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Chen G, Jin Y, Chu C, Zheng Y, Yang C, Chen Y, Zhu X. A cross-tissue transcriptome-wide association study reveals GRK4 as a novel susceptibility gene for COPD. Sci Rep 2024; 14:28438. [PMID: 39558015 PMCID: PMC11574126 DOI: 10.1038/s41598-024-80122-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2024] [Accepted: 11/15/2024] [Indexed: 11/20/2024] Open
Abstract
Chronic obstructive pulmonary disease (COPD) is a prevalent respiratory disorder with environmental factors being the primary risk determinants. However, genetic factors also substantially contribute to the susceptibility and progression of COPD. Although genome-wide association studies (GWAS) have identified several loci associated with COPD susceptibility, the specific pathogenic genes underlying these loci, along with their biological functions and roles within regulatory networks, remain unclear. This lack of clarity constrains our ability to achieve a deeper understanding of the genetic basis of COPD. This study leveraged the FinnGen R11 genetic dataset, comprising 21,617 cases and 372,627 controls, along with GTEx V8 eQTLs data to conduct a cross-tissue transcriptome-wide association study (TWAS). Initially, we performed a cross-tissue TWAS analysis using the Unified Test for Molecular Signatures (UTMOST), followed by validation of the UTMOST findings in single tissues using the Functional Summary-based Imputation (FUSION) method and conditional and joint (COJO) analyses of the identified genes. Subsequently, candidate susceptibility genes were screened using Multi-marker Analysis of Genomic Annotation (MAGMA). The causal relationship between these candidate genes and COPD was further evaluated through summary data-based Mendelian randomization (SMR), colocalization analysis, and Mendelian randomization (MR). Additionally, the identified results were validated against the COPD dataset in the GWAS Catalog (GCST90399694). GeneMANIA was employed to further explore the functional significance of these susceptibility genes. In the cross-tissue TWAS analysis (UTMOST), we identified 17 susceptibility genes associated with COPD. Among these, a novel susceptibility gene, G protein-coupled receptor kinase 4 (GRK4), was validated through single-tissue TWAS (FUSION) and MAGMA analyses, with further confirmation via SMR, MR, and colocalization analyses. Moreover, GRK4 was validated in an independent dataset. This study identifies GRK4 as a potential novel susceptibility gene for COPD, which may influence disease risk by exacerbating inflammatory responses. The findings address gaps in previous single-tissue GWAS studies, revealing consistent expression and potential function of GRK4 across different tissues. However, considering the study's limitations, further investigation and validation of GRK4's role in COPD are warranted.
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Affiliation(s)
- Guanglei Chen
- Guizhou University of Traditional Chinese Medicine, Guiyang, 550025, Guizhou, China
| | - Yaxian Jin
- The First Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, 550000, Guizhou, China
| | - Cancan Chu
- Guizhou University of Traditional Chinese Medicine, Guiyang, 550025, Guizhou, China
| | - Yuhao Zheng
- Guizhou University of Traditional Chinese Medicine, Guiyang, 550025, Guizhou, China
| | - Changfu Yang
- Guizhou University of Traditional Chinese Medicine, Guiyang, 550025, Guizhou, China
| | - Yunzhi Chen
- Guizhou University of Traditional Chinese Medicine, Guiyang, 550025, Guizhou, China
| | - Xing Zhu
- Guizhou University of Traditional Chinese Medicine, Guiyang, 550025, Guizhou, China.
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Liccardo D, Valletta A, Spagnuolo G, Vinciguerra C, Lauria MR, Perrotta A, Del Giudice C, De Luca F, Rengo G, Rengo S, Rengo C, Cannavo A. Porphyromonas gingivalis virulence factors induce toxic effects in SH-SY5Y neuroblastoma cells: GRK5 modulation as a protective strategy. J Biotechnol 2024; 393:7-16. [PMID: 39033880 DOI: 10.1016/j.jbiotec.2024.07.009] [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: 11/07/2023] [Revised: 07/02/2024] [Accepted: 07/14/2024] [Indexed: 07/23/2024]
Abstract
Periodontitis (PDS) is a chronic inflammatory disease initiated by a dysbiosis of oral pathogenic bacterial species, such as Porphyromonas gingivalis (Pg). These bacteria can penetrate the bloodstream, releasing various endo and exotoxins that fuel the infection, and stimulate toxic inflammation in different compartments, including the brain. However, the specific mechanisms by which PDS/Pg contribute to brain disorders, such as Alzheimer's disease (AD), remain unclear. This study assessed the effects of Pg's virulence factors - lipopolysaccharide (LPS-Pg) and gingipains (gps) K (Kgp) and Rgp - on SH-SY5Y cells. Our results demonstrated that LPS-Pg activated signaling through the Toll-like receptor (TLR)-2/4 induced a significant downregulation of G protein-coupled receptor kinase 5 (GRK5). Additionally, LPS-Pg stimulation resulted in a robust increase in Tau phosphorylation (pTau) and p53 levels, while causing a marked reduction in Bcl2 and increased cell death compared to unstimulated cells (Ns). LPS-Pg also elevated inducible nitric oxide synthase (iNOS) expression, leading to oxidative damage. In cells overexpressing GRK5 via Adenovirus, LPS-Pg failed to increase iNOS and pTau levels compared to GFP control cells. High GRK5 levels also prevented the nuclear accumulation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB). Furthermore, the overexpression of a GRK5 mutant form lacking the nuclear localization signal (ΔNLS) nearly abolished LPS-Pg induced p53 and iNOS upregulation. Finally, we tested whether Kgp and Rgp mediated similar effects and our data showed that both gps caused a marked downregulation of GRK5 leading to increased p53 and pTau levels. In conclusion, this study provides further insight into the toxic effects elicited by Pg in cells and suggests that preventing GRK5 deficiency may be a valid strategy to mitigate Pg-induced toxic effects (i.e. cell death, oxidative damage, and Tau hyperphosphorylation) in SH-SY5Y cells, which are typical molecular hallmarks of neurodegenerative disorders.
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Affiliation(s)
- Daniela Liccardo
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, University of Naples Federico II, Naples 80131, Italy
| | - Alessandra Valletta
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, University of Naples Federico II, Naples 80131, Italy
| | - Gianrico Spagnuolo
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, University of Naples Federico II, Naples 80131, Italy
| | - Caterina Vinciguerra
- Department of Translational Medical Sciences, University of Naples Federico II, Naples 80131, Italy
| | - Maria Rosaria Lauria
- Department of Translational Medical Sciences, University of Naples Federico II, Naples 80131, Italy
| | - Alessia Perrotta
- Department of Translational Medical Sciences, University of Naples Federico II, Naples 80131, Italy
| | - Carmela Del Giudice
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, University of Naples Federico II, Naples 80131, Italy
| | - Francesca De Luca
- Department of Translational Medical Sciences, University of Naples Federico II, Naples 80131, Italy
| | - Giuseppe Rengo
- Department of Translational Medical Sciences, University of Naples Federico II, Naples 80131, Italy; Istituti Clinici Scientifici Maugeri IRCCS - Scientific Institute of Telese Terme (BN), Italy
| | - Sandro Rengo
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, University of Naples Federico II, Naples 80131, Italy
| | - Carlo Rengo
- Dental School of Periodontology, University of Naples Federico II, Napoli 80127, Italy.
| | - Alessandro Cannavo
- Department of Translational Medical Sciences, University of Naples Federico II, Naples 80131, Italy.
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3
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Gergs U, Wackerhagen S, Fuhrmann T, Schäfer I, Neumann J. Further investigations on the influence of protein phosphatases on the signaling of muscarinic receptors in the atria of mouse hearts. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2024; 397:5731-5743. [PMID: 38308688 PMCID: PMC11329414 DOI: 10.1007/s00210-024-02973-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 01/21/2024] [Indexed: 02/05/2024]
Abstract
The vagal regulation of cardiac function involves acetylcholine (ACh) receptor activation followed by negative chronotropic and negative as well as positive inotropic effects. The resulting signaling pathways may include Gi/o protein-coupled reduction in adenylyl cyclase (AC) activity, direct Gi/o protein-coupled activation of ACh-activated potassium current (IKACh), inhibition of L-type calcium ion channels, and/or the activation of protein phosphatases. Here, we studied the role of the protein phosphatases 1 (PP1) and 2A (PP2A) for muscarinic receptor signaling in isolated atrial preparations of transgenic mice with cardiomyocyte-specific overexpression of either the catalytic subunit of PP2A (PP2A-TG) or the inhibitor-2 (I2) of PP1 (I2-TG) or in double transgenic mice overexpressing both PP2A and I2 (DT). In mouse left atrial preparations, carbachol (CCh), cumulatively applied (1 nM-10 µM), exerted at low concentrations a negative inotropic effect followed by a positive inotropic effect at higher concentrations. This biphasic effect was noted with CCh alone as well as when CCh was added after β-adrenergic pre-stimulation with isoprenaline (1 µM). Whereas the response to stimulation of β-adrenoceptors or adenosine receptors (used as controls) was changed in PP2A-TG, the response to CCh was unaffected in atrial preparations from all transgenic models studied here. Therefore, the present data tentatively indicate that neither PP2A nor PP1, but possibly other protein phosphatases, is involved in the muscarinic receptor-induced inotropic and chronotropic effects in the mouse heart.
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Affiliation(s)
- Ulrich Gergs
- Institut Für Pharmakologie Und Toxikologie, Medizinische Fakultät, Martin-Luther-Universität Halle-Wittenberg, D-06097, Magdeburger Str. 4, 06112, Halle, Germany.
| | - Silke Wackerhagen
- Institut Für Pharmakologie Und Toxikologie, Medizinische Fakultät, Martin-Luther-Universität Halle-Wittenberg, D-06097, Magdeburger Str. 4, 06112, Halle, Germany
| | - Tobias Fuhrmann
- Institut Für Pharmakologie Und Toxikologie, Medizinische Fakultät, Martin-Luther-Universität Halle-Wittenberg, D-06097, Magdeburger Str. 4, 06112, Halle, Germany
| | - Inka Schäfer
- Institut Für Pharmakologie Und Toxikologie, Medizinische Fakultät, Martin-Luther-Universität Halle-Wittenberg, D-06097, Magdeburger Str. 4, 06112, Halle, Germany
| | - Joachim Neumann
- Institut Für Pharmakologie Und Toxikologie, Medizinische Fakultät, Martin-Luther-Universität Halle-Wittenberg, D-06097, Magdeburger Str. 4, 06112, Halle, Germany
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4
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Ahmed MR, Zheng C, Dunning JL, Ahmed MS, Ge C, Pair FS, Gurevich VV, Gurevich EV. Arrestin-3-assisted activation of JNK3 mediates dopaminergic behavioral sensitization. Cell Rep Med 2024; 5:101623. [PMID: 38936368 PMCID: PMC11293330 DOI: 10.1016/j.xcrm.2024.101623] [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: 11/08/2023] [Revised: 04/15/2024] [Accepted: 06/05/2024] [Indexed: 06/29/2024]
Abstract
In rodents with unilateral ablation of neurons supplying dopamine to the striatum, chronic treatment with the dopamine precursor L-DOPA induces a progressive increase of behavioral responses, a process known as behavioral sensitization. This sensitization is blunted in arrestin-3 knockout mice. Using virus-mediated gene delivery to the dopamine-depleted striatum of these mice, we find that the restoration of arrestin-3 fully rescues behavioral sensitization, whereas its mutant defective in c-Jun N-terminal kinase (JNK) activation does not. A 25-residue arrestin-3-derived peptide that facilitates JNK3 activation in cells, expressed ubiquitously or selectively in direct pathway striatal neurons, also fully rescues sensitization, whereas an inactive homologous arrestin-2-derived peptide does not. Behavioral rescue is accompanied by the restoration of JNK3 activity, as reflected by JNK-dependent phosphorylation of the transcription factor c-Jun in the dopamine-depleted striatum. Thus, arrestin-3-assisted JNK3 activation in direct pathway neurons is a critical element of the molecular mechanism underlying sensitization upon dopamine depletion and chronic L-DOPA treatment.
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Affiliation(s)
- Mohamed R Ahmed
- Department of Pharmacology, Vanderbilt University, 2200 Pierce Avenue, PRB422, Nashville, TN 37232, USA; University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA; The University of Alabama at Birmingham, SHEL 121, 1825 University Boulevard, Birmingham, AL 35294-2182, USA
| | - Chen Zheng
- Department of Pharmacology, Vanderbilt University, 2200 Pierce Avenue, PRB422, Nashville, TN 37232, USA
| | - Jeffery L Dunning
- Contet Laboratory, Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Mohamed S Ahmed
- Department of Pharmacology, Vanderbilt University, 2200 Pierce Avenue, PRB422, Nashville, TN 37232, USA
| | - Connie Ge
- University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA
| | - F Sanders Pair
- The University of Alabama at Birmingham, SHEL 121, 1825 University Boulevard, Birmingham, AL 35294-2182, USA
| | - Vsevolod V Gurevich
- Department of Pharmacology, Vanderbilt University, 2200 Pierce Avenue, PRB422, Nashville, TN 37232, USA
| | - Eugenia V Gurevich
- Department of Pharmacology, Vanderbilt University, 2200 Pierce Avenue, PRB422, Nashville, TN 37232, USA.
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Tóth AD, Soltész-Katona E, Kis K, Guti V, Gilzer S, Prokop S, Boros R, Misák Á, Balla A, Várnai P, Turiák L, Ács A, Drahos L, Inoue A, Hunyady L, Turu G. ArreSTick motif controls β-arrestin-binding stability and extends phosphorylation-dependent β-arrestin interactions to non-receptor proteins. Cell Rep 2024; 43:114241. [PMID: 38758647 DOI: 10.1016/j.celrep.2024.114241] [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: 10/02/2023] [Revised: 03/11/2024] [Accepted: 05/01/2024] [Indexed: 05/19/2024] Open
Abstract
The binding and function of β-arrestins are regulated by specific phosphorylation motifs present in G protein-coupled receptors (GPCRs). However, the exact arrangement of phosphorylated amino acids responsible for establishing a stable interaction remains unclear. We employ a 1D sequence convolution model trained on GPCRs with established β-arrestin-binding properties. With this approach, amino acid motifs characteristic of GPCRs that form stable interactions with β-arrestins can be identified, a pattern that we name "arreSTick." Intriguingly, the arreSTick pattern is also present in numerous non-receptor proteins. Using proximity biotinylation assay and mass spectrometry analysis, we demonstrate that the arreSTick motif controls the interaction between many non-receptor proteins and β-arrestin2. The HIV-1 Tat-specific factor 1 (HTSF1 or HTATSF1), a nuclear transcription factor, contains the arreSTick pattern, and its subcellular localization is influenced by β-arrestin2. Our findings unveil a broader role for β-arrestins in phosphorylation-dependent interactions, extending beyond GPCRs to encompass non-receptor proteins as well.
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Affiliation(s)
- András Dávid Tóth
- Institute of Molecular Life Sciences, Centre of Excellence of the Hungarian Academy of Sciences, HUN-REN Research Centre for Natural Sciences, Magyar Tudósok krt. 2., 1117 Budapest, Hungary; Department of Internal Medicine and Haematology, Semmelweis University, Szentkirályi street 46, 1088 Budapest, Hungary
| | - Eszter Soltész-Katona
- Institute of Molecular Life Sciences, Centre of Excellence of the Hungarian Academy of Sciences, HUN-REN Research Centre for Natural Sciences, Magyar Tudósok krt. 2., 1117 Budapest, Hungary; Department of Physiology, Semmelweis University, Tűzoltó street 37-47, 1094 Budapest, Hungary
| | - Katalin Kis
- Department of Physiology, Semmelweis University, Tűzoltó street 37-47, 1094 Budapest, Hungary
| | - Viktor Guti
- Department of Physiology, Semmelweis University, Tűzoltó street 37-47, 1094 Budapest, Hungary
| | - Sharon Gilzer
- Department of Physiology, Semmelweis University, Tűzoltó street 37-47, 1094 Budapest, Hungary
| | - Susanne Prokop
- Department of Physiology, Semmelweis University, Tűzoltó street 37-47, 1094 Budapest, Hungary
| | - Roxána Boros
- Department of Physiology, Semmelweis University, Tűzoltó street 37-47, 1094 Budapest, Hungary
| | - Ádám Misák
- Department of Physiology, Semmelweis University, Tűzoltó street 37-47, 1094 Budapest, Hungary
| | - András Balla
- Department of Physiology, Semmelweis University, Tűzoltó street 37-47, 1094 Budapest, Hungary; HUN-REN SE Hungarian Research Network Laboratory of Molecular Physiology, Budapest, Hungary
| | - Péter Várnai
- Department of Physiology, Semmelweis University, Tűzoltó street 37-47, 1094 Budapest, Hungary; HUN-REN SE Hungarian Research Network Laboratory of Molecular Physiology, Budapest, Hungary
| | - Lilla Turiák
- Institute of Organic Chemistry, HUN-REN Research Centre for Natural Sciences, Magyar Tudósok krt. 2., 1117 Budapest, Hungary
| | - András Ács
- Institute of Organic Chemistry, HUN-REN Research Centre for Natural Sciences, Magyar Tudósok krt. 2., 1117 Budapest, Hungary
| | - László Drahos
- Institute of Organic Chemistry, HUN-REN Research Centre for Natural Sciences, Magyar Tudósok krt. 2., 1117 Budapest, Hungary
| | - Asuka Inoue
- Molecular and Cellular Biochemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - László Hunyady
- Institute of Molecular Life Sciences, Centre of Excellence of the Hungarian Academy of Sciences, HUN-REN Research Centre for Natural Sciences, Magyar Tudósok krt. 2., 1117 Budapest, Hungary; Department of Physiology, Semmelweis University, Tűzoltó street 37-47, 1094 Budapest, Hungary.
| | - Gábor Turu
- Institute of Molecular Life Sciences, Centre of Excellence of the Hungarian Academy of Sciences, HUN-REN Research Centre for Natural Sciences, Magyar Tudósok krt. 2., 1117 Budapest, Hungary; Department of Physiology, Semmelweis University, Tűzoltó street 37-47, 1094 Budapest, Hungary.
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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: 3] [Impact Index Per Article: 1.5] [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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Ahmed MR, Zheng C, Dunning JL, Ahmed MS, Ge C, Sanders Pair F, Gurevich VV, Gurevich EV. Arrestin-3-assisted activation of JNK3 mediates dopaminergic behavioral and signaling plasticity in vivo. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.27.564447. [PMID: 37961199 PMCID: PMC10634923 DOI: 10.1101/2023.10.27.564447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
In rodents with unilateral ablation of the substantia nigra neurons supplying dopamine to the striatum, chronic treatment with the dopamine precursor L-DOPA or dopamine agonists induces a progressive increase of behavioral responses, a process known as behavioral sensitization. The sensitization is blunted in arrestin-3 knockout mice. Using virus-mediated gene delivery to the dopamine-depleted striatum of arrestin-3 knockout mice, we found that the restoration of arrestin-3 fully rescued behavioral sensitization, whereas its mutant defective in JNK activation did not. A 25-residue arrestin-3-derived peptide that facilitates JNK3 activation in cells, expressed ubiquitously or selectively in the direct pathway striatal neurons, fully rescued sensitization, whereas an inactive homologous arrestin-2-derived peptide did not. Behavioral rescue was accompanied by the restoration of JNK3 activity and of JNK-dependent phosphorylation of the transcription factor c-Jun in the dopamine-depleted striatum. Thus, arrestin-3-dependent JNK3 activation in direct pathway neurons is a critical element of the molecular mechanism underlying sensitization.
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Affiliation(s)
- Mohamed R. Ahmed
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232
| | - Chen Zheng
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232
| | | | - Mohamed S. Ahmed
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232
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8
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Sánchez-Soto M, Boldizsar NM, Schardien KA, Madaras NS, Willette BKA, Inbody LR, Dasaro C, Moritz AE, Drube J, Haider RS, Free RB, Hoffman C, Sibley DR. G Protein-Coupled Receptor Kinase 2 Selectively Enhances β-Arrestin Recruitment to the D 2 Dopamine Receptor through Mechanisms That Are Independent of Receptor Phosphorylation. Biomolecules 2023; 13:1552. [PMID: 37892234 PMCID: PMC10605370 DOI: 10.3390/biom13101552] [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: 09/26/2023] [Revised: 10/16/2023] [Accepted: 10/18/2023] [Indexed: 10/29/2023] Open
Abstract
The D2 dopamine receptor (D2R) signals through both G proteins and β-arrestins to regulate important physiological processes, such as movement, reward circuitry, emotion, and cognition. β-arrestins are believed to interact with G protein-coupled receptors (GPCRs) at the phosphorylated C-terminal tail or intracellular loops. GPCR kinases (GRKs) are the primary drivers of GPCR phosphorylation, and for many receptors, receptor phosphorylation is indispensable for β-arrestin recruitment. However, GRK-mediated receptor phosphorylation is not required for β-arrestin recruitment to the D2R, and the role of GRKs in D2R-β-arrestin interactions remains largely unexplored. In this study, we used GRK knockout cells engineered using CRISPR-Cas9 technology to determine the extent to which β-arrestin recruitment to the D2R is GRK-dependent. Genetic elimination of all GRK expression decreased, but did not eliminate, agonist-stimulated β-arrestin recruitment to the D2R or its subsequent internalization. However, these processes were rescued upon the re-introduction of various GRK isoforms in the cells with GRK2/3 also enhancing dopamine potency. Further, treatment with compound 101, a pharmacological inhibitor of GRK2/3 isoforms, decreased β-arrestin recruitment and receptor internalization, highlighting the importance of this GRK subfamily for D2R-β-arrestin interactions. These results were recapitulated using a phosphorylation-deficient D2R mutant, emphasizing that GRKs can enhance β-arrestin recruitment and activation independently of receptor phosphorylation.
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Affiliation(s)
- Marta Sánchez-Soto
- Molecular Neuropharmacology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 35 Convent Drive, Bethesda, MD 20892, USA (R.B.F.)
| | - Noelia M. Boldizsar
- Molecular Neuropharmacology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 35 Convent Drive, Bethesda, MD 20892, USA (R.B.F.)
| | - Kayla A. Schardien
- Molecular Neuropharmacology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 35 Convent Drive, Bethesda, MD 20892, USA (R.B.F.)
| | - Nora S. Madaras
- Molecular Neuropharmacology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 35 Convent Drive, Bethesda, MD 20892, USA (R.B.F.)
| | - Blair K. A. Willette
- Molecular Neuropharmacology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 35 Convent Drive, Bethesda, MD 20892, USA (R.B.F.)
| | - Laura R. Inbody
- Molecular Neuropharmacology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 35 Convent Drive, Bethesda, MD 20892, USA (R.B.F.)
| | - Christopher Dasaro
- Molecular Neuropharmacology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 35 Convent Drive, Bethesda, MD 20892, USA (R.B.F.)
| | - Amy E. Moritz
- Molecular Neuropharmacology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 35 Convent Drive, Bethesda, MD 20892, USA (R.B.F.)
| | - Julia Drube
- Institut für Molekulare Zellbiologie, CMB-Center for Molecular Biomedicine, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, Hans-Knöll-Straße 2, D-07745 Jena, Germany (R.S.H.); (C.H.)
| | - Raphael S. Haider
- Institut für Molekulare Zellbiologie, CMB-Center for Molecular Biomedicine, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, Hans-Knöll-Straße 2, D-07745 Jena, Germany (R.S.H.); (C.H.)
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen’s Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK
- Centre of Membrane Protein and Receptors, Universities of Birmingham and Nottingham, Birmingham B15 2TT, UK
| | - R. Benjamin Free
- Molecular Neuropharmacology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 35 Convent Drive, Bethesda, MD 20892, USA (R.B.F.)
| | - Carsten Hoffman
- Institut für Molekulare Zellbiologie, CMB-Center for Molecular Biomedicine, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, Hans-Knöll-Straße 2, D-07745 Jena, Germany (R.S.H.); (C.H.)
| | - David R. Sibley
- Molecular Neuropharmacology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 35 Convent Drive, Bethesda, MD 20892, USA (R.B.F.)
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Tao Y, Luo W, Chen Y, Chen C, Chen S, Li X, Chen K, Zeng C. Exercise ameliorates skeletal muscle insulin resistance by modulating GRK4-mediated D1R expression. Clin Sci (Lond) 2023; 137:1391-1407. [PMID: 37622333 DOI: 10.1042/cs20230664] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 08/24/2023] [Accepted: 08/24/2023] [Indexed: 08/26/2023]
Abstract
Exercise has been recommended as a nonpharmaceutical therapy to treat insulin resistance (IR). Previous studies showed that dopamine D1-like receptor agonists, such as fenoldopam, could improve peripheral insulin sensitivity, while antipsychotics, which are dopamine receptor antagonists, increased susceptibility to Type 2 diabetes mellitus (T2DM). Meanwhile, exercise has been proved to stimulate dopamine receptors. However, whether the dopamine D1 receptor (D1R) is involved in exercise-mediated amelioration of IR remains unclear. We found that the D1-like receptor antagonist, SCH23390, reduced the effect of exercise on lowering blood glucose and insulin in insulin-resistant mice and inhibited the contraction-induced glucose uptake in C2C12 myotubes. Similarly, the opposite was true for the D1-like receptor agonist, fenoldopam. Furthermore, the expression of D1R was decreased in skeletal muscles from streptozotocin (STZ)- and high-fat intake-induced T2DM mice, accompanied by increased D1R phosphorylation, which was reversed by exercise. A screening study showed that G protein-coupled receptor kinase 4 (GRK4) may be the candidate kinase for the regulation of D1R function, because, in addition to the increased GRK4 expression in skeletal muscles of T2DM mice, GRK4 transgenic T2DM mice exhibited lower insulin sensitivity, accompanied by higher D1R phosphorylation than control mice, whereas the AAV9-shGRK4 mice were much more sensitive to insulin than AAV9-null mice. Mechanistically, the up-regulation of GRK4 expression caused by increased reactive oxygen species (ROS) in IR was ascribed to the enhanced expression of c-Myc, a transcriptional factor of GRK4. Taken together, the present study shows that exercise, via regulation of ROS/c-Myc/GRK4 pathway, ameliorates D1R dysfunction and improves insulin sensitivity.
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Affiliation(s)
- Yu Tao
- Department of Cardiology, Daping Hospital, Third Military Medical University (Army Medical University), Chongqing, China
- Key Laboratory of Geriatric Cardiovascular and Cerebrovascular Disease Research, Ministry of Education of China, Chongqing Key Laboratory for Hypertension Research, Chongqing Cardiovascular Clinical Research Center, Chongqing Institute of Cardiology, Chongqing, China
- State Key Laboratory of Trauma, Burns and Combined Injury, Daping Hospital, Army Medical University, Chongqing, China
| | - Wenbin Luo
- Department of Cardiology, Daping Hospital, Third Military Medical University (Army Medical University), Chongqing, China
- Key Laboratory of Geriatric Cardiovascular and Cerebrovascular Disease Research, Ministry of Education of China, Chongqing Key Laboratory for Hypertension Research, Chongqing Cardiovascular Clinical Research Center, Chongqing Institute of Cardiology, Chongqing, China
- State Key Laboratory of Trauma, Burns and Combined Injury, Daping Hospital, Army Medical University, Chongqing, China
| | - Yue Chen
- Department of Cardiology, Daping Hospital, Third Military Medical University (Army Medical University), Chongqing, China
- Key Laboratory of Geriatric Cardiovascular and Cerebrovascular Disease Research, Ministry of Education of China, Chongqing Key Laboratory for Hypertension Research, Chongqing Cardiovascular Clinical Research Center, Chongqing Institute of Cardiology, Chongqing, China
- State Key Laboratory of Trauma, Burns and Combined Injury, Daping Hospital, Army Medical University, Chongqing, China
| | - Caiyu Chen
- Department of Cardiology, Daping Hospital, Third Military Medical University (Army Medical University), Chongqing, China
- Key Laboratory of Geriatric Cardiovascular and Cerebrovascular Disease Research, Ministry of Education of China, Chongqing Key Laboratory for Hypertension Research, Chongqing Cardiovascular Clinical Research Center, Chongqing Institute of Cardiology, Chongqing, China
- State Key Laboratory of Trauma, Burns and Combined Injury, Daping Hospital, Army Medical University, Chongqing, China
| | - Shengnan Chen
- Department of Cardiology, Daping Hospital, Third Military Medical University (Army Medical University), Chongqing, China
- Key Laboratory of Geriatric Cardiovascular and Cerebrovascular Disease Research, Ministry of Education of China, Chongqing Key Laboratory for Hypertension Research, Chongqing Cardiovascular Clinical Research Center, Chongqing Institute of Cardiology, Chongqing, China
- State Key Laboratory of Trauma, Burns and Combined Injury, Daping Hospital, Army Medical University, Chongqing, China
| | - Xiaoping Li
- Department of Cardiology, Daping Hospital, Third Military Medical University (Army Medical University), Chongqing, China
- Key Laboratory of Geriatric Cardiovascular and Cerebrovascular Disease Research, Ministry of Education of China, Chongqing Key Laboratory for Hypertension Research, Chongqing Cardiovascular Clinical Research Center, Chongqing Institute of Cardiology, Chongqing, China
- State Key Laboratory of Trauma, Burns and Combined Injury, Daping Hospital, Army Medical University, Chongqing, China
| | - Ken Chen
- Department of Cardiology, Daping Hospital, Third Military Medical University (Army Medical University), Chongqing, China
- Key Laboratory of Geriatric Cardiovascular and Cerebrovascular Disease Research, Ministry of Education of China, Chongqing Key Laboratory for Hypertension Research, Chongqing Cardiovascular Clinical Research Center, Chongqing Institute of Cardiology, Chongqing, China
- State Key Laboratory of Trauma, Burns and Combined Injury, Daping Hospital, Army Medical University, Chongqing, China
| | - Chunyu Zeng
- Department of Cardiology, Daping Hospital, Third Military Medical University (Army Medical University), Chongqing, China
- Key Laboratory of Geriatric Cardiovascular and Cerebrovascular Disease Research, Ministry of Education of China, Chongqing Key Laboratory for Hypertension Research, Chongqing Cardiovascular Clinical Research Center, Chongqing Institute of Cardiology, Chongqing, China
- State Key Laboratory of Trauma, Burns and Combined Injury, Daping Hospital, Army Medical University, Chongqing, China
- Cardiovascular Research Center of Chongqing College, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Chongqing, P.R. China
- Department of Cardiology, The First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan Province, P.R. China
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10
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Zeghal M, Laroche G, Freitas JD, Wang R, Giguère PM. Profiling of basal and ligand-dependent GPCR activities by means of a polyvalent cell-based high-throughput platform. Nat Commun 2023; 14:3684. [PMID: 37407564 DOI: 10.1038/s41467-023-39132-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Accepted: 05/25/2023] [Indexed: 07/07/2023] Open
Abstract
Representing the most attractive and successful druggable receptors of the proteome, GPCRs regulate a myriad of physiological and pathophysiological functions. Although over half of present pharmaceuticals target GPCRs, the advancement of drug discovery is hampered by a lack of adequate screening tools, the majority of which are limited to probing agonist-induced G-protein and β-arrestin-2-mediated events as a measure of receptor activation. Here, we develop Tango-Trio, a comprehensive cell-based high-throughput platform comprising cumate-inducible expression of transducers, capable of the parallelized profiling of both basal and agonist-dependent GPCR activities. We capture the functional diversity of GPCRs, reporting β-arrestin-1/2 couplings, selectivities, and receptor internalization signatures across the GPCRome. Moreover, we present the construction of cumate-induced basal activation curves at approximately 200 receptors, including over 50 orphans. Overall, Tango-Trio's robustness is well-suited for the functional characterization and screening of GPCRs, especially for parallel interrogation, and is a valuable addition to the pharmacological toolbox.
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Affiliation(s)
- Manel Zeghal
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, K1H8M5, Canada
| | - Geneviève Laroche
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, K1H8M5, Canada
| | - Julia Douglas Freitas
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, K1H8M5, Canada
| | - Rebecca Wang
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, K1H8M5, Canada
| | - Patrick M Giguère
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, K1H8M5, Canada.
- Brain and Mind Research Institute, University of Ottawa, Ottawa, ON, K1H8M5, Canada.
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11
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Yang J, Hall JE, Jose PA, Chen K, Zeng C. Comprehensive insights in GRK4 and hypertension: From mechanisms to potential therapeutics. Pharmacol Ther 2022; 239:108194. [PMID: 35487286 PMCID: PMC9728143 DOI: 10.1016/j.pharmthera.2022.108194] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 03/30/2022] [Accepted: 04/21/2022] [Indexed: 11/24/2022]
Abstract
G protein-coupled receptors (GPCRs) mediate cellular responses to diverse extracellular stimuli that play vital roles in the regulation of biology, including behavior. Abnormal G protein-coupled receptor kinase (GRK)-mediated regulation of GPCR function is involved in the pathogenesis of hypertension. Among the seven GRK subtypes, GRK4 has attracted attention because of its constitutive activity and tissue-specific expression. Increasing number of studies show that GRK4 affects blood pressure by GPCR-mediated regulation of renal and arterial function. The target receptor of GRK4 is confined not only to GPCRs, but also to other blood pressure-regulating receptors, such as the adiponectin receptor. Genetic studies in humans show that in several ethnic groups, GRK4 gene variants (R65L, A142V, and A486V) are associated with salt-sensitive or salt-resistant essential hypertension and blood pressure responses to antihypertensive medicines. In this article, we present a comprehensive overview of GRK-mediated regulation of blood pressure, focusing on the latest research progress on GRK4 and hypertension and highlighting potential and novel strategies for the prevention and treatment of hypertension.
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Affiliation(s)
- Jian Yang
- Department of Clinical Nutrition, The Third Affiliated Hospital of Chongqing Medical University, Chongqing, PR China; Research Center for Metabolic and Cardiovascular Diseases, The Third Affiliated Hospital of Chongqing Medical University, Chongqing, China.
| | - John E Hall
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, University of Mississippi Medical Center, Jackson, MS, USA
| | - Pedro A Jose
- Division of Renal Diseases & Hypertension, The George Washington University School of Medicine & Health Sciences, Washington, DC, USA
| | - Ken Chen
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing, PR China; Cardiovascular Research Center of Chongqing College, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Chongqing, PR China.
| | - Chunyu Zeng
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing, PR China; Heart Center of Fujian Province, Union Hospital, Fujian Medical University, Fuzhou, PR China; Department of Cardiology, Chongqing General Hospital, Chongqing, PR China; Cardiovascular Research Center of Chongqing College, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Chongqing, PR China.
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12
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Pearce A, Redfern-Nichols T, Harris M, Poyner DR, Wigglesworth M, Ladds G. Determining the Effects of Differential Expression of GRKs and β-arrestins on CLR-RAMP Agonist Bias. Front Physiol 2022; 13:840763. [PMID: 35422711 PMCID: PMC9001978 DOI: 10.3389/fphys.2022.840763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 03/08/2022] [Indexed: 11/17/2022] Open
Abstract
Signalling of the calcitonin-like receptor (CLR) is multifaceted, due to its interaction with receptor activity modifying proteins (RAMPs), and three endogenous peptide agonists. Previous studies have focused on the bias of G protein signalling mediated by the receptor and receptor internalisation of the CLR-RAMP complex has been assumed to follow the same pattern as other Class B1 G Protein-Coupled Receptors (GPCRs). Here we sought to measure desensitisation of the three CLR-RAMP complexes in response to the three peptide agonists, through the measurement of β-arrestin recruitment and internalisation. We then delved further into the mechanism of desensitisation through modulation of β-arrestin activity and the expression of GPCR kinases (GRKs), a key component of homologous GPCR desensitisation. First, we have shown that CLR-RAMP1 is capable of potently recruiting β-arrestin1 and 2, subsequently undergoing rapid endocytosis, and that CLR-RAMP2 and -RAMP3 also utilise these pathways, although to a lesser extent. Following this we have shown that agonist-dependent internalisation of CLR is β-arrestin dependent, but not required for full agonism. Overexpression of GRK2-6 was then found to decrease receptor signalling, due to an agonist-independent reduction in surface expression of the CLR-RAMP complex. These results represent the first systematic analysis of the importance of β-arrestins and GRKs in CLR-RAMP signal transduction and pave the way for further investigation regarding other Class B1 GPCRs.
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Affiliation(s)
- Abigail Pearce
- Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom
| | | | - Matthew Harris
- Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom
| | - David R. Poyner
- School of Life and Health Sciences, Aston University, Birmingham, United Kingdom
| | - Mark Wigglesworth
- Hit Discovery, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, London, United Kingdom
| | - Graham Ladds
- Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom
- *Correspondence: Graham Ladds,
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13
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Drube J, Haider RS, Matthees ESF, Reichel M, Zeiner J, Fritzwanker S, Ziegler C, Barz S, Klement L, Filor J, Weitzel V, Kliewer A, Miess-Tanneberg E, Kostenis E, Schulz S, Hoffmann C. GPCR kinase knockout cells reveal the impact of individual GRKs on arrestin binding and GPCR regulation. Nat Commun 2022; 13:540. [PMID: 35087057 PMCID: PMC8795447 DOI: 10.1038/s41467-022-28152-8] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 01/06/2022] [Indexed: 12/19/2022] Open
Abstract
G protein-coupled receptors (GPCRs) activate G proteins and undergo a complex regulation by interaction with GPCR kinases (GRKs) and the formation of receptor-arrestin complexes. However, the impact of individual GRKs on arrestin binding is not clear. We report the creation of eleven combinatorial HEK293 knockout cell clones lacking GRK2/3/5/6, including single, double, triple and the quadruple GRK knockout. Analysis of β-arrestin1/2 interactions for twelve GPCRs in our GRK knockout cells enables the differentiation of two main receptor subsets: GRK2/3-regulated and GRK2/3/5/6-regulated receptors. Furthermore, we identify GPCRs that interact with β-arrestins via the overexpression of specific GRKs even in the absence of agonists. Finally, using GRK knockout cells, PKC inhibitors and β-arrestin mutants, we present evidence for differential receptor-β-arrestin1/2 complex configurations mediated by selective engagement of kinases. We anticipate our GRK knockout platform to facilitate the elucidation of previously unappreciated details of GRK-specific GPCR regulation and β-arrestin complex formation.
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Affiliation(s)
- J Drube
- Institut für Molekulare Zellbiologie, CMB - Center for Molecular Biomedicine, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, Hans-Knöll-Straße 2, D-07745, Jena, Germany
| | - R S Haider
- Institut für Molekulare Zellbiologie, CMB - Center for Molecular Biomedicine, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, Hans-Knöll-Straße 2, D-07745, Jena, Germany
| | - E S F Matthees
- Institut für Molekulare Zellbiologie, CMB - Center for Molecular Biomedicine, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, Hans-Knöll-Straße 2, D-07745, Jena, Germany
| | - M Reichel
- Institut für Molekulare Zellbiologie, CMB - Center for Molecular Biomedicine, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, Hans-Knöll-Straße 2, D-07745, Jena, Germany
| | - J Zeiner
- Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115, Bonn, Germany
| | - S Fritzwanker
- Institut für Pharmakologie und Toxikologie, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, Drackendorfer Straße 1, D-07747, Jena, Germany
| | - C Ziegler
- Institut für Molekulare Zellbiologie, CMB - Center for Molecular Biomedicine, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, Hans-Knöll-Straße 2, D-07745, Jena, Germany
| | - S Barz
- Institut für Molekulare Zellbiologie, CMB - Center for Molecular Biomedicine, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, Hans-Knöll-Straße 2, D-07745, Jena, Germany
| | - L Klement
- Institut für Molekulare Zellbiologie, CMB - Center for Molecular Biomedicine, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, Hans-Knöll-Straße 2, D-07745, Jena, Germany
| | - J Filor
- Institut für Molekulare Zellbiologie, CMB - Center for Molecular Biomedicine, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, Hans-Knöll-Straße 2, D-07745, Jena, Germany
| | - V Weitzel
- Institut für Molekulare Zellbiologie, CMB - Center for Molecular Biomedicine, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, Hans-Knöll-Straße 2, D-07745, Jena, Germany
| | - A Kliewer
- Institut für Pharmakologie und Toxikologie, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, Drackendorfer Straße 1, D-07747, Jena, Germany
| | - E Miess-Tanneberg
- Institut für Pharmakologie und Toxikologie, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, Drackendorfer Straße 1, D-07747, Jena, Germany
| | - E Kostenis
- Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115, Bonn, Germany
| | - S Schulz
- Institut für Pharmakologie und Toxikologie, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, Drackendorfer Straße 1, D-07747, Jena, Germany
| | - C Hoffmann
- Institut für Molekulare Zellbiologie, CMB - Center for Molecular Biomedicine, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, Hans-Knöll-Straße 2, D-07745, Jena, Germany.
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14
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Nanoluciferase-based complementation assay for systematic profiling of GPCR–GRK interactions. Methods Cell Biol 2022; 169:309-321. [DOI: 10.1016/bs.mcb.2022.04.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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15
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Agonist dependency of the second phase access of β-arrestin 2 to the heteromeric µ-V1b receptor. Sci Rep 2021; 11:15813. [PMID: 34349143 PMCID: PMC8339129 DOI: 10.1038/s41598-021-94894-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 07/19/2021] [Indexed: 12/02/2022] Open
Abstract
During the development of analgesic tolerance to morphine, the V1b vasopressin receptor has been proposed to bind to β-arrestin 2 and the µ-opioid receptor to enable their interaction. However, direct evidence of such a high-order complex is lacking. Using bioluminescent resonance energy transfer between a split Nanoluciferase and the Venus fluorescent protein, the NanoBit-NanoBRET system, we found that β-arrestin 2 closely located near the heteromer µ-V1b receptor in the absence of an agonist and moved closer to the receptor carboxyl-termini upon agonist stimulation. An additive effect of the two agonists for opioid and vasopressin receptors was detected on the NanoBRET between the µ-V1b heteromer and β-arrestin 2. To increase the agonist response of NanoBRET, the ratio of the donor luminophore to the acceptor fluorophore was decreased to the detection limit of luminescence. In the first phase of access, β-arrestin 2 was likely to bind to the unstimulated V1b receptor in both its phosphorylated and unphosphorylated forms. In contrast, the second-phase access of β-arrestin 2 was agonist dependent, indicating a possible pharmacological intervention strategy. Therefore, our efficient method should be useful for evaluating chemicals that directly target the vasopressin binding site in the µ-V1b heteromer to reduce the second-phase access of β-arrestin 2 and thereby to alleviate tolerance to morphine analgesia.
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16
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The Open Question of How GPCRs Interact with GPCR Kinases (GRKs). Biomolecules 2021; 11:biom11030447. [PMID: 33802765 PMCID: PMC8002388 DOI: 10.3390/biom11030447] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 03/13/2021] [Accepted: 03/15/2021] [Indexed: 01/14/2023] Open
Abstract
G protein-coupled receptors (GPCRs), which regulate a vast number of eukaryotic processes, are desensitized by various mechanisms but, most importantly, by the GPCR kinases (GRKs). Ever since GRKs were first identified, investigators have sought to determine which structural features of GRKs are used to select for the agonist-bound states of GPCRs and how this binding event in turn enhances GRK catalytic activity. Despite a wealth of molecular information from high-resolution crystal structures of GRKs, the mechanisms driving activation have remained elusive, in part because the GRK N-terminus and active site tether region, previously proposed to serve as a receptor docking site and to be key to kinase domain closure, are often disordered or adopt inconsistent conformations. However, two recent studies have implicated other regions of GRKs as being involved in direct interactions with active GPCRs. Atomic resolution structures of GPCR–GRK complexes would help refine these models but are, so far, lacking. Here, we assess three distinct models for how GRKs recognize activated GPCRs, discuss limitations in the approaches used to generate them, and then experimentally test a hypothetical GPCR interaction site in GRK2 suggested by the two newest models.
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17
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Stegen M, Engler A, Ochsenfarth C, Manthey I, Peters J, Siffert W, Frey UH. Characterization of the G protein-coupled receptor kinase 6 promoter reveals a functional CREB binding site. PLoS One 2021; 16:e0247087. [PMID: 33600497 PMCID: PMC7891717 DOI: 10.1371/journal.pone.0247087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 02/01/2021] [Indexed: 11/21/2022] Open
Abstract
Background G protein-coupled receptor kinase 6 (GRK6) is part of the G protein-coupled receptor kinase family, whose members act as key regulators of seven-transmembrane receptor signalling. GRK6 seems to play a role in regulation of inflammatory processes, but mechanisms of transcriptional regulation of GRK6 expression in inflammatory cell lines have not been characterized. Protein kinase C (PKC) signalling is also involved in inflammatory regulation and an impact of PKC activation on GRK6 protein expression was described previously. Thus, the aim of this study was to 1) characterize the GRK6 promoter, and 2) investigate a potential influence of PKC on GRK6 expression. Methods Five deletion constructs of the GRK6 promoter were cloned. After transient transfection into a human T cell line, promoter activity was assessed using luciferase reporter gene assays. Putative transcription factor binding sites were identified, mutated, and binding was investigated using electrophoretic mobility shift assays (EMSA). Following stimulation with a PKC activator, GRK6 expression on mRNA and protein levels was assessed by reverse transcriptase qPCR and Western blots. Results Investigation of the GRK6 promoter revealed a putative cAMP responsive element (CRE), whose mutation led to decreased promoter activity (p = 0.0006). Functionality of the CRE binding protein (CREB) binding site was verified in EMSA blots. Stimulation with a PKC activator resulted in decreased GRK6 promoter activity (p = 0.0027), mRNA (p = 0.04) and protein expression. Conclusion We characterized the human GRK6 promoter and identified promoter activity to be influenced by a CREB binding site. PKC might be one determinant contributing to altered GRK6 expression.
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Affiliation(s)
- Maike Stegen
- Department of Anaesthesiology and Intensive Care Medicine, Essen University Hospital and University of Duisburg-Essen, Essen, Germany
- * E-mail:
| | - Andrea Engler
- Department of Anaesthesiology and Intensive Care Medicine, Essen University Hospital and University of Duisburg-Essen, Essen, Germany
| | - Crista Ochsenfarth
- Department of Anaesthesiology, Operative Intensive Care Medicine, Pain and Palliative Medicine, Marien Hospital Herne, Ruhr-University Bochum, Bochum, Germany
| | - Iris Manthey
- Institute of Pharmacogenetics, Essen University Hospital and University of Duisburg-Essen, Essen, Germany
| | - Jürgen Peters
- Department of Anaesthesiology and Intensive Care Medicine, Essen University Hospital and University of Duisburg-Essen, Essen, Germany
| | - Winfried Siffert
- Institute of Pharmacogenetics, Essen University Hospital and University of Duisburg-Essen, Essen, Germany
| | - Ulrich H. Frey
- Department of Anaesthesiology and Intensive Care Medicine, Essen University Hospital and University of Duisburg-Essen, Essen, Germany
- Department of Anaesthesiology, Operative Intensive Care Medicine, Pain and Palliative Medicine, Marien Hospital Herne, Ruhr-University Bochum, Bochum, Germany
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18
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Receptor-Arrestin Interactions: The GPCR Perspective. Biomolecules 2021; 11:biom11020218. [PMID: 33557162 PMCID: PMC7913897 DOI: 10.3390/biom11020218] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 01/25/2021] [Accepted: 02/01/2021] [Indexed: 02/06/2023] Open
Abstract
Arrestins are a small family of four proteins in most vertebrates that bind hundreds of different G protein-coupled receptors (GPCRs). Arrestin binding to a GPCR has at least three functions: precluding further receptor coupling to G proteins, facilitating receptor internalization, and initiating distinct arrestin-mediated signaling. The molecular mechanism of arrestin–GPCR interactions has been extensively studied and discussed from the “arrestin perspective”, focusing on the roles of arrestin elements in receptor binding. Here, we discuss this phenomenon from the “receptor perspective”, focusing on the receptor elements involved in arrestin binding and emphasizing existing gaps in our knowledge that need to be filled. It is vitally important to understand the role of receptor elements in arrestin activation and how the interaction of each of these elements with arrestin contributes to the latter’s transition to the high-affinity binding state. A more precise knowledge of the molecular mechanisms of arrestin activation is needed to enable the construction of arrestin mutants with desired functional characteristics.
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19
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Gurevich EV, Gurevich VV. GRKs as Modulators of Neurotransmitter Receptors. Cells 2020; 10:cells10010052. [PMID: 33396400 PMCID: PMC7823573 DOI: 10.3390/cells10010052] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 12/23/2020] [Accepted: 12/30/2020] [Indexed: 01/08/2023] Open
Abstract
Many receptors for neurotransmitters, such as dopamine, norepinephrine, acetylcholine, and neuropeptides, belong to the superfamily of G protein-coupled receptors (GPCRs). A general model posits that GPCRs undergo two-step homologous desensitization: the active receptor is phosphorylated by kinases of the G protein-coupled receptor kinase (GRK) family, whereupon arrestin proteins specifically bind active phosphorylated receptors, shutting down G protein-mediated signaling, facilitating receptor internalization, and initiating distinct signaling pathways via arrestin-based scaffolding. Here, we review the mechanisms of GRK-dependent regulation of neurotransmitter receptors, focusing on the diverse modes of GRK-mediated phosphorylation of receptor subtypes. The immediate signaling consequences of GRK-mediated receptor phosphorylation, such as arrestin recruitment, desensitization, and internalization/resensitization, are equally diverse, depending not only on the receptor subtype but also on phosphorylation by GRKs of select receptor residues. We discuss the signaling outcome as well as the biological and behavioral consequences of the GRK-dependent phosphorylation of neurotransmitter receptors where known.
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20
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Crudden C, Shibano T, Song D, Dragomir MP, Cismas S, Serly J, Nedelcu D, Fuentes-Mattei E, Tica A, Calin GA, Girnita A, Girnita L. Inhibition of G Protein-Coupled Receptor Kinase 2 Promotes Unbiased Downregulation of IGF1 Receptor and Restrains Malignant Cell Growth. Cancer Res 2020; 81:501-514. [PMID: 33158816 DOI: 10.1158/0008-5472.can-20-1662] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 10/03/2020] [Accepted: 10/30/2020] [Indexed: 11/16/2022]
Abstract
The ability of a receptor to preferentially activate only a subset of available downstream signal cascades is termed biased signaling. Although comprehensively recognized for the G protein-coupled receptors (GPCR), this process is scarcely explored downstream of receptor tyrosine kinases (RTK), including the cancer-relevant insulin-like growth factor-1 receptor (IGF1R). Successful IGF1R targeting requires receptor downregulation, yet therapy-mediated removal from the cell surface activates cancer-protective β-arrestin-biased signaling (β-arr-BS). As these overlapping processes are initiated by the β-arr/IGF1R interaction and controlled by GPCR-kinases (GRK), we explored GRKs as potential anticancer therapeutic targets to disconnect IGF1R downregulation and β-arr-BS. Transgenic modulation demonstrated that GRK2 inhibition or GRK6 overexpression enhanced degradation of IGF1R, but both scenarios sustained IGF1-induced β-arr-BS. Pharmacologic inhibition of GRK2 by the clinically approved antidepressant, serotonin reuptake inhibitor paroxetine (PX), recapitulated the effects of GRK2 silencing with dose- and time-dependent IGF1R downregulation without associated β-arr-BS. In vivo, PX treatment caused substantial downregulation of IGF1R, suppressing the growth of Ewing's sarcoma xenografts. Functional studies reveal that PX exploits the antagonism between β-arrestin isoforms; in low ligand conditions, PX favored β-arrestin1/Mdm2-mediated ubiquitination/degradation of IGF1R, a scenario usually exclusive to ligand abundancy, making PX more effective than antibody-mediated IGF1R downregulation. This study provides the rationale, molecular mechanism, and validation of a clinically feasible concept for "system bias" targeting of the IGF1R to uncouple downregulation from signaling. Demonstrating system bias as an effective anticancer approach, our study reveals a novel strategy for the rational design or repurposing of therapeutics to selectively cross-target the IGF1R or other RTK. SIGNIFICANCE: This work provides insight into the molecular and biological roles of biased signaling downstream RTK and provides a novel "system bias" strategy to increase the efficacy of anti-IGF1R-targeted therapy in cancer.
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Affiliation(s)
- Caitrin Crudden
- Department of Oncology and Pathology, BioClinicum, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden.,Department of Pathology, Cancer Center Amsterdam, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Takashi Shibano
- Department of Oncology and Pathology, BioClinicum, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden
| | - Dawei Song
- Department of Oncology and Pathology, BioClinicum, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden
| | - Mihnea P Dragomir
- Department of Experimental Therapeutics, The University of Texas, MD Anderson Cancer Center, Houston, Texas
| | - Sonia Cismas
- Department of Oncology and Pathology, BioClinicum, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden
| | - Julianna Serly
- Department of Oncology and Pathology, BioClinicum, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden
| | - Daniela Nedelcu
- Department of Oncology and Pathology, BioClinicum, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden
| | - Enrique Fuentes-Mattei
- Department of Experimental Therapeutics, The University of Texas, MD Anderson Cancer Center, Houston, Texas
| | - Andrei Tica
- Department of Pharmacology, University of Medicine and Pharmacy of Craiova, Craiova, Romania
| | - George A Calin
- Department of Experimental Therapeutics, The University of Texas, MD Anderson Cancer Center, Houston, Texas
| | - Ada Girnita
- Department of Oncology and Pathology, BioClinicum, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden.,Dermatology Department, Karolinska University Hospital, Stockholm, Sweden
| | - Leonard Girnita
- Department of Oncology and Pathology, BioClinicum, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden.
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21
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Structural Insights into β-arrestin/CB1 Receptor Interaction: NMR and CD Studies on Model Peptides. Int J Mol Sci 2020; 21:ijms21218111. [PMID: 33143110 PMCID: PMC7662265 DOI: 10.3390/ijms21218111] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 10/21/2020] [Accepted: 10/28/2020] [Indexed: 12/30/2022] Open
Abstract
Activation of the cannabinoid CB1 receptor induces different cellular signaling cascades through coupling to different effector proteins (G-proteins and β-arrestins), triggering numerous therapeutic effects. Conformational changes and rearrangements at the intracellular domain of this GPCR receptor that accompany ligand binding dictate the signaling pathways. The GPCR-binding interface for G proteins has been extensively studied, whereas β-arrestin/GPCR complexes are still poorly understood. To gain knowledge in this direction, we designed peptides that mimic the motifs involved in the putative interacting region: β-arrestin1 finger loop and the transmembrane helix 7-helix 8 (TMH7-H8) elbow located at the intracellular side of the CB1 receptor. According to circular dichroism and NMR data, these peptides form a native-like, helical conformation and interact with each other in aqueous solution, in the presence of trifluoroethanol, and using zwitterionic detergent micelles as membrane mimics. These results increase our understanding of the binding mode of β-arrestin and CB1 receptor and validate minimalist approaches to structurally comprehend complex protein systems.
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22
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Chen R, Ferris MJ, Wang S. Dopamine D2 autoreceptor interactome: Targeting the receptor complex as a strategy for treatment of substance use disorder. Pharmacol Ther 2020; 213:107583. [PMID: 32473160 PMCID: PMC7434700 DOI: 10.1016/j.pharmthera.2020.107583] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 05/11/2020] [Indexed: 02/06/2023]
Abstract
Dopamine D2 autoreceptors (D2ARs), located in somatodendritic and axon terminal compartments of dopamine (DA) neurons, function to provide a negative feedback regulatory control on DA neuron firing, DA synthesis, reuptake and release. Dysregulation of D2AR-mediated DA signaling is implicated in vulnerability to substance use disorder (SUD). Due to the extreme low abundance of D2ARs compared to postsynaptic D2 receptors (D2PRs) and the lack of experimental tools to differentiate the signaling of D2ARs from D2PRs, the regulation of D2ARs by drugs of abuse is poorly understood. The recent availability of conditional D2AR knockout mice and newly developed virus-mediated gene delivery approaches have provided means to specifically study the function of D2ARs at the molecular, cellular and behavioral levels. There is a growing revelation of novel mechanisms and new proteins that mediate D2AR activity, suggesting that D2ARs act cooperatively with an array of membrane and intracellular proteins to tightly control DA transmission. This review highlights D2AR-interacting partners including transporters, G-protein-coupled receptors, ion channels, intracellular signaling modulators, and protein kinases. The complexity of the D2AR interaction network illustrates the functional divergence of D2ARs. Pharmacological targeting of multiple D2AR-interacting partners may be more effective to restore disrupted DA homeostasis by drugs of abuse.
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Affiliation(s)
- Rong Chen
- Dept. of Physiology & Pharmacology, Wake Forest School of Medicine, Winston Salem, NC 27157, United States of America; Center for the Neurobiology of Addiction Treatment, Wake Forest School of Medicine, Winston Salem, NC 27157, United States of America.
| | - Mark J Ferris
- Dept. of Physiology & Pharmacology, Wake Forest School of Medicine, Winston Salem, NC 27157, United States of America; Center for the Neurobiology of Addiction Treatment, Wake Forest School of Medicine, Winston Salem, NC 27157, United States of America
| | - Shiyu Wang
- Dept. of Physiology & Pharmacology, Wake Forest School of Medicine, Winston Salem, NC 27157, United States of America
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23
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Zhao P, Furness SGB. The nature of efficacy at G protein-coupled receptors. Biochem Pharmacol 2019; 170:113647. [PMID: 31585071 DOI: 10.1016/j.bcp.2019.113647] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 09/27/2019] [Indexed: 12/31/2022]
Abstract
G protein-coupled receptors (GPCRs) participate in many pathophysiological processes as well as almost all aspects of normal physiology. They are present at the surface of all cell types making them amenable and attractive targets for pharmaceutical therapeutics. GPCRs possess complex pharmacology with the ability to be turned on to various extents, have their constitutive activity suppressed and even switch between signaling pathways to which they couple. Underlying this complex pharmacology is GPCR signaling efficacy, and differences in efficacy promoted by alternative ligands and in different tissues is of great interest to biology in general and also the pharmaceutical industry. In this review we hope to discuss what the molecular foundations of efficacy are and whether a new approach utilizing a rate-dependent model may provide new insights into this phenomenon.
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Affiliation(s)
- Peishen Zhao
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria 3052, Australia.
| | - Sebastian G B Furness
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria 3052, Australia.
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24
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Azimzadeh P, Talamantez-Lyburn SC, Chang KT, Inoue A, Balenga N. Spatial regulation of GPR64/ADGRG2 signaling by β-arrestins and GPCR kinases. Ann N Y Acad Sci 2019; 1456:26-43. [PMID: 31502283 DOI: 10.1111/nyas.14227] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 08/05/2019] [Accepted: 08/13/2019] [Indexed: 12/28/2022]
Abstract
Mechanisms of activation, signaling, and trafficking of adhesion G protein-coupled receptors (aGPCRs) have remained largely unknown. Several aGPCRs, including GPR56/ADGRG1 and GPR64/ADGRG2, show increased activity in the absence of their N-terminal fragment (NTF). This constitutive signaling is plausibly caused by the binding of extracellular N-terminal 15-25 amino acid-long tethered agonist to extracellular domains of the cognate aGPCRs. To test the role of NTF and tethered agonist in GPR64 signaling and endocytosis, we generated mutants that lack either NTF alone (ΔNTF) or NTF and tethered agonist (P622). We discover that unlike full-length GPR64, ΔNTF and P622 mutants interact with β-arrestin1 and β-arrestins2 and are constitutively internalized in steady states. However, only ΔNTF shows exaggerated basal activation of the Gαs -cAMP-CRE signaling cascade. Neither ΔNTF nor P622 shows constitutive activation of the Gα13 -SRE pathway, but both mutants respond to exogenously added agonistic peptide via CRE and SRE. GPCR kinases and dynamin mediate the constitutive internalization of ΔNTF and P622 to early endosomes, where ΔNTF constantly induces CRE. These data suggest that NTF not only shields the tethered agonist to prevent G protein signaling but also confers a conformation that inhibits the interaction with β-arrestins and the consequent endocytosis and sustained signaling from endosomes.
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Affiliation(s)
- Pedram Azimzadeh
- Division of General and Oncologic Surgery, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland
| | | | - Katarina T Chang
- Graduate Program in Life Sciences, University of Maryland, Baltimore, Maryland
| | - Asuka Inoue
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Nariman Balenga
- Division of General and Oncologic Surgery, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland.,Molecular and Structural Biology Program at University of Maryland Marlene and Stewart Greenebaum Comprehensive Cancer Center, Baltimore, Maryland
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25
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Al-Zoubi R, Morales P, Reggio PH. Structural Insights into CB1 Receptor Biased Signaling. Int J Mol Sci 2019; 20:E1837. [PMID: 31013934 PMCID: PMC6515405 DOI: 10.3390/ijms20081837] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 04/09/2019] [Accepted: 04/11/2019] [Indexed: 12/21/2022] Open
Abstract
The endocannabinoid system has emerged as a promising target for the treatment of numerous diseases, including cancer, neurodegenerative disorders, and metabolic syndromes. Thus far, two cannabinoid receptors, CB1 and CB2, have been discovered, which are found predominantly in the central nervous system (CB1) or the immune system (CB2), among other organs and tissues. CB1 receptor ligands have been shown to induce a complex pattern of intracellular effects. The binding of a ligand induces distinct conformational changes in the receptor, which will eventually translate into distinct intracellular signaling pathways through coupling to specific intracellular effector proteins. These proteins can mediate receptor desensitization, trafficking, or signaling. Ligand specificity and selectivity, complex cellular components, and the concomitant expression of other proteins (which either regulate the CB1 receptor or are regulated by the CB1 receptor) will affect the therapeutic outcome of its targeting. With an increased interest in G protein-coupled receptors (GPCR) research, in-depth studies using mutations, biological assays, and spectroscopic techniques (such as NMR, EPR, MS, FRET, and X-ray crystallography), as well as computational modelling, have begun to reveal a set of concerted structural features in Class A GPCRs which relate to signaling pathways and the mechanisms of ligand-induced activation, deactivation, or activity modulation. This review will focus on the structural features of the CB1 receptor, mutations known to bias its signaling, and reported studies of CB1 receptor ligands to control its specific signaling.
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Affiliation(s)
- Rufaida Al-Zoubi
- Department of Medicinal Chemistry and Pharmacognosy, Faculty of Pharmacy, Jordan University of Science & Technology, P.O.BOX 3030, Irbid 22110, Jordan.
| | - Paula Morales
- Departamento de Química-Física Biológica, Instituto de Química Física Rocasolano (IQFR-CSIC), Serrano 119, 28006 Madrid, Spain.
| | - Patricia H Reggio
- Chemistry and Biochemistry Department, UNC Greensboro, Greensboro, NC 27412, USA.
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26
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Gurevich VV, Gurevich EV. The structural basis of the arrestin binding to GPCRs. Mol Cell Endocrinol 2019; 484:34-41. [PMID: 30703488 PMCID: PMC6377262 DOI: 10.1016/j.mce.2019.01.019] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 01/04/2019] [Accepted: 01/17/2019] [Indexed: 12/12/2022]
Abstract
G protein-coupled receptors (GPCRs) are the largest family of signaling proteins targeted by more clinically used drugs than any other protein family. GPCR signaling via G proteins is quenched (desensitized) by the phosphorylation of the active receptor by specific GPCR kinases (GRKs) followed by tight binding of arrestins to active phosphorylated receptors. Thus, arrestins engage two types of receptor elements: those that contain GRK-added phosphates and those that change conformation upon activation. GRKs attach phosphates to serines and threonines in the GPCR C-terminus or any one of the cytoplasmic loops. In addition to these phosphates, arrestins engage the cavity that appears between trans-membrane helices upon receptor activation and several other non-phosphorylated elements. The residues that bind GPCRs are localized on the concave side of both arrestin domains. Arrestins undergo a global conformational change upon receptor binding (become activated). Arrestins serve as important hubs of cellular signaling, emanating from activated GPCRs and receptor-independent.
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Affiliation(s)
- Vsevolod V Gurevich
- Department of Pharmacology, Vanderbilt University, Nashville, TN, 37232, USA.
| | - Eugenia V Gurevich
- Department of Pharmacology, Vanderbilt University, Nashville, TN, 37232, USA
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27
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Littmann T, Buschauer A, Bernhardt G. Split luciferase-based assay for simultaneous analyses of the ligand concentration- and time-dependent recruitment of β-arrestin2. Anal Biochem 2019; 573:8-16. [PMID: 30853375 DOI: 10.1016/j.ab.2019.02.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 02/22/2019] [Accepted: 02/25/2019] [Indexed: 12/17/2022]
Abstract
Functional selectivity of agonists has gained increasing interest in G protein-coupled receptor (GPCR) research, e.g. due to expectations of drugs with reduced adverse effects. Different agonist-dependent GPCR conformations are conceived to selectively activate a balanced or imbalanced intracellular signalling response, involving e.g. different Gα subtypes, Gβγ-subunits and β-arrestins. To discriminate between the different signalling pathways (bias), sensitive techniques are needed that do not interfere with signalling. We applied split luciferase complementation to the GPCR/β-arrestin2 interaction and thoroughly analysed the influence of its implementation on intracellular signalling. This led to an assay enabling the functional characterization of ligands at the hH1R, the hM1,5R and the hNTS1R in live HEK293T cells. As demonstrated at the hM1,5R, the assay was sensitive enough to identify iperoxo as a superagonist. Time-dependent analyses of the recruitment of β-arrestin2 became possible, allowing the identification of class A and class B GPCRs, due to the differential duration of their interaction with β-arrestin2 and their recycling to the cell membrane. The developed β-arrestin2 recruitment assay, which provides concentration- and time-dependent information on the interaction between GPCRs and β-arrestin2 upon stimulation of the receptor, should be broadly applicable and of high value for the analysis of agonist bias.
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Affiliation(s)
- Timo Littmann
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053, Regensburg, Germany.
| | - Armin Buschauer
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053, Regensburg, Germany
| | - Günther Bernhardt
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053, Regensburg, Germany.
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28
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Gurevich VV, Gurevich EV. GPCR Signaling Regulation: The Role of GRKs and Arrestins. Front Pharmacol 2019; 10:125. [PMID: 30837883 PMCID: PMC6389790 DOI: 10.3389/fphar.2019.00125] [Citation(s) in RCA: 353] [Impact Index Per Article: 58.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 01/31/2019] [Indexed: 12/13/2022] Open
Abstract
Every animal species expresses hundreds of different G protein-coupled receptors (GPCRs) that respond to a wide variety of external stimuli. GPCRs-driven signaling pathways are involved in pretty much every physiological function and in many pathologies. Therefore, GPCRs are targeted by about a third of clinically used drugs. The signaling of most GPCRs via G proteins is terminated by the phosphorylation of active receptor by specific kinases (GPCR kinases, or GRKs) and subsequent binding of arrestin proteins, that selectively recognize active phosphorylated receptors. In addition, GRKs and arrestins play a role in multiple signaling pathways in the cell, both GPCR-initiated and receptor-independent. Here we focus on the mechanisms of GRK- and arrestin-mediated regulation of GPCR signaling, which includes homologous desensitization and redirection of signaling to additional pathways by bound arrestins.
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Affiliation(s)
- Vsevolod V Gurevich
- Department of Pharmacology, Vanderbilt University, Nashville, TN, United States
| | - Eugenia V Gurevich
- Department of Pharmacology, Vanderbilt University, Nashville, TN, United States
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29
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Klein MO, Battagello DS, Cardoso AR, Hauser DN, Bittencourt JC, Correa RG. Dopamine: Functions, Signaling, and Association with Neurological Diseases. Cell Mol Neurobiol 2019; 39:31-59. [PMID: 30446950 DOI: 10.1007/s10571-018-0632-3] [Citation(s) in RCA: 519] [Impact Index Per Article: 86.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 11/02/2018] [Indexed: 02/07/2023]
Abstract
The dopaminergic system plays important roles in neuromodulation, such as motor control, motivation, reward, cognitive function, maternal, and reproductive behaviors. Dopamine is a neurotransmitter, synthesized in both central nervous system and the periphery, that exerts its actions upon binding to G protein-coupled receptors. Dopamine receptors are widely expressed in the body and function in both the peripheral and the central nervous systems. Dopaminergic signaling pathways are crucial to the maintenance of physiological processes and an unbalanced activity may lead to dysfunctions that are related to neurodegenerative diseases. Unveiling the neurobiology and the molecular mechanisms that underlie these illnesses may contribute to the development of new therapies that could promote a better quality of life for patients worldwide. In this review, we summarize the aspects of dopamine as a catecholaminergic neurotransmitter and discuss dopamine signaling pathways elicited through dopamine receptor activation in normal brain function. Furthermore, we describe the potential involvement of these signaling pathways in evoking the onset and progression of some diseases in the nervous system, such as Parkinson's, Schizophrenia, Huntington's, Attention Deficit and Hyperactivity Disorder, and Addiction. A brief description of new dopaminergic drugs recently approved and under development treatments for these ailments is also provided.
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Affiliation(s)
- Marianne O Klein
- Laboratory of Chemical Neuroanatomy, Department of Anatomy, Institute of Biomedical Sciences, University of São Paulo (USP), São Paulo, 05508-000, Brazil
| | - Daniella S Battagello
- Laboratory of Chemical Neuroanatomy, Department of Anatomy, Institute of Biomedical Sciences, University of São Paulo (USP), São Paulo, 05508-000, Brazil
| | - Ariel R Cardoso
- Laboratory of Chemical Neuroanatomy, Department of Anatomy, Institute of Biomedical Sciences, University of São Paulo (USP), São Paulo, 05508-000, Brazil
| | - David N Hauser
- Center for Translational Neuroscience, Sanford Burnham Prebys (SBP) Medical Discovery Institute, 10901 North Torrey Pines Rd., La Jolla, CA, 92037, USA
| | - Jackson C Bittencourt
- Laboratory of Chemical Neuroanatomy, Department of Anatomy, Institute of Biomedical Sciences, University of São Paulo (USP), São Paulo, 05508-000, Brazil.
- Center for Neuroscience and Behavior, Institute of Psychology, USP, São Paulo, Brazil.
| | - Ricardo G Correa
- Center for Translational Neuroscience, Sanford Burnham Prebys (SBP) Medical Discovery Institute, 10901 North Torrey Pines Rd., La Jolla, CA, 92037, USA.
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30
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Hendrickx JO, van Gastel J, Leysen H, Santos-Otte P, Premont RT, Martin B, Maudsley S. GRK5 - A Functional Bridge Between Cardiovascular and Neurodegenerative Disorders. Front Pharmacol 2018; 9:1484. [PMID: 30618771 PMCID: PMC6304357 DOI: 10.3389/fphar.2018.01484] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 12/03/2018] [Indexed: 12/15/2022] Open
Abstract
Complex aging-triggered disorders are multifactorial programs that comprise a myriad of alterations in interconnected protein networks over a broad range of tissues. It is evident that rather than being randomly organized events, pathophysiologies that possess a strong aging component such as cardiovascular diseases (hypertensions, atherosclerosis, and vascular stiffening) and neurodegenerative conditions (dementia, Alzheimer's disease, mild cognitive impairment, Parkinson's disease), in essence represent a subtly modified version of the intricate molecular programs already in place for normal aging. To control such multidimensional activities there are layers of trophic protein control across these networks mediated by so-called "keystone" proteins. We propose that these "keystones" coordinate and interconnect multiple signaling pathways to control whole somatic activities such as aging-related disease etiology. Given its ability to control multiple receptor sensitivities and its broad protein-protein interactomic nature, we propose that G protein coupled receptor kinase 5 (GRK5) represents one of these key network controllers. Considerable data has emerged, suggesting that GRK5 acts as a bridging factor, allowing signaling regulation in pathophysiological settings to control the connectivity between both the cardiovascular and neurophysiological complications of aging.
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Affiliation(s)
- Jhana O. Hendrickx
- Department of Biomedical Science, University of Antwerp, Antwerp, Belgium
- Center for Molecular Neurology, University of Antwerp – Flanders Institute for Biotechnology (VIB), Antwerp, Belgium
| | - Jaana van Gastel
- Department of Biomedical Science, University of Antwerp, Antwerp, Belgium
- Center for Molecular Neurology, University of Antwerp – Flanders Institute for Biotechnology (VIB), Antwerp, Belgium
| | - Hanne Leysen
- Department of Biomedical Science, University of Antwerp, Antwerp, Belgium
- Center for Molecular Neurology, University of Antwerp – Flanders Institute for Biotechnology (VIB), Antwerp, Belgium
| | - Paula Santos-Otte
- Institute of Biophysics, Humboldt-Universitat zu Berlin, Berlin, Germany
| | - Richard T. Premont
- Harrington Discovery Institute, Case Western Reserve University, Cleveland, GA, United States
| | - Bronwen Martin
- Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Antwerp, Belgium
| | - Stuart Maudsley
- Department of Biomedical Science, University of Antwerp, Antwerp, Belgium
- Center for Molecular Neurology, University of Antwerp – Flanders Institute for Biotechnology (VIB), Antwerp, Belgium
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31
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Haque ME, Kim IS, Jakaria M, Akther M, Choi DK. Importance of GPCR-Mediated Microglial Activation in Alzheimer's Disease. Front Cell Neurosci 2018; 12:258. [PMID: 30186116 PMCID: PMC6110855 DOI: 10.3389/fncel.2018.00258] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 07/30/2018] [Indexed: 12/11/2022] Open
Abstract
Alzheimer’s disease (AD) is a progressive neurodegenerative disorder associated with impairment of cognition, memory deficits and behavioral abnormalities. Accumulation of amyloid beta (Aβ) is a characteristic hallmark of AD. Microglia express several GPCRs, which, upon activation by modulators, mediate microglial activation and polarization phenotype. This GPCR-mediated microglial activation has both protective and detrimental effects. Microglial GPCRs are involved in amyloid precursor protein (APP) cleavage and Aβ generation. In addition, microglial GPCRs are featured in the regulation of Aβ degradation and clearance through microglial phagocytosis and chemotaxis. Moreover, in response to Aβ binding on microglial Aβ receptors, they can trigger multiple inflammatory pathways. However, there is still a lack of insight into the mechanistic link between GPCR-mediated microglial activation and its pathological consequences in AD. Currently, the available drugs for the treatment of AD are mostly symptomatic and dominated by acetylcholinesterase inhibitors (AchEI). The selection of a specific microglial GPCR that is highly expressed in the AD brain and capable of modulating AD progression through Aβ generation, degradation and clearance will be a potential source of therapeutic intervention. Here, we have highlighted the expression and distribution of various GPCRs connected to microglial activation in the AD brain and their potential to serve as therapeutic targets of AD.
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Affiliation(s)
- Md Ezazul Haque
- Department of Applied Life Science, Graduate School, Konkuk University, Chungju, South Korea
| | - In-Su Kim
- Department of Integrated Bioscience and Biotechnology, College of Biomedical and Health Science, Research Institute of Inflammatory Disease, Konkuk University, Chungju, South Korea
| | - Md Jakaria
- Department of Applied Life Science, Graduate School, Konkuk University, Chungju, South Korea
| | - Mahbuba Akther
- Department of Applied Life Science, Graduate School, Konkuk University, Chungju, South Korea
| | - Dong-Kug Choi
- Department of Applied Life Science, Graduate School, Konkuk University, Chungju, South Korea.,Department of Integrated Bioscience and Biotechnology, College of Biomedical and Health Science, Research Institute of Inflammatory Disease, Konkuk University, Chungju, South Korea
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32
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Gurevich VV, Gurevich EV. GPCRs and Signal Transducers: Interaction Stoichiometry. Trends Pharmacol Sci 2018; 39:672-684. [PMID: 29739625 DOI: 10.1016/j.tips.2018.04.002] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 04/11/2018] [Accepted: 04/13/2018] [Indexed: 12/12/2022]
Abstract
Until the late 1990s, class A G protein-coupled receptors (GPCRs) were believed to function as monomers. Indirect evidence that they might internalize or even signal as dimers has emerged, along with proof that class C GPCRs are obligatory dimers. Crystal structures of GPCRs and their much larger binding partners were consistent with the idea that two receptors might engage a single G protein, GRK, or arrestin. However, recent biophysical, biochemical, and structural evidence invariably suggests that a single GPCR binds G proteins, GRKs, and arrestins. Here we review existing evidence of the stoichiometry of GPCR interactions with signal transducers and discuss potential biological roles of class A GPCR oligomers, including proposed homo- and heterodimers.
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Affiliation(s)
- Vsevolod V Gurevich
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA.
| | - Eugenia V Gurevich
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
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Yes-associated protein (YAP) in pancreatic cancer: at the epicenter of a targetable signaling network associated with patient survival. Signal Transduct Target Ther 2018; 3:11. [PMID: 29682330 PMCID: PMC5908807 DOI: 10.1038/s41392-017-0005-2] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 11/27/2017] [Accepted: 12/13/2017] [Indexed: 12/14/2022] Open
Abstract
Pancreatic ductal adenocarcinoma (PDAC) is generally a fatal disease with no efficacious treatment modalities. Elucidation of signaling mechanisms that will lead to the identification of novel targets for therapy and chemoprevention is urgently needed. Here, we review the role of Yes-associated protein (YAP) and WW-domain-containing Transcriptional co-Activator with a PDZ-binding motif (TAZ) in the development of PDAC. These oncogenic proteins are at the center of a signaling network that involves multiple upstream signals and downstream YAP-regulated genes. We also discuss the clinical significance of the YAP signaling network in PDAC using a recently published interactive open-access database (www.proteinatlas.org/pathology) that allows genome-wide exploration of the impact of individual proteins on survival outcomes. Multiple YAP/TEAD-regulated genes, including AJUBA, ANLN, AREG, ARHGAP29, AURKA, BUB1, CCND1, CDK6, CXCL5, EDN2, DKK1, FOSL1,FOXM1, HBEGF, IGFBP2, JAG1, NOTCH2, RHAMM, RRM2, SERP1, and ZWILCH, are associated with unfavorable survival of PDAC patients. Similarly, components of AP-1 that synergize with YAP (FOSL1), growth factors (TGFα, EPEG, and HBEGF), a specific integrin (ITGA2), heptahelical receptors (P2Y2R, GPR87) and an inhibitor of the Hippo pathway (MUC1), all of which stimulate YAP activity, are associated with unfavorable survival of PDAC patients. By contrast, YAP inhibitory pathways (STRAD/LKB-1/AMPK, PKA/LATS, and TSC/mTORC1) indicate a favorable prognosis. These associations emphasize that the YAP signaling network correlates with poor survival of pancreatic cancer patients. We conclude that the YAP pathway is a major determinant of clinical aggressiveness in PDAC patients and a target for therapeutic and preventive strategies in this disease. Yes-associated protein (YAP) signaling contributes to pancreatic cancer progression and is associated with poor patient survival. Previous studies have shown that YAP activates genes involved in cell proliferation to incite tumor growth and metastasis. Enrique Rozengurt and colleagues at University of California Los Angeles review the latest knowledge on YAP signaling and used the open access database The Human Protein Atlas to analyze the gene expression profile and prognosis of 176 patients with pancreatic ductal adenocarcinoma. Activation of upstream or downstream elements of the YAP signaling pathway correlated with shorter survival in patients. Conversely, the activation of signaling pathways that oppose YAP signaling were associated with a more favorable prognosis. These findings highlight YAP signaling pathway components as both prognostic markers and potential targets for developing much needed therapeutic and preventative strategies.
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Steury MD, Kang HJ, Lee T, Lucas PC, McCabe LR, Parameswaran N. G protein-coupled receptor kinase-2-deficient mice are protected from dextran sodium sulfate-induced acute colitis. Physiol Genomics 2018; 50:407-415. [PMID: 29570431 DOI: 10.1152/physiolgenomics.00006.2018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
G protein-coupled receptor kinase 2 (GRK2) is a serine/threonine kinase and plays a key role in different disease processes. Previously, we showed that GRK2 knockdown enhances wound healing in colonic epithelial cells. Therefore, we hypothesized that ablation of GRK2 would protect mice from dextran sodium sulfate (DSS)-induced acute colitis. To test this, we administered DSS to wild-type (GRK2+/+) and GRK2 heterozygous (GRK+/-) mice in their drinking water for 7 days. As predicted, GRK2+/- mice were protected from colitis as demonstrated by decreased weight loss (20% loss in GRK2+/+ vs. 11% loss in GRK2+/-). lower disease activity index (GRK2+/+ 9.1 vs GRK2+/- 4.1), and increased colon lengths (GRK2+/+ 4.7 cm vs GRK2+/- 5.3 cm). To examine the mechanisms by which GRK2+/- mice are protected from colitis, we investigated expression of inflammatory genes in the colon as well as immune cell profiles in colonic lamina propria, mesenteric lymph node, and in bone marrow. Our results did not reveal differences in immune cell profiles between the two genotypes. However, expression of inflammatory genes was significantly decreased in DSS-treated GRK2+/- mice compared with GRK2+/+. To understand the mechanisms, we generated myeloid-specific GRK2 knockout mice and subjected them to DSS-induced colitis. Similar to whole body GRK2 heterozygous knockout mice, myeloid-specific knockout of GRK2 was sufficient for the protection from DSS-induced colitis. Together our results indicate that deficiency of GRK2 protects mice from DSS-induced colitis and further suggests that the mechanism of this effect is likely via GRK2 regulation of inflammatory genes in the myeloid cells.
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Affiliation(s)
- Michael D Steury
- Department of Physiology, Michigan State University , East Lansing, Michigan
| | - Ho Jun Kang
- Department of Physiology, Michigan State University , East Lansing, Michigan
| | - Taehyung Lee
- Department of Physiology, Michigan State University , East Lansing, Michigan
| | - Peter C Lucas
- Department of Pathology, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Laura R McCabe
- Department of Physiology, Michigan State University , East Lansing, Michigan
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Signal transduction in L-DOPA-induced dyskinesia: from receptor sensitization to abnormal gene expression. J Neural Transm (Vienna) 2018; 125:1171-1186. [PMID: 29396608 PMCID: PMC6060907 DOI: 10.1007/s00702-018-1847-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 01/23/2018] [Indexed: 01/06/2023]
Abstract
A large number of signaling abnormalities have been implicated in the emergence and expression of l-DOPA-induced dyskinesia (LID). The primary cause for many of these changes is the development of sensitization at dopamine receptors located on striatal projection neurons (SPN). This initial priming, which is particularly evident at the level of dopamine D1 receptors (D1R), can be viewed as a homeostatic response to dopamine depletion and is further exacerbated by chronic administration of l-DOPA, through a variety of mechanisms affecting various components of the G-protein-coupled receptor machinery. Sensitization of dopamine receptors in combination with pulsatile administration of l-DOPA leads to intermittent and coordinated hyperactivation of signal transduction cascades, ultimately resulting in long-term modifications of gene expression and protein synthesis. A detailed mapping of these pathological changes and of their involvement in LID has been produced during the last decade. According to this emerging picture, activation of sensitized D1R results in the stimulation of cAMP-dependent protein kinase and of the dopamine- and cAMP-regulated phosphoprotein of 32 kDa. This, in turn, activates the extracellular signal-regulated kinases 1 and 2 (ERK), leading to chromatin remodeling and aberrant gene transcription. Dysregulated ERK results also in the stimulation of the mammalian target of rapamycin complex 1, which promotes protein synthesis. Enhanced levels of multiple effector targets, including several transcription factors have been implicated in LID and associated changes in synaptic plasticity and morphology. This article provides an overview of the intracellular modifications occurring in SPN and associated with LID.
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Steury MD, McCabe LR, Parameswaran N. G Protein-Coupled Receptor Kinases in the Inflammatory Response and Signaling. Adv Immunol 2017; 136:227-277. [PMID: 28950947 DOI: 10.1016/bs.ai.2017.05.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
G protein-coupled receptor kinases (GRKs) are serine/threonine kinases that regulate a large and diverse class of G protein-coupled receptors (GPCRs). Through GRK phosphorylation and β-arrestin recruitment, GPCRs are desensitized and their signal terminated. Recent work on these kinases has expanded their role from canonical GPCR regulation to include noncanonical regulation of non-GPCR and nonreceptor substrates through phosphorylation as well as via scaffolding functions. Owing to these and other regulatory roles, GRKs have been shown to play a critical role in the outcome of a variety of physiological and pathophysiological processes including chemotaxis, signaling, migration, inflammatory gene expression, etc. This diverse set of functions for these proteins makes them popular targets for therapeutics. Role for these kinases in inflammation and inflammatory disease is an evolving area of research currently pursued in many laboratories. In this review, we describe the current state of knowledge on various GRKs pertaining to their role in inflammation and inflammatory diseases.
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Affiliation(s)
| | - Laura R McCabe
- Michigan State University, East Lansing, MI, United States
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Pereira MSL, Klamt F, Thomé CC, Worm PV, de Oliveira DL. Metabotropic glutamate receptors as a new therapeutic target for malignant gliomas. Oncotarget 2017; 8:22279-22298. [PMID: 28212543 PMCID: PMC5400663 DOI: 10.18632/oncotarget.15299] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 01/03/2017] [Indexed: 12/21/2022] Open
Abstract
Metabotropic glutamate receptors (mGluR) are predominantly involved in maintenance of cellular homeostasis of central nervous system. However, evidences have suggested other roles of mGluR in human tumors. Aberrant mGluR signaling has been shown to participate in transformation and maintenance of various cancer types, including malignant brain tumors. This review intends to summarize recent findings regarding the involvement of mGluR-mediated intracellular signaling pathways in progression, aggressiveness, and recurrence of malignant gliomas, mainly glioblastomas (GBM), highlighting the potential therapeutic applications of mGluR ligands. In addition to the growing number of studies reporting mGluR gene or protein expression in glioma samples (resections, lineages, and primary cultures), pharmacological blockade in vitro of mGluR1 and mGluR3 by selective ligands has been shown to be anti-proliferative and anti-migratory, decreasing activation of MAPK and PI3K pathways. In addition, mGluR3 antagonists promoted astroglial differentiation of GBM cells and also enabled cytotoxic action of temozolomide (TMZ). mGluR3-dependent TMZ toxicity was supported by increasing levels of MGMT transcripts through an intracellular signaling pathway that sequentially involves PI3K and NF-κB. Further, continuous pharmacological blockade of mGluR1 and mGluR3 have been shown to reduced growth of GBM tumor in two independent in vivo xenograft models. In parallel, low levels of mGluR3 mRNA in GBM resections may be a predictor for long survival rate of patients. Since several Phase I, II and III clinical trials are being performed using group I and II mGluR modulators, there is a strong scientifically-based rationale for testing mGluR antagonists as an adjuvant therapy for malignant brain tumors.
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Affiliation(s)
- Mery Stefani Leivas Pereira
- Department of Biochemistry, Laboratory of Cellular Neurochemistry, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre RS, Brazil
| | - Fábio Klamt
- Department of Biochemistry, Laboratory of Cellular Biochemistry, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre RS, Brazil
| | - Chairini Cássia Thomé
- Department of Biochemistry, Laboratory of Cellular Neurochemistry, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre RS, Brazil
| | - Paulo Valdeci Worm
- Department of Neurosurgery, Cristo Redentor Hospital – GHC – Porto Alegre RS, Brazil
- Department of Neurosurgery, São José Hospital, Complexo Hospitalar Santa Casa, Porto Alegre RS, Brazil
| | - Diogo Losch de Oliveira
- Department of Biochemistry, Laboratory of Cellular Neurochemistry, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre RS, Brazil
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Gurevich EV, Gainetdinov RR, Gurevich VV. G protein-coupled receptor kinases as regulators of dopamine receptor functions. Pharmacol Res 2016; 111:1-16. [PMID: 27178731 DOI: 10.1016/j.phrs.2016.05.010] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 05/03/2016] [Accepted: 05/06/2016] [Indexed: 02/08/2023]
Abstract
Actions of the neurotransmitter dopamine in the brain are mediated by dopamine receptors that belong to the superfamily of G protein-coupled receptors (GPCRs). Mammals have five dopamine receptor subtypes, D1 through D5. D1 and D5 couple to Gs/olf and activate adenylyl cyclase, whereas D2, D3, and D4 couple to Gi/o and inhibit it. Most GPCRs upon activation by an agonist are phosphorylated by GPCR kinases (GRKs). The GRK phosphorylation makes receptors high-affinity binding partners for arrestin proteins. Arrestin binding to active phosphorylated receptors stops further G protein activation and promotes receptor internalization, recycling or degradation, thereby regulating their signaling and trafficking. Four non- visual GRKs are expressed in striatal neurons. Here we describe known effects of individual GRKs on dopamine receptors in cell culture and in the two in vivo models of dopamine-mediated signaling: behavioral response to psychostimulants and L-DOPA- induced dyskinesia. Dyskinesia, associated with dopamine super-sensitivity of striatal neurons, is a debilitating side effect of L-DOPA therapy in Parkinson's disease. In vivo, GRK subtypes show greater receptor specificity than in vitro or in cultured cells. Overexpression, knockdown, and knockout of individual GRKs, particularly GRK2 and GRK6, have differential effects on signaling of dopamine receptor subtypes in the brain. Furthermore, deletion of GRK isoforms in select striatal neuronal types differentially affects psychostimulant-induced behaviors. In addition, anti-dyskinetic effect of GRK3 does not require its kinase activity: it is mediated by the binding of its RGS-like domain to Gαq/11, which suppresses Gq/11 signaling. The data demonstrate that the dopamine signaling in defined neuronal types in vivo is regulated by specific and finely orchestrated actions of GRK isoforms.
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Affiliation(s)
- Eugenia V Gurevich
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37221, USA.
| | - Raul R Gainetdinov
- Institute of Translational Biomedicine, St. Petersburg State University, St. Petersburg, 199034, Russia; Skolkovo Institute of Science and Technology, Skolkovo, 143025, Moscow, Russia
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Penela P. Chapter Three - Ubiquitination and Protein Turnover of G-Protein-Coupled Receptor Kinases in GPCR Signaling and Cellular Regulation. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2016; 141:85-140. [PMID: 27378756 DOI: 10.1016/bs.pmbts.2016.04.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
G-protein-coupled receptors (GPCRs) are responsible for regulating a wide variety of physiological processes, and distinct mechanisms for GPCR inactivation exist to guarantee correct receptor functionality. One of the widely used mechanisms is receptor phosphorylation by specific G-protein-coupled receptor kinases (GRKs), leading to uncoupling from G proteins (desensitization) and receptor internalization. GRKs and β-arrestins also participate in the assembly of receptor-associated multimolecular complexes, thus initiating alternative G-protein-independent signaling events. In addition, the abundant GRK2 kinase has diverse "effector" functions in cellular migration, proliferation, and metabolism homeostasis by means of the phosphorylation or interaction with non-GPCR partners. Altered expression of GRKs (particularly of GRK2 and GRK5) occurs during pathological conditions characterized by impaired GPCR signaling including inflammatory syndromes, cardiovascular disease, and tumor contexts. It is increasingly appreciated that different pathways governing GRK protein stability play a role in the modulation of kinase levels in normal and pathological conditions. Thus, enhanced GRK2 degradation by the proteasome pathway occurs upon GPCR stimulation, what allows cellular adaptation to chronic stimulation in a physiological setting. β-arrestins participate in this process by facilitating GRK2 phosphorylation by different kinases and by recruiting diverse E3 ubiquitin ligase to the receptor complex. Different proteolytic systems (ubiquitin-proteasome, calpains), chaperone activities and signaling pathways influence the stability of GRKs in different ways, thus endowing specificity to GPCR regulation as protein turnover of GRKs can be differentially affected. Therefore, modulation of protein stability of GRKs emerges as a versatile mechanism for feedback regulation of GPCR signaling and basic cellular processes.
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Affiliation(s)
- P Penela
- Department of Molecular Biology and Centre of Molecular Biology "Severo Ochoa" (CSIC-UAM), Madrid, Autonomous University of Madrid, Madrid, Spain; Spain Health Research Institute The Princesa, Madrid, Spain.
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Yu LJ, Wall BA, Wangari-Talbot J, Chen S. Metabotropic glutamate receptors in cancer. Neuropharmacology 2016; 115:193-202. [PMID: 26896755 DOI: 10.1016/j.neuropharm.2016.02.011] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 02/07/2016] [Accepted: 02/09/2016] [Indexed: 01/31/2023]
Abstract
Metabotropic glutamate receptors (mGluRs) are widely known for their roles in synaptic signaling. However, accumulating evidence suggests roles of mGluRs in human malignancies in addition to synaptic transmission. Somatic cell homeostasis presents intriguing possibilities of mGluRs and glutamate signaling as novel targets for human cancers. More recently, aberrant glutamate signaling has been shown to participate in the transformation and maintenance of various cancer types, including glioma, melanoma skin cancer, breast cancer, and prostate cancer, indicating that genes encoding mGluRs, GRMs, can function as oncogenes. Here, we provide a review on the interactions of mGluRs and their ligand, glutamate, in processes that promote the growth of tumors of neuronal and non-neuronal origins. Further, we discuss the evolution of riluzole, a glutamate release inhibitor approved for amyotrophic lateral sclerosis (ALS), but now fashioned as an mGluR1 inhibitor for melanoma therapy and as a radio-sensitizer for tumors that have metastasized to the brain. With the success of riluzole, it is not far-fetched to believe that other drugs that may act directly or indirectly on other mGluRs can be beneficial for multiple applications. This article is part of the Special Issue entitled 'Metabotropic Glutamate Receptors, 5 years on'.
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Affiliation(s)
- Lumeng J Yu
- Susan Lehman Cullman Laboratory for Cancer Research, Ernest Mario School of Pharmacy, Rutgers University, NJ, USA
| | - Brian A Wall
- Susan Lehman Cullman Laboratory for Cancer Research, Ernest Mario School of Pharmacy, Rutgers University, NJ, USA; Global Product Safety, Colgate-Palmolive Company, Piscataway, NJ, USA
| | - Janet Wangari-Talbot
- Susan Lehman Cullman Laboratory for Cancer Research, Ernest Mario School of Pharmacy, Rutgers University, NJ, USA
| | - Suzie Chen
- Susan Lehman Cullman Laboratory for Cancer Research, Ernest Mario School of Pharmacy, Rutgers University, NJ, USA; The Cancer Institute of New Jersey, 195 Little Albany Street, New Brunswick, NJ 08903, USA.
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Gurevich EV, Gainetdinov RR, Gurevich VV. Regulation of Dopamine-Dependent Behaviors by G Protein-Coupled Receptor Kinases. METHODS IN PHARMACOLOGY AND TOXICOLOGY 2016. [DOI: 10.1007/978-1-4939-3798-1_11] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Receptor, Ligand and Transducer Contributions to Dopamine D2 Receptor Functional Selectivity. PLoS One 2015; 10:e0141637. [PMID: 26516769 PMCID: PMC4627803 DOI: 10.1371/journal.pone.0141637] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 10/12/2015] [Indexed: 12/20/2022] Open
Abstract
Functional selectivity (or biased agonism) is a property exhibited by some G protein-coupled receptor (GPCR) ligands, which results in the modulation of a subset of a receptor's signaling capabilities and more precise control over complex biological processes. The dopamine D2 receptor (D2R) exhibits pleiotropic responses to the biogenic amine dopamine (DA) to mediate complex central nervous system functions through activation of G proteins and β-arrestins. D2R is a prominent therapeutic target for psychological and neurological disorders in which DA biology is dysregulated and targeting D2R with functionally selective drugs could provide a means by which pharmacotherapies could be developed. However, factors that determine GPCR functional selectivity in vivo may be multiple with receptors, ligands and transducers contributing to the process. We have recently described a mutagenesis approach to engineer biased D2R mutants in which G protein-dependent ([Gprot]D2R) and β-arrestin-dependent signaling ([βarr]D2R) were successfully separated (Peterson, et al. PNAS, 2015). Here, permutations of these mutants were used to identify critical determinants of the D2R signaling complex that impart signaling bias in response to the natural or synthetic ligands. Critical residues identified in generating [Gprot]D2R and [βarr]D2R conferred control of partial agonism at G protein and/or β-arrestin activity. Another set of mutations that result in G protein bias was identified that demonstrated that full agonists can impart unique activation patterns, and provided further credence to the concept of ligand texture. Finally, the contributions and interplay between different transducers indicated that G proteins are not aberrantly activated, and that receptor kinase and β-arrestin activities are inextricably linked. These data provide a thorough elucidation of the feasibility and malleability of D2R functional selectivity and point to means by which novel in vivo therapies could be modeled.
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Abstract
G-protein-coupled receptor kinases (GRKs) are serine/threonine protein kinases originally discovered for their role in G-protein-coupled receptor (GPCR) phosphorylation. Recent studies have demonstrated a much broader function for this kinase family including phosphorylation of cytosolic substrates involved in cell signaling pathways stimulated by GPCRs, as well as by non-GPCRs. In addition, GRKs modulate signaling via phosphorylation-independent functions. Because of these various biochemical functions, GRKs have been shown to affect critical physiological and pathophysiological processes, and thus are considered as drug targets in diseases such as heart failure. Role of GRKs in inflammation and inflammatory diseases is an evolving area of research and several studies including work from our lab in the recent years have demonstrated critical role of GRKs in the immune system. In this review, we discuss the classical and the newly emerging functions of GRKs in the immune system and their role in inflammation and disease processes.
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Inagaki S, Ghirlando R, Vishnivetskiy SA, Homan KT, White JF, Tesmer JJG, Gurevich VV, Grisshammer R. G Protein-Coupled Receptor Kinase 2 (GRK2) and 5 (GRK5) Exhibit Selective Phosphorylation of the Neurotensin Receptor in Vitro. Biochemistry 2015; 54:4320-9. [PMID: 26120872 PMCID: PMC4512254 DOI: 10.1021/acs.biochem.5b00285] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
![]()
G protein-coupled
receptor kinases (GRKs) play an important role
in the desensitization of G protein-mediated signaling of G protein-coupled
receptors (GPCRs). The level of interest in mapping their phosphorylation
sites has increased because recent studies suggest that the differential
pattern of receptor phosphorylation has distinct biological consequences. In vitro phosphorylation experiments using well-controlled
systems are useful for deciphering the complexity of these physiological
reactions and understanding the targeted event. Here, we report on
the phosphorylation of the class A GPCR neurotensin receptor 1 (NTSR1)
by GRKs under defined experimental conditions afforded by nanodisc
technology. Phosphorylation of NTSR1 by GRK2 was agonist-dependent,
whereas phosphorylation by GRK5 occurred in an activation-independent
manner. In addition, the negatively charged lipids in the immediate
vicinity of NTSR1 directly affect phosphorylation by GRKs. Identification
of phosphorylation sites in agonist-activated NTSR1 revealed that
GRK2 and GRK5 target different residues located on the intracellular
receptor elements. GRK2 phosphorylates only the C-terminal Ser residues,
whereas GRK5 phosphorylates Ser and Thr residues located in intracellular
loop 3 and the C-terminus. Interestingly, phosphorylation assays using
a series of NTSR1 mutants show that GRK2 does not require acidic residues
upstream of the phospho-acceptors for site-specific phosphorylation,
in contrast to the β2-adrenergic and μ-opioid
receptors. Differential phosphorylation of GPCRs by GRKs is thought
to encode a particular signaling outcome, and our in vitro study revealed NTSR1 differential phosphorylation by GRK2 and GRK5.
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Affiliation(s)
- Sayaka Inagaki
- †Membrane Protein Structure Function Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Department of Health and Human Services, Rockville, Maryland 20852, United States
| | - Rodolfo Ghirlando
- ‡Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland 20892, United States
| | - Sergey A Vishnivetskiy
- §Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Kristoff T Homan
- ∥Departments of Pharmacology and Biological Sciences, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Jim F White
- †Membrane Protein Structure Function Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Department of Health and Human Services, Rockville, Maryland 20852, United States
| | - John J G Tesmer
- ∥Departments of Pharmacology and Biological Sciences, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Vsevolod V Gurevich
- §Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Reinhard Grisshammer
- †Membrane Protein Structure Function Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Department of Health and Human Services, Rockville, Maryland 20852, United States
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Allen SJ, Parthasarathy G, Darke PL, Diehl RE, Ford RE, Hall DL, Johnson SA, Reid JC, Rickert KW, Shipman JM, Soisson SM, Zuck P, Munshi SK, Lumb KJ. Structure and Function of the Hypertension Variant A486V of G Protein-coupled Receptor Kinase 4. J Biol Chem 2015; 290:20360-73. [PMID: 26134571 DOI: 10.1074/jbc.m115.648907] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Indexed: 11/06/2022] Open
Abstract
G-protein-coupled receptor (GPCR) kinases (GRKs) bind to and phosphorylate GPCRs, initiating the process of GPCR desensitization and internalization. GRK4 is implicated in the regulation of blood pressure, and three GRK4 polymorphisms (R65L, A142V, and A486V) are associated with hypertension. Here, we describe the 2.6 Å structure of human GRK4α A486V crystallized in the presence of 5'-adenylyl β,γ-imidodiphosphate. The structure of GRK4α is similar to other GRKs, although slight differences exist within the RGS homology (RH) bundle subdomain, substrate-binding site, and kinase C-tail. The RH bundle subdomain and kinase C-terminal lobe form a strikingly acidic surface, whereas the kinase N-terminal lobe and RH terminal subdomain surfaces are much more basic. In this respect, GRK4α is more similar to GRK2 than GRK6. A fully ordered kinase C-tail reveals interactions linking the C-tail with important determinants of kinase activity, including the αB helix, αD helix, and the P-loop. Autophosphorylation of wild-type GRK4α is required for full kinase activity, as indicated by a lag in phosphorylation of a peptide from the dopamine D1 receptor without ATP preincubation. In contrast, this lag is not observed in GRK4α A486V. Phosphopeptide mapping by mass spectrometry indicates an increased rate of autophosphorylation of a number of residues in GRK4α A486V relative to wild-type GRK4α, including Ser-485 in the kinase C-tail.
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Affiliation(s)
- Samantha J Allen
- From Screening and Protein Sciences, Merck Research Laboratories, North Wales, Pennsylvania 19454 and
| | - Gopal Parthasarathy
- Structural Chemistry, Merck Research Laboratories, West Point, Pennsylvania 19486
| | - Paul L Darke
- From Screening and Protein Sciences, Merck Research Laboratories, North Wales, Pennsylvania 19454 and
| | - Ronald E Diehl
- From Screening and Protein Sciences, Merck Research Laboratories, North Wales, Pennsylvania 19454 and
| | - Rachael E Ford
- From Screening and Protein Sciences, Merck Research Laboratories, North Wales, Pennsylvania 19454 and
| | - Dawn L Hall
- From Screening and Protein Sciences, Merck Research Laboratories, North Wales, Pennsylvania 19454 and
| | - Scott A Johnson
- Structural Chemistry, Merck Research Laboratories, West Point, Pennsylvania 19486
| | - John C Reid
- Structural Chemistry, Merck Research Laboratories, West Point, Pennsylvania 19486
| | - Keith W Rickert
- From Screening and Protein Sciences, Merck Research Laboratories, North Wales, Pennsylvania 19454 and
| | - Jennifer M Shipman
- From Screening and Protein Sciences, Merck Research Laboratories, North Wales, Pennsylvania 19454 and
| | - Stephen M Soisson
- Structural Chemistry, Merck Research Laboratories, West Point, Pennsylvania 19486
| | - Paul Zuck
- From Screening and Protein Sciences, Merck Research Laboratories, North Wales, Pennsylvania 19454 and
| | - Sanjeev K Munshi
- From Screening and Protein Sciences, Merck Research Laboratories, North Wales, Pennsylvania 19454 and
| | - Kevin J Lumb
- From Screening and Protein Sciences, Merck Research Laboratories, North Wales, Pennsylvania 19454 and
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Structural dynamics and energetics underlying allosteric inactivation of the cannabinoid receptor CB1. Proc Natl Acad Sci U S A 2015; 112:8469-74. [PMID: 26100912 DOI: 10.1073/pnas.1500895112] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
G protein-coupled receptors (GPCRs) are surprisingly flexible molecules that can do much more than simply turn on G proteins. Some even exhibit biased signaling, wherein the same receptor preferentially activates different G-protein or arrestin signaling pathways depending on the type of ligand bound. Why this behavior occurs is still unclear, but it can happen with both traditional ligands and ligands that bind allosterically outside the orthosteric receptor binding pocket. Here, we looked for structural mechanisms underlying these phenomena in the marijuana receptor CB1. Our work focused on the allosteric ligand Org 27569, which has an unusual effect on CB1-it simultaneously increases agonist binding, decreases G--protein activation, and induces biased signaling. Using classical pharmacological binding studies, we find that Org 27569 binds to a unique allosteric site on CB1 and show that it can act alone (without need for agonist cobinding). Through mutagenesis studies, we find that the ability of Org 27569 to bind is related to how much receptor is in an active conformation that can couple with G protein. Using these data, we estimated the energy differences between the inactive and active states. Finally, site-directed fluorescence labeling studies show the CB1 structure stabilized by Org 27569 is different and unique from that stabilized by antagonist or agonist. Specifically, transmembrane helix 6 (TM6) movements associated with G-protein activation are blocked, but at the same time, helix 8/TM7 movements are enhanced, suggesting a possible mechanism for the ability of Org 27569 to induce biased signaling.
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GRK3 suppresses L-DOPA-induced dyskinesia in the rat model of Parkinson's disease via its RGS homology domain. Sci Rep 2015; 5:10920. [PMID: 26043205 PMCID: PMC4455246 DOI: 10.1038/srep10920] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 05/11/2015] [Indexed: 12/31/2022] Open
Abstract
Degeneration of dopaminergic neurons causes Parkinson’s disease. Dopamine replacement therapy with L-DOPA is the best available treatment. However, patients develop L-DOPA-induced dyskinesia (LID). In the hemiparkinsonian rat, chronic L-DOPA increases rotations and abnormal involuntary movements modeling LID, via supersensitive dopamine receptors. Dopamine receptors are controlled by G protein-coupled receptor kinases (GRKs). Here we demonstrate that LID is attenuated by overexpression of GRK3 in the striatum, whereas knockdown of GRK3 by microRNA exacerbated it. Kinase-dead GRK3 and its separated RGS homology domain (RH) suppressed sensitization to L-DOPA, whereas GRK3 with disabled RH did not. RH alleviated LID without compromising anti-akinetic effect of L-DOPA. RH binds striatal Gq. GRK3, kinase-dead GRK3, and RH inhibited accumulation of ∆FosB, a marker of LID. RH-dead mutant was ineffective, whereas GRK3 knockdown exacerbated ∆FosB accumulation. Our findings reveal a novel mechanism of GRK3 control of the dopamine receptor signaling and the role of Gq in LID.
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