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Pearson AC, Shrestha K, Curry TE, Duffy DM. Neurotensin modulates ovarian vascular permeability via adherens junctions. FASEB J 2024; 38:e23602. [PMID: 38581236 PMCID: PMC11034770 DOI: 10.1096/fj.202302652rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 03/21/2024] [Accepted: 03/26/2024] [Indexed: 04/08/2024]
Abstract
Neurotensin (NTS) is a 13-amino acid peptide which is highly expressed in the mammalian ovary in response to the luteinizing hormone surge. Antibody neutralization of NTS in the ovulatory follicle of the cynomolgus macaque impairs ovulation and induces follicular vascular dysregulation, with excessive pooling of red blood cells in the follicle antrum. We hypothesize that NTS is an essential intrafollicular regulator of vascular permeability. In the present study, follicle injection of the NTS receptor antagonist SR142948 also resulted in vascular dysregulation. To measure vascular permeability changes in vitro, primary macaque ovarian microvascular endothelial cells (mOMECs) were enriched from follicle aspirates and studied in vitro. When treated with NTS, permeability of mOMECs decreased. RNA sequencing (RNA-Seq) of mOMECs revealed high mRNA expression of the permeability-regulating adherens junction proteins N-cadherin (CDH2) and K-cadherin (CDH6). Immunofluorescent detection of CDH2 and CDH6 confirmed expression and localized these cadherins to the cell-cell boundaries, consistent with function as components of adherens junctions. mOMECs did not express detectable levels of the typical vascular endothelial cadherin, VE-cadherin (CDH5) as determined by RNA-Seq, qPCR, western blot, and immunofluorescence. Knockdown of CDH2 or CDH6 via siRNA abrogated the NTS effect on mOMEC permeability. Collectively, these data suggest that NTS plays an ovulation-critical role in vascular permeability maintenance, and that CDH2 and CDH6 are involved in the permeability modulating effect of NTS on the ovarian microvasculature. NTS can be added to a growing number of angiogenic regulators which are critical for successful ovulation.
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Affiliation(s)
- Andrew C. Pearson
- Department of Physiological Sciences, Eastern Virginia Medical School, Norfolk, VA, USA, 23507
| | - Ketan Shrestha
- Department of Obstetrics and Gynecology, University of Kentucky, Lexington, KY, USA, 40536
| | - Thomas E. Curry
- Department of Obstetrics and Gynecology, University of Kentucky, Lexington, KY, USA, 40536
| | - Diane M. Duffy
- Department of Physiological Sciences, Eastern Virginia Medical School, Norfolk, VA, USA, 23507
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2
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Hewitt N, Ma N, Arang N, Martin SA, Prakash A, DiBerto JF, Knight KM, Ghosh S, Olsen RHJ, Roth BL, Gutkind JS, Vaidehi N, Campbell SL, Dohlman HG. Catalytic site mutations confer multiple states of G protein activation. Sci Signal 2023; 16:eabq7842. [PMID: 36787384 PMCID: PMC10021883 DOI: 10.1126/scisignal.abq7842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 01/31/2023] [Indexed: 02/16/2023]
Abstract
Heterotrimeric guanine nucleotide-binding proteins (G proteins) that function as molecular switches for cellular growth and metabolism are activated by GTP and inactivated by GTP hydrolysis. In uveal melanoma, a conserved glutamine residue critical for GTP hydrolysis in the G protein α subunit is often mutated in Gαq or Gα11 to either leucine or proline. In contrast, other glutamine mutations or mutations in other Gα subtypes are rare. To uncover the mechanism of the genetic selection and the functional role of this glutamine residue, we analyzed all possible substitutions of this residue in multiple Gα isoforms. Through cell-based measurements of activity, we showed that some mutants were further activated and inactivated by G protein-coupled receptors. Through biochemical, molecular dynamics, and nuclear magnetic resonance-based structural studies, we showed that the Gα mutants were functionally distinct and conformationally diverse, despite their shared inability to hydrolyze GTP. Thus, the catalytic glutamine residue contributes to functions beyond GTP hydrolysis, and these functions include subtype-specific, allosteric modulation of receptor-mediated subunit dissociation. We conclude that G proteins do not function as simple on-off switches. Rather, signaling emerges from an ensemble of active states, a subset of which are favored in disease and may be uniquely responsive to receptor-directed ligands.
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Affiliation(s)
- Natalie Hewitt
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Ning Ma
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, CA 91010, USA
| | - Nadia Arang
- Department of Pharmacology, University of California San Diego, San Diego, CA, 92093, USA
- Moores Cancer Center, University of California San Diego, La Jolla, CA 92093, USA
| | - Sarah A. Martin
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Ajit Prakash
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Jeffrey F. DiBerto
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Kevin M. Knight
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Soumadwip Ghosh
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, CA 91010, USA
- Current address: Illumina Inc, 5200 Illumina Way, San Diego, CA 92037, USA
| | - Reid H. J. Olsen
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Current address: GPCR Pharmacology, Discovery Biology, Exscientia Ai, Oxford, UK OX4 4GE
| | - Bryan L. Roth
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - J. Silvio Gutkind
- Department of Pharmacology, University of California San Diego, San Diego, CA, 92093, USA
- Moores Cancer Center, University of California San Diego, La Jolla, CA 92093, USA
| | - Nagarajan Vaidehi
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, CA 91010, USA
| | - Sharon L. Campbell
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Henrik G. Dohlman
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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Caniceiro AB, Bueschbell B, Schiedel AC, Moreira IS. Class A and C GPCR Dimers in Neurodegenerative Diseases. Curr Neuropharmacol 2022; 20:2081-2141. [PMID: 35339177 PMCID: PMC9886835 DOI: 10.2174/1570159x20666220327221830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 02/21/2022] [Accepted: 03/23/2022] [Indexed: 11/22/2022] Open
Abstract
Neurodegenerative diseases affect over 30 million people worldwide with an ascending trend. Most individuals suffering from these irreversible brain damages belong to the elderly population, with onset between 50 and 60 years. Although the pathophysiology of such diseases is partially known, it remains unclear upon which point a disease turns degenerative. Moreover, current therapeutics can treat some of the symptoms but often have severe side effects and become less effective in long-term treatment. For many neurodegenerative diseases, the involvement of G proteincoupled receptors (GPCRs), which are key players of neuronal transmission and plasticity, has become clearer and holds great promise in elucidating their biological mechanism. With this review, we introduce and summarize class A and class C GPCRs, known to form heterodimers or oligomers to increase their signalling repertoire. Additionally, the examples discussed here were shown to display relevant alterations in brain signalling and had already been associated with the pathophysiology of certain neurodegenerative diseases. Lastly, we classified the heterodimers into two categories of crosstalk, positive or negative, for which there is known evidence.
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Affiliation(s)
- Ana B. Caniceiro
- Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal; ,These authors contributed equally to this work.
| | - Beatriz Bueschbell
- PhD Programme in Experimental Biology and Biomedicine, Institute for Interdisciplinary Research (IIIUC), University of Coimbra, Casa Costa Alemão, 3030-789 Coimbra, Portugal; ,These authors contributed equally to this work.
| | - Anke C. Schiedel
- Department of Pharmaceutical & Medicinal Chemistry, Pharmaceutical Institute, University of Bonn, D-53121 Bonn, Germany;
| | - Irina S. Moreira
- University of Coimbra, Department of Life Sciences, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal; ,Center for Neuroscience and Cell Biology, Center for Innovative Biomedicine and Biotechnology, 3004-504 Coimbra, Portugal,Address correspondence to this author at the Center for Neuroscience and Cell Biology, Center for Innovative Biomedicine and Biotechnology, 3004-504 Coimbra, Portugal; E-mail:
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Brouillette RL, Besserer-Offroy É, Mona CE, Chartier M, Lavenus S, Sousbie M, Belleville K, Longpré JM, Marsault É, Grandbois M, Sarret P. Cell-penetrating pepducins targeting the neurotensin receptor type 1 relieve pain. Pharmacol Res 2020; 155:104750. [PMID: 32151680 DOI: 10.1016/j.phrs.2020.104750] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 02/12/2020] [Accepted: 03/05/2020] [Indexed: 01/29/2023]
Abstract
Pepducins are cell-penetrating, membrane-tethered lipopeptides designed to target the intracellular region of a G protein-coupled receptor (GPCR) in order to allosterically modulate the receptor's signaling output. In this proof-of-concept study, we explored the pain-relief potential of a pepducin series derived from the first intracellular loop of neurotensin receptor type 1 (NTS1), a class A GPCR that mediates many of the effects of the neurotensin (NT) tridecapeptide, including hypothermia, hypotension and analgesia. We used BRET-based biosensors to determine the pepducins' ability to engage G protein signaling pathways associated with NTS1 activation. We observed partial Gαq and Gα13 activation at a 10 μM concentration, indicating that these pepducins may act as allosteric agonists of NTS1. Additionally, we used surface plasmon resonance (SPR) as a label-free assay to monitor pepducin-induced responses in CHO-K1 cells stably expressing hNTS1. This whole-cell integrated assay enabled us to subdivide our pepducin series into three profile response groups. In order to determine the pepducins' antinociceptive potential, we then screened the series in an acute pain model (tail-flick test) by measuring tail withdrawal latencies to a thermal nociceptive stimulus, following intrathecal (i.t.) pepducin administration (275 nmol/kg). We further evaluated promising pepducins in a tonic pain model (formalin test), as well as in neuropathic (Chronic Constriction Injury) and inflammatory (Complete Freund's Adjuvant) chronic pain models. We report one pepducin, PP-001, that consistently reduced rat nociceptive behaviors, even in chronic pain paradigms. Finally, we designed a TAMRA-tagged version of PP-001 and found by confocal microscopy that the pepducin reached the rat dorsal root ganglia post i.t. injection, thus potentially modulating the activity of NTS1 at this location to produce its analgesic effect. Altogether, these results suggest that NTS1-derived pepducins may represent a promising strategy in pain-relief.
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Affiliation(s)
- Rebecca L Brouillette
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada; Institut de pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, QC, Canada.
| | - Élie Besserer-Offroy
- Department of Pharmacology and Therapeutics, McGill University, Montréal, QC, Canada.
| | - Christine E Mona
- Ahmanson Translational Theranostic Division, Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA.
| | - Magali Chartier
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada; Institut de pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, QC, Canada.
| | - Sandrine Lavenus
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada; Institut de pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, QC, Canada.
| | - Marc Sousbie
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada; Institut de pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, QC, Canada.
| | - Karine Belleville
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada; Institut de pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, QC, Canada.
| | - Jean-Michel Longpré
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada; Institut de pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, QC, Canada.
| | - Éric Marsault
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada; Institut de pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, QC, Canada.
| | - Michel Grandbois
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada; Institut de pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, QC, Canada.
| | - Philippe Sarret
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada; Institut de pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, QC, Canada.
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5
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Seyedabadi M, Ghahremani MH, Albert PR. Biased signaling of G protein coupled receptors (GPCRs): Molecular determinants of GPCR/transducer selectivity and therapeutic potential. Pharmacol Ther 2019; 200:148-178. [PMID: 31075355 DOI: 10.1016/j.pharmthera.2019.05.006] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 04/26/2019] [Indexed: 02/07/2023]
Abstract
G protein coupled receptors (GPCRs) convey signals across membranes via interaction with G proteins. Originally, an individual GPCR was thought to signal through one G protein family, comprising cognate G proteins that mediate canonical receptor signaling. However, several deviations from canonical signaling pathways for GPCRs have been described. It is now clear that GPCRs can engage with multiple G proteins and the line between cognate and non-cognate signaling is increasingly blurred. Furthermore, GPCRs couple to non-G protein transducers, including β-arrestins or other scaffold proteins, to initiate additional signaling cascades. Receptor/transducer selectivity is dictated by agonist-induced receptor conformations as well as by collateral factors. In particular, ligands stabilize distinct receptor conformations to preferentially activate certain pathways, designated 'biased signaling'. In this regard, receptor sequence alignment and mutagenesis have helped to identify key receptor domains for receptor/transducer specificity. Furthermore, molecular structures of GPCRs bound to different ligands or transducers have provided detailed insights into mechanisms of coupling selectivity. However, receptor dimerization, compartmentalization, and trafficking, receptor-transducer-effector stoichiometry, and ligand residence and exposure times can each affect GPCR coupling. Extrinsic factors including cell type or assay conditions can also influence receptor signaling. Understanding these factors may lead to the development of improved biased ligands with the potential to enhance therapeutic benefit, while minimizing adverse effects. In this review, evidence for ligand-specific GPCR signaling toward different transducers or pathways is elaborated. Furthermore, molecular determinants of biased signaling toward these pathways and relevant examples of the potential clinical benefits and pitfalls of biased ligands are discussed.
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Affiliation(s)
- Mohammad Seyedabadi
- Department of Pharmacology, School of Medicine, Bushehr University of Medical Sciences, Iran; Education Development Center, Bushehr University of Medical Sciences, Iran
| | | | - Paul R Albert
- Ottawa Hospital Research Institute, Neuroscience, University of Ottawa, Canada.
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Tschumi CW, Beckstead MJ. Diverse actions of the modulatory peptide neurotensin on central synaptic transmission. Eur J Neurosci 2018; 49:784-793. [PMID: 29405480 DOI: 10.1111/ejn.13858] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 01/29/2018] [Accepted: 01/30/2018] [Indexed: 12/27/2022]
Abstract
Neurotensin (NT) is a 13 amino acid neuropeptide that is expressed throughout the central nervous system and is implicated in the etiology of multiple diseases and disorders. Many primary investigations of NT-induced modulation of neuronal excitability at the level of the synapse have been conducted, but they have not been summarized in review form in nearly 30 years. Therefore, the goal of this review is to discuss the many actions of NT on neuronal excitability across brain regions as well as NT circuit architecture. In the basal ganglia as well as other brain nuclei, NT can act through diverse intracellular signaling cascades to enhance or depress neuronal activity by modulating activity of ion channels, ionotropic and metabotropic neurotransmitter receptors, and presynaptic release of neurotransmitters. Further, NT can produce indirect effects by evoking endocannabinoid release, and recently has itself been identified as a putative retrograde messenger. In the basal ganglia, the diverse actions and circuit architecture of NT signaling allow for input-specific control of reward-related behaviors.
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Affiliation(s)
- Christopher W Tschumi
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, 73104-5005, USA
| | - Michael J Beckstead
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, 73104-5005, USA
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Besserer-Offroy É, Brouillette RL, Lavenus S, Froehlich U, Brumwell A, Murza A, Longpré JM, Marsault É, Grandbois M, Sarret P, Leduc R. The signaling signature of the neurotensin type 1 receptor with endogenous ligands. Eur J Pharmacol 2017; 805:1-13. [DOI: 10.1016/j.ejphar.2017.03.046] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 03/15/2017] [Accepted: 03/21/2017] [Indexed: 12/17/2022]
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Bolivar JH, Muñoz-García JC, Castro-Dopico T, Dijkman PM, Stansfeld PJ, Watts A. Interaction of lipids with the neurotensin receptor 1. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:1278-87. [DOI: 10.1016/j.bbamem.2016.02.032] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 02/02/2016] [Accepted: 02/24/2016] [Indexed: 10/22/2022]
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Nimitvilai S, Arora DS, McElvain MA, Brodie MS. Suppression of Gq Function Using Intra-Pipette Delivery of shRNA during Extracellular Recording in the Ventral Tegmental Area. Front Cell Neurosci 2013; 7:7. [PMID: 23408114 PMCID: PMC3569574 DOI: 10.3389/fncel.2013.00007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Accepted: 01/16/2013] [Indexed: 11/13/2022] Open
Abstract
Selective suppression of protein function in the brain can be achieved using specific silencing RNAs administered in vivo. A viral delivery system is often employed to transfect neurons with small hairpin RNA (shRNA) directed against specific proteins, and intervals of several days are allowed between microinjection of the shRNA-containing virus into the brain and experiments to assess suppression of gene function. Here we report studies using extracellular recording of dopaminergic neurons of the ventral tegmental area (DA VTA neurons) recorded in brain slices in which lentivirus containing shRNA directed against Gq was included in the recording pipette, and suppression of Gq-related function was observed within the time frame of the recording. The action of neurotensin (NT) is associated with activation of Gq, and the firing rate of DA VTA neurons is increased by NT. With shRNA directed against Gq in the pipette, there was a significant reduction of NT excitation within 2 h. Likewise, time-dependent dopamine desensitization, which we have hypothesized to be Gq-dependent, was not observed when shRNA directed against Gq was present in the pipette and dopamine was tested 2 h after initiation of recording. As the time interval (2 h) is relatively short, we tested whether blockade of protein synthesis with cycloheximide delivered via the recording pipette would alter Gq-linked responses similarly. Both NT-induced excitation and dopamine desensitization were inhibited in the presence of cycloheximide. Inclusion of shRNA in the recording pipette may be an efficient and selective way to dampen responses linked to Gq, and, more generally, the use of lentiviral-packaged shRNA in the recording pipette is a means to produce selective inhibition of the function of specific proteins in experiments.
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Affiliation(s)
- Sudarat Nimitvilai
- Department of Physiology and Biophysics, University of Illinois at Chicago Chicago, IL, USA
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Zogovic B, Pilowsky PM. Intrathecal neurotensin is hypotensive, sympathoinhibitory and enhances the baroreflex in anaesthetized rat. Br J Pharmacol 2012; 166:378-89. [PMID: 22035146 DOI: 10.1111/j.1476-5381.2011.01760.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND AND PURPOSE The neuromodulatory effects of the gut-neuropeptide neurotensin on sympathetic vasomotor tone, central respiratory drive and adaptive reflexes in the spinal cord, are not known. EXPERIMENTAL APPROACH Neurotensin (0.5 µM-3 mM) was administered into the intrathecal (i.t.) space at the sixth thoracic spinal cord segment in urethane-anaesthetized, paralysed, vagotomized male Sprague-Dawley rats. Pulsatile arterial pressure, splanchnic sympathetic nerve activity (sSNA), phrenic nerve activity, ECG and end-tidal CO(2) were recorded. KEY RESULTS Neurotensin caused a dose-related hypotension, sympathoinhibition and bradycardia. The maximum effects were observed at 3000 µM, where the decreases in mean arterial pressure (MAP), heart rate (HR) and sSNA reached -25 mmHg, -26 beats min(-1) and -26% from baseline, respectively. The sympathetic baroreflex was enhanced. Changes in central respiratory drive were characterized by a fall in the amplitude of the phrenic nerve activity. Finally, administration of SR 142948A (5 mM), a potent, selective antagonist at neurotensin receptors, caused a potent hypotension (-35 mmHg), bradycardia (-54 beats min(-1) ) and sympathoinhibition (-44%). A reduction in the amplitude and frequency of the phrenic nerve activity was also observed. CONCLUSIONS AND IMPLICATIONS The data demonstrate that neurotensin plays an important role in the regulation of spinal cardiovascular function, affecting both tone and adaptive reflexes.
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Affiliation(s)
- B Zogovic
- Australian School of Advanced Medicine, Macquarie University, Sydney, NSW, Australia
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Dupouy S, Mourra N, Doan VK, Gompel A, Alifano M, Forgez P. The potential use of the neurotensin high affinity receptor 1 as a biomarker for cancer progression and as a component of personalized medicine in selective cancers. Biochimie 2011; 93:1369-78. [PMID: 21605619 DOI: 10.1016/j.biochi.2011.04.024] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2011] [Accepted: 04/30/2011] [Indexed: 02/07/2023]
Abstract
A growing challenge in medicine today, is the need to improve the suitability of drug treatments for cancer patients. In this field, biomarkers have become the "flags" to provide additional information in tumor biology. They are a relay between the patient and practitioner and consequently, aid in the diagnosis, providing information for prognosis, or in some cases predicting the response to specific therapies. In addition to being markers, these tumor "flags" can also be major participants in the process of carcinogenesis. Neurotensin receptor 1 (NTSR1) was recently identified as a prognosis marker in breast, lung, and head and neck squamous carcinomas. Neurotensin (NTS) was also shown to exert numerous oncogenic effects involved in tumor growth and metastatic spread. These effects were mostly mediated by NTSR1, making the NTS/NTSR1 complex an actor in cancer progression. In this review, we gather information on the oncogenic effects of the NTS/NTSR1 complex and its associated signaling pathways in order to illuminate its significant role in tumor progression and its potential as a biomarker and a therapeutic target in some tumors.
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Affiliation(s)
- Sandra Dupouy
- INSERM-UPMC UMR_S938, Hôpital Saint-Antoine, 184 rue du Faubourg Saint-Antoine, 75012 Paris, France
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Hwang JI, Kim DK, Kwon HB, Vaudry H, Seong JY. Phylogenetic History, Pharmacological Features, and Signal Transduction of Neurotensin Receptors in Vertebrates. Ann N Y Acad Sci 2009; 1163:169-78. [DOI: 10.1111/j.1749-6632.2008.03636.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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13
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White JF, Grodnitzky J, Louis JM, Trinh LB, Shiloach J, Gutierrez J, Northup JK, Grisshammer R. Dimerization of the class A G protein-coupled neurotensin receptor NTS1 alters G protein interaction. Proc Natl Acad Sci U S A 2007; 104:12199-204. [PMID: 17620610 PMCID: PMC1913548 DOI: 10.1073/pnas.0705312104] [Citation(s) in RCA: 126] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
G protein-coupled receptors (GPCRs) have been found as monomers but also as dimers or higher-order oligomers in cells. The relevance of the monomeric or dimeric receptor state for G protein activation is currently under debate for class A rhodopsin-like GPCRs. Clarification of this issue requires the availability of well defined receptor preparations as monomers or dimers and an assessment of their ligand-binding and G protein-coupling properties. We show by pharmacological and hydrodynamic experiments that purified neurotensin receptor NTS1, a class A GPCR, dimerizes in detergent solution in a concentration-dependent manner, with an apparent affinity in the low nanomolar range. At low receptor concentrations, NTS1 binds the agonist neurotensin with a Hill slope of approximately 1; at higher receptor concentrations, neurotensin binding displays positive cooperativity with a Hill slope of approximately 2. NTS1 monomers activate G alpha q beta(1)gamma(2), whereas receptor dimers catalyze nucleotide exchange with lower affinity. Our results demonstrate that NTS1 dimerization per se is not a prerequisite for G protein activation.
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Affiliation(s)
- Jim F. White
- *Membrane Protein Structure and Function Unit, National Institute of Neurological Disorders and Stroke, and
| | - Justin Grodnitzky
- *Membrane Protein Structure and Function Unit, National Institute of Neurological Disorders and Stroke, and
| | | | - Loc B. Trinh
- Biotechnology Unit, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892; and
| | - Joseph Shiloach
- Biotechnology Unit, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892; and
| | - Joanne Gutierrez
- Laboratory of Cellular Biology, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Department of Health and Human Services, Rockville, MD 20850
| | - John K. Northup
- Laboratory of Cellular Biology, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Department of Health and Human Services, Rockville, MD 20850
| | - Reinhard Grisshammer
- *Membrane Protein Structure and Function Unit, National Institute of Neurological Disorders and Stroke, and
- To whom correspondence should be addressed at:
NINDS, NIH, 5625 Fishers Lane, Room 4S-12, Rockville, MD 20852. E-mail:
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Wu EHT, Wu KKH, Wong YH. Tuberin: a stimulus-regulated tumor suppressor protein controlled by a diverse array of receptor tyrosine kinases and G protein-coupled receptors. Neurosignals 2007; 15:217-27. [PMID: 17389815 DOI: 10.1159/000101333] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2006] [Accepted: 02/09/2007] [Indexed: 02/02/2023] Open
Abstract
Tuberin, a tumor suppressor protein, is involved in various cellular functions including survival, proliferation, and growth. It has emerged as an important effector regulated by receptor tyrosine kinases (RTKs) and G protein-coupled receptors (GPCRs). Regulation of tuberin by RTKs and GPCRs is highly complex and dependent on the type of receptors and their associated signaling molecules. Apart from Akt, the first kinase recognized to phosphorylate and inactivate tuberin upon growth factor stimulation, an increasing number of kinases upstream of tuberin have been identified. Furthermore, recruitment of different scaffolding adaptor components to the activated receptors appears to play an important role in the regulation of tuberin activity. More recently, the differential regulation of tuberin by various G protein family members have also been intensively studied, it appears that G proteins can both facilitate (e.g., G(i/o)) as well as inhibit (e.g., G(q)) tuberin phosphorylation. In the present review, we attempt to summarize our emerging understandings of the roles of RTKs, GPCRs, and their cross-talk on the regulation of tuberin.
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Affiliation(s)
- Eddy H T Wu
- Department of Biochemistry, Molecular Neuroscience Center, and Biotechnology Research Institute, Hong Kong University of Science and Technology, Hong Kong, SAR, China
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15
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Abstract
Three neurotensin (NT) receptors have been cloned to date, two of which, NTS1 and NTS2, belong to the family of seven transmembrane domain receptors coupled to G proteins (GPCRs). NTS1 and NTS2 may activate multiple signal transduction pathways, involving several G proteins. However, whereas NT acts as an agonist towards all NTS1-mediated pathways, this peptide may exert either agonist or antagonist activities, depending on the NTS2-mediated pathway in question. Studies on these receptors reinforce the concept of independence between multiple signals potentially mediated through a single GPCR, generating a wide diversity of functional responses depending on the host cell and the ligand.
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Affiliation(s)
- Didier Pelaprat
- INSERM, U.773, CRB3, EA 3512, Faculté de Médecine Xavier Bichat, 16 rue Henri Huchard, BP416, 75870 Paris Cedex 18, France.
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16
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Abstract
The subtype 1 neurotensin receptor (NTS1) belongs to the family of G protein coupled receptors with seven transmembrane domains and mediates most of the known effects of neurotensin. In the past years, mutagenesis studies have allowed to delineate functional regions of the receptor involved in agonist and antagonist binding, G protein coupling, sodium sensitivity of agonist binding, and agonist-induced receptor internalization. These data are reviewed and discussed in the present paper.
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Affiliation(s)
- Patrick Kitabgi
- INSERM, UMR S 732, Université Pierre et Marie Curie-Paris 6, Hopital St-Antoine, 184 rue du Faubourg St-Antoine, 75571 Paris Cedex 12, France.
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17
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Scarpa RC, Carraway RE, Cochrane DE. Insulin-like growth factor (IGF) induced proliferation of human lung fibroblasts is enhanced by neurotensin. Peptides 2005; 26:2201-10. [PMID: 16269351 DOI: 10.1016/j.peptides.2005.03.044] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2005] [Revised: 03/18/2005] [Accepted: 03/21/2005] [Indexed: 10/25/2022]
Abstract
Fibroblasts are key cells in tissue repair and important contributors to the inflammatory response. Insulin-like growth factors (IGFs) have been shown to participate in growth, in immune responses and in tissue repair where they stimulate cell growth. Neurotensin (NT) has been suggested to participate in inflammation and in tissue repair and is an autocrine or paracrine growth factor for several cancer cell types. Here we show that IGF-induced proliferation of fibroblasts is enhanced by NT in a concentration and type 1 NT-receptor dependent manner. This action of NT was blocked by inhibitors of phospholipase C and protein kinase C but not by inhibitors of phosphoinositide-3-kinase. An inhibitor of MEK 1/2 significantly reduced the proliferative effects of the IGFs but NT's ability to enhance IGF-induced proliferation was not effected. The ability of NT to enhance IGF-induced proliferation did not involve an autocrine factor. These results suggest that interactions between NT and the IGFs may contribute to the regulation of fibroblasts in for example, inflamed or injured tissues.
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Affiliation(s)
- Richard C Scarpa
- Department of Biology, Tufts University, 117 Barnum Hall, Medford, MA 02155, USA
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18
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Liu F, Yang P, Baez M, Ni B. Neurotensin negatively modulates Akt activity in neurotensin receptor-1-transfected AV12 cells. J Cell Biochem 2004; 92:603-11. [PMID: 15156571 DOI: 10.1002/jcb.20098] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Neurotensin (NT) regulates a variety of biological processes primarily through interaction with neurotensin receptor-1 (NTR1), a heterotrimeric G-protein-coupled receptor (GPCR). Stimulation of NTR1 has been linked to activation of multiple signaling transduction pathways via specific coupling to G(q), G(i/o), or G(s), in various cell systems. However, the function of NT/NTR1 in the regulation of the Akt pathway remains unknown. Here, we report that activation of NTR1 by NT inhibits Akt activity as determined by the dephosphorylation of Akt at both Ser473 and Thr308 in AV12 cells constitutively expressing human NTR1 (NTR1/AV12). The inactivation of Akt by NT was rapid and dose-dependent. This effect of NT was completely blocked by the specific NTR1 antagonist, (S)-(+)-[1-(7-chloro-4-quinolinyl)-5-(2,6-dimethoxyphenyl)pyrazol-3-yl)-carbonylamino] cyclohexylacetic acid (SR 48527), but unaffected by the less active enantiomer ((R)-(-)-[1-(7-chloro-4-quinolinyl)-5-(2,6-dimethoxyphenyl)pyrazol-3-yl)-carbonylamino] cyclohexylacetic acid (SR 49711)), indicating the stereospecificity of NTR1 in the negative regulation of Akt. In addition, NT prevented insulin- and epidermal growth factor (EGF)-mediated Akt activation. Our results provide insight into the role of NT in the modulation of Akt signaling and the potential physiological significance of Akt regulation by NT.
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Affiliation(s)
- Feng Liu
- Lilly Research Laboratories, Indianapolis, Indiana 46225, USA.
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19
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Skrzydelski D, Lhiaubet AM, Lebeau A, Forgez P, Yamada M, Hermans E, Rostene W, Pelaprat D. Differential involvement of intracellular domains of the rat NTS1 neurotensin receptor in coupling to G proteins: a molecular basis for agonist-directed trafficking of receptor stimulus. Mol Pharmacol 2003; 64:421-9. [PMID: 12869647 DOI: 10.1124/mol.64.2.421] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In this work, we evidenced characteristic features of agonist-induced trafficking of receptor stimulus for the rat neurotensin receptor 1 (NTS1). Thus, reverse potency orders between two agonists, EISAI-1 and neuromedin N, were observed in inositol 1,4,5-trisphosphate and cAMP assays in Chinese hamster ovary cells transfected with this receptor. Indeed, compared with other agonists, EISAI-1 presented lower relative potency toward inositol 1,4,5-trisphosphate production than toward cAMP accumulation, guanosine 5'-O -(3-[35 S]thio)triphosphate binding, and [3H]arachidonic acid production. These results indicated pathway-dependent differences in EISAI-1 intrinsic efficacies, favoring activations of Gs- and Gi/o-related pathways over the Gq/11-related pathway. Moreover, although coupling to Gq/11 and Gi/o involved the third intracellular loop and the C-terminal domain of the NTS1 receptor, respectively, we demonstrated that deletion of the latter domain suppressed agonist-induced cAMP accumulation, suggesting that this domain also mediated coupling to Gs. Together, these results indicated that, unlike other agonists, EISAI-1 discriminated between the pathways involving the receptor C-terminal domain and that involving the third intracellular loop. These properties of EISAI-1 were also observed in cortical neurons endogenously expressing the NTS1 receptor. They were further attributed to the functionalization of its COOH end by an ethyl group, because the unesterified analog EISAI-2 presented normal behavior on inositol 1,4,5-trisphosphate production. These findings support the hypothesis of agonist-selective receptor states with distinct conformations or accessibilities of intracellular domains. They also suggest that the differential involvement of these domains in coupling to G proteins might represent a molecular basis for agonist-selective responses through G protein-coupled receptors.
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Affiliation(s)
- Delphine Skrzydelski
- Institut National de la Santé et de la Recherche Médicale, Unité 339, Hôpital Saint-Antoine, Paris, France
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20
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Hermans E. Biochemical and pharmacological control of the multiplicity of coupling at G-protein-coupled receptors. Pharmacol Ther 2003; 99:25-44. [PMID: 12804697 DOI: 10.1016/s0163-7258(03)00051-2] [Citation(s) in RCA: 221] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
For decades, it has been generally proposed that a given receptor always interacts with a particular GTP-binding protein (G-protein) or with multiple G-proteins within one family. However, for several G-protein-coupled receptors (GPCR), it now becomes generally accepted that simultaneous functional coupling with distinct unrelated G-proteins can be observed, leading to the activation of multiple intracellular effectors with distinct efficacies and/or potencies. Multiplicity in G-protein coupling is frequently observed in artificial expression systems where high densities of receptors are obtained, raising the question of whether such complex signalling reveals artefactual promiscuous coupling or is a genuine property of GPCRs. Multiple biochemical and pharmacological evidence in favour of an intrinsic property of GPCRs were obtained in recent studies. Thus, there are now many examples showing that the coupling to multiple signalling pathways is dependent on the agonist used (agonist trafficking of receptor signals). In addition, the different couplings were demonstrated to involve distinct molecular determinants of the receptor and to show distinct desensitisation kinetics. Such multiplicity of signalling at the level of G-protein coupling leads to a further complexity in the functional response to agonist stimulation of one of the most elaborate cellular transmission systems. Indeed, the physiological relevance of such versatility in signalling associated with a single receptor requires the existence of critical mechanisms of dynamic regulation of the expression, the compartmentalisation, and the activity of the signalling partners. This review aims at summarising the different studies that support the concept of multiplicity of G-protein coupling. The physiological and pharmacological relevance of this coupling promiscuity will be discussed.
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Affiliation(s)
- Emmanuel Hermans
- Laboratoire de Pharmacologie Expérimentale, Université Catholique de Louvain, FARL 54.10, Avenue Hippocrate 54, B-1200 Brussels, Belgium.
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21
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Najimi M, Maloteaux JM, Hermans E. Cytoskeleton-related trafficking of the EAAC1 glutamate transporter after activation of the G(q/11)-coupled neurotensin receptor NTS1. FEBS Lett 2002; 523:224-8. [PMID: 12123836 DOI: 10.1016/s0014-5793(02)02981-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The possible modulation of the glutamate transporter EAAC1 by a class A G protein-coupled receptor was studied in transfected C6 glioma cells stably expressing the high-affinity neurotensin receptor NTS1. Brief exposure (5 min) to neurotensin increased Na(+)-dependent D-[(3)H]aspartate uptake by about 70%. The effect of neurotensin was found to result from an increase in cell surface expression of EAAC1 and accordingly, cytochalasin D and colchicine were shown to block the effect of neurotensin on aspartate uptake, suggesting that the cytoskeleton participates in this regulation. Neither protein kinase C nor phosphatidylinositol 3-kinase activities, two intracellular signaling pathways known to modulate EAAC1, was required for EAAC1-mediated aspartate transport regulation by neurotensin. Together, these results provide evidence for an acute regulation of EAAC1 trafficking after activation of a G protein-coupled receptor.
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Affiliation(s)
- Mustapha Najimi
- Laboratoire de Pharmacologie Expérimentale, Université Catholique de Louvain, Avenue Hippocrate 54, 1200, Brussels, Belgium.
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22
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Najimi M, Gailly P, Maloteaux JM, Hermans E. Distinct regions of C-terminus of the high affinity neurotensin receptor mediate the functional coupling with pertussis toxin sensitive and insensitive G-proteins. FEBS Lett 2002; 512:329-33. [PMID: 11852105 DOI: 10.1016/s0014-5793(02)02285-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The functional coupling of C-terminally truncated mutants of the high affinity rat neurotensin (NT) receptor (NTS1) was characterized in transfected Chinese hamster ovary cells. On cells expressing NTRDelta372 (truncated NTS1 lacking the entire 52 amino acid C-terminus), NT failed to promote [(35)S]guanosine 5'-[gamma-(35)S]triphosphate binding whereas a robust pertussis toxin (PTx) sensitive response was observed in cells expressing a partially truncated receptor (NTRDelta401 lacking the last 23 residues). Similar results were obtained when measuring the ability of NT to induce the production of arachidonic acid. Since neither deletions impaired the NT-induced phosphoinositide hydrolysis, these results indicate that the membrane proximal region of the C-terminus is specifically involved in the functional coupling of the receptor with PTx sensitive G-proteins. This region was also found to be involved in the control of receptor internalization. However, PTx failed to impair internalization, indicating that these two properties are not directly related.
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Affiliation(s)
- Mustapha Najimi
- Laboratoire de Pharmacologie Exprimentale (FARL), Département de Physiologie et de Pharmacologie, Université catholique de Louvain 54.10, Avenue Hippocrate 54, B-1200, Brussels, Belgium
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23
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Gailly P, Colson-Van Schoor M. Involvement of trp-2 protein in store-operated influx of calcium in fibroblasts. Cell Calcium 2001; 30:157-65. [PMID: 11508995 DOI: 10.1054/ceca.2001.0221] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Mammalian homologues of the Drosophila melanogaster transient receptor potential (trp) gene have been proposed to encode store-operated channels. This assertion essentially stays on the fact that expression of different trp proteins produces trans-membrane cation currents. However, the selectivity of the expressed channels and their mode of activation, in particular, their dependence to store depletion appears to be quite variable. In the present work, we adopted an anti-sense strategy to study this question in transfected Chinese hamster ovary cells expressing the rat neurotensin receptor (CHO-NTR cells), a cellular model characterized by its very large store-dependent entry of Ca(2+). We identified different trp transcripts by RT-PCR, the trp-1 and trp-2 transcripts being by far the most abundant. CHO-NTR cells were then transfected with a mouse trp-2 anti-sense construct (CHO-NTR-TRP2AS cells). We showed that in these cells, trp-2 mRNA was suppressed in comparison with cells transfected with a control plasmid. The store-operated entry of Ca(2+) was evaluated after store depletion by an IP(3)-dependent mechanism (neurotensin stimulation) or by direct inhibition of the endoplasmic reticulum Ca(2+)ATPase (thapsigargin stimulation). In both cases, store-dependent entry of Ca(2+) was largely reduced in CHO-NTR-TRP2AS cells in comparison with control cells, suggesting that trp-2 protein might constitute a functional subunit of store-operated channels.
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Affiliation(s)
- P Gailly
- Département de Physiologie et de Pharmacologie, Université Catholique de Louvain (UCL 5540), Av. Hippocrate 55, 1200 Brussels, Belgium.
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24
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Grisshammer R, Hermans E. Functional coupling with Galpha(q) and Galpha(i1) protein subunits promotes high-affinity agonist binding to the neurotensin receptor NTS-1 expressed in Escherichia coli. FEBS Lett 2001; 493:101-5. [PMID: 11287004 DOI: 10.1016/s0014-5793(01)02281-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
To analyze the coupling of Galpha subunits to the rat neurotensin receptor NTS-1 (NTR), fusion proteins were expressed in Escherichia coli with various Galpha subunits covalently linked to the receptor C-terminus. The presence of Galpha(q) or Galpha(i/q), in which the six C-terminal residues of Galpha(i1) were replaced with those from Galpha(q), increased the percentage of receptors in the agonist high-affinity state. This effect was less pronounced for wild-type Galpha(i1) and not observed for Galpha(i/s). Functional coupling of neurotensin receptor to Galpha was demonstrated by neurotensin-induced [(35)S]GTPgammaS binding for the Galpha(q), Galpha(i/q) and Galpha(i1) subunits, but not for Galpha(i/s). Our results extend previous findings of the dual coupling of NTR to pertussis toxin-sensitive and -insensitive G-proteins in Chinese hamster ovary cells with preference for the latter.
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Affiliation(s)
- R Grisshammer
- MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, UK.
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