1
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Kim K, Ashim J, Ham D, Yu W, Chung KY. Roles of the gate loop in β-arrestin-1 conformational dynamics and phosphorylated receptor interaction. Structure 2024:S0969-2126(24)00191-6. [PMID: 38889722 DOI: 10.1016/j.str.2024.05.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 04/11/2024] [Accepted: 05/22/2024] [Indexed: 06/20/2024]
Abstract
Arrestins interact with phosphorylated G protein-coupled receptors (GPCRs) and regulate the homologous desensitization and internalization of GPCRs. The gate loop in arrestins is a critical region for both stabilization of the basal state and interaction with phosphorylated receptors. We investigated the roles of specific residues in the gate loop (K292, K294, and H295) using β-arrestin-1 and phosphorylated C-tail peptide of vasopressin receptor type 2 (V2Rpp) as a model system. We measured the binding affinity of V2Rpp and analyzed conformational dynamics of β-arrestin-1. Our results suggest that K294 plays a critical role in the interaction with V2Rpp without influencing the overall conformation of the V2Rpp-bound state. The residues K292 and H295 contribute to the stability of the polar core in the basal state and form a specific conformation of the finger loop in the V2Rpp-bound state.
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Affiliation(s)
- Kiae Kim
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Janbolat Ashim
- Department of Brain Sciences, DGIST, Daegu 42988, Republic of Korea
| | - Donghee Ham
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Wookyung Yu
- Department of Brain Sciences, DGIST, Daegu 42988, Republic of Korea.
| | - Ka Young Chung
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea.
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2
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Gurevich VV. Arrestins: A Small Family of Multi-Functional Proteins. Int J Mol Sci 2024; 25:6284. [PMID: 38892473 PMCID: PMC11173308 DOI: 10.3390/ijms25116284] [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: 04/26/2024] [Revised: 05/24/2024] [Accepted: 05/31/2024] [Indexed: 06/21/2024] Open
Abstract
The first member of the arrestin family, visual arrestin-1, was discovered in the late 1970s. Later, the other three mammalian subtypes were identified and cloned. The first described function was regulation of G protein-coupled receptor (GPCR) signaling: arrestins bind active phosphorylated GPCRs, blocking their coupling to G proteins. It was later discovered that receptor-bound and free arrestins interact with numerous proteins, regulating GPCR trafficking and various signaling pathways, including those that determine cell fate. Arrestins have no enzymatic activity; they function by organizing multi-protein complexes and localizing their interaction partners to particular cellular compartments. Today we understand the molecular mechanism of arrestin interactions with GPCRs better than the mechanisms underlying other functions. However, even limited knowledge enabled the construction of signaling-biased arrestin mutants and extraction of biologically active monofunctional peptides from these multifunctional proteins. Manipulation of cellular signaling with arrestin-based tools has research and likely therapeutic potential: re-engineered proteins and their parts can produce effects that conventional small-molecule drugs cannot.
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3
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Zheng C, Weinstein LD, Nguyen KK, Grewal A, Gurevich EV, Gurevich VV. GPCR Binding and JNK3 Activation by Arrestin-3 Have Different Structural Requirements. Cells 2023; 12:1563. [PMID: 37371033 DOI: 10.3390/cells12121563] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 05/30/2023] [Accepted: 06/01/2023] [Indexed: 06/29/2023] Open
Abstract
Arrestins bind active phosphorylated G protein-coupled receptors (GPCRs). Among the four mammalian subtypes, only arrestin-3 facilitates the activation of JNK3 in cells. In available structures, Lys-295 in the lariat loop of arrestin-3 and its homologue Lys-294 in arrestin-2 directly interact with the activator-attached phosphates. We compared the roles of arrestin-3 conformational equilibrium and Lys-295 in GPCR binding and JNK3 activation. Several mutants with enhanced ability to bind GPCRs showed much lower activity towards JNK3, whereas a mutant that does not bind GPCRs was more active. The subcellular distribution of mutants did not correlate with GPCR recruitment or JNK3 activation. Charge neutralization and reversal mutations of Lys-295 differentially affected receptor binding on different backgrounds but had virtually no effect on JNK3 activation. Thus, GPCR binding and arrestin-3-assisted JNK3 activation have distinct structural requirements, suggesting that facilitation of JNK3 activation is the function of arrestin-3 that is not bound to a GPCR.
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Affiliation(s)
- Chen Zheng
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
| | - Liana D Weinstein
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
| | - Kevin K Nguyen
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
| | - Abhijeet Grewal
- 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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4
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Vishnivetskiy SA, Weinstein LD, Zheng C, Gurevich EV, Gurevich VV. Functional Role of Arrestin-1 Residues Interacting with Unphosphorylated Rhodopsin Elements. Int J Mol Sci 2023; 24:ijms24108903. [PMID: 37240250 DOI: 10.3390/ijms24108903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 05/11/2023] [Accepted: 05/16/2023] [Indexed: 05/28/2023] Open
Abstract
Arrestin-1, or visual arrestin, exhibits an exquisite selectivity for light-activated phosphorylated rhodopsin (P-Rh*) over its other functional forms. That selectivity is believed to be mediated by two well-established structural elements in the arrestin-1 molecule, the activation sensor detecting the active conformation of rhodopsin and the phosphorylation sensor responsive to the rhodopsin phosphorylation, which only active phosphorylated rhodopsin can engage simultaneously. However, in the crystal structure of the arrestin-1-rhodopsin complex there are arrestin-1 residues located close to rhodopsin, which do not belong to either sensor. Here we tested by site-directed mutagenesis the functional role of these residues in wild type arrestin-1 using a direct binding assay to P-Rh* and light-activated unphosphorylated rhodopsin (Rh*). We found that many mutations either enhanced the binding only to Rh* or increased the binding to Rh* much more than to P-Rh*. The data suggest that the native residues in these positions act as binding suppressors, specifically inhibiting the arrestin-1 binding to Rh* and thereby increasing arrestin-1 selectivity for P-Rh*. This calls for the modification of a widely accepted model of the arrestin-receptor interactions.
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Affiliation(s)
| | - Liana D Weinstein
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
| | - Chen Zheng
- 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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5
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Zheng C, Weinstein LD, Nguyen KK, Grewal A, Gurevich EV, Gurevich VV. GPCR binding and JNK3 activation by arrestin-3 have different structural requirements. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.01.538990. [PMID: 37205393 PMCID: PMC10187157 DOI: 10.1101/2023.05.01.538990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Arrestins bind active phosphorylated G protein-coupled receptors (GPCRs). Among the four mammalian subtypes, only arrestin-3 facilitates the activation of JNK3 in cells. In available structures, Lys-295 in the lariat loop of arrestin-3 and its homologue Lys-294 in arrestin-2 directly interact with the activator-attached phosphates. We compared the role of arrestin-3 conformational equilibrium and of Lys-295 in GPCR binding and JNK3 activation. Several mutants with enhanced ability to bind GPCRs showed much lower activity towards JNK3, whereas a mutant that does not bind GPCRs was more active. Subcellular distribution of mutants did not correlate with GPCR recruitment or JNK3 activation. Charge neutralization and reversal mutations of Lys-295 differentially affected receptor binding on different backgrounds, but had virtually no effect on JNK3 activation. Thus, GPCR binding and arrestin-3-assisted JNK3 activation have distinct structural requirements, suggesting that facilitation of JNK3 activation is the function of arrestin-3 that is not bound to a GPCR.
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6
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Eiger DS, Smith JS, Shi T, Stepniewski TM, Tsai CF, Honeycutt C, Boldizsar N, Gardner J, Nicora CD, Moghieb AM, Kawakami K, Choi I, Hicks C, Zheng K, Warman A, Alagesan P, Knape NM, Huang O, Silverman JD, Smith RD, Inoue A, Selent J, Jacobs JM, Rajagopal S. Phosphorylation barcodes direct biased chemokine signaling at CXCR3. Cell Chem Biol 2023; 30:362-382.e8. [PMID: 37030291 PMCID: PMC10147449 DOI: 10.1016/j.chembiol.2023.03.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 02/10/2023] [Accepted: 03/13/2023] [Indexed: 04/10/2023]
Abstract
G protein-coupled receptor (GPCR)-biased agonism, selective activation of certain signaling pathways relative to others, is thought to be directed by differential GPCR phosphorylation "barcodes." At chemokine receptors, endogenous chemokines can act as "biased agonists", which may contribute to the limited success when pharmacologically targeting these receptors. Here, mass spectrometry-based global phosphoproteomics revealed that CXCR3 chemokines generate different phosphorylation barcodes associated with differential transducer activation. Chemokine stimulation resulted in distinct changes throughout the kinome in global phosphoproteomics studies. Mutation of CXCR3 phosphosites altered β-arrestin 2 conformation in cellular assays and was consistent with conformational changes observed in molecular dynamics simulations. T cells expressing phosphorylation-deficient CXCR3 mutants resulted in agonist- and receptor-specific chemotactic profiles. Our results demonstrate that CXCR3 chemokines are non-redundant and act as biased agonists through differential encoding of phosphorylation barcodes, leading to distinct physiological processes.
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Affiliation(s)
- Dylan S Eiger
- Department of Biochemistry, Duke University, Durham, NC 27710, USA
| | - Jeffrey S Smith
- Department of Dermatology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Dermatology, Brigham and Women's Hospital, Boston, MA 02115, USA; Department of Dermatology, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA; Dermatology Program, Boston Children's Hospital, Boston, MA 02115, USA; Harvard Medical School, Boston, MA 02115, USA
| | - Tujin Shi
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99354, USA
| | - Tomasz Maciej Stepniewski
- Research Program on Biomedical Informatics (GRIB), Hospital del Mar Medical Research Institute (IMIM), Department of Experimental and Health Sciences of Pompeu Fabra University (UPF), 08003 Barcelona, Spain
| | - Chia-Feng Tsai
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99354, USA
| | | | | | - Julia Gardner
- Trinity College, Duke University, Durham, NC 27710, USA
| | - Carrie D Nicora
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99354, USA
| | | | - Kouki Kawakami
- Department of Pharmaceutical Sciences, Tohoku University, Sendai 980-8577, Japan
| | - Issac Choi
- Department of Medicine, Duke University, Durham, NC 27710, USA
| | - Chloe Hicks
- Trinity College, Duke University, Durham, NC 27710, USA
| | - Kevin Zheng
- Harvard Medical School, Boston, MA 02115, USA
| | - Anmol Warman
- Trinity College, Duke University, Durham, NC 27710, USA
| | - Priya Alagesan
- Department of Biochemistry, Duke University, Durham, NC 27710, USA
| | - Nicole M Knape
- Department of Biochemistry, Duke University, Durham, NC 27710, USA
| | - Ouwen Huang
- Department of Biomedical Engineering, Duke University, Durham, NC 27710, USA
| | - Justin D Silverman
- College of Information Sciences and Technology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Richard D Smith
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99354, USA
| | - Asuka Inoue
- Department of Pharmaceutical Sciences, Tohoku University, Sendai 980-8577, Japan
| | - Jana Selent
- Research Program on Biomedical Informatics (GRIB), Hospital del Mar Medical Research Institute (IMIM), Department of Experimental and Health Sciences of Pompeu Fabra University (UPF), 08003 Barcelona, Spain
| | - Jon M Jacobs
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99354, USA
| | - Sudarshan Rajagopal
- Department of Biochemistry, Duke University, Durham, NC 27710, USA; Department of Pharmaceutical Sciences, Tohoku University, Sendai 980-8577, Japan.
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7
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Seckler JM, Robinson EN, Lewis SJ, Grossfield A. Surveying nonvisual arrestins reveals allosteric interactions between functional sites. Proteins 2023; 91:99-107. [PMID: 35988049 PMCID: PMC9771995 DOI: 10.1002/prot.26413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 07/25/2022] [Accepted: 08/11/2022] [Indexed: 12/24/2022]
Abstract
Arrestins are important scaffolding proteins that are expressed in all vertebrate animals. They regulate cell-signaling events upon binding to active G-protein coupled receptors (GPCR) and trigger endocytosis of active GPCRs. While many of the functional sites on arrestins have been characterized, the question of how these sites interact is unanswered. We used anisotropic network modeling (ANM) together with our covariance compliment techniques to survey all the available structures of the nonvisual arrestins to map how structural changes and protein-binding affect their structural dynamics. We found that activation and clathrin binding have a marked effect on arrestin dynamics, and that these dynamics changes are localized to a small number of distant functional sites. These sites include α-helix 1, the lariat loop, nuclear localization domain, and the C-domain β-sheets on the C-loop side. Our techniques suggest that clathrin binding and/or GPCR activation of arrestin perturb the dynamics of these sites independent of structural changes.
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Affiliation(s)
- James M. Seckler
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
| | - Emily N. Robinson
- Department of Biochemistry and Biophysics, University of Rochester, Rochester, NY, USA
| | - Stephen J. Lewis
- Department of Pediatrics, Case Western Reserve University, Cleveland, Ohio, USA
| | - Alan Grossfield
- Department of Biochemistry and Biophysics, University of Rochester, Rochester, NY, USA
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8
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The Role of Arrestin-1 Middle Loop in Rhodopsin Binding. Int J Mol Sci 2022; 23:ijms232213887. [PMID: 36430370 PMCID: PMC9694801 DOI: 10.3390/ijms232213887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 11/07/2022] [Accepted: 11/09/2022] [Indexed: 11/16/2022] Open
Abstract
Arrestins preferentially bind active phosphorylated G protein-coupled receptors (GPCRs). The middle loop, highly conserved in all arrestin subtypes, is localized in the central crest on the GPCR-binding side. Upon receptor binding, it directly interacts with bound GPCR and demonstrates the largest movement of any arrestin element in the structures of the complexes. Comprehensive mutagenesis of the middle loop of rhodopsin-specific arrestin-1 suggests that it primarily serves as a suppressor of binding to non-preferred forms of the receptor. Several mutations in the middle loop increase the binding to unphosphorylated light-activated rhodopsin severalfold, which makes them candidates for improving enhanced phosphorylation-independent arrestins. The data also suggest that enhanced forms of arrestin do not bind GPCRs exactly like the wild-type protein. Thus, the structures of the arrestin-receptor complexes, in all of which different enhanced arrestin mutants and reengineered receptors were used, must be interpreted with caution.
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9
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Chen Q, Tesmer JJG. G protein-coupled receptor interactions with arrestins and GPCR kinases: the unresolved issue of signal bias. J Biol Chem 2022; 298:102279. [PMID: 35863432 PMCID: PMC9418498 DOI: 10.1016/j.jbc.2022.102279] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 07/05/2022] [Accepted: 07/08/2022] [Indexed: 12/25/2022] Open
Abstract
G protein–coupled receptor (GPCR) kinases (GRKs) and arrestins interact with agonist-bound GPCRs to promote receptor desensitization and downregulation. They also trigger signaling cascades distinct from those of heterotrimeric G proteins. Biased agonists for GPCRs that favor either heterotrimeric G protein or GRK/arrestin signaling are of profound pharmacological interest because they could usher in a new generation of drugs with greatly reduced side effects. One mechanism by which biased agonism might occur is by stabilizing receptor conformations that preferentially bind to GRKs and/or arrestins. In this review, we explore this idea by comparing structures of GPCRs bound to heterotrimeric G proteins with those of the same GPCRs in complex with arrestins and GRKs. The arrestin and GRK complexes all exhibit high conformational heterogeneity, which is likely a consequence of their unusual ability to adapt and bind to hundreds of different GPCRs. This dynamic behavior, along with the experimental tactics required to stabilize GPCR complexes for biophysical analysis, confounds these comparisons, but some possible molecular mechanisms of bias are beginning to emerge. We also examine if and how the recent structures advance our understanding of how arrestins parse the “phosphorylation barcodes” installed in the intracellular loops and tails of GPCRs by GRKs. In the future, structural analyses of arrestins in complex with intact receptors that have well-defined native phosphorylation barcodes, such as those installed by the two nonvisual subfamilies of GRKs, will be particularly illuminating.
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Affiliation(s)
- Qiuyan Chen
- Departments of Biological Sciences and of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, USA
| | - John J G Tesmer
- Departments of Biological Sciences and of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, USA.
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10
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Emerging structural insights into GPCR-β-arrestin interaction and functional outcomes. Curr Opin Struct Biol 2022; 75:102406. [PMID: 35738165 PMCID: PMC7614528 DOI: 10.1016/j.sbi.2022.102406] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 04/28/2022] [Accepted: 05/19/2022] [Indexed: 11/22/2022]
Abstract
Agonist-induced recruitment of β-arrestins (βarrs) to G protein-coupled receptors (GPCRs) plays a central role in regulating the spatio-temporal aspects of GPCR signaling. Several recent studies have provided novel structural and functional insights into our understanding of GPCR-βarr interaction, subsequent βarr activation and resulting functional outcomes. In this review, we discuss these recent advances with a particular emphasis on recognition of receptor-bound phosphates by βarrs, the emerging concept of spatial positioning of key phosphorylation sites, the conformational transition in βarrs during partial to full-engagement, and structural differences driving functional outcomes of βarr isoforms. We also highlight the key directions that require further investigation going forward to fully understand the structural mechanisms driving βarr activation and functional responses.
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11
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Karnam PC, Vishnivetskiy SA, Gurevich VV. Structural Basis of Arrestin Selectivity for Active Phosphorylated G Protein-Coupled Receptors. Int J Mol Sci 2021; 22:ijms222212481. [PMID: 34830362 PMCID: PMC8621391 DOI: 10.3390/ijms222212481] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 11/13/2021] [Accepted: 11/15/2021] [Indexed: 02/06/2023] Open
Abstract
Arrestins are a small family of proteins that bind G protein-coupled receptors (GPCRs). Arrestin binds to active phosphorylated GPCRs with higher affinity than to all other functional forms of the receptor, including inactive phosphorylated and active unphosphorylated. The selectivity of arrestins suggests that they must have two sensors, which detect receptor-attached phosphates and the active receptor conformation independently. Simultaneous engagement of both sensors enables arrestin transition into a high-affinity receptor-binding state. This transition involves a global conformational rearrangement that brings additional elements of the arrestin molecule, including the middle loop, in contact with a GPCR, thereby stabilizing the complex. Here, we review structural and mutagenesis data that identify these two sensors and additional receptor-binding elements within the arrestin molecule. While most data were obtained with the arrestin-1-rhodopsin pair, the evidence suggests that all arrestins use similar mechanisms to achieve preferential binding to active phosphorylated GPCRs.
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12
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Aydin Y, Coin I. Biochemical insights into structure and function of arrestins. FEBS J 2021; 288:2529-2549. [DOI: 10.1111/febs.15811] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 02/26/2021] [Accepted: 03/09/2021] [Indexed: 12/13/2022]
Affiliation(s)
- Yasmin Aydin
- Institute of Biochemistry Faculty of Life Sciences University of Leipzig Germany
| | - Irene Coin
- Institute of Biochemistry Faculty of Life Sciences University of Leipzig Germany
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13
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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: 12.0] [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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14
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Vishnivetskiy SA, Huh EK, Gurevich EV, Gurevich VV. The finger loop as an activation sensor in arrestin. J Neurochem 2020; 157:1138-1152. [PMID: 33159335 DOI: 10.1111/jnc.15232] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 10/23/2020] [Accepted: 11/01/2020] [Indexed: 12/31/2022]
Abstract
The finger loop in the central crest of the receptor-binding site of arrestins engages the cavity between the transmembrane helices of activated G-protein-coupled receptors. Therefore, it was hypothesized to serve as the sensor that detects the activation state of the receptor. We performed comprehensive mutagenesis of the finger loop in bovine visual arrestin-1, generated mutant radiolabeled proteins by cell-free translation, and determined the effects of mutations on the in vitro binding of arrestin-1 to purified phosphorylated light-activated rhodopsin. This interaction is driven by two factors, rhodopsin activation and rhodopsin-attached phosphates. Therefore, the binding of arrestin-1 to light-activated unphosphorylated rhodopsin is low. To evaluate the role of the finger loop specifically in the recognition of the active receptor conformation, we tested the effects of these mutations in the context of truncated arrestin-1 that demonstrates much higher binding to unphosphorylated activated and phosphorylated inactive rhodopsin. The majority of finger loop residues proved important for arrestin-1 binding to light-activated rhodopsin, with six mutations affecting the binding exclusively to this form. Thus, the finger loop is the key element of arrestin-1 activation sensor. The data also suggest that arrestin-1 and its enhanced mutant bind various functional forms of rhodopsin differently.
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Affiliation(s)
| | - Elizabeth K Huh
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA
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15
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Dwivedi-Agnihotri H, Chaturvedi M, Baidya M, Stepniewski TM, Pandey S, Maharana J, Srivastava A, Caengprasath N, Hanyaloglu AC, Selent J, Shukla AK. Distinct phosphorylation sites in a prototypical GPCR differently orchestrate β-arrestin interaction, trafficking, and signaling. SCIENCE ADVANCES 2020; 6:6/37/eabb8368. [PMID: 32917711 PMCID: PMC7486103 DOI: 10.1126/sciadv.abb8368] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Accepted: 07/28/2020] [Indexed: 05/14/2023]
Abstract
Agonist-induced phosphorylation of G protein-coupled receptors (GPCRs) is a key determinant for their interaction with β-arrestins (βarrs) and subsequent functional responses. Therefore, it is important to decipher the contribution and interplay of different receptor phosphorylation sites in governing βarr interaction and functional outcomes. Here, we find that several phosphorylation sites in the human vasopressin receptor (V2R), positioned either individually or in clusters, differentially contribute to βarr recruitment, trafficking, and ERK1/2 activation. Even a single phosphorylation site in V2R, suitably positioned to cross-talk with a key residue in βarrs, has a decisive contribution in βarr recruitment, and its mutation results in strong G-protein bias. Molecular dynamics simulation provides mechanistic insights into the pivotal role of this key phosphorylation site in governing the stability of βarr interaction and regulating the interdomain rotation in βarrs. Our findings uncover important structural aspects to better understand the framework of GPCR-βarr interaction and biased signaling.
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Affiliation(s)
- Hemlata Dwivedi-Agnihotri
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Madhu Chaturvedi
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Mithu Baidya
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Tomasz Maciej Stepniewski
- Research Programme on Biomedical Informatics (GRIB), Department of Experimental and Health Sciences of Pompeu Fabra University (UPF)-Hospital del Mar Medical Research Institute (IMIM), 08003 Barcelona, Spain
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Warsaw, Poland
| | - Shubhi Pandey
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Jagannath Maharana
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Ashish Srivastava
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Natarin Caengprasath
- Institute of Reproductive and Developmental Biology, Department of Metabolism, Digestion and Reproduction, Hammersmith Campus, Imperial College London, Du Cane Road, London, W12 0NN, UK
| | - Aylin C Hanyaloglu
- Institute of Reproductive and Developmental Biology, Department of Metabolism, Digestion and Reproduction, Hammersmith Campus, Imperial College London, Du Cane Road, London, W12 0NN, UK
| | - Jana Selent
- Research Programme on Biomedical Informatics (GRIB), Department of Experimental and Health Sciences of Pompeu Fabra University (UPF)-Hospital del Mar Medical Research Institute (IMIM), 08003 Barcelona, Spain.
| | - Arun K Shukla
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India.
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