteric modulators, including PNU120596. MrIC was a full agonist at PNU120596-modulated α7 nAChR compared with choline, albeit with slower kinetics, but failed to elicit a Ca(2+) response in the absence of PNU120596. Interestingly, the NMR structure of MrIC showed a typical 4/7 α-conotoxin fold, indicating that its unusual pharmacological activity is likely sequence-dependent. Overall, our results suggest that MrIC acts as a biased agonist that can only activate α7 nAChR modified by type II positive allosteric modulators, and thus represents a valuable tool to probe the pharmacological properties of this important ion channel.
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Affiliation(s)
- Alexander Mueller
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Hana Starobova
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Marco C Inserra
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Ai-Hua Jin
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Jennifer R Deuis
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Sébastien Dutertre
- Institut des Biomolécules Max Mousseron, UMR 5247, Université Montpellier 2-CNRS, Place Eugène Bataillon, Montpellier Cedex 5 34095, France
| | - Richard J Lewis
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Paul F Alewood
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Norelle L Daly
- Centre for Biodiscovery and Molecular Development of Therapeutics, AITHM, James Cook University, Queensland 4878, Australia
| | - Irina Vetter
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland 4072, Australia; School of Pharmacy, The University of Queensland, Woolloongabba, Queensland 4102, Australia.
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Maudsley S, Martin B, Gesty-Palmer D, Cheung H, Johnson C, Patel S, Becker KG, Wood WH, Zhang Y, Lehrmann E, Luttrell LM. Delineation of a conserved arrestin-biased signaling repertoire in vivo. Mol Pharmacol 2015; 87:706-17. [PMID: 25637603 DOI: 10.1124/mol.114.095224] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Biased G protein-coupled receptor agonists engender a restricted repertoire of downstream events from their cognate receptors, permitting them to produce mixed agonist-antagonist effects in vivo. While this opens the possibility of novel therapeutics, it complicates rational drug design, since the in vivo response to a biased agonist cannot be reliably predicted from its in cellula efficacy. We have employed novel informatic approaches to characterize the in vivo transcriptomic signature of the arrestin pathway-selective parathyroid hormone analog [d-Trp(12), Tyr(34)]bovine PTH(7-34) in six different murine tissues after chronic drug exposure. We find that [d-Trp(12), Tyr(34)]bovine PTH(7-34) elicits a distinctive arrestin-signaling focused transcriptomic response that is more coherently regulated across tissues than that of the pluripotent agonist, human PTH(1-34). This arrestin-focused network is closely associated with transcriptional control of cell growth and development. Our demonstration of a conserved arrestin-dependent transcriptomic signature suggests a framework within which the in vivo outcomes of arrestin-biased signaling may be generalized.
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Affiliation(s)
- Stuart Maudsley
- National Institutes of Health, National Institute on Aging, Baltimore, Maryland (S.M., B.M., S.P., K.G.B., W.H.W., Y.Z., E.L.); Department of Medicine, Duke University Medical Center, Durham, North Carolina (D.G.-P.); National Institutes of Health, Center for Information Technology, Bethesda, Maryland (H.C., C.J.); Department of Medicine and Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina (L.M.L.); and Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina (L.M.L.)
| | - Bronwen Martin
- National Institutes of Health, National Institute on Aging, Baltimore, Maryland (S.M., B.M., S.P., K.G.B., W.H.W., Y.Z., E.L.); Department of Medicine, Duke University Medical Center, Durham, North Carolina (D.G.-P.); National Institutes of Health, Center for Information Technology, Bethesda, Maryland (H.C., C.J.); Department of Medicine and Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina (L.M.L.); and Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina (L.M.L.)
| | - Diane Gesty-Palmer
- National Institutes of Health, National Institute on Aging, Baltimore, Maryland (S.M., B.M., S.P., K.G.B., W.H.W., Y.Z., E.L.); Department of Medicine, Duke University Medical Center, Durham, North Carolina (D.G.-P.); National Institutes of Health, Center for Information Technology, Bethesda, Maryland (H.C., C.J.); Department of Medicine and Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina (L.M.L.); and Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina (L.M.L.)
| | - Huey Cheung
- National Institutes of Health, National Institute on Aging, Baltimore, Maryland (S.M., B.M., S.P., K.G.B., W.H.W., Y.Z., E.L.); Department of Medicine, Duke University Medical Center, Durham, North Carolina (D.G.-P.); National Institutes of Health, Center for Information Technology, Bethesda, Maryland (H.C., C.J.); Department of Medicine and Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina (L.M.L.); and Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina (L.M.L.)
| | - Calvin Johnson
- National Institutes of Health, National Institute on Aging, Baltimore, Maryland (S.M., B.M., S.P., K.G.B., W.H.W., Y.Z., E.L.); Department of Medicine, Duke University Medical Center, Durham, North Carolina (D.G.-P.); National Institutes of Health, Center for Information Technology, Bethesda, Maryland (H.C., C.J.); Department of Medicine and Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina (L.M.L.); and Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina (L.M.L.)
| | - Shamit Patel
- National Institutes of Health, National Institute on Aging, Baltimore, Maryland (S.M., B.M., S.P., K.G.B., W.H.W., Y.Z., E.L.); Department of Medicine, Duke University Medical Center, Durham, North Carolina (D.G.-P.); National Institutes of Health, Center for Information Technology, Bethesda, Maryland (H.C., C.J.); Department of Medicine and Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina (L.M.L.); and Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina (L.M.L.)
| | - Kevin G Becker
- National Institutes of Health, National Institute on Aging, Baltimore, Maryland (S.M., B.M., S.P., K.G.B., W.H.W., Y.Z., E.L.); Department of Medicine, Duke University Medical Center, Durham, North Carolina (D.G.-P.); National Institutes of Health, Center for Information Technology, Bethesda, Maryland (H.C., C.J.); Department of Medicine and Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina (L.M.L.); and Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina (L.M.L.)
| | - William H Wood
- National Institutes of Health, National Institute on Aging, Baltimore, Maryland (S.M., B.M., S.P., K.G.B., W.H.W., Y.Z., E.L.); Department of Medicine, Duke University Medical Center, Durham, North Carolina (D.G.-P.); National Institutes of Health, Center for Information Technology, Bethesda, Maryland (H.C., C.J.); Department of Medicine and Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina (L.M.L.); and Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina (L.M.L.)
| | - Yongqing Zhang
- National Institutes of Health, National Institute on Aging, Baltimore, Maryland (S.M., B.M., S.P., K.G.B., W.H.W., Y.Z., E.L.); Department of Medicine, Duke University Medical Center, Durham, North Carolina (D.G.-P.); National Institutes of Health, Center for Information Technology, Bethesda, Maryland (H.C., C.J.); Department of Medicine and Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina (L.M.L.); and Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina (L.M.L.)
| | - Elin Lehrmann
- National Institutes of Health, National Institute on Aging, Baltimore, Maryland (S.M., B.M., S.P., K.G.B., W.H.W., Y.Z., E.L.); Department of Medicine, Duke University Medical Center, Durham, North Carolina (D.G.-P.); National Institutes of Health, Center for Information Technology, Bethesda, Maryland (H.C., C.J.); Department of Medicine and Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina (L.M.L.); and Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina (L.M.L.)
| | - Louis M Luttrell
- National Institutes of Health, National Institute on Aging, Baltimore, Maryland (S.M., B.M., S.P., K.G.B., W.H.W., Y.Z., E.L.); Department of Medicine, Duke University Medical Center, Durham, North Carolina (D.G.-P.); National Institutes of Health, Center for Information Technology, Bethesda, Maryland (H.C., C.J.); Department of Medicine and Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina (L.M.L.); and Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina (L.M.L.)
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Singewald N, Schmuckermair C, Whittle N, Holmes A, Ressler KJ. Pharmacology of cognitive enhancers for exposure-based therapy of fear, anxiety and trauma-related disorders. Pharmacol Ther 2014; 149:150-90. [PMID: 25550231 PMCID: PMC4380664 DOI: 10.1016/j.pharmthera.2014.12.004] [Citation(s) in RCA: 272] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Accepted: 12/24/2014] [Indexed: 12/20/2022]
Abstract
Pathological fear and anxiety are highly debilitating and, despite considerable advances in psychotherapy and pharmacotherapy they remain insufficiently treated in many patients with PTSD, phobias, panic and other anxiety disorders. Increasing preclinical and clinical evidence indicates that pharmacological treatments including cognitive enhancers, when given as adjuncts to psychotherapeutic approaches [cognitive behavioral therapy including extinction-based exposure therapy] enhance treatment efficacy, while using anxiolytics such as benzodiazepines as adjuncts can undermine long-term treatment success. The purpose of this review is to outline the literature showing how pharmacological interventions targeting neurotransmitter systems including serotonin, dopamine, noradrenaline, histamine, glutamate, GABA, cannabinoids, neuropeptides (oxytocin, neuropeptides Y and S, opioids) and other targets (neurotrophins BDNF and FGF2, glucocorticoids, L-type-calcium channels, epigenetic modifications) as well as their downstream signaling pathways, can augment fear extinction and strengthen extinction memory persistently in preclinical models. Particularly promising approaches are discussed in regard to their effects on specific aspects of fear extinction namely, acquisition, consolidation and retrieval, including long-term protection from return of fear (relapse) phenomena like spontaneous recovery, reinstatement and renewal of fear. We also highlight the promising translational value of the preclinial research and the clinical potential of targeting certain neurochemical systems with, for example d-cycloserine, yohimbine, cortisol, and L-DOPA. The current body of research reveals important new insights into the neurobiology and neurochemistry of fear extinction and holds significant promise for pharmacologically-augmented psychotherapy as an improved approach to treat trauma and anxiety-related disorders in a more efficient and persistent way promoting enhanced symptom remission and recovery.
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Affiliation(s)
- N Singewald
- Department of Pharmacology and Toxicology, Institute of Pharmacy and CMBI, Leopold-Franzens University of Innsbruck, Innrain 80-82, A-6020 Innsbruck, Austria.
| | - C Schmuckermair
- Department of Pharmacology and Toxicology, Institute of Pharmacy and CMBI, Leopold-Franzens University of Innsbruck, Innrain 80-82, A-6020 Innsbruck, Austria
| | - N Whittle
- Department of Pharmacology and Toxicology, Institute of Pharmacy and CMBI, Leopold-Franzens University of Innsbruck, Innrain 80-82, A-6020 Innsbruck, Austria
| | - A Holmes
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD, USA
| | - K J Ressler
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, USA
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80
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Shukla AK, Singh G, Ghosh E. Emerging structural insights into biased GPCR signaling. Trends Biochem Sci 2014; 39:594-602. [DOI: 10.1016/j.tibs.2014.10.001] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 09/24/2014] [Accepted: 10/01/2014] [Indexed: 01/04/2023]
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81
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Maguire JJ, Davenport AP. Endothelin@25 - new agonists, antagonists, inhibitors and emerging research frontiers: IUPHAR Review 12. Br J Pharmacol 2014; 171:5555-72. [PMID: 25131455 PMCID: PMC4290702 DOI: 10.1111/bph.12874] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 07/22/2014] [Accepted: 07/25/2014] [Indexed: 12/16/2022] Open
Abstract
Since the discovery of endothelin (ET)-1 in 1988, the main components of the signalling pathway have become established, comprising three structurally similar endogenous 21-amino acid peptides, ET-1, ET-2 and ET-3, that activate two GPCRs, ETA and ETB . Our aim in this review is to highlight the recent progress in ET research. The ET-like domain peptide, corresponding to prepro-ET-193-166 , has been proposed to be co-synthesized and released with ET-1, to modulate the actions of the peptide. ET-1 remains the most potent vasoconstrictor in the human cardiovascular system with a particularly long-lasting action. To date, the major therapeutic strategy to block the unwanted actions of ET in disease, principally in pulmonary arterial hypertension, has been to use antagonists that are selective for the ETA receptor (ambrisentan) or that block both receptor subtypes (bosentan). Macitentan represents the next generation of antagonists, being more potent than bosentan, with longer receptor occupancy and it is converted to an active metabolite; properties contributing to greater pharmacodynamic and pharmacokinetic efficacy. A second strategy is now being more widely tested in clinical trials and uses combined inhibitors of ET-converting enzyme and neutral endopeptidase such as SLV306 (daglutril). A third strategy based on activating the ETB receptor, has led to the renaissance of the modified peptide agonist IRL1620 as a clinical candidate in delivering anti-tumour drugs and as a pharmacological tool to investigate experimental pathophysiological conditions. Finally, we discuss biased signalling, epigenetic regulation and targeting with monoclonal antibodies as prospective new areas for ET research.
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Affiliation(s)
- J J Maguire
- Clinical Pharmacology Unit, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK
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82
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Carr R, Du Y, Quoyer J, Panettieri RA, Janz JM, Bouvier M, Kobilka BK, Benovic JL. Development and characterization of pepducins as Gs-biased allosteric agonists. J Biol Chem 2014; 289:35668-84. [PMID: 25395624 DOI: 10.1074/jbc.m114.618819] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The β2-adrenergic receptor (β2AR) is a prototypical G protein-coupled receptor that mediates many hormonal responses, including cardiovascular and pulmonary function. β-Agonists used to combat hypercontractility in airway smooth muscle stimulate β2AR-dependent cAMP production that ultimately promotes airway relaxation. Chronic stimulation of the β2AR by long acting β-agonists used in the treatment of asthma can promote attenuated responsiveness to agonists and an increased frequency of fatal asthmatic attacks. β2AR desensitization to β-agonists is primarily mediated by G protein-coupled receptor kinases and β-arrestins that attenuate receptor-Gs coupling and promote β2AR internalization and degradation. A biased agonist that can selectively stimulate Gs signaling without promoting receptor interaction with G protein-coupled receptor kinases and β-arrestins should serve as an advantageous asthma therapeutic. To identify such molecules, we screened ∼50 lipidated peptides derived from the intracellular loops of the β2AR, known as pepducins. This screen revealed two classes of Gs-biased pepducins, receptor-independent and receptor-dependent, as well as several β-arrestin-biased pepducins. The receptor-independent Gs-biased pepducins operate by directly stimulating G protein activation. In contrast, receptor-dependent Gs-biased pepducins appear to stabilize a Gs-biased conformation of the β2AR that couples to Gs but does not undergo G protein-coupled receptor kinase-mediated phosphorylation or β-arrestin-mediated internalization. Functional studies in primary human airway smooth muscle cells demonstrate that Gs-biased pepducins are not subject to conventional desensitization and thus may be good candidates for the development of next generation asthma therapeutics. Our study reports the first Gs-biased activator of the β2AR and provides valuable tools for the study of β2AR function.
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Affiliation(s)
- Richard Carr
- From the Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Yang Du
- the Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California 94305
| | - Julie Quoyer
- the Department of Biochemistry and Institute for Research in Immunology and Cancer, Université de Montréal, Montreal, Quebec H3C 3J7, Canada
| | - Reynold A Panettieri
- the Department of Medicine, Pulmonary, Allergy and Critical Care Division, Airways Biology Initiative, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104, and
| | - Jay M Janz
- Anchor Therapeutics, Cambridge, Massachusetts 02139
| | - Michel Bouvier
- the Department of Biochemistry and Institute for Research in Immunology and Cancer, Université de Montréal, Montreal, Quebec H3C 3J7, Canada
| | - Brian K Kobilka
- the Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California 94305
| | - Jeffrey L Benovic
- From the Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107,
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83
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Bock A, Kostenis E, Tränkle C, Lohse MJ, Mohr K. Pilot the pulse: controlling the multiplicity of receptor dynamics. Trends Pharmacol Sci 2014; 35:630-8. [PMID: 25455830 DOI: 10.1016/j.tips.2014.10.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 10/07/2014] [Accepted: 10/08/2014] [Indexed: 12/30/2022]
Abstract
G protein-coupled receptors (GPCRs) are involved in almost every (patho)physiological process, which explains their importance as drug targets. GPCRs have long been regarded as on/off-switches, which is reflected by direct activation or blockade of these receptors through the majority of marketed GPCR drugs. In recent years, however, our view of GPCRs has changed dramatically. GPCRs are now appreciated as integrative and highly dynamic signaling machines which can adopt numerous distinct conformations enabling them to initiate a highly ramified signaling network. We argue here that it may be possible to chemically encode distinct signaling profiles into ligands by rational ligand design. We exemplify our hypothesis by fine-tuning partial and biased agonism, thereby exploiting two new principles of GPCR modulation - dynamic and dualsteric ligand binding. We propose that the emerging understanding of the multiplicity of receptor dynamics will eventually lead to rationally designed new drugs which pilot the pulse; in other words, that stabilize distinct receptor states to fine-tune GPCR signaling.
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Affiliation(s)
- Andreas Bock
- Institute of Pharmacology and Toxicology, University of Würzburg, Versbacher Strasse 9, 97078 Würzburg, Germany.
| | - Evi Kostenis
- Molecular-, Cellular-, and Pharmacobiology Section, Institute of Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
| | - Christian Tränkle
- Pharmacology and Toxicology Section, Institute of Pharmacy, University of Bonn, Gerhard-Domagk-Strasse 3, 53121 Bonn, Germany
| | - Martin J Lohse
- Institute of Pharmacology and Toxicology, University of Würzburg, Versbacher Strasse 9, 97078 Würzburg, Germany; Rudolf Virchow Center, University of Würzburg, Versbacher Strasse 9, 97078 Würzburg, Germany
| | - Klaus Mohr
- Pharmacology and Toxicology Section, Institute of Pharmacy, University of Bonn, Gerhard-Domagk-Strasse 3, 53121 Bonn, Germany.
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84
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Abstract
It has been widely assumed that the production of the ubiquitous second messenger cyclic AMP, which is mediated by cell surface G protein–coupled receptors (GPCRs), and its termination take place exclusively at the plasma membrane. Recent studies reveal that diverse GPCRs do not always follow this conventional paradigm. In the new model, GPCRs mediate G-protein signaling not only from the plasma membrane but also from endosomal membranes. This model proposes that following ligand binding and activation, cell surface GPCRs internalize and redistribute into early endosomes, where trimeric G protein signaling can be maintained for an extended period of time. This Perspective discusses the molecular and cellular mechanistic subtleties as well as the physiological consequences of this unexpected process, which is considerably changing how we think about GPCR signaling and regulation and how we study drugs that target this receptor family.
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85
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Marciano DP, Dharmarajan V, Griffin PR. HDX-MS guided drug discovery: small molecules and biopharmaceuticals. Curr Opin Struct Biol 2014; 28:105-11. [PMID: 25179005 DOI: 10.1016/j.sbi.2014.08.007] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Revised: 07/24/2014] [Accepted: 08/13/2014] [Indexed: 12/24/2022]
Abstract
Hydrogen/deuterium exchange coupled with mass spectrometry (HDX-MS or DXMS) has emerged as an important tool for the development of small molecule therapeutics and biopharmaceuticals. Central to these advances have been improvements to automated HDX-MS platforms and software that allow for the rapid acquisition and processing of experimental data. Correlating the HDX-MS profile of large numbers of ligands with their functional outputs has enabled the development of structure activity relationships (SAR) and delineation of ligand classes based on functional selectivity. HDX-MS has also been applied to address many of the unique challenges posed by the continued emergence of biopharmaceuticals. Here we review the latest applications of HDX-MS to drug discovery, recent advances in technology and software, and provide perspective on future outlook.
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Affiliation(s)
- David P Marciano
- Molecular Therapeutics Department, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, United States
| | | | - Patrick R Griffin
- Molecular Therapeutics Department, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, United States.
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86
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Ligand-selective activation of heterologously-expressed mammalian olfactory receptor. Cell Calcium 2014; 56:245-56. [PMID: 25149566 DOI: 10.1016/j.ceca.2014.07.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 07/24/2014] [Accepted: 07/27/2014] [Indexed: 11/23/2022]
Abstract
Mammalian olfactory receptors (ORs) appear to have the capacity to couple to multiple G protein-coupled signaling pathways in a ligand-dependent selective manner. To better understand the mechanisms and molecular range of such ligand selectivity, we expressed the mouse eugenol OR (mOR-EG) in HEK293T cells together with Gα15 to monitor activation of the phospholipase-C (PLC) signaling pathway and/or Gαolf to monitor activation of the adenylate cyclase (AC) signaling pathway, resulting in intracellular Ca(2+) release and/or Ca(2+) influx through a cyclic nucleotide-gated channel, respectively. PLC-dependent responses differed dynamically from AC-dependent responses, allowing them to be distinguished when Gα15 and Gαolf were co-expressed. The dynamic difference in readout was independent of the receptor, the heterologous expression system, and the ligand concentration. Of 17 reported mOR-EG ligands tested, including eugenol, its analogs, and structurally dissimilar compounds (mousse cristal, nootkatone, orivone), some equally activated both signaling pathways, some differentially activated both signaling pathways, and some had no noticeable effect even at 1-5mM. Our findings argue that mOR-EG, when heterologously expressed, can couple to two different signaling pathways in a ligand selective manner. The challenge now is to determine the potential of mOR-EG, and perhaps other ORs, to activate multiple signaling pathways in a ligand selective manner in native ORNs.
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87
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Ligand-specific endocytic dwell times control functional selectivity of the cannabinoid receptor 1. Nat Commun 2014; 5:4589. [PMID: 25081814 PMCID: PMC4227836 DOI: 10.1038/ncomms5589] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 07/03/2014] [Indexed: 12/20/2022] Open
Abstract
G protein-coupled receptors (GPCRs) are the major transducers of external stimuli and
key therapeutic targets in many pathological conditions. When activated by different
ligands, one receptor can elicit multiple signalling cascades that are mediated by G
proteins or β-arrestin, a process defined as functional selectivity or
ligand bias. However, the dynamic mechanisms underlying β-arrestin
signalling remain unknown. Here by studying the cannabinoid receptor 1 (CB1R), we identify ligand-specific endocytic dwell times, that
is, the time during which receptors are clustered into clathrin pits together with
β-arrestins before endocytosis, as the mechanism controlling
β-arrestin signalling. Agonists inducing short endocytic dwell times
produce little or no β-arrestin signalling, whereas those eliciting
prolonged dwell times induce robust signalling. Remarkably, extending CB1R dwell times by preventing endocytosis
substantially increased β-arrestin signalling. These studies reveal how
receptor activation translates into β-arrestin signalling and identify a
mechanism to control this pathway. G-protein coupled receptors can signal through G-proteins or through
β-arrestin, however mechanisms determining pathway selection remain unclear.
Here the authors show that the duration of cannabinoid receptor clustering in clathrin
coated pits prior to endocytosis determines the strength of β-arrestin
signalling.
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88
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Biased ligands: pathway validation for novel GPCR therapeutics. Curr Opin Pharmacol 2014; 16:108-15. [PMID: 24834870 DOI: 10.1016/j.coph.2014.04.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 04/15/2014] [Accepted: 04/18/2014] [Indexed: 01/14/2023]
Abstract
G protein-coupled receptors (GPCRs), in recent years, have been shown to signal via multiple distinct pathways. Furthermore, biased ligands for some receptors can differentially stimulate or inhibit these pathways versus unbiased endogenous ligands or drugs. Biased ligands can be used to gain a deeper understanding of the molecular targets and cellular responses associated with a GPCR, and may be developed into therapeutics with improved efficacy, safety and/or tolerability. Here we review examples and approaches to pathway validation that establish the relevance and therapeutic potential of distinct pathways that can be selectively activated or blocked by biased ligands.
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89
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Cavero I, Guillon JM. Safety Pharmacology assessment of drugs with biased 5-HT2B receptor agonism mediating cardiac valvulopathy. J Pharmacol Toxicol Methods 2014; 69:150-61. [DOI: 10.1016/j.vascn.2013.12.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 12/04/2013] [Accepted: 12/09/2013] [Indexed: 01/31/2023]
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90
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Davis JS, Kumar TR, May JV, Bousfield GR. Naturally Occurring Follicle-Stimulating Hormone Glycosylation Variants. ACTA ACUST UNITED AC 2014; 4:e117. [PMID: 25893134 PMCID: PMC4398967 DOI: 10.4172/2153-0637.1000e117] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- John S Davis
- VA Nebraska-Western Iowa Health Care System and Olson Center for Women's Health, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - T Rajendra Kumar
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Jeffrey V May
- Department of Biological Sciences, Wichita State University, Wichita, Kansas, USA
| | - George R Bousfield
- Department of Biological Sciences, Wichita State University, Wichita, Kansas, USA
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