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Kubota H, Zhou X, Zhang X, Watanabe H, Nagai T. Pramipexole Hyperactivates the External Globus Pallidus and Impairs Decision-Making in a Mouse Model of Parkinson's Disease. Int J Mol Sci 2024; 25:8849. [PMID: 39201535 DOI: 10.3390/ijms25168849] [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: 07/18/2024] [Revised: 08/13/2024] [Accepted: 08/13/2024] [Indexed: 09/02/2024] Open
Abstract
In patients with Parkinson's disease (PD), dopamine replacement therapy with dopamine D2/D3 receptor agonists induces impairments in decision-making, including pathological gambling. The neurobiological mechanisms underlying these adverse effects remain elusive. Here, in a mouse model of PD, we investigated the effects of the dopamine D3 receptor (D3R)-preferring agonist pramipexole (PPX) on decision-making. PD model mice were generated using a bilateral injection of the toxin 6-hydroxydopamine into the dorsolateral striatum. Subsequent treatment with PPX increased disadvantageous choices characterized by a high-risk/high-reward in the touchscreen-based Iowa Gambling Task. This effect was blocked by treatment with the selective D3R antagonist PG-01037. In model mice treated with PPX, the number of c-Fos-positive cells was increased in the external globus pallidus (GPe), indicating dysregulation of the indirect pathway in the corticothalamic-basal ganglia circuitry. In accordance, chemogenetic inhibition of the GPe restored normal c-Fos activation and rescued PPX-induced disadvantageous choices. These findings demonstrate that the hyperactivation of GPe neurons in the indirect pathway impairs decision-making in PD model mice. The results provide a candidate mechanism and therapeutic target for pathological gambling observed during D2/D3 receptor pharmacotherapy in PD patients.
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Affiliation(s)
- Hisayoshi Kubota
- Division of Behavioral Neuropharmacology, International Center for Brain Science (ICBS), Fujita Health University, Toyoake 470-1192, Aichi, Japan
| | - Xinzhu Zhou
- Division of Behavioral Neuropharmacology, International Center for Brain Science (ICBS), Fujita Health University, Toyoake 470-1192, Aichi, Japan
| | - Xinjian Zhang
- Division of Behavioral Neuropharmacology, International Center for Brain Science (ICBS), Fujita Health University, Toyoake 470-1192, Aichi, Japan
| | - Hirohisa Watanabe
- Department of Neurology, School of Medicine, Fujita Health University, Toyoake 470-1192, Aichi, Japan
| | - Taku Nagai
- Division of Behavioral Neuropharmacology, International Center for Brain Science (ICBS), Fujita Health University, Toyoake 470-1192, Aichi, Japan
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2
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Miller WE, O'Connor CM. CMV-encoded GPCRs in infection, disease, and pathogenesis. Adv Virus Res 2024; 118:1-75. [PMID: 38461029 DOI: 10.1016/bs.aivir.2024.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2024]
Abstract
G protein coupled receptors (GPCRs) are seven-transmembrane domain proteins that modulate cellular processes in response to external stimuli. These receptors represent the largest family of membrane proteins, and in mammals, their signaling regulates important physiological functions, such as vision, taste, and olfaction. Many organisms, including yeast, slime molds, and viruses encode GPCRs. Cytomegaloviruses (CMVs) are large, betaherpesviruses, that encode viral GPCRs (vGPCRs). Human CMV (HCMV) encodes four vGPCRs, including UL33, UL78, US27, and US28. Each of these vGPCRs, as well as their rodent and primate orthologues, have been investigated for their contributions to viral infection and disease. Herein, we discuss how the CMV vGPCRs function during lytic and latent infection, as well as our understanding of how they impact viral pathogenesis.
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Affiliation(s)
- William E Miller
- Department of Molecular and Cellular Bioscience, University of Cincinnati College of Medicine, Cincinnati, OH, United States
| | - Christine M O'Connor
- Infection Biology, Sheikha Fatima bint Mubarak Global Center for Pathogen and Human Health Research, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States; Molecular Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland Clinic, Cleveland, OH, United States; Case Comprehensive Cancer Center, Cleveland, OH, United States.
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3
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Zeng X, Wu C, Cao Y, Li H, Zhang X. Mdm2-mediated ubiquitination of PKCβII is responsible for insulin-induced heterologous desensitization of dopamine D 3 receptor. FEBS Lett 2024; 598:400-414. [PMID: 38302840 DOI: 10.1002/1873-3468.14815] [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: 11/13/2023] [Revised: 12/21/2023] [Accepted: 01/05/2024] [Indexed: 02/03/2024]
Abstract
The insulin and dopaminergic systems in the brain are associated with schizophrenia and Parkinson's disease with respect to etiology and treatment. The present study investigated the crosstalk between the insulin receptor (IR) and dopamine receptor and found that insulin stimulation selectively inhibits signaling of D3 R in a PKCβII-dependent manner. Upon insulin stimulation, E3 ligase enzyme Mdm2 moves out of the nucleus to ubiquitinate PKCβII. Subsequently, ubiquitinated PKCβII translocates to the cell membrane and interacts with D3 R in a phosphorylation-dependent manner at S229/257, resulting in the attenuation of D3 R signaling and initiating clathrin-mediated endocytosis and downregulation. Considering that both IR and D3 R are closely related to some neuropsychosis, this study could provide new molecular insight into the etiology of the disorder.
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Affiliation(s)
- Xingyue Zeng
- School of Pharmaceutical Sciences, Guizhou University, Guiyang, China
| | - ChengYan Wu
- School of Pharmaceutical Sciences, Guizhou University, Guiyang, China
| | - Yongkai Cao
- Department of Neurology, Institute of Translational Medicine, The First Affiliated Hospital of Shenzhen University, China
| | - Huijun Li
- Department of Pharmaceuticals, People's Hospital of Zunyi City Bo Zhou District, China
| | - Xiaohan Zhang
- School of Pharmaceutical Sciences, Guizhou University, Guiyang, China
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4
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Liu H, Acharya S, Sudan SK, Hu L, Wu C, Cao Y, Li H, Zhang X. Comparative study of the molecular mechanisms underlying the G protein and β-arrestin-dependent pathways that lead to ERKs activation upon stimulation by dopamine D 2 receptor. FEBS J 2023; 290:5204-5233. [PMID: 37531324 DOI: 10.1111/febs.16921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 06/09/2023] [Accepted: 08/01/2023] [Indexed: 08/04/2023]
Abstract
Dopamine D2 receptor (D2 R) has been shown to activate extracellular signal-regulated kinases (ERKs) via distinct pathways dependent on either G-protein or β-arrestin. However, there has not been a systematic study of the regulatory process of D2 R-mediated ERKs activation by G protein- versus β-arrestin-dependent signaling since D2 R stimulation of ERKs reflects the simultaneous action of both pathways. Here, we investigated that differential regulation of D2 R-mediated ERKs activation via these two pathways. Our results showed that G protein-dependent ERKs activation was transient, rapid, reached maximum level at around 2 min, and importantly, the activated ERKs were entirely confined to the cytoplasm. In contrast, β-arrestin-dependent ERKs activation was more sustained, slower, reached maximum level at around 10 min, and phosphorylated ERKs translocated into the nucleus. Src was found to be commonly involved in both the G protein- and β-arrestin-dependent pathway-mediated ERKs activation. Pertussis toxin Gi/o inhibitor, GRK2-CT, AG1478 epidermal growth factor receptor inhibitor, and wortmannin phosphoinositide 3-kinase inhibitor all blocked G protein-dependent ERKs activation. In contrast, GRK2 and β-Arr2 played a main role in β-arrestin-dependent ERKs activation. Receptor endocytosis showed minimal effect on the activation of ERKs mediated by both pathways. Furthermore, we found that the formation of a complex composed of phospho-ERKs, β-Arr2, and importinβ1 promoted the nuclear translocation of activated ERKs. The differential regulation of various cellular components, as well as temporal and spatial patterns of ERKs activation via these two pathways, suggest the existence of distinct physiological outcomes.
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Affiliation(s)
- Haiping Liu
- School of Pharmaceutical Sciences, Guizhou University, Guiyang, China
| | - Srijan Acharya
- Mitchell Cancer Institute, School of Medicine, University of South Alabama, Mobile, AL, USA
| | - Sarabjeet Kour Sudan
- Mitchell Cancer Institute, School of Medicine, University of South Alabama, Mobile, AL, USA
| | - Li Hu
- School of Pharmaceutical Sciences, Guizhou University, Guiyang, China
| | - Chengyan Wu
- School of Pharmaceutical Sciences, Guizhou University, Guiyang, China
| | - Yongkai Cao
- Institute of Translational Medicine, The First Affiliated Hospital of Shenzhen University, China
| | - Huijun Li
- Department of Pharmaceuticals, People's Hospital of Zunyi City Bo Zhou District, China
| | - Xiaohan Zhang
- School of Pharmaceutical Sciences, Guizhou University, Guiyang, China
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5
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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.
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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.
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6
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Kim KM. Unveiling the Differences in Signaling and Regulatory Mechanisms between Dopamine D2 and D3 Receptors and Their Impact on Behavioral Sensitization. Int J Mol Sci 2023; 24:ijms24076742. [PMID: 37047716 PMCID: PMC10095578 DOI: 10.3390/ijms24076742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 03/25/2023] [Accepted: 03/28/2023] [Indexed: 04/09/2023] Open
Abstract
Dopamine receptors are classified into five subtypes, with D2R and D3R playing a crucial role in regulating mood, motivation, reward, and movement. Whereas D2R are distributed widely across the brain, including regions responsible for motor functions, D3R are primarily found in specific areas related to cognitive and emotional functions, such as the nucleus accumbens, limbic system, and prefrontal cortex. Despite their high sequence homology and similar signaling pathways, D2R and D3R have distinct regulatory properties involving desensitization, endocytosis, posttranslational modification, and interactions with other cellular components. In vivo, D3R is closely associated with behavioral sensitization, which leads to increased dopaminergic responses. Behavioral sensitization is believed to result from D3R desensitization, which removes the inhibitory effect of D3R on related behaviors. Whereas D2R maintains continuous signal transduction through agonist-induced receptor phosphorylation, arrestin recruitment, and endocytosis, which recycle and resensitize desensitized receptors, D3R rarely undergoes agonist-induced endocytosis and instead is desensitized after repeated agonist exposure. In addition, D3R undergoes more extensive posttranslational modifications, such as glycosylation and palmitoylation, which are needed for its desensitization. Overall, a series of biochemical settings more closely related to D3R could be linked to D3R-mediated behavioral sensitization.
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Affiliation(s)
- Kyeong-Man Kim
- Department of Pharmacology, College of Pharmacy, Chonnam National University, Gwang-Ju 61186, Republic of Korea
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7
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Min X, Wang S, Zhang X, Sun N, Kim KM. PKCβII activation requires nuclear trafficking for phosphorylation and Mdm2-mediated ubiquitination. Life Sci Alliance 2023; 6:e202201748. [PMID: 36717249 PMCID: PMC9887771 DOI: 10.26508/lsa.202201748] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 01/11/2023] [Accepted: 01/11/2023] [Indexed: 01/31/2023] Open
Abstract
PKCβII, a conventional PKC family member, plays critical roles in the regulation of a variety of cellular functions. Here, we employed loss-of-function approaches and mutants of PKCβII with altered phosphorylation and protein interaction behaviors to identify the cellular mechanisms underlying the activation of PKCβII. Our results show that 3-phosphoinositide-dependent protein kinase-1 (PDK1)-mediated constitutive phosphorylation of PKCβII at the activation loop (T500) is required for phorbol ester-induced nuclear entry and subsequent Mdm2-mediated ubiquitination of PKCβII, whereas ubiquitination of PKCβII is required for the PDK1-mediated inducible phosphorylation of PKCβII at T500 in the nucleus. After moving out of the nucleus, PKCβII interacts with actin, undergoes inducible mTORC2-mediated phosphorylation at the turn motif (T641), interacts with clathrin, and then translocates to the plasma membrane. This overall cascade of cellular events intertwined with the phosphorylation at critical residues and Mdm2-mediated ubiquitination in the nucleus and along with interactions with actin and clathrin plays roles that encompass the core processes of PKC activation.
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Affiliation(s)
- Xiao Min
- Department of Pharmacology, College of Pharmacy, Chonnam National University, Gwang-Ju, Republic of Korea
| | - Shujie Wang
- Department of Pharmacology, College of Pharmacy, Chonnam National University, Gwang-Ju, Republic of Korea
| | - Xiaohan Zhang
- Department of Pharmacology, College of Pharmacy, Chonnam National University, Gwang-Ju, Republic of Korea
| | - Ningning Sun
- Department of Pharmacology, College of Pharmacy, Chonnam National University, Gwang-Ju, Republic of Korea
| | - Kyeong-Man Kim
- Department of Pharmacology, College of Pharmacy, Chonnam National University, Gwang-Ju, Republic of Korea
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8
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Min X, Zhang X, Wang S, Kim KM. Activation of PKCβII through nuclear trafficking guided by βγ subunits of trimeric G protein and 14-3-3ε. Life Sci 2022; 312:121245. [PMID: 36503900 DOI: 10.1016/j.lfs.2022.121245] [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: 08/24/2022] [Revised: 11/22/2022] [Accepted: 11/23/2022] [Indexed: 11/27/2022]
Abstract
AIMS Conventional members of protein kinase C (PKC) family, including PKCβII, are constitutively phosphorylated on three major motifs and located in the cytosol in a primed state. In response to cellular stimuli, PKCβII is activated through inducible phosphorylation and Mdm2-mediated ubiquitination. In this study, we aimed to identify the activation mechanism of PKCβII, focusing on the signaling cascade that regulate the phosphorylation and ubiquitination. MATERIALS AND METHODS Loss-of-function approaches and mutants of PDK1/PKCβII that display different regulatory properties were used to identify the cellular components and processes responsible for endocytosis. KEY FINDINGS Phorbol 12-myristate 13-acetate (PMA)-induced phosphorylation and ubiquitination of PKCβII, which are needed for its translocation to the plasma membrane, required the presence of both Gβγ and 14-3-3ε. Gβγ and 14-3-3ε mediated the constitutive phosphorylation of PKCβII by scaffolding PI3K and PDK1 in the cytosol, which is an inactive but required state for the activation of PKCβII by subsequent signals. In response to PMA treatment, the signaling complex translocated to the nucleus with dissociation of PI3K from it. Thereafter, PDK1 stably interacted with 14-3-3ε and was dephosphorylated; PKCβII interacted with Mdm2 along with Gβγ, leading to its ubiquitination at two lysine residues on its C-tail. Finally, PDK1/14-3-3ε and ubiquitinated PKCβII translocated to the plasma membrane. SIGNIFICANCE As PKCβII mediates a wide range of cellular functions and plays important roles in the pathogenesis of various diseases, our results will provide clues to understand the pathogenesis of PKCβII-related disorders and facilitate their treatment.
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Affiliation(s)
- Xiao Min
- Department of Pharmacology, College of Pharmacy, Chonnam National University, Gwang-Ju, Republic of Korea
| | - Xiaohan Zhang
- School of Pharmaceutical Sciences, Guizhou University, Guiyang 550025, China
| | - Shujie Wang
- Department of Pharmacology, College of Pharmacy, Chonnam National University, Gwang-Ju, Republic of Korea
| | - Kyeong-Man Kim
- Department of Pharmacology, College of Pharmacy, Chonnam National University, Gwang-Ju, Republic of Korea.
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Chagraoui A, Di Giovanni G, De Deurwaerdère P. Neurobiological and Pharmacological Perspectives of D3 Receptors in Parkinson’s Disease. Biomolecules 2022; 12:biom12020243. [PMID: 35204744 PMCID: PMC8961531 DOI: 10.3390/biom12020243] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 01/19/2022] [Accepted: 01/26/2022] [Indexed: 12/02/2022] Open
Abstract
The discovery of the D3 receptor (D3R) subtypes of dopamine (DA) has generated an understandable increase in interest in the field of neurological diseases, especially Parkinson’s disease (PD). Indeed, although DA replacement therapy with l-DOPA has provided an effective treatment for patients with PD, it is responsible for invalidating abnormal involuntary movements, known as L-DOPA-induced dyskinesia, which constitutes a serious limitation of the use of this therapy. Of particular interest is the finding that chronic l-DOPA treatment can trigger the expression of D1R–D3R heteromeric interactions in the dorsal striatum. The D3R is expressed in various tissues of the central nervous system, including the striatum. Compelling research has focused on striatal D3Rs in the context of PD and motor side effects, including dyskinesia, occurring with DA replacement therapy. Therefore, this review will briefly describe the basal ganglia (BG) and the DA transmission within these brain regions, before going into more detail with regard to the role of D3Rs in PD and their participation in the current treatments. Numerous studies have also highlighted specific interactions between D1Rs and D3Rs that could promote dyskinesia. Finally, this review will also address the possibility that D3Rs located outside of the BG may mediate some of the effects of DA replacement therapy.
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Affiliation(s)
- Abdeslam Chagraoui
- Différenciation et Communication Neuroendocrine, Endocrine et Germinale Laboratory, Institute for Research and Innovation in Biomedicine of Normandy (IRIB), University of Rouen, INSERM 1239, 76000 Rouen, France
- Department of Medical Biochemistry, Rouen University Hospital, 76000 Rouen, France
- Correspondence: ; Tel.: +33-2-35-14-83-69
| | - Giuseppe Di Giovanni
- Laboratory of Neurophysiology, Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, 2080 Msida, Malta;
- Neuroscience Division, School of Biosciences, Cardiff University, Cardiff CF10 3AT, UK
| | - Philippe De Deurwaerdère
- Unité Mixte de Recherche (UMR) 5287, Centre National de la Recherche Scientifique (CNRS), CEDEX, 33000 Bordeaux, France;
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Budzinski J, Maschauer S, Kobayashi H, Couvineau P, Vogt H, Gmeiner P, Roggenhofer A, Prante O, Bouvier M, Weikert D. Bivalent ligands promote endosomal trafficking of the dopamine D3 receptor-neurotensin receptor 1 heterodimer. Commun Biol 2021; 4:1062. [PMID: 34508168 PMCID: PMC8433439 DOI: 10.1038/s42003-021-02574-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 08/18/2021] [Indexed: 02/08/2023] Open
Abstract
Bivalent ligands are composed of two pharmacophores connected by a spacer of variable size. These ligands are able to simultaneously recognize two binding sites, for example in a G protein-coupled receptor heterodimer, resulting in enhanced binding affinity. Taking advantage of previously described heterobivalent dopamine-neurotensin receptor ligands, we demonstrate specific interactions between dopamine D3 (D3R) and neurotensin receptor 1 (NTSR1), two receptors with expression in overlapping brain areas that are associated with neuropsychiatric diseases and addiction. Bivalent ligand binding to D3R-NTSR1 dimers results in picomolar binding affinity and high selectivity compared to the binding to monomeric receptors. Specificity of the ligands for the D3R-NTSR1 receptor pair over D2R-NTSR1 dimers can be achieved by a careful choice of the linker length. Bivalent ligands enhance and stabilize the receptor-receptor interaction leading to NTSR1-controlled internalization of D3R into endosomes via recruitment of β-arrestin, highlighting a potential mechanism for dimer-specific receptor trafficking and signalling.
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Affiliation(s)
- Julian Budzinski
- grid.5330.50000 0001 2107 3311Department of Chemistry and Pharmacy, Medicinal Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Simone Maschauer
- grid.5330.50000 0001 2107 3311Department of Nuclear Medicine, Molecular Imaging and Radiochemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Hiroyuki Kobayashi
- grid.14848.310000 0001 2292 3357Department of Biochemistry and Molecular Medicine, Institute for Research in Immunology and Cancer, Université de Montréal, Montreal, QC Canada
| | - Pierre Couvineau
- grid.14848.310000 0001 2292 3357Department of Biochemistry and Molecular Medicine, Institute for Research in Immunology and Cancer, Université de Montréal, Montreal, QC Canada
| | - Hannah Vogt
- grid.5330.50000 0001 2107 3311Department of Chemistry and Pharmacy, Medicinal Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Peter Gmeiner
- grid.5330.50000 0001 2107 3311Department of Chemistry and Pharmacy, Medicinal Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Anna Roggenhofer
- grid.5330.50000 0001 2107 3311Department of Chemistry and Pharmacy, Medicinal Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Olaf Prante
- grid.5330.50000 0001 2107 3311Department of Nuclear Medicine, Molecular Imaging and Radiochemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Michel Bouvier
- grid.14848.310000 0001 2292 3357Department of Biochemistry and Molecular Medicine, Institute for Research in Immunology and Cancer, Université de Montréal, Montreal, QC Canada
| | - Dorothee Weikert
- grid.5330.50000 0001 2107 3311Department of Chemistry and Pharmacy, Medicinal Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
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11
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Mechanistic diversity involved in the desensitization of G protein-coupled receptors. Arch Pharm Res 2021; 44:342-353. [PMID: 33761113 DOI: 10.1007/s12272-021-01320-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 03/14/2021] [Indexed: 01/14/2023]
Abstract
The desensitization of G protein-coupled receptors (GPCRs), which involves rapid loss of responsiveness due to repeated or chronic exposure to agonists, can occur through various mechanisms at different levels of signaling pathways. In this review, the mechanisms of GPCR desensitization are classified according to their occurrence at the receptor level and downstream to the receptor. The desensitization at the receptor level occurs in a phosphorylation-dependent manner, wherein the activated receptors are phosphorylated by GPCR kinases (GRKs), thereby increasing their affinities for arrestins. Arrestins bind to receptors through the cavity on the cytoplasmic region of heptahelical domains and interfere with the binding and activation of G-protein. Diverse mechanisms are involved in the desensitization that occurs downstream of the receptor. Some of these include the sequestration of G proteins, such as Gq and Gi/o by GRK2/3 and deubiquitinated arrestins, respectively. Mechanistically, GRK2/3 attenuates GPCR signaling by sequestering the Gα subunits of the Gq family and Gβγ via regulators of G protein signaling and pleckstrin homology domains, respectively. Moreover, studies on Gi/o-coupled D2-like receptors have reported that arrestins are deubiquitinated under desensitization condition and form a stable complex with Gβγ, thereby preventing them from coupling with Gα and the receptor, eventually leading to receptor signaling inhibition. Notably, the desensitization mechanism that involves arrestin deubiquitination is interesting; however, this is a new mechanism and needs to be explored further.
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12
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Luis-Ravelo D, Fumagallo-Reading F, Castro-Hernandez J, Barroso-Chinea P, Afonso-Oramas D, Febles-Casquero A, Cruz-Muros I, Salas-Hernandez J, Mesa-Infante V, Rodriguez-Nuñez J, Gonzalez-Hernandez T. Prolonged dopamine D 3 receptor stimulation promotes dopamine transporter ubiquitination and degradation through a PKC-dependent mechanism. Pharmacol Res 2021; 165:105434. [PMID: 33484816 DOI: 10.1016/j.phrs.2021.105434] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 12/17/2020] [Accepted: 01/06/2021] [Indexed: 12/12/2022]
Abstract
The dopamine transporter (DAT) is a membrane glycoprotein in dopaminergic neurons, which modulates extracellular and intracellular dopamine levels. DAT is regulated by different presynaptic proteins, including dopamine D2 (D2R) and D3 (D3R) receptors. While D2R signalling enhances DAT activity, some data suggest that D3R has a biphasic effect. However, despite the extensive therapeutic use of D2R/D3R agonists in neuropsychiatric disorders, this phenomenon has been little studied. In order to shed light on this issue, DAT activity, expression and posttranslational modifications were studied in mice and DAT-D3R-transfected HEK cells. Consistent with previous reports, acute treatment with D2R/D3R agonists promoted DAT recruitment to the plasma membrane and an increase in DA uptake. However, when the treatment was prolonged, DA uptake and total striatal DAT protein declined below basal levels. These effects were inhibited in mice by genetic and pharmacological inactivation of D3R, but not D2R, indicating that they are D3R-dependent. No changes were detected in mesostriatal tyrosine hydroxylase (TH) protein expression and midbrain TH and DAT mRNAs, suggesting that the dopaminergic system is intact and DAT is posttranslationally regulated. The use of immunoprecipitation and cell surface biotinylation revealed that DAT is phosphorylated at serine residues, ubiquitinated and released into late endosomes through a PKCβ-dependent mechanism. In sum, the results indicate that long-term D3R activation promotes DAT down-regulation, an effect that may underlie neuroprotective and antidepressant actions described for some D2R/D3R agonists.
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Affiliation(s)
- Diego Luis-Ravelo
- Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad de La Laguna, Tenerife, Spain; Instituto de Tecnologías Biomédicas (ITB), Universidad de La Laguna, Tenerife, Spain
| | - Felipe Fumagallo-Reading
- Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad de La Laguna, Tenerife, Spain; Instituto de Tecnologías Biomédicas (ITB), Universidad de La Laguna, Tenerife, Spain
| | - Javier Castro-Hernandez
- Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad de La Laguna, Tenerife, Spain
| | - Pedro Barroso-Chinea
- Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad de La Laguna, Tenerife, Spain; Instituto de Tecnologías Biomédicas (ITB), Universidad de La Laguna, Tenerife, Spain
| | - Domingo Afonso-Oramas
- Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad de La Laguna, Tenerife, Spain; Instituto de Tecnologías Biomédicas (ITB), Universidad de La Laguna, Tenerife, Spain
| | - Alejandro Febles-Casquero
- Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad de La Laguna, Tenerife, Spain
| | - Ignacio Cruz-Muros
- Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad de La Laguna, Tenerife, Spain; Instituto de Tecnologías Biomédicas (ITB), Universidad de La Laguna, Tenerife, Spain
| | - Josmar Salas-Hernandez
- Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad de La Laguna, Tenerife, Spain; Instituto de Tecnologías Biomédicas (ITB), Universidad de La Laguna, Tenerife, Spain
| | - Virginia Mesa-Infante
- Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad de La Laguna, Tenerife, Spain
| | - Julia Rodriguez-Nuñez
- Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad de La Laguna, Tenerife, Spain
| | - Tomas Gonzalez-Hernandez
- Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad de La Laguna, Tenerife, Spain; Instituto de Tecnologías Biomédicas (ITB), Universidad de La Laguna, Tenerife, Spain.
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13
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Forster L, Grätz L, Mönnich D, Bernhardt G, Pockes S. A Split Luciferase Complementation Assay for the Quantification of β-Arrestin2 Recruitment to Dopamine D 2-Like Receptors. Int J Mol Sci 2020; 21:ijms21176103. [PMID: 32847148 PMCID: PMC7503597 DOI: 10.3390/ijms21176103] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 08/12/2020] [Accepted: 08/21/2020] [Indexed: 12/12/2022] Open
Abstract
Investigations on functional selectivity of GPCR ligands have become increasingly important to identify compounds with a potentially more beneficial side effect profile. In order to discriminate between individual signaling pathways, the determination of β-arrestin2 recruitment, in addition to G-protein activation, is of great value. In this study, we established a sensitive split luciferase-based assay with the ability to quantify β-arrestin2 recruitment to D2long and D3 receptors and measure time-resolved β-arrestin2 recruitment to the D2long receptor after agonist stimulation. We were able to characterize several standard (inverse) agonists as well as antagonists at the D2longR and D3R subtypes, whereas for the D4.4R, no β-arrestin2 recruitment was detected, confirming previous reports. Extensive radioligand binding studies and comparisons with the respective wild-type receptors confirm that the attachment of the Emerald luciferase fragment to the receptors does not affect the integrity of the receptor proteins. Studies on the involvement of GRK2/3 and PKC on the β-arrestin recruitment to the D2longR and D3R, as well as at the D1R using different kinase inhibitors, showed that the assay could also contribute to the elucidation of signaling mechanisms. Its broad applicability, which provides concentration-dependent and kinetic information on receptor/β-arrestin2 interactions, renders this homogeneous assay a valuable method for the identification of biased agonists.
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Affiliation(s)
- Lisa Forster
- Correspondence: (L.F.); (S.P.); Tel.: +49-941-943-4796 (L.F.); +49-941-943-4825 (S.P.)
| | | | | | | | - Steffen Pockes
- Correspondence: (L.F.); (S.P.); Tel.: +49-941-943-4796 (L.F.); +49-941-943-4825 (S.P.)
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14
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Acharya S, Kundu D, Choi HJ, Kim KM. Metabotropic signaling cascade involved in α4β2 nicotinic acetylcholine receptor-mediated PKCβII activation. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1867:118721. [PMID: 32304729 DOI: 10.1016/j.bbamcr.2020.118721] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Revised: 04/04/2020] [Accepted: 04/10/2020] [Indexed: 01/27/2023]
Abstract
Nicotinic acetylcholine receptors (nAChRs) belong to the ionophore receptor family, which regulates plasma membrane conductance to Na+, K+, and Ca2+ ions. Some studies, however, have shown that nAChRs also employ second messengers for intracellular signaling. We previously showed that α4β2 nAChR mediates the translocation of protein kinase CβII (PKCβII) from the cytoplasm to the plasma membrane, which is a typical activation marker for PKCβII. In this study, we investigated the molecular mechanisms underlying PKCβII activation through α4β2 nAChR. α4β2 nAChR is the most abundant nAChR subtype and is implicated in various brain functions and diseases. Putative α4β2 nAChR signaling components were identified by knockdown or chemical inhibition of candidate proteins, and the signaling cascade was deduced by protein interactions in predicted cellular components. α4β2 nAChR-mediated PKCβII translocation was found to occur in an ionophore activity-independent manner. Nicotinic stimulation of α4β2 nAChR activated Src in a β-arrestin1 and 14-3-3η-dependent manner. Activated Src phosphorylated the tyrosine residue(s) on Syk molecules, which in turn interacted with phospholipase C γ1 to trigger the translocation of PKCβII to the cell membrane by elevating cellular diacylglycerol levels. The activated PKCβII in turn exerted a positive feedback effect on Src activation, suggesting that α4β2 nAChR signaling is amplified by a positive feedback loop. These findings provide novel information for unveiling the previously unclear metabotropic second messenger-based signal transduction pathway of nAChRs.
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Affiliation(s)
- Srijan Acharya
- Department of Pharmacology, College of Pharmacy, Chonnam National University, Gwang-Ju 61186, Republic of Korea
| | - Dooti Kundu
- Department of Pharmacology, College of Pharmacy, Chonnam National University, Gwang-Ju 61186, Republic of Korea
| | - Hyun Jin Choi
- College of Pharmacy, Cha University, Seongnam, Gyeonggi-do 13488, Republic of Korea
| | - Kyeong-Man Kim
- Department of Pharmacology, College of Pharmacy, Chonnam National University, Gwang-Ju 61186, Republic of Korea.
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15
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Zhang X, Min X, Zhu A, Kim KM. A novel molecular mechanism involved in the crosstalks between homologous and PKC-mediated heterologous regulatory pathway of dopamine D2 receptor. Biochem Pharmacol 2020; 174:113791. [DOI: 10.1016/j.bcp.2020.113791] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 01/02/2020] [Indexed: 11/15/2022]
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16
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Treppiedi D, Mangili F, Giardino E, Catalano R, Locatelli M, Lania AG, Spada A, Arosio M, Calebiro D, Mantovani G, Peverelli E. Cytoskeleton Protein Filamin A Is Required for Efficient Somatostatin Receptor Type 2 Internalization and Recycling through Rab5 and Rab4 Sorting Endosomes in Tumor Somatotroph Cells. Neuroendocrinology 2020; 110:642-652. [PMID: 31574507 DOI: 10.1159/000503791] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 09/30/2019] [Indexed: 11/19/2022]
Abstract
The high expression of somatostatin receptor 2 (SST2) in growth hormone (GH)-secreting tumors represents the rationale for the clinical use of somatostatin analogs (SSAs) in acromegaly. Recently, the cytoskeletal protein Filamin A (FLNA) has emerged as key modulator of the responsiveness of GH-secreting pituitary tumors to SSAs by regulating SST2 signaling and expression. The aim of this study was to explore FLNA involvement in SST2 intracellular trafficking in tumor somatotroph cells. By biotinylation assay, we found that FLNA silencing abolished octreotide-mediated SST2 internalization in rat GH3 cell line (28.0 ± 2.7 vs. 4 ± 4.3% SST2 internalization, control versus FLNA small interfering RNAs (siRNA) cells, respectively, p < 0.001) and human GH-secreting primary cultured cells (70.3 ± 21.1 vs. 24 ± 19.2% SST2 internalization, control versus FLNA siRNA cells, respectively, p < 0.05). In addition, confocal imaging revealed impaired SST2 recycling to the plasma membrane in FLNA silenced GH3 cells. Coimmunoprecipitation and immunofluorescence experiments showed that FLNA, as well as β-arrestin2, is timely dependent recruited to octreotide-stimulated SST2 receptors both in rat and human tumor somatotroph cells. Although FLNA expression knock down did not prevent the formation of β-arrestin2-SST2 complex in GH3 cells, it significantly impaired efficient SST2 loading into cytosolic vesicles positive for the early endocytic and recycling markers Rab5 and 4, respectively (33.7 ± 8.9% down to 25.9 ± 6.9%, p < 0.05, and 28.4 ± 7.4% down to 17.6 ± 5.7%, p < 0.01, for SST2-Rab5 and SST2-Rab4 colocalization, respectively, in control versus FLNA siRNA cells). Altogether these data support an important role for FLNA in the mediation of octreotide-induced SST2 trafficking in GH-secreting pituitary tumor cells through Rab5 and 4 sorting endosomes.
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Affiliation(s)
- Donatella Treppiedi
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Federica Mangili
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Elena Giardino
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Rosa Catalano
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
- PhD Program in Endocrinological Sciences, Sapienza University of Rome, Rome, Italy
| | - Marco Locatelli
- Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
- Neurosurgery Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Andrea Gerardo Lania
- Endocrine Unit, IRCCS Humanitas Clinical Institute, Humanitas University, Rozzano, Italy
| | - Anna Spada
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
- Endocrinology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Maura Arosio
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
- Endocrinology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Davide Calebiro
- Institute of Pharmacology and Toxicology and Bio-Imaging Center, University of Würzburg, Würzburg, Germany
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom
- Centre of Membrane Proteins and Receptors, University of Birmingham, Birmingham, United Kingdom
| | - Giovanna Mantovani
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy,
- Endocrinology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy,
| | - Erika Peverelli
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
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17
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Min X, Zhang X, Sun N, Acharya S, Kim KM. Mdm2-mediated ubiquitination of PKCβII in the nucleus mediates clathrin-mediated endocytic activity. Biochem Pharmacol 2019; 170:113675. [DOI: 10.1016/j.bcp.2019.113675] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 10/16/2019] [Indexed: 11/30/2022]
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18
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He D, Lasek AW. Anaplastic Lymphoma Kinase Regulates Internalization of the Dopamine D2 Receptor. Mol Pharmacol 2019; 97:123-131. [PMID: 31734646 DOI: 10.1124/mol.119.117473] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 11/11/2019] [Indexed: 12/16/2022] Open
Abstract
The dopamine D2 receptor (D2R) is a G protein-coupled receptor (GPCR) expressed in regions of the brain that control motor function, cognition, and motivation. As a result, D2R is involved in the pathophysiology of disorders such as schizophrenia and drug addiction. Understanding the signaling pathways activated by D2R is crucial to finding new therapeutic targets for these disorders. D2R stimulation by its agonist, dopamine, causes desensitization and internalization of the receptor. A previous study found that inhibitors of the receptor tyrosine kinase anaplastic lymphoma kinase (ALK) blocked D2R desensitization in neurons in the ventral tegmental area of the brain. In the present study, using a cell-based system, we investigated whether ALK regulates D2R internalization. The ALK inhibitor alectinib completely inhibited dopamine-induced D2R internalization. Since GPCRs can transactivate receptor tyrosine kinases, we also examined if D2R stimulation activated ALK signaling. ALK phosphorylation increased by almost 2-fold after dopamine treatment and ALK coimmunoprecipitated with D2R. To identify the signaling pathways downstream of ALK that might regulate D2R internalization, we used pharmacological inhibitors of proteins activated by ALK signaling. Protein kinase Cγ was activated by dopamine in an ALK-dependent manner, and a protein kinase C inhibitor completely blocked dopamine-induced D2R internalization. Taken together, these results identify ALK as a receptor tyrosine kinase transactivated by D2R that promotes its internalization, possibly through activation of protein kinase C. ALK inhibitors could be useful in enhancing D2R signaling. SIGNIFICANCE STATEMENT: Receptor internalization is a mechanism by which receptors are desensitized. In this study we found that agonist-induced internalization of the dopamine D2 receptor is regulated by the receptor tyrosine kinase ALK. ALK was also transactivated by and associated with dopamine D2 receptor. Dopamine activated protein kinase C in an ALK-dependent manner and a PKC inhibitor blocked dopamine D2 receptor internalization. These results indicate that ALK regulates dopamine D2 receptor trafficking, which has implications for psychiatric disorders involving dysregulated dopamine signaling.
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Affiliation(s)
- Donghong He
- Center for Alcohol Research in Epigenetics and Department of Psychiatry, University of Illinois at Chicago, Chicago, Illinois
| | - Amy W Lasek
- Center for Alcohol Research in Epigenetics and Department of Psychiatry, University of Illinois at Chicago, Chicago, Illinois
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19
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Barroso-Chinea P, Luis-Ravelo D, Fumagallo-Reading F, Castro-Hernandez J, Salas-Hernandez J, Rodriguez-Nuñez J, Febles-Casquero A, Cruz-Muros I, Afonso-Oramas D, Abreu-Gonzalez P, Moratalla R, Millan MJ, Gonzalez-Hernandez T. DRD3 (dopamine receptor D3) but not DRD2 activates autophagy through MTORC1 inhibition preserving protein synthesis. Autophagy 2019; 16:1279-1295. [PMID: 31538542 DOI: 10.1080/15548627.2019.1668606] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Growing evidence shows that autophagy is deficient in neurodegenerative and psychiatric diseases, and that its induction may have beneficial effects in these conditions. However, as autophagy shares signaling pathways with cell death and interferes with protein synthesis, prolonged use of autophagy inducers available nowadays is considered unwise. The search for novel autophagy inducers indicates that DRD2 (dopamine receptor 2)-DRD3 ligands may also activate autophagy, though critical aspects of the action mechanisms and effects of dopamine ligands on autophagy are still unknown. In order to shed light on this issue, DRD2- and DRD3-overexpressing cells and drd2 KO, drd3 KO and wild-type mice were treated with the DRD2-DRD3 agonist pramipexole. The results revealed that pramipexole induces autophagy through MTOR inhibition and a DRD3-dependent but DRD2-independent mechanism. DRD3 activated AMPK followed by inhibitory phosphorylation of RPTOR, MTORC1 and RPS6KB1 inhibition and ULK1 activation. Interestingly, despite RPS6KB1 inhibition, the activity of RPS6 was maintained through activation of the MAPK1/3-RPS6KA pathway, and the activity of MTORC1 kinase target EIF4EBP1 along with protein synthesis and cell viability, were also preserved. This pattern of autophagy through MTORC1 inhibition without suppression of protein synthesis, contrasts with that of direct allosteric and catalytic MTOR inhibitors and opens up new opportunities for G protein-coupled receptor ligands as autophagy inducers in the treatment of neurodegenerative and psychiatric diseases. ABBREVIATIONS AKT/Protein kinase B: thymoma viral proto-oncogene 1; AMPK: AMP-activated protein kinase; BECN1: beclin 1; EGFP: enhanced green fluorescent protein; EIF4EBP1/4E-BP1: eukaryotic translation initiation factor 4E binding protein 1; GPCR; G protein-coupled receptor; GFP: green fluorescent protein; HEK: human embryonic kidney; MAP1LC3/LC3: microtubule-associated protein 1 light chain 3; MAP2K/MEK: mitogen-activated protein kinase kinase; MAPK1/ERK2: mitogen-activated protein kinase 1; MAPK3/ERK1: mitogen-activated protein kinase 3; MDA: malonildialdehyde; MTOR: mechanistic target of rapamycin kinase; MTT: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; PPX: pramipexole; RPTOR/raptor: regulatory associated protein of MTOR, complex 1; RPS6: ribosomal protein S6; RPS6KA/p90S6K: ribosomal protein S6 kinase A; RPS6KB1/p70S6K: ribosomal protein S6 kinase B1; SQSTM1/p62: sequestosome 1; ULK1: unc-51 like autophagy activating kinase 1; WT: wild type.
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Affiliation(s)
- Pedro Barroso-Chinea
- Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad de La Laguna , Tenerife, Spain.,Instituto de Tecnologías Biomédicas (ITB), Universidad de La Laguna , Tenerife, Spain
| | - Diego Luis-Ravelo
- Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad de La Laguna , Tenerife, Spain.,Instituto de Tecnologías Biomédicas (ITB), Universidad de La Laguna , Tenerife, Spain
| | - Felipe Fumagallo-Reading
- Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad de La Laguna , Tenerife, Spain.,Instituto de Tecnologías Biomédicas (ITB), Universidad de La Laguna , Tenerife, Spain
| | - Javier Castro-Hernandez
- Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad de La Laguna , Tenerife, Spain
| | - Josmar Salas-Hernandez
- Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad de La Laguna , Tenerife, Spain.,Instituto de Tecnologías Biomédicas (ITB), Universidad de La Laguna , Tenerife, Spain
| | - Julia Rodriguez-Nuñez
- Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad de La Laguna , Tenerife, Spain
| | - Alejandro Febles-Casquero
- Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad de La Laguna , Tenerife, Spain
| | - Ignacio Cruz-Muros
- Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad de La Laguna , Tenerife, Spain.,Instituto de Tecnologías Biomédicas (ITB), Universidad de La Laguna , Tenerife, Spain
| | - Domingo Afonso-Oramas
- Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad de La Laguna , Tenerife, Spain.,Instituto de Tecnologías Biomédicas (ITB), Universidad de La Laguna , Tenerife, Spain
| | - Pedro Abreu-Gonzalez
- Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad de La Laguna , Tenerife, Spain
| | - Rosario Moratalla
- Departamento de Biología Funcional y de Sistemas. Instituto Cajal, Consejo Superior de Investigaciones Científicas , Madrid, Spain.,CIBERNED, ISCIII , Madrid, Spain
| | - Mark J Millan
- Department of Psychopharmacology, Institut Centre de Recherches Servier , Paris, France
| | - Tomas Gonzalez-Hernandez
- Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad de La Laguna , Tenerife, Spain.,Instituto de Tecnologías Biomédicas (ITB), Universidad de La Laguna , Tenerife, Spain
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20
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Yang Y, Kreko-Pierce T, Howell R, Pugh JR. Long-term depression of presynaptic cannabinoid receptor function at parallel fibre synapses. J Physiol 2019; 597:3167-3181. [PMID: 31020998 DOI: 10.1113/jp277727] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 04/18/2019] [Indexed: 12/22/2022] Open
Abstract
KEY POINTS Inhibition of synaptic responses by activation of presynaptic cannabinoid type-1 (Cb1) receptors is reduced at parallel fibre synapses in the cerebellum following 4 Hz stimulation. Activation of adenylyl cyclase is necessary and sufficient for down-regulation of Cb1 receptors induced by 4 Hz stimulation. 4 Hz stimulation reduces Cb1 receptor function by (i) increasing the rate of endocannabinoid clearance from the synapse and (ii) decreasing expression of Cb1 receptors. ABSTRACT Cannabinoid type-1 receptors (Cb1R) are expressed in the presynaptic membrane of many synapses, including parallel fibre-Purkinje cell synapses in the cerebellum, where they are involved in short- and long-term plasticity of synaptic responses. We show that Cb1R expression itself is a plastic property of the synapse regulated by physiological activity patterns. We made patch clamp recordings from Purkinje cells in cerebellar slices and assessed Cb1R activity by measuring depolarization-induced suppression of excitation (DSE). We find that DSE is normally stable at parallel fibre synapses but, following 4 Hz stimulation, DSE is persistently reduced and recovers more rapidly. Using a combination of electrophysiology, pharmacology and biochemistry, we show that changes in DSE are a result of the reduced expression of Cb1Rs and increased degradation of endocannabinoids by monoacylglycerol lipase. Long-term changes in presynaptic Cb1R expression may alter other forms of Cb1R-dependent plasticity at parallel fibre synapses, priming or inhibiting the circuit for associative learning.
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Affiliation(s)
- Ying Yang
- University of Texas Health Science Center at San Antonio, Department of Cellular and Integrative Physiology, San Antonio, TX, USA.,Xiangya School of Medicine, Department of Pain, The Third Xiangya Hospital and Institute of Pain Medicine, Central South University, Changsha, Hunan Province, China
| | - Tabita Kreko-Pierce
- University of Texas Health Science Center at San Antonio, Department of Cellular and Integrative Physiology, San Antonio, TX, USA
| | - Rebecca Howell
- University of Texas Health Science Center at San Antonio, Department of Cellular and Integrative Physiology, San Antonio, TX, USA.,Present address: Oklahoma Medical Research Foundation & University of Oklahoma Health Science Center, Oklahoma City, OK, USA
| | - Jason R Pugh
- University of Texas Health Science Center at San Antonio, Department of Cellular and Integrative Physiology, San Antonio, TX, USA.,Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
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21
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Acharya S, Kim KM. α4β2 nicotinic acetylcholine receptor downregulates D 3 dopamine receptor expression through protein kinase C activation. Biochem Biophys Res Commun 2019; 514:665-671. [PMID: 31078264 DOI: 10.1016/j.bbrc.2019.05.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 05/03/2019] [Indexed: 02/08/2023]
Abstract
Receptor transactivation or crosstalk refers to instances in which the signaling of a given receptor is regulated by different classes of receptors. Functional crosstalk between α4β2 nicotinic acetylcholine receptor (nAChR) and D3 dopamine receptor (D3R) that belong to the family of ligand-gated ion channels and G protein-coupled receptors, respectively, has been reported from brain dopaminergic neurons. For example, D3R is involved in the development of reward-related behaviors induced by α4β2 nAChR stimulation. However, the molecular mechanisms involved in their crosstalk remain unclear. Among PKC isoforms (α, βII, γ, and δ) evaluated in this study, PKCβII interacted with D3R and potentiated D3R endocytosis. Following α4β2 nAChR stimulation, activated PKCβII translocated to the plasma membrane to induce clathrin-mediated endocytosis of D3R, resulting in downregulation and signal inhibition. Considering that D3R plays important roles in mediating reward-related physiological actions of α4β2 nAChR, this study could provide a new insight into the regulatory mechanism involved in nicotine addiction.
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Affiliation(s)
- Srijan Acharya
- Department of Pharmacology, College of Pharmacy, Chonnam National University, Gwang-Ju, 61186, Republic of Korea
| | - Kyeong-Man Kim
- Department of Pharmacology, College of Pharmacy, Chonnam National University, Gwang-Ju, 61186, Republic of Korea.
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22
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Xu W, Reith MEA, Liu-Chen LY, Kortagere S. Biased signaling agonist of dopamine D3 receptor induces receptor internalization independent of β-arrestin recruitment. Pharmacol Res 2019; 143:48-57. [PMID: 30844536 DOI: 10.1016/j.phrs.2019.03.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 03/01/2019] [Accepted: 03/01/2019] [Indexed: 12/14/2022]
Abstract
Agonist-induced internalization of G protein-coupled receptors (GPCRs) is a significant step in receptor kinetics and is known to be involved in receptor down-regulation. However, the dopamine D3 receptor (D3R) has been an exception wherein agonist induces D3Rs to undergo desensitization followed by pharmacological sequestration - which is defined as the sequestration of cell surface receptors into a more hydrophobic fraction within the plasma membrane without undergoing the process of receptor internalization. Pharmacological sequestration renders the receptor in an inactive state on the membrane. In our previous study we demonstrated that a novel class of D3R agonists exemplified by SK608 have biased signaling properties via the G-protein dependent pathway and do not induce D3R desensitization. In this study, using radioligand binding assay, immunoblot or immunocytochemistry methods, we observed that SK608 induced internalization of human D3R stably expressed in CHO, HEK and SH-SY5Y cells which are derived from neuroblastoma cells, suggesting that it is not a cell-type specific event. Further, we have evaluated the potential mechanism of D3R internalization induced by these biased signaling agonists. SK608-induced D3R internalization was time- and concentration-dependent. In comparison, dopamine induced D3R upregulation and pharmacological sequestration in the same assays. GRK2 and clathrin/dynamin I/II are the key molecular players in the SK608-induced D3R internalization process, while β-arrestin 1/2 and GRK-interacting protein 1(GIT1) are not involved. These results suggest that SK608-promoted D3R internalization is similar to the type II internalization observed among peptide binding GPCRs.
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Affiliation(s)
- Wei Xu
- Department of Microbiology and Immunology, Drexel University College of Medicine, PA 19129, United States
| | - Maarten E A Reith
- Department of Psychiatry, Biochemistry and Molecular Pharmacology, NYU School of Medicine, New York, NY 10016, United States
| | - Lee-Yuan Liu-Chen
- Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA 19140, United States
| | - Sandhya Kortagere
- Department of Microbiology and Immunology, Drexel University College of Medicine, PA 19129, United States; Department of Pharmacology and Physiology, Drexel University College of Medicine, PA 19102, United States.
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Zestos AG, Carpenter C, Kim Y, Low MJ, Kennedy RT, Gnegy ME. Ruboxistaurin Reduces Cocaine-Stimulated Increases in Extracellular Dopamine by Modifying Dopamine-Autoreceptor Activity. ACS Chem Neurosci 2019; 10:1960-1969. [PMID: 30384585 DOI: 10.1021/acschemneuro.8b00259] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Cocaine is a highly abused drug, and cocaine addiction affects millions of individuals worldwide. Cocaine blocks normal uptake function at the dopamine transporter (DAT), thus increasing extracellular dopamine. Currently, no chemical therapies are available to treat cocaine abuse. Previous works showed that the selective inhibitors of protein kinase Cβ (PKCβ), enzastaurin and ruboxistaurin, attenuate dopamine overflow and locomotion stimulated by another psychostimulant drug, amphetamine. We now test if ruboxistaurin similarly affects cocaine action. Perfusion of 1 μM ruboxistaurin directly into the core of the nucleus accumbens via retrodialysis reduced cocaine-stimulated increases in dopamine overflow, measured using microdialysis sampling, with simultaneous reductions in locomotor behavior. Because cocaine activity is highly regulated by dopamine autoreceptors, we examined whether ruboxistaurin was acting at the level of the D2 autoreceptor. Perfusion of 5 μM raclopride, a selective D2-like receptor antagonist, before addition of ruboxistaurin, abrogated the effect of ruboxistaurin on cocaine-stimulated dopamine overflow and hyperlocomotion. Further, ruboxistaurin was inactive against cocaine-stimulated locomotor activity in mice with a genetic deletion in D2 receptors as compared to wild-type mice. In contrast, blockade or deletion of dopamine D2 receptors did not abolish the attenuating effect of ruboxistaurin on amphetamine-stimulated activities. Therefore, the inhibition of PKCβ reduces dopamine overflow and locomotor activity stimulated by both cocaine and amphetamine, but the mechanism of action differs for each stimulant. These data suggest that inhibition of PKCβ would serve as a target to reduce the abuse of either amphetamine or cocaine.
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Affiliation(s)
- Alexander G. Zestos
- Department of Chemistry and Center for Behavioral Neuroscience, American University, Washington, D.C. 20016, United States
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Treppiedi D, Jobin ML, Peverelli E, Giardino E, Sungkaworn T, Zabel U, Arosio M, Spada A, Mantovani G, Calebiro D. Single-Molecule Microscopy Reveals Dynamic FLNA Interactions Governing SSTR2 Clustering and Internalization. Endocrinology 2018; 159:2953-2965. [PMID: 29931263 DOI: 10.1210/en.2018-00368] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 06/14/2018] [Indexed: 11/19/2022]
Abstract
The cytoskeletal protein filamin A (FLNA) has been suggested to play an important role in the responsiveness of GH-secreting pituitary tumors to somatostatin receptor subtype 2 (SSTR2) agonists by regulating SSTR2 expression and signaling. However, the underlying mechanisms are unknown. In this study, we use fast multicolor single-molecule microscopy to image individual SSTR2 and FLNA molecules at the surface of living cells with unprecedented spatiotemporal resolution. We find that SSTR2 and FLNA undergo transient interactions, which occur preferentially along actin fibers and contribute to restraining SSTR2 diffusion. Agonist stimulation increases the localization of SSTR2 along actin fibers and, subsequently, SSTR2 clustering and recruitment to clathrin-coated pits (CCPs). Interfering with FLNA-SSTR2 binding with a dominant-negative FLNA fragment increases SSTR2 mobility, hampers the formation and alignment of SSTR2 clusters along actin fibers, and impairs both SSTR2 recruitment to CCPs and SSTR2 internalization. These findings indicate that dynamic SSTR2-FLNA interactions critically control the nanoscale localization of SSTR2 at the plasma membrane and are required for coupling SSTR2 clustering to internalization. These mechanisms explain the critical role of FLNA in the control of SSTR2 expression and signaling and suggest the possibility of targeting SSTR2-FLNA interactions for the therapy of pharmacologically resistant GH-secreting pituitary tumors.
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Affiliation(s)
- Donatella Treppiedi
- Endocrinology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Marie-Lise Jobin
- Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany
- Bio-Imaging Center/Rudolf Virchow Center, University of Würzburg, Würzburg, Germany
| | - Erika Peverelli
- Endocrinology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Elena Giardino
- Endocrinology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Titiwat Sungkaworn
- Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany
- Bio-Imaging Center/Rudolf Virchow Center, University of Würzburg, Würzburg, Germany
| | - Ulrike Zabel
- Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany
- Bio-Imaging Center/Rudolf Virchow Center, University of Würzburg, Würzburg, Germany
| | - Maura Arosio
- Endocrinology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Anna Spada
- Endocrinology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Giovanna Mantovani
- Endocrinology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Davide Calebiro
- Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany
- Bio-Imaging Center/Rudolf Virchow Center, University of Würzburg, Würzburg, Germany
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom
- Centre of Membrane Proteins and Receptors (COMPARE), Universities of Birmingham and Nottingham, Birmingham, United Kingdom
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25
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β-Arrestin2 directly or through GRK2 inhibits PKCβII activation in a ubiquitination-dependent manner. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1865:142-157. [DOI: 10.1016/j.bbamcr.2017.10.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 10/15/2017] [Accepted: 10/16/2017] [Indexed: 11/23/2022]
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26
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The EGF receptor inhibits the signaling of dopamine D 3 receptor through the phosphorylation of GRK2 on tyrosine residues. Biochem Biophys Res Commun 2017; 489:515-522. [DOI: 10.1016/j.bbrc.2017.05.183] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 05/31/2017] [Indexed: 01/25/2023]
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Shimizu Y, Koyama R, Kawamoto T. Rho kinase-dependent desensitization of GPR39; a unique mechanism of GPCR downregulation. Biochem Pharmacol 2017; 140:105-114. [PMID: 28619258 DOI: 10.1016/j.bcp.2017.06.115] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 06/09/2017] [Indexed: 12/14/2022]
Abstract
GPR39, a G-protein-coupled receptor activated by zinc, reportedly activates multiple intracellular signaling pathways via Gs, Gq, G12/13, and β-arrestin, but little is known about downregulation of the receptor upon its activation. To our knowledge, this is the first report on the mechanism of feedback regulation of GPR39 function determined in GPR39-expressing HEK293 cells (HEK293-GPR39) as a model cell system. In HEK293-GPR39 cells, GPR39-C3, which is a positive allosteric modulator, activated cAMP production (downstream of Gs), IP1 accumulation (downstream of Gq), SRF-RE-dependent transcription (downstream of G12/13), and β-arrestin recruitment. GPR39-C3 induced dose- and time-dependent loss of response in cAMP production by second challenge of the compound. This functional desensitization was blocked by the Rho kinase (ROCK) inhibitor, Y-27632, but not by Gq or Gs-pathway inhibitors or inhibition of β-arrestin recruitment. In the receptor localization assay, GPR39-C3 induced internalization of GFP-tagged GPR39. This internalization was also inhibited by Y-27632, which suggested that ROCK activation is critical for internalization and desensitization of GPR39. A novel biased GPR39 positive allosteric modulator, 5-[2-[(2,4-dichlorophenyl)methoxy]phenyl]-2,2-dimethyl-1,3,5,6-tetrahydrobenzo[a]phenanthridin-4-one (GSB-118), which activated cAMP responses and β-arrestin recruitment but showed no effect on SRF-RE-dependent transcription, did not induce desensitization. These results revealed a unique mechanism of desensitization of GPR39.
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Affiliation(s)
- Yuji Shimizu
- Biomolecular Research Laboratories, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-higashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan.
| | - Ryokichi Koyama
- Biomolecular Research Laboratories, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-higashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Tomohiro Kawamoto
- Biomolecular Research Laboratories, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-higashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
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Min C, Zhang X, Zheng M, Sun N, Acharya S, Zhang X, Kim KM. Molecular Signature That Determines the Acute Tolerance of G Protein-Coupled Receptors. Biomol Ther (Seoul) 2017; 25:239-248. [PMID: 27956717 PMCID: PMC5424633 DOI: 10.4062/biomolther.2016.193] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 10/08/2016] [Accepted: 11/15/2016] [Indexed: 11/05/2022] Open
Abstract
Desensitization and acute tolerance are terms used to describe the attenuation of receptor responsiveness by prolonged or intermittent exposure to an agonist. Unlike desensitization of G protein-coupled receptors (GPCRs), which is commonly explained by steric hindrance caused by the β-arrestins that are translocated to the activated receptors, molecular mechanisms involved in the acute tolerance of GPCRs remain unclear. Our studies with several GPCRs and related mutants showed that the acute tolerance of GPCRs could occur independently of agonist-induced β-arrestin translocation. A series of co-immunoprecipitation experiments revealed a correlation between receptor tolerance and interactions among receptors, β-arrestin2, and Gβγ. Gβγ displayed a stable interaction with receptors and β-arrestin2 in cells expressing GPCRs that were prone to undergo tolerance compared to the GPCRs that were resistant to acute tolerance. Strengthening the interaction between Gβγ and β-arrestin rendered the GPCRs to acquire the tendency of acute tolerance. Overall, stable interaction between the receptor and Gβγ complex is required for the formation of a complex with β-arrestin, and determines the potential of a particular GPCR to undergo acute tolerance. Rather than turning off the signal, β-arrestins seem to contribute on continuous signaling when they are in the context of complex with receptor and Gβγ.
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Affiliation(s)
- Chengchun Min
- Pharmacology Laboratory, College of Pharmacy, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Xiaohan Zhang
- Pharmacology Laboratory, College of Pharmacy, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Mei Zheng
- Pharmacology Laboratory, College of Pharmacy, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Ningning Sun
- Pharmacology Laboratory, College of Pharmacy, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Srijan Acharya
- Pharmacology Laboratory, College of Pharmacy, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Xiaowei 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
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29
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Treppiedi D, Peverelli E, Giardino E, Ferrante E, Calebiro D, Spada A, Mantovani G. Somatostatin Receptor Type 2 (SSTR2) Internalization and Intracellular Trafficking in Pituitary GH-Secreting Adenomas: Role of Scaffold Proteins and Implications for Pharmacological Resistance. Horm Metab Res 2017; 49:259-268. [PMID: 27632151 DOI: 10.1055/s-0042-116025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
AbstractSomatostatin receptor type 2 (SSTR2), together with SSTR5, represents the main
target of medical treatment for growth hormone (GH)-secreting pituitary tumors,
since it is expressed in most of these tumors and exerts both antiproliferative
and cytostatic effects, and reduces hormone secretion, as well. However,
clinical practice indicates a great variability in the frequency and entity of
favorable responses of acromegalic patients to long-acting somatostatin
analogues (SSAs), but the molecular mechanisms regulating this pharmacological
resistance are not completely understood. So far, several potentially implied
mechanisms have been suggested, including impaired expression of SSTRs, or
post-receptor signal transduction alterations. More recently, new studies
exploited the molecular factors involved in SSTRs intracellular trafficking
regulation, this being a critical point for the modulation of the available
active G-coupled receptors (GPCRs) amount at the cell surface. In this respect,
the role of the scaffold proteins such as β-arrestins, and the cytoskeleton
protein Filamin A (FLNA), have become of relevant importance for GH-secreting
pituitary tumors. In fact, β-arrestins are linked to SSTR2 desensitization and
internalization, and FLNA is able to regulate SSTR2 trafficking and stability at
the plasma membrane. Therefore, the present review will summarize emerging
evidence highlighting the role of β-arrestins and FLNA, as possible novel
players in the modulation of agonist activated-SSTR2 receptor trafficking and
response in GH-secreting pituitary tumors.
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Affiliation(s)
- D Treppiedi
- Endocrine Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico; Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - E Peverelli
- Endocrine Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico; Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - E Giardino
- Endocrine Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico; Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - E Ferrante
- Endocrine Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico; Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - D Calebiro
- Institute of Pharmacology and Toxicology, University of Würzburg, and Rudolf Virchow Center, Bio-Imaging Center, Würzburg, Germany
| | - A Spada
- Endocrine Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico; Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - G Mantovani
- Endocrine Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico; Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
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30
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Yang Z, Yang F, Zhang D, Liu Z, Lin A, Liu C, Xiao P, Yu X, Sun JP. Phosphorylation of G Protein-Coupled Receptors: From the Barcode Hypothesis to the Flute Model. Mol Pharmacol 2017; 92:201-210. [DOI: 10.1124/mol.116.107839] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2016] [Accepted: 02/23/2017] [Indexed: 12/21/2022] Open
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31
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Zhang X, Le HT, Zhang X, Zheng M, Choi BG, Kim KM. Palmitoylation on the carboxyl terminus tail is required for the selective regulation of dopamine D 2 versus D 3 receptors. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:2152-2162. [DOI: 10.1016/j.bbamem.2016.06.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 06/09/2016] [Accepted: 06/22/2016] [Indexed: 11/15/2022]
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32
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Zheng M, Zhang X, Min C, Choi BG, Oh IJ, Kim KM. Functional Regulation of Dopamine D₃ Receptor through Interaction with PICK1. Biomol Ther (Seoul) 2016; 24:475-81. [PMID: 27169823 PMCID: PMC5012871 DOI: 10.4062/biomolther.2016.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Revised: 03/10/2016] [Accepted: 03/17/2016] [Indexed: 11/10/2022] Open
Abstract
PICK1, a PDZ domain-containing protein, is known to increase the reuptake activities of dopamine transporters by increasing their expressions on the cell surface. Here, we report a direct and functional interaction between PICK1 and dopamine D3 receptors (D3R), which act as autoreceptors to negatively regulate dopaminergic neurons. PICK1 colocalized with both dopamine D2 receptor (D2R) and D3R in clusters but exerted different functional influences on them. The cell surface expression, agonist affinity, endocytosis, and signaling of D2R were unaffected by the coexpression of PICK1. On the other hand, the surface expression and tolerance of D3R were inhibited by the coexpression of PICK1. These findings show that PICK1 exerts multiple effects on D3R functions.
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Affiliation(s)
- Mei Zheng
- Pharmacology Laboratory, College of Pharmacy, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Xiaohan Zhang
- Pharmacology Laboratory, College of Pharmacy, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Chengchun Min
- Pharmacology Laboratory, College of Pharmacy, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Bo-Gil Choi
- Medicinal Chemistry Laboratory, College of Pharmacy, Chonnam National University, Gwangju 61186, Republic of Korea
| | - In-Joon Oh
- Physical Pharmacy 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
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33
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Zhang X, Choi BG, Kim KM. Roles of Dopamine D₂ Receptor Subregions in Interactions with β-Arrestin2. Biomol Ther (Seoul) 2016; 24:517-22. [PMID: 27068263 PMCID: PMC5012877 DOI: 10.4062/biomolther.2015.198] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Revised: 12/24/2015] [Accepted: 01/05/2016] [Indexed: 01/04/2023] Open
Abstract
β-Arrestins are one of the protein families that interact with G protein-coupled receptors (GPCRs). The roles of β-arrestins are multifaceted, as they mediate different processes including receptor desensitization, endocytosis, and G protein-independent signaling. Thus, determining the GPCR regions involved in the interactions with β-arrestins would be a preliminary step in understanding the molecular mechanisms involved in the selective direction of each function. In the current study, we determined the roles of the N-terminus, intracellular loops, and C-terminal tail of a representative GPCR in the interaction with β-arrestin2. For this, we employed dopamine D2 and D3 receptors (D2R and D3R, respectively), since they display distinct agonist-induced interactions with β-arrestins. Our results showed that the second and third intracellular loops of D2R are involved in the agonist-induced translocation of β-arrestins toward plasma membranes. In contrast, the N- and C-termini of D2R exerted negative effects on the basal interaction with β-arrestins.
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Affiliation(s)
- Xiaohan Zhang
- Pharmacology Laboratory, College of Pharmacy, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Bo-Gil Choi
- Medicinal Chemistry 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
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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.
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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.
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35
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Zhang X, Sun N, Zheng M, Kim KM. Clathrin-mediated endocytosis is responsible for the lysosomal degradation of dopamine D3 receptor. Biochem Biophys Res Commun 2016; 476:245-251. [PMID: 27240955 DOI: 10.1016/j.bbrc.2016.05.104] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Accepted: 05/20/2016] [Indexed: 11/30/2022]
Abstract
GRK2-/β-Arrestin- and PKA-/PKC-mediated desensitization, internalization, and degradation are three representative pathways for regulating G protein-coupled receptors (GPCRs). Compared with GRK2/β-arrestin-mediated ones, functional relationship among the aforementioned three regulatory processes mediated by PKA/PKC is less clear. Dopamine D3 receptor (D3R), a major target of currently available antipsychotic drugs, is a typical GPCR that selectively undergoes PKC-mediated regulation. In the present study, we examined PKC-mediated internalization of D3R in correlation with its roles in desensitization and degradation. Our results showed that the kinase activity of PKCβII and the 229th and 257th serine residues of D3R were required for PKC-mediated desensitization, internalization, and degradation of D3R. PMA treatment ubiquitinated D3R and induced its degradation through lysosomal pathway. Blockade of clathrin-mediated internalization inhibited PKC-mediated lysosomal degradation of D3R but did not affect its desensitization. These results suggested that PKC-mediated phosphorylation of D3R involved clathrin-mediated internalization, which was important for the lysosomal degradation of D3R.
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Affiliation(s)
- Xiaohan Zhang
- Department of Pharmacology, College of Pharmacy, Chonnam National University, GwangJu 61186, Republic of Korea
| | - Ningning Sun
- Department of Pharmacology, College of Pharmacy, Chonnam National University, GwangJu 61186, Republic of Korea
| | - Mei Zheng
- Department of Pharmacology, College of Pharmacy, Chonnam National University, GwangJu 61186, Republic of Korea
| | - Kyeong-Man Kim
- Department of Pharmacology, College of Pharmacy, Chonnam National University, GwangJu 61186, Republic of Korea.
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36
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Zheng M, Zhang X, Sun N, Min C, Zhang X, Kim KM. RalA employs GRK2 and β-arrestins for the filamin A-mediated regulation of trafficking and signaling of dopamine D2 and D3 receptor. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:2072-83. [PMID: 27188791 DOI: 10.1016/j.bbamcr.2016.05.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 05/10/2016] [Accepted: 05/13/2016] [Indexed: 12/13/2022]
Abstract
Filamin A (FLNA) is known to act as platform for the signaling and intracellular trafficking of various GPCRs including dopamine D2 and D3 receptors (D2R, D3R). To understand molecular mechanisms involved in the FLNA-mediated regulation of D2R and D3R, comparative studies were conducted on the signaling and intracellular trafficking of the D2R and D3R in FLNA-knockdown cells, with a specific focus on the roles of the proteins that interact with FLNA and the D2R and D3R. Lowering the level of cellular FLNA caused an elevation in RalA activity and resulted in selective interference with the normal intracellular trafficking and signaling of the D2R and D3R, through GRK2 and β-arrestins, respectively. Knockdown of FLNA or coexpression of active RalA interfered with the recycling of the internalized D2R and resulted in the development of receptor tolerance. Active RalA was found to interact with GRK2 to sequester it from D2R. Knockdown of FLNA or coexpression of active RalA prevented D3R from coupling with G protein. The selective involvement of GRK2- and β-arrestins in the RalA-mediated cellular processes of the D2R and D3R was achieved via their different modes of interactions with the receptor and their distinct functional roles in receptor regulation. Our results show that FLNA is a multi-functional protein that acts as a platform on which D2R and D3R can interact with various proteins, through which selective regulation of these receptors occurs in combination with GRK2 and β-arrestins.
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Affiliation(s)
- Mei Zheng
- Department of Pharmacology, College of Pharmacy, Drug Development Research Institute, Chonnam National University, Gwang-Ju 500-757, Republic of Korea
| | - Xiaohan Zhang
- Department of Pharmacology, College of Pharmacy, Drug Development Research Institute, Chonnam National University, Gwang-Ju 500-757, Republic of Korea
| | - NingNing Sun
- Department of Pharmacology, College of Pharmacy, Drug Development Research Institute, Chonnam National University, Gwang-Ju 500-757, Republic of Korea
| | - Chengchun Min
- Department of Pharmacology, College of Pharmacy, Drug Development Research Institute, Chonnam National University, Gwang-Ju 500-757, Republic of Korea
| | - Xiaowei Zhang
- Department of Pharmacology, College of Pharmacy, Drug Development Research Institute, Chonnam National University, Gwang-Ju 500-757, Republic of Korea
| | - Kyeong-Man Kim
- Department of Pharmacology, College of Pharmacy, Drug Development Research Institute, Chonnam National University, Gwang-Ju 500-757, Republic of Korea.
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Dotson D, Woodruff EA, Villalta F, Dong X. Filamin A Is Involved in HIV-1 Vpu-mediated Evasion of Host Restriction by Modulating Tetherin Expression. J Biol Chem 2016; 291:4236-46. [PMID: 26742839 DOI: 10.1074/jbc.m115.708123] [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: 12/02/2015] [Indexed: 11/06/2022] Open
Abstract
Tetherin, also known as bone marrow stromal antigen 2 (BST-2), inhibits the release of a wide range of enveloped viruses, including human immunodeficiency virus, type 1 (HIV-1) by directly tethering nascent virions to the surface of infected cells. The HIV-1 accessary protein Vpu counteracts tetherin restriction via sequestration, down-regulation, and/or displacement mechanisms to remove tetherin from sites of virus budding. However, the exact mechanism of Vpu-mediated antagonism of tetherin restriction remains to be fully understood. Here we report a novel role for the actin cross-linking regulator filamin A (FLNa) in Vpu anti-tetherin activities. We demonstrate that FLNa associates with tetherin and that FLNa modulates tetherin turnover. FLNa deficiency was found to enhance cell surface and steady-state levels of tetherin expression. In contrast, we observed that overexpression of FLNa reduced tetherin expression levels both on the plasma membrane and in intracellular compartments. Although FLNb shows high amino acid sequence similarity with FLNa, we reveal that only FLNa, but not FLNb, plays an essential role in tetherin turnover. We further showed that FLNa deficiency inhibited Vpu-mediated enhancement of virus release through interfering with the activity of Vpu to down-regulate cellular tetherin. Taken together, our studies suggest that Vpu hijacks the FLNa function in the modulation of tetherin to neutralize the antiviral factor tetherin. These findings may provide novel strategies for the treatment of HIV-1 infection.
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Affiliation(s)
- Dominique Dotson
- From the Department of Microbiology and Immunology and Center for AIDS Health Disparities Research, School of Medicine, Meharry Medical College, Nashville, Tennessee 37208
| | - Elvin A Woodruff
- From the Department of Microbiology and Immunology and Center for AIDS Health Disparities Research, School of Medicine, Meharry Medical College, Nashville, Tennessee 37208
| | - Fernando Villalta
- From the Department of Microbiology and Immunology and Center for AIDS Health Disparities Research, School of Medicine, Meharry Medical College, Nashville, Tennessee 37208
| | - Xinhong Dong
- From the Department of Microbiology and Immunology and Center for AIDS Health Disparities Research, School of Medicine, Meharry Medical College, Nashville, Tennessee 37208
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Pons M, Izquierdo I, Andreu-Carbó M, Garrido G, Planagumà J, Muriel O, Geli MI, Aragay AM. Regulation of chemokine receptor CCR2 recycling by filamin a phosphorylation. J Cell Sci 2016; 130:490-501. [DOI: 10.1242/jcs.193821] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 11/18/2016] [Indexed: 12/20/2022] Open
Abstract
Proper endosomal trafficking of ligand-activated G protein-coupled receptors (GPCRs) is essential to spatiotemporally tune their physiological responses. For the monocyte chemoattractant receptor 2 (CCR2B), endocytic recycling is important to sustain monocyte migration; while filamin A (FLNa) is essential for CCL2-induced monocyte migration. Here, we analyze the role of FLNa in the trafficking of CCR2B along the endocytic pathway. In FLNa knockdown cells, activated CCR2B accumulated in enlarged EEA-1-positive endosomes, which exhibited slow movement and fast fluorescence recovery, suggesting an imbalance between receptor entry and exit rates. Utilizing super-resolution microscopy, we observed that FLNa-GFP, CCR2B and β2-adrenergic receptor (β2AR) were present in actin-enriched endosomal microdomains. Depletion of FLNa decreased CCR2B association with these microdomains and concomitantly delayed CCR2B endosomal traffic, without apparently affecting the number of microdomains. Interestingly, CCR2B and β2AR signaling induced phosphorylation of FLNa at S2152 and this phosphorylation event was contributes to sustain receptor recycling. Thus, our data strongly suggest that CCR2B and β2AR signals to FLNa to stimulate its endocytosis and recycling to the plasma membrane.
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Affiliation(s)
- Mònica Pons
- Molecular Biology Institute of Barcelona (IBMB), Spanish National Research Council (CSIC), 08028 Barcelona, Spain
| | - Ismael Izquierdo
- Molecular Biology Institute of Barcelona (IBMB), Spanish National Research Council (CSIC), 08028 Barcelona, Spain
| | - Mireia Andreu-Carbó
- Molecular Biology Institute of Barcelona (IBMB), Spanish National Research Council (CSIC), 08028 Barcelona, Spain
| | - Georgina Garrido
- Molecular Biology Institute of Barcelona (IBMB), Spanish National Research Council (CSIC), 08028 Barcelona, Spain
- Present addresse: Centre for Genomic Regulation (CRG), 08003 Barcelona, Spain
| | - Jesús Planagumà
- Department of Biomedicine, University of Bergen, Bergen, Norway
- Present addresse: Department of Neuroimmunology, IDIBAPS, Barcelona, Spain
| | - Olivia Muriel
- Centro Nacional de Investigaciones Cardiovasculares, 28029 Madrid, Spain
| | - M. Isabel Geli
- Molecular Biology Institute of Barcelona (IBMB), Spanish National Research Council (CSIC), 08028 Barcelona, Spain
| | - Anna M. Aragay
- Molecular Biology Institute of Barcelona (IBMB), Spanish National Research Council (CSIC), 08028 Barcelona, Spain
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Zheng M, Zhang X, Guo S, Zhang X, Choi HJ, Lee MY, Kim KM. PKCβII inhibits the ubiquitination of β-arrestin2 in an autophosphorylation-dependent manner. FEBS Lett 2015; 589:3929-37. [DOI: 10.1016/j.febslet.2015.10.031] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 09/07/2015] [Accepted: 10/23/2015] [Indexed: 01/19/2023]
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Kassel S, Schwed JS, Stark H. Dopamine D3 receptor agonists as pharmacological tools. Eur Neuropsychopharmacol 2015; 25:1480-99. [PMID: 25498414 DOI: 10.1016/j.euroneuro.2014.11.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 09/23/2014] [Accepted: 11/04/2014] [Indexed: 01/10/2023]
Abstract
Dysregulation of the dopaminergic innervation in the central nervous system plays a key role in different neurological disorders like Parkinson´s disease, restless legs syndrome, schizophrenia etc. Although dopamine D3 receptors have been recognized as an important target in these diseases, their full pharmacological properties need further investigations. With focus on dopamine D3 receptor full agonists, this review has divided the ergoline and non-ergoline ligands in dissimilar chemical subclasses describing their pharmacodynamic properties on different related receptors, on species differences and their functional properties on different signaling mechanism. This is combined with a short description of structure-activity relationships for each class. Therefore, this overview should support the rational choice for the optimal compound selection based on affinity, selectivity and efficacy data in biochemical and pharmacological studies.
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Affiliation(s)
- S Kassel
- Heinrich-Heine-University, Universitaetsstr. 1, 40225 Duesseldorf, Germany
| | - J S Schwed
- Heinrich-Heine-University, Universitaetsstr. 1, 40225 Duesseldorf, Germany
| | - H Stark
- Heinrich-Heine-University, Universitaetsstr. 1, 40225 Duesseldorf, Germany.
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Min C, Zheng M, Zhang X, Guo S, Kwon KJ, Shin CY, Kim HS, Cheon SH, Kim KM. N-linked Glycosylation on the N-terminus of the dopamine D2 and D3 receptors determines receptor association with specific microdomains in the plasma membrane. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1853:41-51. [PMID: 25289757 DOI: 10.1016/j.bbamcr.2014.09.024] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 08/30/2014] [Accepted: 09/29/2014] [Indexed: 10/24/2022]
Abstract
Numerous G protein-coupled receptors (GPCRs) are glycosylated at extracellular regions. The regulatory roles of glycosylation on receptor function vary across receptor types. In this study, we used the dopamine D₂and D₃receptors as an experimental model to understand the underlying principles governing the functional roles of glycosylation. We used the pharmacological inhibitor, tunicamycin, to inhibit glycosylation, generated chimeric D₂and D₃receptors by swapping their respective N-termini, and produced the glycosylation site mutant D₂and D₃receptors to study the roles of glycosylation on receptor functions, including cell surface expression, signaling, and internalization through specific microdomains. Our results demonstrate that glycosylation on the N-terminus of the D₃ receptor is involved in the development of desensitization and proper cell surface expression. In addition, glycosylation on the N-terminus mediates the internalization of D₂and D₃receptors within the caveolae and clathrin-coated pit microdomains of the plasma membrane, respectively, by regulating receptor interactions with caveolin-1 and clathrin. In conclusion, this study shows for the first time that glycosylation on the N-terminus of GPCRs is involved in endocytic pathway selection through specific microdomains. These data suggest that changes in the cellular environment that influence posttranslational modification could be an important determinant of intracellular GPCR trafficking.
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Affiliation(s)
- Chengchun Min
- Department of Pharmacology, College of Pharmacy, Chonnam National University, Gwang-Ju, Republic of Korea
| | - Mei Zheng
- Department of Pharmacology, College of Pharmacy, Chonnam National University, Gwang-Ju, Republic of Korea
| | - Xiaohan Zhang
- Department of Pharmacology, College of Pharmacy, Chonnam National University, Gwang-Ju, Republic of Korea
| | - Shuohan Guo
- Department of Pharmacology, College of Pharmacy, Chonnam National University, Gwang-Ju, Republic of Korea
| | - Kyoung-Ja Kwon
- Department of Pharmacology, College of Medicine, Konkuk University, Seoul, Republic of Korea
| | - Chan Young Shin
- Department of Pharmacology, College of Medicine, Konkuk University, Seoul, Republic of Korea
| | - Hyeong-Suk Kim
- Department of Forensic Medicine, College of Medicine, Chonnam National University, Gwang-Ju, Republic of Korea
| | - Seung Hoon Cheon
- Department of Medicinal Chemistry, College of Pharmacy, Chonnam National University, Gwang-Ju, Republic of Korea
| | - Kyeong-Man Kim
- Department of Pharmacology, College of Pharmacy, Chonnam National University, Gwang-Ju, Republic of Korea.
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Min C, Zheng M, Zhang X, Caron MG, Kim KM. Novel roles for β-arrestins in the regulation of pharmacological sequestration to predict agonist-induced desensitization of dopamine D3 receptors. Br J Pharmacol 2014; 170:1112-29. [PMID: 23992580 DOI: 10.1111/bph.12357] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Revised: 07/24/2013] [Accepted: 08/18/2013] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND AND PURPOSE In addition to typical GPCR kinase (GRK)-/β-arrestin-dependent internalization, dopamine D3 receptor employed an additional GRK-independent sequestration pathway. In this study, we investigated the molecular mechanism of this novel sequestration pathway. EXPERIMENTAL APPROACH Radioligand binding, flow cytometry and cell surface biotinylation assay were used to characterize trafficking properties of D2 and D3 receptors. Serine/threonine and N-linked glycosylation mutants of the D3 receptor were utilized to locate receptor regions involved in pharmacological sequestration and desensitization. Various point mutants of the D2 and D3 receptors, whose sequestration and desensitization properties were altered, were combined with knockdown cells of GRKs or β-arrestins to functionally correlate pharmacological sequestration and desensitization. KEY RESULTS The D3 receptor, but not the D2 receptor, showed characteristic trafficking behaviour in which receptors were shifted towards the more hydrophobic domains within the plasma membrane without translocation into other intracellular compartments. Among various amino acid residues tested, S145/S146, C147 and N12/19 were involved in pharmacological sequestration and receptor desensitization. Both pharmacological sequestration and desensitization of D3 receptor required β-arrestins, and functional relationship was observed between two processes when it was tested for D3 receptor variants and agonists. CONCLUSIONS AND IMPLICATIONS Pharmacological sequestration of D3 receptor accompanies movement of cell surface receptors into a more hydrophobic fraction within the plasma membrane and renders D3 receptor inaccessible to hydrophilic ligands. Pharmacological sequestration is correlated with desensitization of the D3 receptor in a Gβγ- and β-arrestin-dependent manner. This study provides new insights into molecular mechanism governing GPCR trafficking and desensitization.
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Affiliation(s)
- C Min
- Department of Pharmacology, College of Pharmacy, Drug Development Research Institute, Chonnam National University, Gwang-Ju, 500-757, Korea
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The influence of different cellular environments on PET radioligand binding: an application to D2/3-dopamine receptor imaging. Neuropharmacology 2014; 85:305-13. [PMID: 24910074 PMCID: PMC4109028 DOI: 10.1016/j.neuropharm.2014.05.040] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2014] [Revised: 05/01/2014] [Accepted: 05/26/2014] [Indexed: 01/10/2023]
Abstract
Various D2/3 receptor PET radioligands are sensitive to endogenous dopamine release in vivo. The Occupancy Model is generally used to interpret changes in binding observed in in vivo competition binding studies; an Internalisation Hypothesis may also contribute to these changes in signal. Extension of in vivo competition imaging to other receptor systems has been relatively unsuccessful. A greater understanding of the cellular processes underlying signal changes following endogenous neurotransmitter release may help translate this imaging paradigm to other receptor systems. To investigate the Internalisation Hypothesis we assessed the effects of different cellular environments, representative of those experienced by a receptor following agonist-induced internalisation, on the binding of three D2/3 PET ligands with previously reported sensitivities to endogenous dopamine in vivo, namely [3H]spiperone, [3H]raclopride and [3H]PhNO. Furthermore, we determined the contribution of each cellular compartment to total striatal binding for these D2/3 ligands. These studies suggest that sensitivity to endogenous dopamine release in vivo is related to a decrease in affinity in the endosomal environment compared with those found at the cell surface. In agreement with these findings we also demonstrate that ∼25% of total striatal binding for [3H]spiperone originates from sub-cellular, microsomal receptors, whereas for [3H]raclopride and [3H]PhNO, this fraction is lower, representing ∼14% and 17%, respectively. This pharmacological approach is fully translatable to other receptor systems. Assessment of affinity shifts in different cellular compartments may play a crucial role for understanding if a radioligand is sensitive to endogenous release in vivo, for not just the D2/3, but other receptor systems. The internalisation hypothesis was investigated in relation to D2/3 receptor PET ligand binding. KD and Bmax were determined for [3H]Raclopride, PhNO and Spiperone in different cellular buffers. The cellular distribution of [3H]Raclopride, PhNO and Spiperone binding was also determined. Reductions in KD were observed in the endosomal condition in the following order PhNO > Raclopride > Spiperone. KD shifts in different cellular compartments may predict sensitivity to neurotransmitter release in vivo.
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Noam Y, Ehrengruber MU, Koh A, Feyen P, Manders EMM, Abbott GW, Wadman WJ, Baram TZ. Filamin A promotes dynamin-dependent internalization of hyperpolarization-activated cyclic nucleotide-gated type 1 (HCN1) channels and restricts Ih in hippocampal neurons. J Biol Chem 2014; 289:5889-903. [PMID: 24403084 PMCID: PMC3937658 DOI: 10.1074/jbc.m113.522060] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Revised: 12/27/2013] [Indexed: 11/06/2022] Open
Abstract
The actin-binding protein filamin A (FLNa) regulates neuronal migration during development, yet its roles in the mature brain remain largely obscure. Here, we probed the effects of FLNa on the regulation of ion channels that influence neuronal properties. We focused on the HCN1 channels that conduct Ih, a hyperpolarization-activated current crucial for shaping intrinsic neuronal properties. Whereas regulation of HCN1 channels by FLNa has been observed in melanoma cell lines, its physiological relevance to neuronal function and the underlying cellular pathways that govern this regulation remain unknown. Using a combination of mutational, pharmacological, and imaging approaches, we find here that FLNa facilitates a selective and reversible dynamin-dependent internalization of HCN1 channels in HEK293 cells. This internalization is accompanied by a redistribution of HCN1 channels on the cell surface, by accumulation of the channels in endosomal compartments, and by reduced Ih density. In hippocampal neurons, expression of a truncated dominant-negative FLNa enhances the expression of native HCN1. Furthermore, acute abrogation of HCN1-FLNa interaction in neurons, with the use of decoy peptides that mimic the FLNa-binding domain of HCN1, abolishes the punctate distribution of HCN1 channels in neuronal cell bodies, augments endogenous Ih, and enhances the rebound-response ("voltage-sag") of the neuronal membrane to transient hyperpolarizing events. Together, these results support a major function of FLNa in modulating ion channel abundance and membrane trafficking in neurons, thereby shaping their biophysical properties and function.
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Affiliation(s)
- Yoav Noam
- From the Departments of Anatomy/Neurobiology and Pediatrics and
| | | | - Annie Koh
- From the Departments of Anatomy/Neurobiology and Pediatrics and
| | | | - Erik M. M. Manders
- van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, 1098XH Amsterdam, The Netherlands
| | - Geoffrey W. Abbott
- Pharmacology, University of California at Irvine, Irvine, California 92697-4475 and
| | | | - Tallie Z. Baram
- From the Departments of Anatomy/Neurobiology and Pediatrics and
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McGovern KW, DeFea KA. Molecular mechanisms underlying beta-arrestin-dependent chemotaxis and actin-cytoskeletal reorganization. Handb Exp Pharmacol 2014; 219:341-359. [PMID: 24292838 DOI: 10.1007/978-3-642-41199-1_17] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
β-Arrestins play a crucial role in cell migration downstream of multiple G-protein-coupled receptors (GPCRs) through multiple mechanisms. There is considerable evidence that β-arrestin-dependent scaffolding of actin assembly proteins facilitates the formation of a leading edge in response to a chemotactic signal. Conversely, there is substantial support for the hypothesis that β-arrestins facilitate receptor turnover through their ability to desensitize and internalize GPCRs. This chapter discusses both theories for β-arrestin-dependent chemotaxis in the context of recent studies, specifically addressing known actin assembly proteins regulated by β-arrestins, chemokine receptors, and signaling by chemotactic receptors.
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Affiliation(s)
- Kathryn W McGovern
- Biochemistry and Molecular Biology Graduate Program, University of California, Riverside, CA, USA
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Smith L, Litman P, Kohli E, Amick J, Page RC, Misra S, Liedtke CM. RACK1 interacts with filamin-A to regulate plasma membrane levels of the cystic fibrosis transmembrane conductance regulator. Am J Physiol Cell Physiol 2013; 305:C111-20. [PMID: 23636454 PMCID: PMC3725521 DOI: 10.1152/ajpcell.00026.2013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Accepted: 04/25/2013] [Indexed: 01/27/2023]
Abstract
Mutations in cystic fibrosis transmembrane regulator (CFTR), a chloride channel in the apical membranes of secretory epithelial cells, underlie the fatal genetic disorder cystic fibrosis. Certain CFTR mutations, including the common mutation ΔF508-CFTR, result in greatly decreased levels of active CFTR at the apical membrane. Direct interactions between CFTR and the cytoskeletal adaptors filamin-A (FlnA) and Na(+)/H(+) exchanger regulatory factor 1 (NHERF1) stabilize the expression and localization of CFTR at the plasma membrane. The scaffold protein receptor for activated C kinase 1 (RACK1) also stabilizes CFTR surface expression; however, RACK1 does not interact directly with CFTR and its mechanism of action is unknown. In the present study, we report that RACK1 interacts directly with FlnA in vitro and in a Calu-3 airway epithelial cell line. We mapped the interaction between RACK1 and FlnA to the WD4 and WD6 repeats of RACK1 and to a segment of the large rod domain of FlnA, consisting of immunoglobulin-like repeats 8-15. Disruption of the RACK1-FlnA interaction causes a reduction in CFTR surface levels. Our results suggest that a novel RACK1-FlnA interaction is an important regulator of CFTR surface localization.
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Affiliation(s)
- Laura Smith
- Willard Alan Bernbaum Center for Cystic Fibrosis Research, Case Western Reserve University, Cleveland, OH 44106, USA
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Cho DI, Zheng M, Min C, Kwon KJ, Shin CY, Choi HK, Kim KM. ARF6 and GASP-1 are post-endocytic sorting proteins selectively involved in the intracellular trafficking of dopamine D₂ receptors mediated by GRK and PKC in transfected cells. Br J Pharmacol 2013; 168:1355-74. [PMID: 23082996 PMCID: PMC3596642 DOI: 10.1111/bph.12025] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Revised: 09/07/2012] [Accepted: 09/28/2012] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE GPCRs undergo both homologous and heterologous regulatory processes in which receptor phosphorylation plays a critical role. The protein kinases responsible for each pathway are well established; however, other molecular details that characterize each pathway remain unclear. In this study, the molecular mechanisms that determine the differences in the functional roles and intracellular trafficking between homologous and PKC-mediated heterologous internalization pathways for the dopamine D₂ receptor were investigated. EXPERIMENTAL APPROACH All of the S/T residues located within the intracellular loops of D₂ receptor were mutated, and the residues responsible for GRK- and PKC-mediated internalization were determined in HEK-293 cells and SH-SY5Y cells. The functional role of receptor internalization and the cellular components that determine the post-endocytic fate of internalized D₂ receptors were investigated in the transfected cells. KEY RESULTS T134, T225/S228/S229 and S325 were involved in PKC-mediated D₂ receptor desensitization. S229 and adjacent S/T residues mediated the PKC-dependent internalization of D₂ receptors, which induced down-regulation and desensitization. S/T residues within the second intracellular loop and T225 were the major residues involved in GRK-mediated internalization of D₂ receptors, which induced receptor resensitization. ARF6 mediated the recycling of D₂ receptors internalized in response to agonist stimulation. In contrast, GASP-1 mediated the down-regulation of D₂ receptors internalized in a PKC-dependent manner. CONCLUSIONS AND IMPLICATIONS GRK- and PKC-mediated internalizations of D₂ receptors occur through different intracellular trafficking pathways and mediate distinct functional roles. Distinct S/T residues within D₂ receptors and different sorting proteins are involved in the dissimilar regulation of D₂ receptors by GRK2 and PKC.
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Affiliation(s)
- D I Cho
- Department of Pharmacology, College of Pharmacy, Drug Development Research Institute, Chonnam National University, Gwang-Ju, Korea
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Lee DK, Oh JH, Yang JH, Youn B, Shim YB, Shim I, Wang JQ, Choe ES. Protein kinase G linked to dopamine D3 receptors in the dorsal striatum controls dopamine release, ΔFosB expression and locomotor activity after repeated cocaine administration. Neurosci Lett 2013; 541:120-5. [PMID: 23428510 DOI: 10.1016/j.neulet.2013.02.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2012] [Revised: 01/29/2013] [Accepted: 02/04/2013] [Indexed: 01/11/2023]
Abstract
Protein kinase G (PKG) has been implicated in a variety of physiological functions including synaptic plasticity in the brain. This study investigated the involvement of dopamine D3 (D3) receptors in PKG-regulated dopamine release, long-term changes in gene expression and behavioral sensitization after repeated cocaine administration. Repeated systemic injections of cocaine (20mg/kg), once a day for seven consecutive days, increased extracellular dopamine concentrations in the dorsal striatum. Inhibition of neuronal nitric oxide synthase, cGMP or PKG, stimulation of D3 receptors, and simultaneous inhibition of each of them with D3 receptor stimulation decreased the repeated cocaine-induced increase in dopamine concentrations and locomotor activity. Similarly, inhibition of PKG and simultaneous inhibition of PKG with D3 receptor stimulation decreased ΔFosB immunoreactivity elevated by repeated cocaine administration, however stimulation of D3 receptors alone did not. These findings suggest that activation of PKG after repeated cocaine administration is more sensitive to interact with D3 receptors in the dopamine terminals than those in medium spiny neurons. This interaction may result in the development of behavioral sensitization by the upregulation of dopamine releases in the dorsal striatum.
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Affiliation(s)
- Dong Kun Lee
- Department of Biological Sciences, Pusan National University, 63-2 Pusandaehak-ro, Kumjeong-gu, Pusan 609-735, Republic of Korea
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Arrestins in actin reorganization and cell migration. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2013; 118:205-22. [PMID: 23764055 DOI: 10.1016/b978-0-12-394440-5.00008-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Arrestins have emerged as important regulators of actin reorganization and cell migration. Both in their classical roles as mediators of receptor desensitization and internalization, and in their newer role as signaling scaffolds, β-arrestins help orchestrate the cellular response to chemotactic signals. However, there is still a considerable amount to be learned about the precise molecular mechanisms underlying these processes. This review discusses how, by regulating receptor internalization and by scaffolding of signaling molecules in discrete cellular locations, arrestins facilitate gradient sensing and cytoskeletal reorganization, ultimately resulting in cell migration. In addition, putative new targets of β-arrestin regulation that may play important roles in cell migration are discussed, as continued research on these targets may provide important details to fill in the current gaps in our understanding of these processes.
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50
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Cho DI, Min C, Jung KS, Cheong SY, Zheng M, Cheong SJ, Oak MH, Cheong JH, Lee BK, Kim KM. The N-terminal region of the dopamine D2 receptor, a rhodopsin-like GPCR, regulates correct integration into the plasma membrane and endocytic routes. Br J Pharmacol 2012; 166:659-75. [PMID: 22117524 DOI: 10.1111/j.1476-5381.2011.01787.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND AND PURPOSE Functional roles of the N-terminal region of rhodopsin-like GPCR family remain unclear. Using dopamine D(2) and D(3) receptors as a model system, we probed the roles of the N-terminal region in the signalling, intracellular trafficking of receptor proteins, and explored the critical factors that determine the functionality of the N-terminal region. EXPERIMENTAL APPROACH The N-terminal region of the D(2) receptor was gradually shortened or switched with that of the D(3) receptor or a non-specific sequence (FLAG), or potential N-terminal glycosylation sites were mutated. Effects of these manipulations on surface expression, internalization, post-endocytic behaviours and signalling were determined. KEY RESULTS Shortening the N-terminal region of the D(2) receptor enhanced receptor internalization and impaired surface expression and signalling; ligand binding, desensitization and down-regulation were not affected but their association with a particular microdomain, caveolae, was disrupted. Replacement of critical residues within the N-terminal region with the FLAG epitope failed to restore surface expression but partially restored the altered internalization and signalling. When the N-terminal regions were switched between D(2) and D(3) receptors, cell surface expression pattern of each receptor was switched. Mutations of potential N-terminal glycosylation sites inhibited surface expression but enhanced internalization of D(2) receptors. CONCLUSIONS AND IMPLICATIONS Shortening of N-terminus or mutation of glycosylation sites located within the N-terminus enhanced receptor internalization but impaired the surface expression of D(2) receptors. The N-terminal region of the D(2) receptor, in a sequence-specific manner, controls the receptor's conformation and integration into the plasma membrane, which determine its subcellular localization, intracellular trafficking and signalling properties.
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Affiliation(s)
- D I Cho
- Department of Pharmacology, College of Pharmacy, Research Institute of Drug Development, Chonnam National University, Gwang-Ju, 500-757 Korea
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