1
|
Llada IM, Mote RS, Hill NS, Lourenco JM, Jones DP, Suen G, Ross MK, Filipov NM. Ruminal ergovaline and volatile fatty acid dynamics: Association with poor performance and a key growth regulator in steers grazing toxic tall fescue. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2024; 105:104354. [PMID: 38151218 DOI: 10.1016/j.etap.2023.104354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 12/22/2023] [Indexed: 12/29/2023]
Abstract
Fescue toxicosis (FT) is produced by an ergot alkaloid (i.e., ergovaline [EV])-producing fungus residing in toxic fescue plants. Associations between EV, decreased weight gain and ruminal volatile fatty acids are unclear. Feces, rumen fluid, and blood were collected from 12 steers that grazed non-toxic (NT) or toxic (E +) fescue for 28 days. The E + group exhibited decreased propionate (P), increased acetate (A), and increased ruminal A:P ratio, with similar trends in feces. Plasma GASP-1 (G-Protein-Coupled-Receptor-Associated-Sorting-Protein), a myostatin inhibitor, decreased (day 14) only in E + steers. Ergovaline was present only in E + ruminal fluid and peaked on day 14. The lower ruminal propionate and higher A:P ratio might contribute to FT while reduced GASP-1 might be a new mechanism linked to E + -related weight gain reduction. Day 14 ergovaline zenith likely reflects ruminal adaptations favoring EV breakdown and its presence only in rumen points to local, rather than systemic effects.
Collapse
Affiliation(s)
- I M Llada
- Interdisciplinary Toxicology Program, United States; Department of Physiology and Pharmacology, United States
| | - R S Mote
- Interdisciplinary Toxicology Program, United States; Department of Physiology and Pharmacology, United States
| | - N S Hill
- Department of Crop and Soil Sciences, United States
| | - J M Lourenco
- Department of Animal and Dairy Sciences, University of Georgia, Athens, GA, United States
| | - D P Jones
- Department of Medicine, Division of Pulmonary, Allergy, and Critical Care Medicine, Emory University, Atlanta, GA, United States
| | - G Suen
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, United States
| | - M K Ross
- Center for Environmental Health Sciences, Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, United States
| | - N M Filipov
- Interdisciplinary Toxicology Program, United States; Department of Physiology and Pharmacology, United States.
| |
Collapse
|
2
|
Schamiloglu S, Lewis E, Keeshen CM, Hergarden AC, Bender KJ, Whistler JL. Arrestin-3 Agonism at Dopamine D 3 Receptors Defines a Subclass of Second-Generation Antipsychotics That Promotes Drug Tolerance. Biol Psychiatry 2023; 94:531-542. [PMID: 36931452 PMCID: PMC10914650 DOI: 10.1016/j.biopsych.2023.03.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 02/09/2023] [Accepted: 03/02/2023] [Indexed: 03/19/2023]
Abstract
BACKGROUND Second-generation antipsychotics (SGAs) are frontline treatments for serious mental illness. Often, individual patients benefit only from some SGAs and not others. The mechanisms underlying this unpredictability in treatment efficacy remain unclear. All SGAs bind the dopamine D3 receptor (D3R) and are traditionally considered antagonists for dopamine receptor signaling. METHODS Here, we used a combination of two-photon calcium imaging, in vitro signaling assays, and mouse behavior to assess signaling by SGAs at D3R. RESULTS We report that some clinically important SGAs function as arrestin-3 agonists at D3R, resulting in modulation of calcium channels localized to the site of action potential initiation in prefrontal cortex pyramidal neurons. We further show that chronic treatment with an arrestin-3 agonist SGA, but not an antagonist SGA, abolishes D3R function through postendocytic receptor degradation by GASP1 (G protein-coupled receptor-associated sorting protein-1). CONCLUSIONS These results implicate D3R-arrestin-3 signaling as a source of SGA variability, highlighting the importance of including arrestin-3 signaling in characterizations of drug action. Furthermore, they suggest that postendocytic receptor trafficking that occurs during chronic SGA treatment may contribute to treatment efficacy.
Collapse
Affiliation(s)
- Selin Schamiloglu
- Neuroscience Graduate Program, University of California San Francisco, San Francisco, California
| | - Elinor Lewis
- Neuroscience Graduate Group, University of California Davis, Davis, California; Center for Neuroscience, University of California Davis, Davis, California
| | - Caroline M Keeshen
- Neuroscience Graduate Group, University of California Davis, Davis, California; Center for Neuroscience, University of California Davis, Davis, California
| | - Anne C Hergarden
- Center for Neuroscience, University of California Davis, Davis, California
| | - Kevin J Bender
- Neuroscience Graduate Program, University of California San Francisco, San Francisco, California; Department of Neurology, Kavli Institute for Fundamental Neuroscience, Weill Institute for Neurosciences, University of California San Francisco, San Francisco, California.
| | - Jennifer L Whistler
- Center for Neuroscience, University of California Davis, Davis, California; Department of Physiology and Membrane Biology, University of California Davis School of Medicine, Davis, California.
| |
Collapse
|
3
|
Mastrogiacomo R, Trigilio G, Devroye C, Dautan D, Ferretti V, Losi G, Caffino L, Orso G, Marotta R, Maltese F, Vitali E, Piras G, Forgiarini A, Pacinelli G, Lia A, Rothmond DA, Waddington JL, Drago F, Fumagalli F, Luca MAD, Leggio GM, Carmignoto G, Weickert CS, Managò F, Papaleo F. Dysbindin-1A modulation of astrocytic dopamine and basal ganglia dependent behaviors relevant to schizophrenia. Mol Psychiatry 2022; 27:4201-4217. [PMID: 35821415 DOI: 10.1038/s41380-022-01683-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 06/21/2022] [Accepted: 06/27/2022] [Indexed: 02/07/2023]
Abstract
The mechanisms underlying the dichotomic cortical/basal ganglia dopaminergic abnormalities in schizophrenia are unclear. Astrocytes are important non-neuronal modulators of brain circuits, but their role in dopaminergic system remains poorly explored. Microarray analyses, immunohistochemistry, and two-photon laser scanning microscopy revealed that Dys1 hypofunction increases the reactivity of astrocytes, which express only the Dys1A isoform. Notably, behavioral and electrochemical assessments in mice selectively lacking the Dys1A isoform unraveled a more prominent impact of Dys1A in behavioral and dopaminergic/D2 alterations related to basal ganglia, but not cortical functioning. Ex vivo electron microscopy and protein expression analyses indicated that selective Dys1A disruption might alter intracellular trafficking in astrocytes, but not in neurons. In agreement, Dys1A disruption only in astrocytes resulted in decreased motivation and sensorimotor gating deficits, increased astrocytic dopamine D2 receptors and decreased dopaminergic tone within basal ganglia. These processes might have clinical relevance because the caudate, but not the cortex, of patients with schizophrenia shows a reduction of the Dys1A isoform. Therefore, we started to show a hitherto unknown role for the Dys1A isoform in astrocytic-related modulation of basal ganglia behavioral and dopaminergic phenotypes, with relevance to schizophrenia.
Collapse
Affiliation(s)
- Rosa Mastrogiacomo
- Genetics of Cognition laboratory, Neuroscience area, Istituto Italiano di Tecnologia, via Morego, 30, 16163, Genova, Italy
| | - Gabriella Trigilio
- Genetics of Cognition laboratory, Neuroscience area, Istituto Italiano di Tecnologia, via Morego, 30, 16163, Genova, Italy.,Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Céline Devroye
- Genetics of Cognition laboratory, Neuroscience area, Istituto Italiano di Tecnologia, via Morego, 30, 16163, Genova, Italy
| | - Daniel Dautan
- Genetics of Cognition laboratory, Neuroscience area, Istituto Italiano di Tecnologia, via Morego, 30, 16163, Genova, Italy.,Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milano, Italy
| | - Valentina Ferretti
- Genetics of Cognition laboratory, Neuroscience area, Istituto Italiano di Tecnologia, via Morego, 30, 16163, Genova, Italy
| | - Gabriele Losi
- Neuroscience Institute, CNR, Padova, Italy.,Department of Biomedical Science, University of Padova, Padova, Italy
| | - Lucia Caffino
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - Genny Orso
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy
| | - Roberto Marotta
- Genetics of Cognition laboratory, Neuroscience area, Istituto Italiano di Tecnologia, via Morego, 30, 16163, Genova, Italy
| | - Federica Maltese
- Genetics of Cognition laboratory, Neuroscience area, Istituto Italiano di Tecnologia, via Morego, 30, 16163, Genova, Italy
| | - Enrica Vitali
- Genetics of Cognition laboratory, Neuroscience area, Istituto Italiano di Tecnologia, via Morego, 30, 16163, Genova, Italy
| | - Gessica Piras
- Department of Biomedical Sciences, University of Cagliari, Cagliari, Italy
| | - Alessia Forgiarini
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy
| | - Giada Pacinelli
- Genetics of Cognition laboratory, Neuroscience area, Istituto Italiano di Tecnologia, via Morego, 30, 16163, Genova, Italy
| | - Annamaria Lia
- Neuroscience Institute, CNR, Padova, Italy.,Department of Biomedical Science, University of Padova, Padova, Italy
| | - Debora A Rothmond
- Schizophrenia Research Laboratory, Neuroscience Research Australia, Sydney, NSW, Australia
| | - John L Waddington
- School of Pharmacy and Biomolecular Sciences, Royal College of Surgeons in Ireland, Dublin 2, Ireland
| | - Filippo Drago
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Fabio Fumagalli
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | | | - Gian Marco Leggio
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Giorgio Carmignoto
- Neuroscience Institute, CNR, Padova, Italy.,Department of Biomedical Science, University of Padova, Padova, Italy
| | - Cynthia S Weickert
- Schizophrenia Research Laboratory, Neuroscience Research Australia, Sydney, NSW, Australia
| | - Francesca Managò
- Genetics of Cognition laboratory, Neuroscience area, Istituto Italiano di Tecnologia, via Morego, 30, 16163, Genova, Italy.
| | - Francesco Papaleo
- Genetics of Cognition laboratory, Neuroscience area, Istituto Italiano di Tecnologia, via Morego, 30, 16163, Genova, Italy. .,Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milano, Italy.
| |
Collapse
|
4
|
Liu Z, Meng D, Wang J, Cao H, Feng P, Wu S, Wang N, Dang C, Hou P, Xia P. GASP1 enhances malignant phenotypes of breast cancer cells and decreases their response to paclitaxel by forming a vicious cycle with IGF1/IGF1R signaling pathway. Cell Death Dis 2022; 13:751. [PMID: 36042202 PMCID: PMC9427794 DOI: 10.1038/s41419-022-05198-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 08/16/2022] [Accepted: 08/17/2022] [Indexed: 01/21/2023]
Abstract
There is a potential correlation between G-protein-coupled receptor-associated sorting protein 1 (GASP1) and breast tumorigenesis. However, its biological function and underlying molecular mechanism in breast cancer have not been clearly delineated. Here, we demonstrated that GASP1 was highly expressed in breast cancers, and patients harboring altered GASP1 showed a worse prognosis than those with wild-type GASP1. Functional studies showed that GASP1 knockout significantly suppressed malignant properties of breast cancer cells, such as inhibition of cell proliferation, colony formation, migration, invasion and xenograft tumor growth in nude mice as well as induction of G1-phase cell cycle arrest, and vice versa. Mechanistically, GASP1 inhibited proteasomal degradation of insulin-like growth factor 1 receptor (IGF1R) by competitively binding to IGF1R with ubiquitin E3 ligase MDM2, thereby activating its downstream signaling pathways such as NF-κB, PI3K/AKT, and MAPK/ERK pathways given their critical roles in breast tumorigenesis and progression. IGF1, in turn, stimulated GASP1 expression by activating the PI3K/AKT pathway, forming a vicious cycle propelling the malignant progression of breast cancer. Besides, we found that GASP1 knockout obviously improved the response of breast cancer cells to paclitaxel. Collectively, this study demonstrates that GASP1 enhances malignant behaviors of breast cancer cells and decreases their cellular response to paclitaxel by interacting with and stabilizing IGF1R, and suggests that it may serve as a valuable prognostic factor and potential therapeutic target in breast cancer.
Collapse
Affiliation(s)
- Zhao Liu
- grid.452438.c0000 0004 1760 8119Department of Surgical Oncology, The First Affiliated Hospital of Xi’an Jiaotong University, 710061 Xi’an, People’s Republic of China ,grid.452438.c0000 0004 1760 8119Key Laboratory for Tumor Precision Medicine of Shaanxi Province, The First Affiliated Hospital of Xi’an Jiaotong University, 710061 Xi’an, People’s Republic of China
| | - Du Meng
- grid.452438.c0000 0004 1760 8119Department of Radio Oncology, The First Affiliated Hospital of Xi’an Jiaotong University, 710061 Xi’an, People’s Republic of China
| | - Jianling Wang
- grid.452438.c0000 0004 1760 8119Key Laboratory for Tumor Precision Medicine of Shaanxi Province, The First Affiliated Hospital of Xi’an Jiaotong University, 710061 Xi’an, People’s Republic of China
| | - Hongxin Cao
- grid.452438.c0000 0004 1760 8119Key Laboratory for Tumor Precision Medicine of Shaanxi Province, The First Affiliated Hospital of Xi’an Jiaotong University, 710061 Xi’an, People’s Republic of China
| | - Peng Feng
- grid.452438.c0000 0004 1760 8119Department of Surgical Oncology, The First Affiliated Hospital of Xi’an Jiaotong University, 710061 Xi’an, People’s Republic of China
| | - Siyu Wu
- grid.452438.c0000 0004 1760 8119Department of Surgical Oncology, The First Affiliated Hospital of Xi’an Jiaotong University, 710061 Xi’an, People’s Republic of China
| | - Na Wang
- grid.478124.c0000 0004 1773 123XDepartment of Endocrinology, Xi’an Central Hospital, 710003 Xi’an, People’s Republic of China
| | - Chengxue Dang
- grid.452438.c0000 0004 1760 8119Department of Surgical Oncology, The First Affiliated Hospital of Xi’an Jiaotong University, 710061 Xi’an, People’s Republic of China
| | - Peng Hou
- grid.452438.c0000 0004 1760 8119Key Laboratory for Tumor Precision Medicine of Shaanxi Province, The First Affiliated Hospital of Xi’an Jiaotong University, 710061 Xi’an, People’s Republic of China ,grid.452438.c0000 0004 1760 8119Department of Endocrinology, The First Affiliated Hospital of Xi’an Jiaotong University, 710061 Xi’an, People’s Republic of China
| | - Peng Xia
- grid.452438.c0000 0004 1760 8119Department of Surgical Oncology, The First Affiliated Hospital of Xi’an Jiaotong University, 710061 Xi’an, People’s Republic of China
| |
Collapse
|
5
|
The epistatic interaction between the dopamine D3 receptor and dysbindin-1 modulates higher-order cognitive functions in mice and humans. Mol Psychiatry 2021; 26:1272-1285. [PMID: 31492942 DOI: 10.1038/s41380-019-0511-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 07/15/2019] [Accepted: 07/26/2019] [Indexed: 11/08/2022]
Abstract
The dopamine D2 and D3 receptors are implicated in schizophrenia and its pharmacological treatments. These receptors undergo intracellular trafficking processes that are modulated by dysbindin-1 (Dys). Indeed, Dys variants alter cognitive responses to antipsychotic drugs through D2-mediated mechanisms. However, the mechanism by which Dys might selectively interfere with the D3 receptor subtype is unknown. Here, we revealed an interaction between functional genetic variants altering Dys and D3. Specifically, both in patients with schizophrenia and in genetically modified mice, concomitant reduction in D3 and Dys functionality was associated with improved executive and working memory abilities. This D3/Dys interaction produced a D2/D3 imbalance favoring increased D2 signaling in the prefrontal cortex (PFC) but not in the striatum. No epistatic effects on the clinical positive and negative syndrome scale (PANSS) scores were evident, while only marginal effects on sensorimotor gating, locomotor functions, and social behavior were observed in mice. This genetic interaction between D3 and Dys suggests the D2/D3 imbalance in the PFC as a target for patient stratification and procognitive treatments in schizophrenia.
Collapse
|
6
|
Morales-Hernández A, Benaksas C, Chabot A, Caprio C, Ferdous M, Zhao X, Kang G, McKinney-Freeman S. GPRASP proteins are critical negative regulators of hematopoietic stem cell transplantation. Blood 2020; 135:1111-1123. [PMID: 32027737 PMCID: PMC7118811 DOI: 10.1182/blood.2019003435] [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: 09/20/2019] [Accepted: 01/21/2020] [Indexed: 11/20/2022] Open
Abstract
Hematopoietic stem cell (HSC) transplantation (HSCT) is often exploited to treat hematologic disease. Donor HSCs must survive, proliferate, and differentiate in the damaged environment of the reconstituting niche. Illuminating molecular mechanisms regulating the activity of transplanted HSCs will inform efforts to improve HSCT. Here, we report that G-protein-coupled receptor-associated sorting proteins (GPRASPs) function as negative regulators of HSCT. Silencing of Gprasp1 or Gprasp2 increased the survival, quiescence, migration, niche retention, and hematopoietic repopulating activity of hematopoietic stem and progenitor cells (HSPCs) posttransplant. We further show that GPRASP1 and GPRASP2 promote the degradation of CXCR4, a master regulator of HSC function during transplantation. CXCR4 accumulates in Gprasp-deficient HSPCs, boosting their function posttransplant. Thus, GPRASPs negatively regulate CXCR4 stability in HSCs. Our work reveals GPRASP proteins as negative regulators of HSCT and CXCR4 activity. Disruption of GPRASP/CXCR4 interactions could be exploited in the future to enhance the efficiency of HSCT.
Collapse
Affiliation(s)
| | - Chaïma Benaksas
- Department of Hematology, St. Jude Children's Research Hospital, Memphis, TN
- Paris Diderot University, Paris, France; and
| | - Ashley Chabot
- Department of Hematology, St. Jude Children's Research Hospital, Memphis, TN
| | - Claire Caprio
- Department of Hematology, St. Jude Children's Research Hospital, Memphis, TN
| | - Maheen Ferdous
- Department of Hematology, St. Jude Children's Research Hospital, Memphis, TN
| | - Xiwen Zhao
- Department of Biostatistics, St. Jude Children's Research Hospital, Memphis, TN
| | - Guolian Kang
- Department of Biostatistics, St. Jude Children's Research Hospital, Memphis, TN
| | | |
Collapse
|
7
|
Zenko D, Thompson D, Hislop JN. Endocytic sorting and downregulation of the M2 acetylcholine receptor is regulated by ubiquitin and the ESCRT complex. Neuropharmacology 2020; 162:107828. [PMID: 31654703 DOI: 10.1016/j.neuropharm.2019.107828] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 10/16/2019] [Accepted: 10/21/2019] [Indexed: 01/14/2023]
Abstract
Cholinergic dysfunction plays a critical role in a number of disease states, and the loss of functional muscarinic acetylcholine receptors plays a key role in disease pathogenesis. Therefore, preventing receptor downregulation would maintain functional receptor number, and be predicted to alleviate symptoms. However, the molecular mechanism(s) underlying muscarinic receptor downregulation are currently unknown. Here we demonstrate that the M2 muscarinic receptor undergoes rapid lysosomal proteolysis, and this lysosomal trafficking is facilitated by ubiquitination of the receptor. Importantly, we show that this trafficking is driven specifically by ESCRT mediated involution. Critically, we provide evidence that disruption of this process leads to a re-routing of the trafficking of the M2 receptor away from the lysosome and into recycling pathway, and eventually back to the plasma membrane. This study is the first to identify the process by which the M2 muscarinic acetylcholine receptor undergoes endocytic sorting, and critically reveals a regulatory checkpoint that represents a target to pharmacologically increase the number of functional muscarinic receptors within the central nervous system.
Collapse
Affiliation(s)
- Dmitry Zenko
- Institute of Medical Sciences, School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, AB25 2ZD, UK
| | - Dawn Thompson
- Institute of Medical Sciences, School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, AB25 2ZD, UK
| | - James N Hislop
- Institute of Medical Sciences, School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, AB25 2ZD, UK.
| |
Collapse
|
8
|
Zhang X, Kim KM. Multifactorial Regulation of G Protein-Coupled Receptor Endocytosis. Biomol Ther (Seoul) 2017; 25:26-43. [PMID: 28035080 PMCID: PMC5207461 DOI: 10.4062/biomolther.2016.186] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 11/21/2016] [Accepted: 11/30/2016] [Indexed: 12/26/2022] Open
Abstract
Endocytosis is a process by which cells absorb extracellular materials via the inward budding of vesicles formed from the plasma membrane. Receptor-mediated endocytosis is a highly selective process where receptors with specific binding sites for extracellular molecules internalize via vesicles. G protein-coupled receptors (GPCRs) are the largest single family of plasma-membrane receptors with more than 1000 family members. But the molecular mechanisms involved in the regulation of GPCRs are believed to be highly conserved. For example, receptor phosphorylation in collaboration with β-arrestins plays major roles in desensitization and endocytosis of most GPCRs. Nevertheless, a number of subsequent studies showed that GPCR regulation, such as that by endocytosis, occurs through various pathways with a multitude of cellular components and processes. This review focused on i) functional interactions between homologous and heterologous pathways, ii) methodologies applied for determining receptor endocytosis, iii) experimental tools to determine specific endocytic routes, iv) roles of small guanosine triphosphate-binding proteins in GPCR endocytosis, and v) role of post-translational modification of the receptors in endocytosis.
Collapse
Affiliation(s)
- Xiaohan Zhang
- Pharmacology Laboratory, College of Pharmacy, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Kyeong-Man Kim
- Pharmacology Laboratory, College of Pharmacy, Chonnam National University, Gwangju 61186, Republic of Korea
| |
Collapse
|
9
|
Yang S, Ben-Shalom R, Ahn M, Liptak AT, van Rijn RM, Whistler JL, Bender KJ. β-Arrestin-Dependent Dopaminergic Regulation of Calcium Channel Activity in the Axon Initial Segment. Cell Rep 2016; 16:1518-1526. [PMID: 27452469 DOI: 10.1016/j.celrep.2016.06.098] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Revised: 05/27/2016] [Accepted: 06/29/2016] [Indexed: 11/26/2022] Open
Abstract
G-protein-coupled receptors (GPCRs) initiate a variety of signaling cascades, depending on effector coupling. β-arrestins, which were initially characterized by their ability to "arrest" GPCR signaling by uncoupling receptor and G protein, have recently emerged as important signaling effectors for GPCRs. β-arrestins engage signaling pathways that are distinct from those mediated by G protein. As such, arrestin-dependent signaling can play a unique role in regulating cell function, but whether neuromodulatory GPCRs utilize β-arrestin-dependent signaling to regulate neuronal excitability remains unclear. Here, we find that D3 dopamine receptors (D3R) regulate axon initial segment (AIS) excitability through β-arrestin-dependent signaling, modifying CaV3 voltage dependence to suppress high-frequency action potential generation. This non-canonical D3R signaling thereby gates AIS excitability via pathways distinct from classical GPCR signaling pathways.
Collapse
Affiliation(s)
- Sungchil Yang
- Center for Integrative Neuroscience, University of California, San Francisco, San Francisco, CA 94158, USA; Alcohol and Addiction Research Group, Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Roy Ben-Shalom
- Center for Integrative Neuroscience, University of California, San Francisco, San Francisco, CA 94158, USA; Alcohol and Addiction Research Group, Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Misol Ahn
- Department of Pathology and Institute for Neurodegenerative Diseases, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Alayna T Liptak
- Center for Integrative Neuroscience, University of California, San Francisco, San Francisco, CA 94158, USA; Alcohol and Addiction Research Group, Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Richard M van Rijn
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN 47907, USA
| | - Jennifer L Whistler
- Alcohol and Addiction Research Group, Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Kevin J Bender
- Center for Integrative Neuroscience, University of California, San Francisco, San Francisco, CA 94158, USA; Alcohol and Addiction Research Group, Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA.
| |
Collapse
|
10
|
Schmieg N, Rocchi C, Romeo S, Maggio R, Millan MJ, Mannoury la Cour C. Dysbindin-1 modifies signaling and cellular localization of recombinant, human D₃ and D₂ receptors. J Neurochem 2016; 136:1037-51. [PMID: 26685100 DOI: 10.1111/jnc.13501] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Accepted: 12/09/2015] [Indexed: 01/20/2023]
Abstract
Dystrobrevin binding protein-1 (dysbindin-1), a candidate gene for schizophrenia, modulates cognition, synaptic plasticity and frontocortical circuitry and interacts with glutamatergic and dopaminergic transmission. Loss of dysbindin-1 modifies cellular trafficking of dopamine (DA) D2 receptors to increase cell surface expression, but its influence upon signaling has never been characterized. Further, the effects of dysbindin-1 upon closely related D3 receptors remain unexplored. Hence, we examined the impact of dysbindin-1 (isoform A) co-expression on the localization and coupling of human D2L and D3 receptors stably expressed in Chinese hamster ovary or SH-SY5Y cells lacking endogenous dysbindin-1. Dysbindin-1 co-transfection decreased cell surface expression of both D3 and D2L receptors. Further, while their affinity for DA was unchanged, dysbindin-1 reduced the magnitude and potency of DA-induced adenylate cylase recruitment/cAMP production. Dysbindin-1 also blunted the amplitude of DA-induced phosphorylation of ERK1/2 and Akt at both D2L and D3 receptors without, in contrast to cAMP, affecting the potency of DA. Interference with calveolin/clathrin-mediated processes of internalization prevented the modification by dysbindin-1 of ERK1/2 and adenylyl cyclase stimulation at D2L and D3 receptors. Finally, underpinning the specificity of the influence of dysbindin-1 on D2L and D3 receptors, dysbindin-1 did not modify recruitment of adenylyl cyclase by D1 receptors. These observations demonstrate that dysbindin-1 influences cell surface expression of D3 in addition to D2L receptors, and that it modulates activation of their signaling pathways. Accordingly, both a deficiency and an excess of dysbindin-1 may be disruptive for dopaminergic transmission, supporting its link to schizophrenia and other CNS disorders. Dysbindin-1, a candidate gene for schizophrenia, alters D2 receptors cell surface expression. We demonstrate that dysbindin-1 expression also influences cell surface levels of D3 receptors. Further, Dysbindin-1 reduces DA-induced adenylate cylase recruitment/cAMP production and modifies major signaling pathways (Akt and extracellular signal-regulated kinases1/2 (ERK1/2)) of both D2 and D3 receptors. Dysbindin-1 modulates thus D2 and D3 receptor signaling, supporting a link to schizophrenia.
Collapse
Affiliation(s)
- Nathalie Schmieg
- PIT-Neuropsychiatry, Institut de Recherches Servier, Centre de Recherches de Croissy, Croissy-sur-Seine, France
| | - Cristina Rocchi
- Biotechnological and Applied Clinical Sciences Department, University of L'Aquila, L'Aquila, Italy
| | - Stefania Romeo
- Biotechnological and Applied Clinical Sciences Department, University of L'Aquila, L'Aquila, Italy
| | - Roberto Maggio
- Biotechnological and Applied Clinical Sciences Department, University of L'Aquila, L'Aquila, Italy
| | - Mark J Millan
- PIT-Neuropsychiatry, Institut de Recherches Servier, Centre de Recherches de Croissy, Croissy-sur-Seine, France
| | - Clotilde Mannoury la Cour
- PIT-Neuropsychiatry, Institut de Recherches Servier, Centre de Recherches de Croissy, Croissy-sur-Seine, France
| |
Collapse
|
11
|
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.
Collapse
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
| |
Collapse
|
12
|
Thompson D, McArthur S, Hislop JN, Flower RJ, Perretti M. Identification of a novel recycling sequence in the C-tail of FPR2/ALX receptor: association with cell protection from apoptosis. J Biol Chem 2014; 289:36166-78. [PMID: 25326384 PMCID: PMC4276880 DOI: 10.1074/jbc.m114.612630] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Formyl-peptide receptor type 2 (FPR2; also called ALX because it is the receptor for lipoxin A4) sustains a variety of biological responses relevant to the development and control of inflammation, yet the cellular regulation of this G-protein-coupled receptor remains unexplored. Here we report that, in response to peptide agonist activation, FPR2/ALX undergoes β-arrestin-mediated endocytosis followed by rapid recycling to the plasma membrane. We identify a transplantable recycling sequence that is both necessary and sufficient for efficient receptor recycling. Furthermore, removal of this C-terminal recycling sequence alters the endocytic fate of FPR2/ALX and evokes pro-apoptotic effects in response to agonist activation. This study demonstrates the importance of endocytic recycling in the anti-apoptotic properties of FPR2/ALX and identifies the molecular determinant required for modulation of this process fundamental for the control of inflammation.
Collapse
Affiliation(s)
- Dawn Thompson
- From the William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, United Kingdom and the School of Medical Sciences, College of Life Sciences and Medicine, University of Aberdeen, Institute of Medical Sciences, Foresterhill, Aberdeen AB25 2ZD, Scotland, United Kingdom
| | - Simon McArthur
- From the William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, United Kingdom and
| | - James N Hislop
- the School of Medical Sciences, College of Life Sciences and Medicine, University of Aberdeen, Institute of Medical Sciences, Foresterhill, Aberdeen AB25 2ZD, Scotland, United Kingdom
| | - Roderick J Flower
- From the William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, United Kingdom and
| | - Mauro Perretti
- From the William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, United Kingdom and
| |
Collapse
|
13
|
Rosciglione S, Thériault C, Boily MO, Paquette M, Lavoie C. Gαs regulates the post-endocytic sorting of G protein-coupled receptors. Nat Commun 2014; 5:4556. [PMID: 25089012 PMCID: PMC4846350 DOI: 10.1038/ncomms5556] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 06/30/2014] [Indexed: 12/31/2022] Open
Abstract
The role of Gαs in G protein-coupled receptor (GPCR) signalling at the cell surface is well established. Recent evidence has revealed the presence of Gαs on endosomes and its capacity to elicit GPCR-promoted signalling from this intracellular compartment. Here, we report an unconventional role for Gαs in the endocytic sorting of GPCRs to lysosomes. Cellular depletion of Gαs specifically delays the lysosomal degradation of GPCRs by disrupting the transfer of GPCRs into the intraluminal vesicles (ILVs) of multivesicular bodies. We show that Gαs interacts with GPCR-associated binding protein-1 (GASP1) and dysbindin, two key proteins that serve as linkers between GPCRs and the endosomal-sorting complex required for transport (ESCRT) machinery involved in receptor sorting into ILVs. Our findings reveal that Gαs plays a role in both GPCR signalling and trafficking pathways, providing another piece in the intertwining molecular network between these processes.
Collapse
Affiliation(s)
- Stéphanie Rosciglione
- Department of Pharmacology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Caroline Thériault
- Department of Pharmacology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Marc-Olivier Boily
- Department of Pharmacology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Marilène Paquette
- Department of Pharmacology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Christine Lavoie
- Department of Pharmacology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| |
Collapse
|
14
|
Dores MR, Trejo J. Atypical regulation of G protein-coupled receptor intracellular trafficking by ubiquitination. Curr Opin Cell Biol 2013; 27:44-50. [PMID: 24680429 DOI: 10.1016/j.ceb.2013.11.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Revised: 11/07/2013] [Accepted: 11/15/2013] [Indexed: 01/24/2023]
Abstract
G protein-coupled receptor (GPCR) signaling is precisely regulated. After activation, GPCRs are desensitized, internalized and either recycled to the cell surface or sorted to lysosomes for degradation. The main route for GPCR lysosomal sorting requires ubiquitination and the endosomal-sorting complex required for transport (ESCRT). Four distinct ESCRT adaptor protein complexes act sequentially to bind and sort ubiquitinated cargo to lysosomes. Several studies now indicate that alternate pathways exist for GPCR lysosomal sorting that require only some components of the ESCRT and autophagy machinery. While direct GPCR ubiquitination is not required for alternate lysosomal sorting, new evidence suggests that ubiquitin may function indirectly to modulate adaptor protein activity. Here, we discuss the atypical regulation of GPCR lysosomal sorting by ubiquitination.
Collapse
Affiliation(s)
- Michael R Dores
- Department of Pharmacology, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - JoAnn Trejo
- Department of Pharmacology, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA.
| |
Collapse
|
15
|
Kargl J, Balenga NA, Platzer W, Martini L, Whistler JL, Waldhoer M. The GPCR-associated sorting protein 1 regulates ligand-induced down-regulation of GPR55. Br J Pharmacol 2012; 165:2611-9. [PMID: 21718301 PMCID: PMC3366063 DOI: 10.1111/j.1476-5381.2011.01562.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND AND PURPOSE Many GPCRs, including the CB1 cannabinoid receptor, are down-regulated following prolonged agonist exposure by interacting with the GPCR-associated sorting protein-1 (GASP-1). The CB1 receptor antagonist rimonabant has also recently been described to be an agonist at GPR55, a cannabinoid-related receptor. Here we investigated the post-endocytic properties of GPR55 after agonist exposure and tested whether GASP-1 is involved in this process. EXPERIMENTAL APPROACH We evaluated the direct protein-protein interaction of GPR55 with GASP-1 using (i) GST-binding assays and (ii) co-immunoprecipitation assays in GPR55-HEK293 cells with endogenous GASP-1 expression. We further tested the internalization, recycling and degradation of GPR55 using confocal fluorescence microscopy and biotinylation assays in the presence and absence of GASP-1 (lentiviral small hairpin RNA knockdown of GASP-1) under prolonged agonist [rimonabant (RIM), lysophosphatidylinositol (LPI)] stimulation. KEY RESULTS We showed that the prolonged activation of GPR55 with rimonabant or LPI down-regulates GPR55 via GASP-1. GASP-1 binds to GPR55 in vitro, and this interaction was required for targeting GPR55 for degradation. Disrupting the GPR55-GASP-1 interaction prevented post-endocytic receptor degradation, and thereby allowed receptor recycling. CONCLUSION AND IMPLICATIONS These data implicate GASP-1 as an important regulator of ligand-mediated down-regulation of GPR55. By identifying GASP-1 as a key regulator of the trafficking and, by extension, functional expression of GPR55, we may be one step closer to gaining a better understanding of this receptor in response to cannabinoid drugs. LINKED ARTICLES This article is part of a themed section on Cannabinoids in Biology and Medicine. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.165.issue-8. To view Part I of Cannabinoids in Biology and Medicine visit http://dx.doi.org/10.1111/bph.2011.163.issue-7
Collapse
Affiliation(s)
- J Kargl
- Institute for Experimental and Clinical Pharmacology, Medical University of Graz, Graz, Austria.
| | | | | | | | | | | |
Collapse
|
16
|
Schubert KO, Föcking M, Prehn JHM, Cotter DR. Hypothesis review: are clathrin-mediated endocytosis and clathrin-dependent membrane and protein trafficking core pathophysiological processes in schizophrenia and bipolar disorder? Mol Psychiatry 2012; 17:669-81. [PMID: 21986877 DOI: 10.1038/mp.2011.123] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Clathrin-mediated endocytosis (CME) is the best-characterized mechanism governing cellular membrane and protein trafficking. In this hypothesis review, we integrate recent evidence implicating CME and related cellular trafficking mechanisms in the pathophysiology of psychotic disorders such as schizophrenia and bipolar disorder. The evidence includes proteomic and genomic findings implicating proteins and genes of the clathrin interactome. Additionally, several important candidate genes for schizophrenia, such as dysbindin, are involved in processes closely linked to CME and membrane trafficking. We discuss that key aspects of psychosis neuropathology such as synaptic dysfunction, white matter changes and aberrant neurodevelopment are all influenced by clathrin-dependent processes, and that other cellular trafficking mechanisms previously linked to psychoses interact with the clathrin interactome in important ways. Furthermore, many antipsychotic drugs have been shown to affect clathrin-interacting proteins. We propose that the targeted pharmacological manipulation of the clathrin interactome may offer fruitful opportunities for novel treatments of schizophrenia.
Collapse
Affiliation(s)
- K O Schubert
- Department of Psychiatry, Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin, Republic of Ireland
| | | | | | | |
Collapse
|
17
|
Kleyer J, Nicolussi S, Taylor P, Simonelli D, Furger E, Anderle P, Gertsch J. Cannabinoid receptor trafficking in peripheral cells is dynamically regulated by a binary biochemical switch. Biochem Pharmacol 2012; 83:1393-412. [PMID: 22387618 DOI: 10.1016/j.bcp.2012.02.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Revised: 02/16/2012] [Accepted: 02/17/2012] [Indexed: 12/20/2022]
Abstract
The cannabinoid G protein-coupled receptors (GPCRs) CB₁ and CB₂ are expressed in different peripheral cells. Localization of GPCRs in the cell membrane determines signaling via G protein pathways. Here we show that unlike in transfected cells, CB receptors in cell lines and primary human cells are not internalized upon agonist interaction, but move between cytoplasm and cell membranes by ligand-independent trafficking mechanisms. Even though CB receptors are expressed in many cells of peripheral origin they are not always localized in the cell membrane and in most cancer cell lines the ratios between CB₁ and CB₂ receptor gene and surface expression vary significantly. In contrast, CB receptor cell surface expression in HL60 cells is subject to significant oscillations and CB₂ receptors form oligomers and heterodimers with CB₁ receptors, showing synchronized surface expression, localization and trafficking. We show that hydrogen peroxide and other nonspecific protein tyrosine phosphatase inhibitors (TPIs) such as phenylarsine oxide trigger both CB₂ receptor internalization and externalization, depending on receptor localization. Phorbol ester-mediated internalization of CB receptors can be inhibited via this switch. In primary human immune cells hydrogen peroxide and other TPIs lead to a robust internalization of CB receptors in monocytes and an externalization in T cells. This study describes, for the first time, the dynamic nature of CB receptor trafficking in the context of a biochemical switch, which may have implications for studies on the cell-type specific effects of cannabinoids and our understanding of the regulation of CB receptor cell surface expression.
Collapse
Affiliation(s)
- Jonas Kleyer
- Institute of Biochemistry and Molecular Medicine, Swiss National Centre of Competence in Research NCCR TransCure, University of Bern, Bühlstrasse 28, CH-3012 Bern, Switzerland
| | | | | | | | | | | | | |
Collapse
|
18
|
|
19
|
Tschammer N, Elsner J, Goetz A, Ehrlich K, Schuster S, Ruberg M, Kühhorn J, Thompson D, Whistler J, Hübner H, Gmeiner P. Highly potent 5-aminotetrahydropyrazolopyridines: enantioselective dopamine D3 receptor binding, functional selectivity, and analysis of receptor-ligand interactions. J Med Chem 2011; 54:2477-91. [PMID: 21388142 DOI: 10.1021/jm101639t] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Heterocyclic dopamine surrogates of types 5 and 7 were synthesized and investigated for their dopaminergic properties. The enantiomerically pure biphenylcarboxamide (S)-5a displayed an outstanding K(i) of 27 pM at the agonist-labeled D(3) receptor and significant selectivity over the D(2) subtype. Measurement of [(35)S]GTPγS incorporation in the presence of a coexpressed PTX-insensitive G(α0-1) subunit indicated highly efficient G-protein coupling. Comparison of ligand efficacy data from cAMP accumulation and [(3)H]thymidine incorporation experiments revealed that ligand biased signaling is exerted by the test compound (S)-5a. Starting from the D(3) crystal structure, a combination of homology modeling and site directed mutagenesis gave valuable insights into the binding mode and the intermolecular origins of stereospecific receptor recognition. According to these data, the superior affinity of the eutomer 5a is caused by the favorable binding energy that results from interaction between the ligand's central ammonium unit and the aspartate residue in position 3.32 of the receptor.
Collapse
Affiliation(s)
- Nuska Tschammer
- Department of Chemistry and Pharmacy, Emil Fischer Center, Friedrich Alexander University, Schuhstrasse 19, D-91052 Erlangen, Germany
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Maurice P, Guillaume JL, Benleulmi-Chaachoua A, Daulat AM, Kamal M, Jockers R. GPCR-Interacting Proteins, Major Players of GPCR Function. PHARMACOLOGY OF G PROTEIN COUPLED RECEPTORS 2011; 62:349-80. [DOI: 10.1016/b978-0-12-385952-5.00001-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
|