1
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Bighinati A, D'Alessandro S, Felline A, Zeitz C, Bocquet B, Casarini L, Kalatzis V, Meunier I, Fanelli F, Manes G, Marigo V. Differential pathogenetic mechanisms of mutations in helix 2 and helix 6 of rhodopsin. Int J Biol Macromol 2024; 279:135089. [PMID: 39197629 DOI: 10.1016/j.ijbiomac.2024.135089] [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: 07/24/2024] [Revised: 08/20/2024] [Accepted: 08/24/2024] [Indexed: 09/01/2024]
Abstract
Variants in rhodopsin (RHO) have been linked to autosomal dominant congenital stationary night blindness (adCSNB), which affects the ability to see in dim light, and the pathogenetic mechanism is still not well understood. In this study we report two novel RHO variants found in adCSNB families, p.W265R and p.A269V, that map in the sixth transmembrane domain of RHO protein. We applied in silico molecular simulation and in vitro biochemical and molecular studies to characterize the two new variants and compare the molecular determinants to two previously characterized adCSNB variants, p.G90D and p.T94I, that map in the second transmembrane domain of the RHO protein. We demonstrate that W265R and A269V cause constitutive activation of RHO with light-independent G protein coupling and impaired binding to arrestin. Differently, G90D and T94I are characterized by slow kinetics of RHO activation and deactivation. This study provides new evidence on the differential contribution of transmembrane α-helixes two and six to the interaction with intracellular transducers of RHO and mutations in these helixes result in a similar phenotype in patients but with distinct molecular effects.
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Affiliation(s)
- Andrea Bighinati
- University of Modena and Reggio Emilia, Department of Life Sciences, via G. Campi 287, 41125 Modena, Italy
| | - Sara D'Alessandro
- University of Modena and Reggio Emilia, Department of Life Sciences, via G. Campi 287, 41125 Modena, Italy
| | - Angelo Felline
- University of Modena and Reggio Emilia, Department of Life Sciences, via G. Campi 287, 41125 Modena, Italy
| | - Christina Zeitz
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, 75012 Paris, France
| | - Béatrice Bocquet
- INM, Univ Montpellier, INSERM, CHU Montpellier, 80 Av. Augustin Fliche, 34295 Montpellier, France
| | - Livio Casarini
- University of Modena and Reggio Emilia, Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, via P. Giardini, 1355, 41126 Baggiovara, Modena, Italy
| | - Vasiliki Kalatzis
- INM, Univ Montpellier, INSERM, 80 rue Augustin Fliche, 34091 Montpellier, France
| | - Isabelle Meunier
- INM, Univ Montpellier, INSERM, CHU Montpellier, 80 Av. Augustin Fliche, 34295 Montpellier, France
| | - Francesca Fanelli
- University of Modena and Reggio Emilia, Department of Life Sciences, via G. Campi 287, 41125 Modena, Italy.
| | - Gaël Manes
- INM, Univ Montpellier, INSERM, 80 rue Augustin Fliche, 34091 Montpellier, France.
| | - Valeria Marigo
- University of Modena and Reggio Emilia, Department of Life Sciences, via G. Campi 287, 41125 Modena, Italy.
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2
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Mancinelli CD, Marx DC, Gonzalez-Hernandez AJ, Huynh K, Mancinelli L, Arefin A, Khelashvilli G, Levitz J, Eliezer D. Control of G protein-coupled receptor function via membrane-interacting intrinsically disordered C-terminal domains. Proc Natl Acad Sci U S A 2024; 121:e2407744121. [PMID: 38985766 PMCID: PMC11260148 DOI: 10.1073/pnas.2407744121] [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: 04/29/2024] [Accepted: 06/07/2024] [Indexed: 07/12/2024] Open
Abstract
G protein-coupled receptors (GPCRs) control intracellular signaling cascades via agonist-dependent coupling to intracellular transducers including heterotrimeric G proteins, GPCR kinases (GRKs), and arrestins. In addition to their critical interactions with the transmembrane core of active GPCRs, all three classes of transducers have also been reported to interact with receptor C-terminal domains (CTDs). An underexplored aspect of GPCR CTDs is their possible role as lipid sensors given their proximity to the membrane. CTD-membrane interactions have the potential to control the accessibility of key regulatory CTD residues to downstream effectors and transducers. Here, we report that the CTDs of two closely related family C GPCRs, metabotropic glutamate receptor 2 (mGluR2) and mGluR3, bind to membranes and that this interaction can regulate receptor function. We first characterize CTD structure with NMR spectroscopy, revealing lipid composition-dependent modes of membrane binding. Using molecular dynamics simulations and structure-guided mutagenesis, we then identify key conserved residues and cancer-associated mutations that modulate CTD-membrane binding. Finally, we provide evidence that mGluR3 transducer coupling is controlled by CTD-membrane interactions in live cells, which may be subject to regulation by CTD phosphorylation and changes in membrane composition. This work reveals an additional mechanism of GPCR modulation, suggesting that CTD-membrane binding may be a general regulatory mode throughout the broad GPCR superfamily.
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Affiliation(s)
| | - Dagan C. Marx
- Department of Biochemistry, Weill Cornell Medicine, New York, NY10065
| | | | - Kevin Huynh
- Department of Biochemistry, Weill Cornell Medicine, New York, NY10065
| | - Lucia Mancinelli
- Department of Biochemistry, Weill Cornell Medicine, New York, NY10065
| | - Anisul Arefin
- Department of Biochemistry, Weill Cornell Medicine, New York, NY10065
| | - George Khelashvilli
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY10065
| | - Joshua Levitz
- Department of Biochemistry, Weill Cornell Medicine, New York, NY10065
- Department of Psychiatry, Weill Cornell Medicine, New York, NY10065
| | - David Eliezer
- Department of Biochemistry, Weill Cornell Medicine, New York, NY10065
- Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY10065
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3
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Mukhaleva E, Ma N, van der Velden WJC, Gogoshin G, Branciamore S, Bhattacharya S, Rodin AS, Vaidehi N. Bayesian network models identify cooperative GPCR:G protein interactions that contribute to G protein coupling. J Biol Chem 2024; 300:107362. [PMID: 38735478 PMCID: PMC11176750 DOI: 10.1016/j.jbc.2024.107362] [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: 11/03/2023] [Revised: 05/03/2024] [Accepted: 05/04/2024] [Indexed: 05/14/2024] Open
Abstract
Cooperative interactions in protein-protein interfaces demonstrate the interdependency or the linked network-like behavior and their effect on the coupling of proteins. Cooperative interactions also could cause ripple or allosteric effects at a distance in protein-protein interfaces. Although they are critically important in protein-protein interfaces, it is challenging to determine which amino acid pair interactions are cooperative. In this work, we have used Bayesian network modeling, an interpretable machine learning method, combined with molecular dynamics trajectories to identify the residue pairs that show high cooperativity and their allosteric effect in the interface of G protein-coupled receptor (GPCR) complexes with Gα subunits. Our results reveal six GPCR:Gα contacts that are common to the different Gα subtypes and show strong cooperativity in the formation of interface. Both the C terminus helix5 and the core of the G protein are codependent entities and play an important role in GPCR coupling. We show that a promiscuous GPCR coupling to different Gα subtypes, makes all the GPCR:Gα contacts that are specific to each Gα subtype (Gαs, Gαi, and Gαq). This work underscores the potential of data-driven Bayesian network modeling in elucidating the intricate dependencies and selectivity determinants in GPCR:G protein complexes, offering valuable insights into the dynamic nature of these essential cellular signaling components.
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Affiliation(s)
- Elizaveta Mukhaleva
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, California, USA; Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, Duarte, California, USA
| | - Ning Ma
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, California, USA
| | - Wijnand J C van der Velden
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, California, USA
| | - Grigoriy Gogoshin
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, California, USA
| | - Sergio Branciamore
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, California, USA; Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, Duarte, California, USA.
| | - Supriyo Bhattacharya
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, California, USA.
| | - Andrei S Rodin
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, California, USA; Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, Duarte, California, USA.
| | - Nagarajan Vaidehi
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, California, USA; Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, Duarte, California, USA.
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4
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Mancinelli C, Marx DC, Gonzalez-Hernandez AJ, Huynh K, Mancinelli L, Arefin A, Khelashvilli G, Levitz J, Eliezer D. Control of G protein-coupled receptor function via membrane-interacting intrinsically disordered C-terminal domains. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.08.16.553551. [PMID: 37645938 PMCID: PMC10462050 DOI: 10.1101/2023.08.16.553551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
G protein-coupled receptors (GPCRs) control intracellular signaling cascades via agonist-dependent coupling to intracellular transducers including heterotrimeric G proteins, GPCR kinases (GRKs), and arrestins. In addition to their critical interactions with the transmembrane core of active GPCRs, all three classes of transducers have also been reported to interact with receptor C-terminal domains (CTDs). An underexplored aspect of GPCR CTDs is their possible role as lipid sensors given their proximity to the membrane. CTD-membrane interactions have the potential to control the accessibility of key regulatory CTD residues to downstream effectors and transducers. Here we report that the CTDs of two closely related family C GPCRs, metabotropic glutamate receptor 2 (mGluR2) and mGluR3, bind to membranes and that this interaction can regulate receptor function. We first characterize CTD structure with NMR spectroscopy, revealing lipid composition-dependent modes of membrane binding. Using molecular dynamics simulations and structure-guided mutagenesis, we then identify key conserved residues and cancer-associated mutations that modulate CTD-membrane binding. Finally, we provide evidence that mGluR3 transducer coupling is controlled by CTD-membrane interactions in live cells, which may be subject to regulation by CTD phosphorylation and changes in membrane composition. This work reveals a novel mechanism of GPCR modulation, suggesting that CTD-membrane binding may be a general regulatory mode throughout the broad GPCR superfamily.
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Affiliation(s)
- Chiara Mancinelli
- Department of Biochemistry, Weill Cornell Medicine, New York, NY 10065, USA
- equal contribution
| | - Dagan C. Marx
- Department of Biochemistry, Weill Cornell Medicine, New York, NY 10065, USA
- equal contribution
| | | | - Kevin Huynh
- Department of Biochemistry, Weill Cornell Medicine, New York, NY 10065, USA
| | - Lucia Mancinelli
- Department of Biochemistry, Weill Cornell Medicine, New York, NY 10065, USA
| | - Anisul Arefin
- Department of Biochemistry, Weill Cornell Medicine, New York, NY 10065, USA
| | - George Khelashvilli
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY 10065, USA
| | - Joshua Levitz
- Department of Biochemistry, Weill Cornell Medicine, New York, NY 10065, USA
- Department of Psychiatry, Weill Cornell Medicine, New York, NY 10065, USA
| | - David Eliezer
- Department of Biochemistry, Weill Cornell Medicine, New York, NY 10065, USA
- Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10065, USA
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5
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Nürnberg B, Beer-Hammer S, Reisinger E, Leiss V. Non-canonical G protein signaling. Pharmacol Ther 2024; 255:108589. [PMID: 38295906 DOI: 10.1016/j.pharmthera.2024.108589] [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: 07/03/2023] [Revised: 12/18/2023] [Accepted: 01/08/2024] [Indexed: 02/17/2024]
Abstract
The original paradigm of classical - also referred to as canonical - cellular signal transduction of heterotrimeric G proteins (G protein) is defined by a hierarchical, orthograde interaction of three players: the agonist-activated G protein-coupled receptor (GPCR), which activates the transducing G protein, that in turn regulates its intracellular effectors. This receptor-transducer-effector concept was extended by the identification of regulators and adapters such as the regulators of G protein signaling (RGS), receptor kinases like βARK, or GPCR-interacting arrestin adapters that are integrated into this canonical signaling process at different levels to enable fine-tuning. Finally, the identification of atypical signaling mechanisms of classical regulators, together with the discovery of novel modulators, added a new and fascinating dimension to the cellular G protein signal transduction. This heterogeneous group of accessory G protein modulators was coined "activators of G protein signaling" (AGS) proteins and plays distinct roles in canonical and non-canonical G protein signaling pathways. AGS proteins contribute to the control of essential cellular functions such as cell development and division, intracellular transport processes, secretion, autophagy or cell movements. As such, they are involved in numerous biological processes that are crucial for diseases, like diabetes mellitus, cancer, and stroke, which represent major health burdens. Although the identification of a large number of non-canonical G protein signaling pathways has broadened the spectrum of this cellular communication system, their underlying mechanisms, functions, and biological effects are poorly understood. In this review, we highlight and discuss atypical G protein-dependent signaling mechanisms with a focus on inhibitory G proteins (Gi) involved in canonical and non-canonical signal transduction, review recent developments and open questions, address the potential of new approaches for targeted pharmacological interventions.
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Affiliation(s)
- Bernd Nürnberg
- Department of Pharmacology, Experimental Therapy and Toxicology, Institute of Experimental and Clinical Pharmacology and Pharmacogenomics, and ICePhA Mouse Clinic, University of Tübingen, Wilhelmstraße 56, D-72074 Tübingen, Germany.
| | - Sandra Beer-Hammer
- Department of Pharmacology, Experimental Therapy and Toxicology, Institute of Experimental and Clinical Pharmacology and Pharmacogenomics, and ICePhA Mouse Clinic, University of Tübingen, Wilhelmstraße 56, D-72074 Tübingen, Germany
| | - Ellen Reisinger
- Gene Therapy for Hearing Impairment Group, Department of Otolaryngology - Head & Neck Surgery, University of Tübingen Medical Center, Elfriede-Aulhorn-Straße 5, D-72076 Tübingen, Germany
| | - Veronika Leiss
- Department of Pharmacology, Experimental Therapy and Toxicology, Institute of Experimental and Clinical Pharmacology and Pharmacogenomics, and ICePhA Mouse Clinic, University of Tübingen, Wilhelmstraße 56, D-72074 Tübingen, Germany
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6
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Mukhaleva E, Ma N, van der Velden WJC, Gogoshin G, Branciamore S, Bhattacharya S, Rodin AS, Vaidehi N. Bayesian network models identify co-operative GPCR:G protein interactions that contribute to G protein coupling. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.09.561618. [PMID: 37873104 PMCID: PMC10592737 DOI: 10.1101/2023.10.09.561618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Cooperative interactions in protein-protein interfaces demonstrate the interdependency or the linked network-like behavior of interface interactions and their effect on the coupling of proteins. Cooperative interactions also could cause ripple or allosteric effects at a distance in protein-protein interfaces. Although they are critically important in protein-protein interfaces it is challenging to determine which amino acid pair interactions are cooperative. In this work we have used Bayesian network modeling, an interpretable machine learning method, combined with molecular dynamics trajectories to identify the residue pairs that show high cooperativity and their allosteric effect in the interface of G protein-coupled receptor (GPCR) complexes with G proteins. Our results reveal a strong co-dependency in the formation of interface GPCR:G protein contacts. This observation indicates that cooperativity of GPCR:G protein interactions is necessary for the coupling and selectivity of G proteins and is thus critical for receptor function. We have identified subnetworks containing polar and hydrophobic interactions that are common among multiple GPCRs coupling to different G protein subtypes (Gs, Gi and Gq). These common subnetworks along with G protein-specific subnetworks together confer selectivity to the G protein coupling. This work underscores the potential of data-driven Bayesian network modeling in elucidating the intricate dependencies and selectivity determinants in GPCR:G protein complexes, offering valuable insights into the dynamic nature of these essential cellular signaling components.
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Affiliation(s)
- Elizaveta Mukhaleva
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, CA 91010
- Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, Duarte, CA 91010
| | - Ning Ma
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, CA 91010
| | - Wijnand J. C. van der Velden
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, CA 91010
| | - Grigoriy Gogoshin
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, CA 91010
| | - Sergio Branciamore
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, CA 91010
- Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, Duarte, CA 91010
| | - Supriyo Bhattacharya
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, CA 91010
| | - Andrei S. Rodin
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, CA 91010
- Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, Duarte, CA 91010
| | - Nagarajan Vaidehi
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, CA 91010
- Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, Duarte, CA 91010
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7
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Rysiewicz B, Błasiak E, Mystek P, Dziedzicka-Wasylewska M, Polit A. Beyond the G protein α subunit: investigating the functional impact of other components of the Gαi 3 heterotrimers. Cell Commun Signal 2023; 21:279. [PMID: 37817242 PMCID: PMC10566112 DOI: 10.1186/s12964-023-01307-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: 06/16/2023] [Accepted: 09/05/2023] [Indexed: 10/12/2023] Open
Abstract
BACKGROUND Specific interactions between G protein-coupled receptors (GPCRs) and G proteins play a key role in mediating signaling events. While there is little doubt regarding receptor preference for Gα subunits, the preferences for specific Gβ and Gγ subunits and the effects of different Gβγ dimer compositions on GPCR signaling are poorly understood. In this study, we aimed to investigate the subcellular localization and functional response of Gαi3-based heterotrimers with different combinations of Gβ and Gγ subunits. METHODS Live-cell imaging microscopy and colocalization analysis were used to investigate the subcellular localization of Gαi3 in combination with Gβ1 or Gβ2 heterotrimers, along with representative Gγ subunits. Furthermore, fluorescence lifetime imaging microscopy (FLIM-FRET) was used to investigate the nanoscale distribution of Gαi3-based heterotrimers in the plasma membrane, specifically with the dopamine D2 receptor (D2R). In addition, the functional response of the system was assessed by monitoring intracellular cAMP levels and conducting bioinformatics analysis to further characterize the heterotrimer complexes. RESULTS Our results show that Gαi3 heterotrimers mainly localize to the plasma membrane, although the degree of colocalization is influenced by the accompanying Gβ and Gγ subunits. Heterotrimers containing Gβ2 showed slightly lower membrane localization compared to those containing Gβ1, but certain combinations, such as Gαi3β2γ8 and Gαi3β2γ10, deviated from this trend. Examination of the spatial arrangement of Gαi3 in relation to D2R and of changes in intracellular cAMP level showed that the strongest functional response is observed for those trimers for which the distance between the receptor and the Gα subunit is smallest, i.e. complexes containing Gβ1 and Gγ8 or Gγ10 subunit. Deprivation of Gαi3 lipid modifications resulted in a significant decrease in the amount of protein present in the cell membrane, but did not always affect intracellular cAMP levels. CONCLUSION Our studies show that the composition of G protein heterotrimers has a significant impact on the strength and specificity of GPCR-mediated signaling. Different heterotrimers may exhibit different conformations, which further affects the interactions of heterotrimers and GPCRs, as well as their interactions with membrane lipids. This study contributes to the understanding of the complex signaling mechanisms underlying GPCR-G-protein interactions and highlights the importance of the diversity of Gβ and Gγ subunits in G-protein signaling pathways. Video Abstract.
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Affiliation(s)
- Beata Rysiewicz
- Department of Physical Biochemistry, Faculty of Biochemistry Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387, Kraków, Poland
| | - Ewa Błasiak
- Department of Physical Biochemistry, Faculty of Biochemistry Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387, Kraków, Poland
| | - Paweł Mystek
- Department of Physical Biochemistry, Faculty of Biochemistry Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387, Kraków, Poland
| | - Marta Dziedzicka-Wasylewska
- Department of Physical Biochemistry, Faculty of Biochemistry Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387, Kraków, Poland
| | - Agnieszka Polit
- Department of Physical Biochemistry, Faculty of Biochemistry Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387, Kraków, Poland.
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8
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Liu H, Zhang Q, He X, Jiang M, Wang S, Yan X, Cheng X, Liu Y, Nan FJ, Xu HE, Xie X, Yin W. Structural insights into ligand recognition and activation of the medium-chain fatty acid-sensing receptor GPR84. Nat Commun 2023; 14:3271. [PMID: 37277332 DOI: 10.1038/s41467-023-38985-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 05/23/2023] [Indexed: 06/07/2023] Open
Abstract
GPR84 is an orphan class A G protein-coupled receptor (GPCR) that is predominantly expressed in immune cells and plays important roles in inflammation, fibrosis, and metabolism. Here, we present cryo-electron microscopy (cryo-EM) structures of Gαi protein-coupled human GPR84 bound to a synthetic lipid-mimetic ligand, LY237, or a putative endogenous ligand, a medium-chain fatty acid (MCFA) 3-hydroxy lauric acid (3-OH-C12). Analysis of these two ligand-bound structures reveals a unique hydrophobic nonane tail -contacting patch, which forms a blocking wall to select MCFA-like agonists with the correct length. We also identify the structural features in GPR84 that coordinate the polar ends of LY237 and 3-OH-C12, including the interactions with the positively charged side chain of R172 and the downward movement of the extracellular loop 2 (ECL2). Together with molecular dynamics simulations and functional data, our structures reveal that ECL2 not only contributes to direct ligand binding, but also plays a pivotal role in ligand entry from the extracellular milieu. These insights into the structure and function of GPR84 could improve our understanding of ligand recognition, receptor activation, and Gαi-coupling of GPR84. Our structures could also facilitate rational drug discovery against inflammation and metabolic disorders targeting GPR84.
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Affiliation(s)
- Heng Liu
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Qing Zhang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, 310024, Hangzhou, China
- Shandong Laboratory of Yantai Drug Discovery, Bohai Rim Advanced Research Institute for Drug Discovery, 264117, Yantai, Shandong, China
- National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 201203, Shanghai, China
| | - Xinheng He
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Mengting Jiang
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, 210023, Nanjing, China
| | - Siwei Wang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 201203, Shanghai, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Xiaoci Yan
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, 310024, Hangzhou, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Xi Cheng
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Yang Liu
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 201203, Shanghai, China
| | - Fa-Jun Nan
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, 310024, Hangzhou, China
- Shandong Laboratory of Yantai Drug Discovery, Bohai Rim Advanced Research Institute for Drug Discovery, 264117, Yantai, Shandong, China
- National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 201203, Shanghai, China
| | - H Eric Xu
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.
- University of Chinese Academy of Sciences, 100049, Beijing, China.
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, 210023, Nanjing, China.
- School of Life Science and Technology, ShanghaiTech University, 201210, Shanghai, China.
| | - Xin Xie
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, 310024, Hangzhou, China.
- Shandong Laboratory of Yantai Drug Discovery, Bohai Rim Advanced Research Institute for Drug Discovery, 264117, Yantai, Shandong, China.
- National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 201203, Shanghai, China.
- University of Chinese Academy of Sciences, 100049, Beijing, China.
| | - Wanchao Yin
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.
- University of Chinese Academy of Sciences, 100049, Beijing, China.
- Zhongshan Institute for Drug Discovery, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 528400, Guangdong, China.
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9
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Ahn D, Provasi D, Duc NM, Xu J, Salas-Estrada L, Spasic A, Yun MW, Kang J, Gim D, Lee J, Du Y, Filizola M, Chung KY. Gαs slow conformational transition upon GTP binding and a novel Gαs regulator. iScience 2023; 26:106603. [PMID: 37128611 PMCID: PMC10148139 DOI: 10.1016/j.isci.2023.106603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 03/16/2023] [Accepted: 03/29/2023] [Indexed: 05/03/2023] Open
Abstract
G proteins are major signaling partners for G protein-coupled receptors (GPCRs). Although stepwise structural changes during GPCR-G protein complex formation and guanosine diphosphate (GDP) release have been reported, no information is available with regard to guanosine triphosphate (GTP) binding. Here, we used a novel Bayesian integrative modeling framework that combines data from hydrogen-deuterium exchange mass spectrometry, tryptophan-induced fluorescence quenching, and metadynamics simulations to derive a kinetic model and atomic-level characterization of stepwise conformational changes incurred by the β2-adrenergic receptor (β2AR)-Gs complex after GDP release and GTP binding. Our data suggest rapid GTP binding and GTP-induced dissociation of Gαs from β2AR and Gβγ, as opposed to a slow closing of the Gαs α-helical domain (AHD). Yeast-two-hybrid screening using Gαs AHD as bait identified melanoma-associated antigen D2 (MAGE D2) as a novel AHD-binding protein, which was also shown to accelerate the GTP-induced closing of the Gαs AHD.
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Affiliation(s)
- Donghoon Ahn
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Davide Provasi
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Nguyen Minh Duc
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Jun Xu
- Molecular and Cellular Physiology, School of Medicine, Stanford University, Stanford, CA 94305, USA
| | - Leslie Salas-Estrada
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Aleksandar Spasic
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Min Woo Yun
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Juyeong Kang
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea
- Department of Biopharmaceutical Convergence, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Dongmin Gim
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea
- Department of Biopharmaceutical Convergence, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Jaecheol Lee
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea
- Department of Biopharmaceutical Convergence, Sungkyunkwan University, Suwon 16419, Republic of Korea
- Biomedical Institute for Convergence at SKKU (BICS), Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Yang Du
- School of Life and Health Sciences, Kobilka Institute of Innovative Drug Discovery, Chinese University of Hong Kong, Shenzhen, Guangdong 518172, China
| | - Marta Filizola
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Ka Young Chung
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea
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10
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Abstract
Rhodopsin is the photoreceptor in human rod cells responsible for dim-light vision. The visual receptors are part of the large superfamily of G protein-coupled receptors (GPCRs) that mediate signal transduction in response to diverse diffusible ligands. The high level of sequence conservation within the transmembrane helices of the visual receptors and the family A GPCRs has long been considered evidence for a common pathway for signal transduction. I review recent studies that reveal a comprehensive mechanism for how light absorption by the retinylidene chromophore drives rhodopsin activation and highlight those features of the mechanism that are conserved across the ligand-activated GPCRs.
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Affiliation(s)
- Steven O Smith
- Department of Biochemistry and Cell Biology, Center for Structural Biology, Stony Brook University, Stony Brook, New York, USA;
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11
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Hanai S, Nagata T, Katayama K, Inukai S, Koyanagi M, Inoue K, Terakita A, Kandori H. Difference FTIR Spectroscopy of Jumping Spider Rhodopsin-1 at 77 K. Biochemistry 2023; 62:1347-1359. [PMID: 37001008 DOI: 10.1021/acs.biochem.3c00022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
Abstract
Animal visual rhodopsins can be classified into monostable and bistable rhodopsins, which are typically found in vertebrates and invertebrates, respectively. The former example is bovine rhodopsin (BovRh), whose structures and functions have been extensively studied. On the other hand, those of bistable rhodopsins are less known, despite their importance in optogenetics. Here, low-temperature Fourier-transform infrared (FTIR) spectroscopy was applied to jumping spider rhodopsin-1 (SpiRh1) at 77 K, and the obtained light-induced spectral changes were compared with those of squid rhodopsin (SquRh) and BovRh. Although chromophore distortion of the resting state monitored by HOOP vibrations is not distinctive between invertebrate and vertebrate rhodopsins, distortion of the all-trans chromophore after photoisomerization is unique for BovRh, and the distortion was localized at the center of the chromophore in SpiRh1 and SquRh. Highly conserved aspartate (D83 in BovRh) does not change the hydrogen-bonding environment in invertebrate rhodopsins. Thus, present FTIR analysis provides specific structural changes, leading to activation of invertebrate and vertebrate rhodopsins. On the other hand, the analysis of O-D stretching vibrations in D2O revealed unique features of protein-bound water molecules. Numbers of water bands in SpiRh1 and SquRh were less and more than those in BovRh. The X-ray crystal structure of SpiRh1 observed a bridged water molecule between the protonated Schiff base and its counterion (E194), but strongly hydrogen-bonded water molecules were never detected in SpiRh1, as well as SquRh and BovRh. Thus, absence of strongly hydrogen-bonded water molecules is substantial for animal rhodopsins, which is distinctive from microbial rhodopsins.
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12
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Two-step structural changes in M3 muscarinic receptor activation rely on the coupled G q protein cycle. Nat Commun 2023; 14:1276. [PMID: 36882424 PMCID: PMC9992711 DOI: 10.1038/s41467-023-36911-4] [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: 07/30/2022] [Accepted: 02/23/2023] [Indexed: 03/09/2023] Open
Abstract
G protein-coupled receptors (GPCRs) regulate diverse intracellular signaling pathways through the activation of heterotrimeric G proteins. However, the effects of the sequential activation-deactivation cycle of G protein on the conformational changes of GPCRs remains unknown. By developing a Förster resonance energy transfer (FRET) tool for human M3 muscarinic receptor (hM3R), we find that a single-receptor FRET probe can display the consecutive structural conversion of a receptor by G protein cycle. Our results reveal that the G protein activation evokes a two-step change in the hM3R structure, including the fast step mediated by Gq protein binding and the subsequent slower step mediated by the physical separation of the Gαq and Gβγ subunits. We also find that the separated Gαq-GTP forms a stable complex with the ligand-activated hM3R and phospholipase Cβ. In sum, the present study uncovers the real-time conformational dynamics of innate hM3R during the downstream Gq protein cycle.
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13
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Rodrigues MJ, Casadei CM, Weinert T, Panneels V, Schertler GFX. Correction of rhodopsin serial crystallography diffraction intensities for a lattice-translocation defect. Acta Crystallogr D Struct Biol 2023; 79:224-233. [PMID: 36876432 PMCID: PMC9986800 DOI: 10.1107/s2059798323000931] [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: 12/01/2022] [Accepted: 02/01/2023] [Indexed: 03/01/2023] Open
Abstract
Rhodopsin is a G-protein-coupled receptor that detects light and initiates the intracellular signalling cascades that underpin vertebrate vision. Light sensitivity is achieved by covalent linkage to 11-cis retinal, which isomerizes upon photo-absorption. Serial femtosecond crystallography data collected from rhodopsin microcrystals grown in the lipidic cubic phase were used to solve the room-temperature structure of the receptor. Although the diffraction data showed high completeness and good consistency to 1.8 Å resolution, prominent electron-density features remained unaccounted for throughout the unit cell after model building and refinement. A deeper analysis of the diffraction intensities uncovered the presence of a lattice-translocation defect (LTD) within the crystals. The procedure followed to correct the diffraction intensities for this pathology enabled the building of an improved resting-state model. The correction was essential to both confidently model the structure of the unilluminated state and interpret the light-activated data collected after photo-excitation of the crystals. It is expected that similar cases of LTD will be observed in other serial crystallography experiments and that correction will be required in a variety of systems.
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Affiliation(s)
- Matthew J. Rodrigues
- Laboratory of Biomolecular Research, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Cecilia M. Casadei
- Laboratory of Biomolecular Research, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
- Department of Biology, ETH-Zurich, Zurich, Switzerland
| | - Tobias Weinert
- Laboratory of Biomolecular Research, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Valerie Panneels
- Laboratory of Biomolecular Research, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Gebhard F. X. Schertler
- Laboratory of Biomolecular Research, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
- Department of Biology, ETH-Zurich, Zurich, Switzerland
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14
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Hofmann KP, Lamb TD. Rhodopsin, light-sensor of vision. Prog Retin Eye Res 2023; 93:101116. [PMID: 36273969 DOI: 10.1016/j.preteyeres.2022.101116] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Revised: 08/20/2022] [Accepted: 08/22/2022] [Indexed: 11/06/2022]
Abstract
The light sensor of vertebrate scotopic (low-light) vision, rhodopsin, is a G-protein-coupled receptor comprising a polypeptide chain with bound chromophore, 11-cis-retinal, that exhibits remarkable physicochemical properties. This photopigment is extremely stable in the dark, yet its chromophore isomerises upon photon absorption with 70% efficiency, enabling the activation of its G-protein, transducin, with high efficiency. Rhodopsin's photochemical and biochemical activities occur over very different time-scales: the energy of retinaldehyde's excited state is stored in <1 ps in retinal-protein interactions, but it takes milliseconds for the catalytically active state to form, and many tens of minutes for the resting state to be restored. In this review, we describe the properties of rhodopsin and its role in rod phototransduction. We first introduce rhodopsin's gross structural features, its evolution, and the basic mechanisms of its activation. We then discuss light absorption and spectral sensitivity, photoreceptor electrical responses that result from the activity of individual rhodopsin molecules, and recovery of rhodopsin and the visual system from intense bleaching exposures. We then provide a detailed examination of rhodopsin's molecular structure and function, first in its dark state, and then in the active Meta states that govern its interactions with transducin, rhodopsin kinase and arrestin. While it is clear that rhodopsin's molecular properties are exquisitely honed for phototransduction, from starlight to dawn/dusk intensity levels, our understanding of how its molecular interactions determine the properties of scotopic vision remains incomplete. We describe potential future directions of research, and outline several major problems that remain to be solved.
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Affiliation(s)
- Klaus Peter Hofmann
- Institut für Medizinische Physik und Biophysik (CC2), Charité, and, Zentrum für Biophysik und Bioinformatik, Humboldt-Unversität zu Berlin, Berlin, 10117, Germany.
| | - Trevor D Lamb
- Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2600, Australia.
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15
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Dmitrieva DA, Kotova TV, Safronova NA, Sadova AA, Dashevskii DE, Mishin AV. Protein Design Strategies for the Structural–Functional Studies of G Protein-Coupled Receptors. BIOCHEMISTRY (MOSCOW) 2023; 88:S192-S226. [PMID: 37069121 DOI: 10.1134/s0006297923140110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
G protein-coupled receptors (GPCRs) are an important family of membrane proteins responsible for many physiological functions in human body. High resolution GPCR structures are required to understand their molecular mechanisms and perform rational drug design, as GPCRs play a crucial role in a variety of diseases. That is difficult to obtain for the wild-type proteins because of their low stability. In this review, we discuss how this problem can be solved by using protein design strategies developed to obtain homogeneous stabilized GPCR samples for crystallization and cryoelectron microscopy.
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Affiliation(s)
- Daria A Dmitrieva
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, 141701, Russia
| | - Tatiana V Kotova
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, 141701, Russia
| | - Nadezda A Safronova
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, 141701, Russia
| | - Alexandra A Sadova
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, 141701, Russia
| | - Dmitrii E Dashevskii
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, 141701, Russia
| | - Alexey V Mishin
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, 141701, Russia.
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16
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Leemann S, Kleinlogel S. Functional optimization of light-activatable Opto-GPCRs: Illuminating the importance of the proximal C-terminus in G-protein specificity. Front Cell Dev Biol 2023; 11:1053022. [PMID: 36936685 PMCID: PMC10014536 DOI: 10.3389/fcell.2023.1053022] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 02/14/2023] [Indexed: 03/05/2023] Open
Abstract
Introduction: G-protein coupled receptors (GPCRs) are the largest family of human receptors that transmit signals from natural ligands and pharmaceutical drugs into essentially every physiological process. One main characteristic of G-protein coupled receptors is their ability to specifically couple with different families of G-proteins, thereby triggering specific downstream signaling pathways. While an abundance of structural information is available on G-protein coupled receptorn interactions with G-proteins, little is known about the G-protein coupled receptor domains functionally mediating G-protein specificity, in particular the proximal C-terminus, the structure which cannot be predicted with high confidentiality due to its flexibility. Methods: In this study, we exploited OptoGPCR chimeras between lightgated G-protein coupled receptors (opsins) and ligand-gated G-protein coupled receptors to systematically investigate the involvement of the C-terminus steering G-protein specificity. We employed rhodopsin-beta2-adrenoceptor and melanopsin-mGluR6 chimeras in second messenger assays and developed structural models of the chimeras. Results: We discovered a dominant role of the proximal C-terminus, dictating G-protein selectivity in the melanopsin-mGluR6 chimera, whereas it is the intracellular loop 3, which steers G-protein tropism in the rhodopsin-beta2-adrenoceptor. From the functional results and structural predictions, melanopsin and mGluR6 use a different mechanism to bovine rhodopsin and b2AR to couple to a selective G-protein. Discussion: Collectively, this work adds knowledge to the G-protein coupled receptor domains mediating G-protein selectivity, ultimately paving the way to optogenetically elicited specific G-protein signaling on demand.
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17
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Sandhu M, Cho A, Ma N, Mukhaleva E, Namkung Y, Lee S, Ghosh S, Lee JH, Gloriam DE, Laporte SA, Babu MM, Vaidehi N. Dynamic spatiotemporal determinants modulate GPCR:G protein coupling selectivity and promiscuity. Nat Commun 2022; 13:7428. [PMID: 36460632 PMCID: PMC9718833 DOI: 10.1038/s41467-022-34055-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 10/11/2022] [Indexed: 12/03/2022] Open
Abstract
Recent studies have shown that G protein coupled receptors (GPCRs) show selective and promiscuous coupling to different Gα protein subfamilies and yet the mechanisms of the range of coupling preferences remain unclear. Here, we use Molecular Dynamics (MD) simulations on ten GPCR:G protein complexes and show that the location (spatial) and duration (temporal) of intermolecular contacts at the GPCR:Gα protein interface play a critical role in how GPCRs selectively interact with G proteins. We identify that some GPCR:G protein interface contacts are common across Gα subfamilies and others specific to Gα subfamilies. Using large scale data analysis techniques on the MD simulation snapshots we derive a spatio-temporal code for contacts that confer G protein selective coupling and validated these contacts using G protein activation BRET assays. Our results demonstrate that promiscuous GPCRs show persistent sampling of the common contacts more than G protein specific contacts. These findings suggest that GPCRs maintain contact with G proteins through a common central interface, while the selectivity comes from G protein specific contacts at the periphery of the interface.
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Affiliation(s)
- Manbir Sandhu
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, CA, 91010, USA.
- Department of Structural Biology, Center for Data Driven Discovery, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA.
| | - Aaron Cho
- Department of Medicine, Research Institute of the McGill University Health Centre, Montreal, QC, H4A 3J1, Canada
| | - Ning Ma
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, CA, 91010, USA
| | - Elizaveta Mukhaleva
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, CA, 91010, USA
- Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, Duarte, CA, 91010, USA
| | - Yoon Namkung
- Department of Medicine, Research Institute of the McGill University Health Centre, Montreal, QC, H4A 3J1, Canada
| | - Sangbae Lee
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, CA, 91010, USA
| | - Soumadwip Ghosh
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, CA, 91010, USA
| | - John H Lee
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, CA, 91010, USA
| | - David E Gloriam
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Stéphane A Laporte
- Department of Medicine, Research Institute of the McGill University Health Centre, Montreal, QC, H4A 3J1, Canada
- Department of Pharmacology and Therapeutics, McGill University, Montréal, QC, H3G 1Y6, Canada
| | - M Madan Babu
- Department of Structural Biology, Center for Data Driven Discovery, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA.
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK.
| | - Nagarajan Vaidehi
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, CA, 91010, USA.
- Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, Duarte, CA, 91010, USA.
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18
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Helmer N, Wolf S, Stock G. Energy Transport and Its Function in Heptahelical Transmembrane Proteins. J Phys Chem B 2022; 126:8735-8746. [PMID: 36261792 DOI: 10.1021/acs.jpcb.2c05892] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Photoproteins such as bacteriorhodopsin (bR) and rhodopsin (Rho) need to effectively dissipate photoinduced excess energy to prevent themselves from damage. Another well-studied seven transmembrane (TM) helices protein is the β2 adrenergic receptor (β2AR), a G protein-coupled receptor for which energy dissipation paths have been linked with allosteric communication. To study the vibrational energy transport in the active and inactive states of these proteins, a master equation approach [J. Chem. Phys.2020, 152, 045103] is employed, which uses scaling rules that allow us to calculate energy transport rates solely based on the protein structure. Despite their overall structural similarity, the three 7TM proteins reveal quite different strategies to redistribute excess energy. While bR quickly removes the energy using the TM7 helix as a "lightning rod", Rho exhibits a rather poor energy dissipation, which might eventually require the hydrolysis of the Schiff base between the protein and the retinal chromophore to prevent overheating. Heating the ligand adrenaline of β2AR, the resulting energy transport network of the protein is found to change significantly upon switching from the active state to the inactive state. While the energy flow may highlight aspects of the inter-residue couplings of β2AR, it seems not particularly suited to explain allosteric phenomena.
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Affiliation(s)
- Nadja Helmer
- Biomolecular Dynamics, Institute of Physics, University of Freiburg, 79104Freiburg, Germany
| | - Steffen Wolf
- Biomolecular Dynamics, Institute of Physics, University of Freiburg, 79104Freiburg, Germany
| | - Gerhard Stock
- Biomolecular Dynamics, Institute of Physics, University of Freiburg, 79104Freiburg, Germany
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19
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Kim H, Baek IY, Seong J. Genetically encoded fluorescent biosensors for GPCR research. Front Cell Dev Biol 2022; 10:1007893. [PMID: 36247000 PMCID: PMC9559200 DOI: 10.3389/fcell.2022.1007893] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Accepted: 09/09/2022] [Indexed: 11/13/2022] Open
Abstract
G protein-coupled receptors (GPCRs) regulate a wide range of physiological and pathophysiological cellular processes, thus it is important to understand how GPCRs are activated and function in various cellular contexts. In particular, the activation process of GPCRs is dynamically regulated upon various extracellular stimuli, and emerging evidence suggests the subcellular functions of GPCRs at endosomes and other organelles. Therefore, precise monitoring of the GPCR activation process with high spatiotemporal resolution is required to investigate the underlying molecular mechanisms of GPCR functions. In this review, we will introduce genetically encoded fluorescent biosensors that can precisely monitor the real-time GPCR activation process in live cells. The process includes the binding of extracellular GPCR ligands, conformational change of GPCR, recruitment of G proteins or β-arrestin, GPCR internalization and trafficking, and the GPCR-related downstream signaling events. We will introduce fluorescent GPCR biosensors based on a variety of strategies such as fluorescent resonance energy transfer (FRET), bioluminescence resonance energy transfer (BRET), circular permuted fluorescent protein (cpFP), and nanobody. We will discuss the pros and cons of these GPCR biosensors as well as their applications in GPCR research.
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Affiliation(s)
- Hyunbin Kim
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, South Korea
- Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology, Seoul, South Korea
| | - In-Yeop Baek
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, South Korea
- Department of Converging Science and Technology, Kyung Hee University, Seoul, South Korea
| | - Jihye Seong
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, South Korea
- Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology, Seoul, South Korea
- Department of Converging Science and Technology, Kyung Hee University, Seoul, South Korea
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20
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de Grip WJ, Ganapathy S. Rhodopsins: An Excitingly Versatile Protein Species for Research, Development and Creative Engineering. Front Chem 2022; 10:879609. [PMID: 35815212 PMCID: PMC9257189 DOI: 10.3389/fchem.2022.879609] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Accepted: 05/16/2022] [Indexed: 01/17/2023] Open
Abstract
The first member and eponym of the rhodopsin family was identified in the 1930s as the visual pigment of the rod photoreceptor cell in the animal retina. It was found to be a membrane protein, owing its photosensitivity to the presence of a covalently bound chromophoric group. This group, derived from vitamin A, was appropriately dubbed retinal. In the 1970s a microbial counterpart of this species was discovered in an archaeon, being a membrane protein also harbouring retinal as a chromophore, and named bacteriorhodopsin. Since their discovery a photogenic panorama unfolded, where up to date new members and subspecies with a variety of light-driven functionality have been added to this family. The animal branch, meanwhile categorized as type-2 rhodopsins, turned out to form a large subclass in the superfamily of G protein-coupled receptors and are essential to multiple elements of light-dependent animal sensory physiology. The microbial branch, the type-1 rhodopsins, largely function as light-driven ion pumps or channels, but also contain sensory-active and enzyme-sustaining subspecies. In this review we will follow the development of this exciting membrane protein panorama in a representative number of highlights and will present a prospect of their extraordinary future potential.
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Affiliation(s)
- Willem J. de Grip
- Leiden Institute of Chemistry, Department of Biophysical Organic Chemistry, Leiden University, Leiden, Netherlands
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Srividya Ganapathy
- Department of Imaging Physics, Delft University of Technology, Netherlands
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21
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McIntire WE. A model for how Gβγ couples Gα to GPCR. J Gen Physiol 2022; 154:213096. [PMID: 35333292 PMCID: PMC8961292 DOI: 10.1085/jgp.202112982] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 02/28/2022] [Indexed: 11/20/2022] Open
Abstract
Representing ∼5% of the human genome, G-protein-coupled receptors (GPCRs) are a primary target for drug discovery; however, the molecular details of how they couple to heterotrimeric G protein subunits are incompletely understood. Here, I propose a hypothetical initial docking model for the encounter between GPCR and Gβγ that is defined by transient interactions between the cytosolic surface of the GPCR and the prenyl moiety and the tripeptide motif, asparagine-proline-phenylalanine (NPF), in the C-terminus of the Gγ subunit. Analysis of class A GPCRs reveals a conserved NPF binding site formed by the interaction of the TM1 and H8. Functional studies using differentially prenylated proteins and peptides further suggest that the intracellular hydrophobic core of the GPCR is a prenyl binding site. Upon binding TM1 and H8 of GPCRs, the propensity of the C-terminal region of Gγ to convert into an α helix allows it to extend into the hydrophobic core of the GPCR, facilitating the GPCR active state. Conservation of the NPF motif in Gγ isoforms and interacting residues in TM1 and H8 suggest that this is a general mechanism of GPCR-G protein signaling. Analysis of the rhodopsin dimer also suggests that Gγ-rhodopsin interactions may facilitate GPCR dimer transactivation.
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Affiliation(s)
- William E McIntire
- Department of Molecular Physiology and Biological Physics, University of Virginia Health System, Charlottesville, VA
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22
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Ferré S, Ciruela F, Dessauer CW, González-Maeso J, Hébert TE, Jockers R, Logothetis DE, Pardo L. G protein-coupled receptor-effector macromolecular membrane assemblies (GEMMAs). Pharmacol Ther 2022; 231:107977. [PMID: 34480967 PMCID: PMC9375844 DOI: 10.1016/j.pharmthera.2021.107977] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 08/11/2021] [Accepted: 08/17/2021] [Indexed: 12/12/2022]
Abstract
G protein-coupled receptors (GPCRs) are the largest group of receptors involved in cellular signaling across the plasma membrane and a major class of drug targets. The canonical model for GPCR signaling involves three components - the GPCR, a heterotrimeric G protein and a proximal plasma membrane effector - that have been generally thought to be freely mobile molecules able to interact by 'collision coupling'. Here, we synthesize evidence that supports the existence of GPCR-effector macromolecular membrane assemblies (GEMMAs) comprised of specific GPCRs, G proteins, plasma membrane effector molecules and other associated transmembrane proteins that are pre-assembled prior to receptor activation by agonists, which then leads to subsequent rearrangement of the GEMMA components. The GEMMA concept offers an alternative and complementary model to the canonical collision-coupling model, allowing more efficient interactions between specific signaling components, as well as the integration of the concept of GPCR oligomerization as well as GPCR interactions with orphan receptors, truncated GPCRs and other membrane-localized GPCR-associated proteins. Collision-coupling and pre-assembled mechanisms are not exclusive and likely both operate in the cell, providing a spectrum of signaling modalities which explains the differential properties of a multitude of GPCRs in their different cellular environments. Here, we explore the unique pharmacological characteristics of individual GEMMAs, which could provide new opportunities to therapeutically modulate GPCR signaling.
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Affiliation(s)
- Sergi Ferré
- Integrative Neurobiology Section, National Institute on Drug Addiction, Intramural Research Program, NIH, DHHS, Baltimore, MD, USA.
| | - Francisco Ciruela
- Department of Pathology and Experimental Therapeutics, Faculty of Medicine and Health Sciences, Institute of Neurosciences, IDIBELL, University of Barcelona, L’Hospitalet de Llobregat, Spain
| | - Carmen W. Dessauer
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Javier González-Maeso
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Terence E. Hébert
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec
| | - Ralf Jockers
- University of Paris, Institute Cochin, INSERM, CNRS, Paris, France
| | - Diomedes E. Logothetis
- Laboratory of Electrophysiology, Departments of Pharmaceutical Sciences, Chemistry and Chemical Biology and Center for Drug Discovery, School of Pharmacy at the Bouvé College of Health Sciences and College of Science, Northeastern University, Boston, Massachusetts, USA
| | - Leonardo Pardo
- Laboratory of Computational Medicine, Biostatistics Unit, Faculty of Medicine, Autonomous University of Barcelona, Bellaterra, Spain
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23
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Nicoli A, Dunkel A, Giorgino T, de Graaf C, Di Pizio A. Classification Model for the Second Extracellular Loop of Class A GPCRs. J Chem Inf Model 2022; 62:511-522. [PMID: 35113559 DOI: 10.1021/acs.jcim.1c01056] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The extracellular loop 2 (ECL2) is the longest and the most diverse loop among class A G protein-coupled receptors (GPCRs). It connects the transmembrane (TM) helices 4 and 5 and contains a highly conserved cysteine through which it is bridged with TM3. In this paper, experimental ECL2 structures were analyzed based on their sequences, shapes, and intramolecular contacts. To take into account the flexibility, we incorporated into our analyses information from the molecular dynamics trajectories available on the GPCRmd website. Despite the high sequence variability, shapes of the analyzed structures, defined by the backbone volume overlaps, can be clustered into seven main groups. Conformational differences within the clusters can be then identified by intramolecular interactions with other GPCR structural domains. Overall, our work provides a reorganization of the structural information of the ECL2 of class A GPCR subfamilies, highlighting differences and similarities on sequence and conformation levels.
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Affiliation(s)
- Alessandro Nicoli
- Leibniz Institute for Food Systems Biology at the Technical University of Munich, 85354 Freising, Germany
| | - Andreas Dunkel
- Leibniz Institute for Food Systems Biology at the Technical University of Munich, 85354 Freising, Germany
| | - Toni Giorgino
- Biophysics Institute, National Research Council (CNR-IBF), 20133 Milan, Italy
| | - Chris de Graaf
- Sosei Heptares, Steinmetz Building, Granta Park, Great Abington, Cambridge CB21 6DG, U.K
| | - Antonella Di Pizio
- Leibniz Institute for Food Systems Biology at the Technical University of Munich, 85354 Freising, Germany
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24
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Preparation of a stable CCL5·CCR5·Gi signaling complex for Cryo-EM analysis. Methods Cell Biol 2022; 169:115-141. [DOI: 10.1016/bs.mcb.2022.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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25
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Guérin DMA, Digilio A, Branda MM. Dimeric Rhodopsin R135L Mutant-Transducin-like Complex Sheds Light on Retinitis Pigmentosa Misfunctions. J Phys Chem B 2021; 125:12958-12971. [PMID: 34793169 DOI: 10.1021/acs.jpcb.1c06348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Rhodopsin (RHO) is a light-sensitive pigment in the retina and the main prototypical protein of the G-protein-coupled receptor (GCPR) family. After receiving a light stimulus, RHO and its cofactor retinylidene undergo a series of structural changes that initiate an intricate transduction mechanism. Along with RHO, other partner proteins play key roles in the signaling pathway. These include transducin, a GTPase, kinases that phosphorylate RHO, and arrestin (Arr), which ultimately stops the signaling process and promotes RHO regeneration. A large number of RHO genetic mutations may lead to very severe retinal dysfunction and eventually to impaired dark adaptation disease called autosomal dominant retinitis pigmentosa (adRP). In this study, we used molecular dynamics (MD) simulations to evaluate the different behaviors of the dimeric form of wild-type RHO (WT dRHO) and its mutant at position 135 of arginine to leucine (dR135L), both in the free (noncomplexed) and in complex with the transducin-like protein (Gtl). Gtl is a heterotrimeric model composed of a mixture of human and bovine G proteins. Our calculations allow us to explain how the mutation causes structural changes in the RHO dimer and how this can affect the signal that transducin generates when it is bound to RHO. Moreover, the structural modifications induced by the R135L mutation can also account for other misfunctions observed in the up- and downstream signaling pathways. The mechanism of these dysfunctions, together with the transducin activity reduction, provides structure-based explanations of the impairment of some key processes that lead to adRP.
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Affiliation(s)
- Diego M A Guérin
- Department of Biochemistry and Molecular Biology, University of the Basque Country (EHU) and Instituto Biofisika (CSIC, UPV/EHU), Barrio Sarriena S/N, 48940 Leioa, Vizcaya, Spain
| | - Ayelen Digilio
- Department of Physics, National University of San Luis (UNSL), Av. Ejército de los Andes 950, 5700 San Luis, Argentina
| | - María Marta Branda
- Institute of Applied Physics (CONICET-UNSL), Av. Ejercito de los Andes 950, 5700 San Luis, Argentina
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26
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Pamula F, Tsai CJ. Biochemical Characterization of GPCR-G Protein Complex Formation. Methods Mol Biol 2021; 2302:37-48. [PMID: 33877621 DOI: 10.1007/978-1-0716-1394-8_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The complex of G protein-coupled receptors (GPCR) and G proteins is the core assembly in GPCR signaling in eukaryotes. With the recent development of cryo-electron microscopy, there has been a rapid growth in structures of GPCR-G protein complexes solved to near-atomic resolution, giving important insights into this signaling complex. Here we describe the biochemical protocol to study the interaction between GPCRs and G proteins before preparation of GPCR-G protein complexes for structural studies. We use gel filtration to analyze the binding properties between GPCR and G protein with the presence of agonist or antagonist, as well as the complex dissociation in the presence of GTP analogue. Methods used in the protocol are affinity purification and gel filtration, which are also commonly used in protein sample preparation for structural work. Therefore, the protocol can be easily adapted for large-scale sample preparation.
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Affiliation(s)
- Filip Pamula
- Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen, Switzerland
| | - Ching-Ju Tsai
- Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen, Switzerland.
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27
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High-mass MALDI-MS unravels ligand-mediated G protein-coupling selectivity to GPCRs. Proc Natl Acad Sci U S A 2021; 118:2024146118. [PMID: 34326250 PMCID: PMC8346855 DOI: 10.1073/pnas.2024146118] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
G protein–coupled receptors (GPCRs) are important pharmaceutical targets for the treatment of a broad spectrum of diseases. Upon ligand binding, GPCRs initiate intracellular signaling pathways by interacting with partner proteins. Assays that quantify the interplay between ligand binding and initiation of downstream signaling cascades are critical in the early stages of drug development. We have developed a high-throughput mass spectrometry method to unravel GPCR–protein complex interplay and demonstrated its use with three GPCRs to provide quantitative information about ligand-modulated coupling selectivity. This method provides insights into the molecular details of GPCR interactions and could serve as an approach for discovery of drugs that initiate specific cell-signaling pathways. G protein–coupled receptors (GPCRs) are important pharmaceutical targets for the treatment of a broad spectrum of diseases. Although there are structures of GPCRs in their active conformation with bound ligands and G proteins, the detailed molecular interplay between the receptors and their signaling partners remains challenging to decipher. To address this, we developed a high-sensitivity, high-throughput matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) method to interrogate the first stage of signal transduction. GPCR–G protein complex formation is detected as a proxy for the effect of ligands on GPCR conformation and on coupling selectivity. Over 70 ligand–GPCR–partner protein combinations were studied using as little as 1.25 pmol protein per sample. We determined the selectivity profile and binding affinities of three GPCRs (rhodopsin, beta-1 adrenergic receptor [β1AR], and angiotensin II type 1 receptor) to engineered Gα-proteins (mGs, mGo, mGi, and mGq) and nanobody 80 (Nb80). We found that GPCRs in the absence of ligand can bind mGo, and that the role of the G protein C terminus in GPCR recognition is receptor-specific. We exemplified our quantification method using β1AR and demonstrated the allosteric effect of Nb80 binding in assisting displacement of nadolol to isoprenaline. We also quantified complex formation with wild-type heterotrimeric Gαiβγ and β-arrestin-1 and showed that carvedilol induces an increase in coupling of β-arrestin-1 and Gαiβγ to β1AR. A normalization strategy allows us to quantitatively measure the binding affinities of GPCRs to partner proteins. We anticipate that this methodology will find broad use in screening and characterization of GPCR-targeting drugs.
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28
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Nubbemeyer B, Pepanian A, Paul George AA, Imhof D. Strategies towards Targeting Gαi/s Proteins: Scanning of Protein-Protein Interaction Sites To Overcome Inaccessibility. ChemMedChem 2021; 16:1696-1715. [PMID: 33615736 PMCID: PMC8252600 DOI: 10.1002/cmdc.202100039] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Indexed: 12/16/2022]
Abstract
Heterotrimeric G proteins are classified into four subfamilies and play a key role in signal transduction. They transmit extracellular signals to intracellular effectors subsequent to the activation of G protein-coupled receptors (GPCRs), which are targeted by over 30 % of FDA-approved drugs. However, addressing G proteins as drug targets represents a compelling alternative, for example, when G proteins act independently of the corresponding GPCRs, or in cases of complex multifunctional diseases, when a large number of different GPCRs are involved. In contrast to Gαq, efforts to target Gαi/s by suitable chemical compounds has not been successful so far. Here, a comprehensive analysis was conducted examining the most important interface regions of Gαi/s with its upstream and downstream interaction partners. By assigning the existing compounds and the performed approaches to the respective interfaces, the druggability of the individual interfaces was ranked to provide perspectives for selective targeting of Gαi/s in the future.
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Affiliation(s)
- Britta Nubbemeyer
- Pharmaceutical Biochemistry and BioanalyticsPharmaceutical InstituteUniversity of BonnAn der Immenburg 453121BonnGermany
| | - Anna Pepanian
- Pharmaceutical Biochemistry and BioanalyticsPharmaceutical InstituteUniversity of BonnAn der Immenburg 453121BonnGermany
| | | | - Diana Imhof
- Pharmaceutical Biochemistry and BioanalyticsPharmaceutical InstituteUniversity of BonnAn der Immenburg 453121BonnGermany
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29
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Isaikina P, Tsai CJ, Dietz N, Pamula F, Grahl A, Goldie KN, Guixà-González R, Branco C, Paolini-Bertrand M, Calo N, Cerini F, Schertler GFX, Hartley O, Stahlberg H, Maier T, Deupi X, Grzesiek S. Structural basis of the activation of the CC chemokine receptor 5 by a chemokine agonist. SCIENCE ADVANCES 2021; 7:7/25/eabg8685. [PMID: 34134983 PMCID: PMC8208711 DOI: 10.1126/sciadv.abg8685] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 04/29/2021] [Indexed: 05/10/2023]
Abstract
The human CC chemokine receptor 5 (CCR5) is a G protein-coupled receptor (GPCR) that plays a major role in inflammation and is involved in cancer, HIV, and COVID-19. Despite its importance as a drug target, the molecular activation mechanism of CCR5, i.e., how chemokine agonists transduce the activation signal through the receptor, is yet unknown. Here, we report the cryo-EM structure of wild-type CCR5 in an active conformation bound to the chemokine super-agonist [6P4]CCL5 and the heterotrimeric Gi protein. The structure provides the rationale for the sequence-activity relation of agonist and antagonist chemokines. The N terminus of agonist chemokines pushes onto specific structural motifs at the bottom of the orthosteric pocket that activate the canonical GPCR microswitch network. This activation mechanism differs substantially from other CC chemokine receptors that bind chemokines with shorter N termini in a shallow binding mode involving unique sequence signatures and a specialized activation mechanism.
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Affiliation(s)
- Polina Isaikina
- Focal Area Structural Biology and Biophysics, Biozentrum, University of Basel, CH-4056 Basel, Switzerland
| | - Ching-Ju Tsai
- Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
| | - Nikolaus Dietz
- Focal Area Structural Biology and Biophysics, Biozentrum, University of Basel, CH-4056 Basel, Switzerland
| | - Filip Pamula
- Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
- Department of Biology, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Anne Grahl
- Focal Area Structural Biology and Biophysics, Biozentrum, University of Basel, CH-4056 Basel, Switzerland
| | - Kenneth N Goldie
- Center for Cellular Imaging and NanoAnalytics, Biozentrum, University of Basel, CH-4058 Basel, Switzerland
| | | | - Camila Branco
- Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Marianne Paolini-Bertrand
- Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Nicolas Calo
- Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Fabrice Cerini
- Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Gebhard F X Schertler
- Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland.
- Department of Biology, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Oliver Hartley
- Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Geneva, Switzerland.
- Orion Biotechnology, Ottawa, Canada
| | - Henning Stahlberg
- Center for Cellular Imaging and NanoAnalytics, Biozentrum, University of Basel, CH-4058 Basel, Switzerland
| | - Timm Maier
- Focal Area Structural Biology and Biophysics, Biozentrum, University of Basel, CH-4056 Basel, Switzerland
| | - Xavier Deupi
- Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland.
| | - Stephan Grzesiek
- Focal Area Structural Biology and Biophysics, Biozentrum, University of Basel, CH-4056 Basel, Switzerland.
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30
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Elgeti M, Hubbell WL. DEER Analysis of GPCR Conformational Heterogeneity. Biomolecules 2021; 11:778. [PMID: 34067265 PMCID: PMC8224605 DOI: 10.3390/biom11060778] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 05/18/2021] [Accepted: 05/19/2021] [Indexed: 02/06/2023] Open
Abstract
G protein-coupled receptors (GPCRs) represent a large class of transmembrane helical proteins which are involved in numerous physiological signaling pathways and therefore represent crucial pharmacological targets. GPCR function and the action of therapeutic molecules are defined by only a few parameters, including receptor basal activity, ligand affinity, intrinsic efficacy and signal bias. These parameters are encoded in characteristic receptor conformations existing in equilibrium and their populations, which are thus of paramount interest for the understanding of receptor (mal-)functions and rational design of improved therapeutics. To this end, the combination of site-directed spin labeling and EPR spectroscopy, in particular double electron-electron resonance (DEER), is exceedingly valuable as it has access to sub-Angstrom spatial resolution and provides a detailed picture of the number and populations of conformations in equilibrium. This review gives an overview of existing DEER studies on GPCRs with a focus on the delineation of structure/function frameworks, highlighting recent developments in data analysis and visualization. We introduce "conformational efficacy" as a parameter to describe ligand-specific shifts in the conformational equilibrium, taking into account the loose coupling between receptor segments observed for different GPCRs using DEER.
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Affiliation(s)
- Matthias Elgeti
- Jules Stein Eye Institute and Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA
| | - Wayne L. Hubbell
- Jules Stein Eye Institute and Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA
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31
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Amphipathic environments for determining the structure of membrane proteins by single-particle electron cryo-microscopy. Q Rev Biophys 2021; 54:e6. [PMID: 33785082 DOI: 10.1017/s0033583521000044] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Over the past decade, the structural biology of membrane proteins (MPs) has taken a new turn thanks to epoch-making technical progress in single-particle electron cryo-microscopy (cryo-EM) as well as to improvements in sample preparation. The present analysis provides an overview of the extent and modes of usage of the various types of surfactants for cryo-EM studies. Digitonin, dodecylmaltoside, protein-based nanodiscs, lauryl maltoside-neopentyl glycol, glyco-diosgenin, and amphipols (APols) are the most popular surfactants at the vitrification step. Surfactant exchange is frequently used between MP purification and grid preparation, requiring extensive optimization each time the study of a new MP is undertaken. The variety of both the surfactants and experimental approaches used over the past few years bears witness to the need to continue developing innovative surfactants and optimizing conditions for sample preparation. The possibilities offered by novel APols for EM applications are discussed.
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32
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Fanelli F, Felline A, Marigo V. Structural aspects of rod opsin and their implication in genetic diseases. Pflugers Arch 2021; 473:1339-1359. [PMID: 33728518 DOI: 10.1007/s00424-021-02546-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Revised: 02/17/2021] [Accepted: 02/22/2021] [Indexed: 01/04/2023]
Abstract
Vision in dim-light conditions is triggered by photoactivation of rhodopsin, the visual pigment of rod photoreceptor cells. Rhodopsin is made of a protein, the G protein coupled receptor (GPCR) opsin, and the chromophore 11-cis-retinal. Vertebrate rod opsin is the GPCR best characterized at the atomic level of detail. Since the release of the first crystal structure 20 years ago, a huge number of structures have been released that, in combination with valuable spectroscopic determinations, unveiled most aspects of the photobleaching process. A number of spontaneous mutations of rod opsin have been found linked to vision-impairing diseases like autosomal dominant or autosomal recessive retinitis pigmentosa (adRP or arRP, respectively) and autosomal congenital stationary night blindness (adCSNB). While adCSNB is mainly caused by constitutive activation of rod opsin, RP shows more variegate determinants affecting different aspects of rod opsin function. The vast majority of missense rod opsin mutations affects folding and trafficking and is linked to adRP, an incurable disease that awaits light on its molecular structure determinants. This review article summarizes all major structural information available on vertebrate rod opsin conformational states and the insights gained so far into the structural determinants of adCSNB and adRP linked to rod opsin mutations. Strategies to design small chaperones with therapeutic potential for selected adRP rod opsin mutants will be discussed as well.
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Affiliation(s)
- Francesca Fanelli
- Department of Life Sciences, University of Modena and Reggio Emilia, via Campi 103, 41125, Modena, Italy. .,Center for Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, via Campi 287, Modena, 41125, Italy.
| | - Angelo Felline
- Department of Life Sciences, University of Modena and Reggio Emilia, via Campi 103, 41125, Modena, Italy
| | - Valeria Marigo
- Center for Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, via Campi 287, Modena, 41125, Italy.,Department of Life Sciences, University of Modena and Reggio Emilia, via Campi 287, 41125, Modena, Italy
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33
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A set of common movements within GPCR-G-protein complexes from variability analysis of cryo-EM datasets. J Struct Biol 2021; 213:107699. [PMID: 33545352 DOI: 10.1016/j.jsb.2021.107699] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 01/05/2021] [Accepted: 01/22/2021] [Indexed: 12/11/2022]
Abstract
G-protein coupled receptors (GPCRs) are among the most versatile signal transducers in the cell. Once activated, GPCRs sample a large conformational space and couple to G-proteins to initiate distinct signaling pathways. The dynamical behavior of GPCR-G-protein complexes is difficult characterize structurally, and it might hinder obtaining routine high-resolution density maps in single-particle reconstructions. Here, we used variability analysis on the rhodopsin-Gi-Fab16 complex cryo-EM dataset, and the results provide insights into the dynamic nature of the receptor-complex interaction. We compare the outcome of this analysis with recent results obtained on the cannabinoid-Gi- and secretin-Gs-receptor complexes. Despite differences related to the biochemical compositions of the three samples, a set of consensus movements emerges. We anticipate that systematic variability analysis on GPCR-G-protein complexes may provide useful information not only at the biological level, but also for improving the preparation of more stable samples for cryo-EM single-particle analysis.
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34
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Ham D, Ahn D, Ashim J, Cho Y, Kim HR, Yu W, Chung KY. Conformational switch that induces GDP release from Gi. J Struct Biol 2021; 213:107694. [PMID: 33418033 DOI: 10.1016/j.jsb.2020.107694] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 12/14/2020] [Accepted: 12/24/2020] [Indexed: 12/26/2022]
Abstract
Heterotrimeric guanine nucleotide-binding proteins (G proteins) are composed of α, β, and γ subunits. Gα switches between guanosine diphosphate (GDP)-bound inactive and guanosine triphosphate (GTP)-bound active states, and Gβγ interacts with the GDP-bound state. The GDP-binding regions are composed of two sites: the phosphate-binding and guanine-binding regions. The turnover of GDP and GTP is induced by guanine nucleotide-exchange factors (GEFs), including G protein-coupled receptors (GPCRs), Ric8A, and GIV/Girdin. However, the key structural factors for stabilizing the GDP-bound state of G proteins and the direct structural event for GDP release remain unclear. In this study, we investigated structural factors affecting GDP release by introducing point mutations in selected, conserved residues in Gαi3. We examined the effects of these mutations on the GDP/GTP turnover rate and the overall conformation of Gαi3 as well as the binding free energy between Gαi3 and GDP. We found that dynamic changes in the phosphate-binding regions are an immediate factor for the release of GDP.
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Affiliation(s)
- Donghee Ham
- School of Pharmacy, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon 16419, Republic of Korea
| | - Donghoon Ahn
- School of Pharmacy, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon 16419, Republic of Korea
| | - Janbolat Ashim
- Department of Brain and Cognitive Sciences, DGIST, 333 Techno jungang-daero, Daegu 42988, Republic of Korea
| | - Yejin Cho
- School of Pharmacy, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon 16419, Republic of Korea
| | - Hee Ryung Kim
- School of Pharmacy, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon 16419, Republic of Korea
| | - Wookyung Yu
- Department of Brain and Cognitive Sciences, DGIST, 333 Techno jungang-daero, Daegu 42988, Republic of Korea; Core Protein Resources Center, DGIST, 333 Techno jungang-daero, Daegu 42988, Republic of Korea.
| | - Ka Young Chung
- School of Pharmacy, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon 16419, Republic of Korea.
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35
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Calebiro D, Koszegi Z, Lanoiselée Y, Miljus T, O'Brien S. G protein-coupled receptor-G protein interactions: a single-molecule perspective. Physiol Rev 2020; 101:857-906. [PMID: 33331229 DOI: 10.1152/physrev.00021.2020] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
G protein-coupled receptors (GPCRs) regulate many cellular and physiological processes, responding to a diverse range of extracellular stimuli including hormones, neurotransmitters, odorants, and light. Decades of biochemical and pharmacological studies have provided fundamental insights into the mechanisms of GPCR signaling. Thanks to recent advances in structural biology, we now possess an atomistic understanding of receptor activation and G protein coupling. However, how GPCRs and G proteins interact in living cells to confer signaling efficiency and specificity remains insufficiently understood. The development of advanced optical methods, including single-molecule microscopy, has provided the means to study receptors and G proteins in living cells with unprecedented spatio-temporal resolution. The results of these studies reveal an unexpected level of complexity, whereby GPCRs undergo transient interactions among themselves as well as with G proteins and structural elements of the plasma membrane to form short-lived signaling nanodomains that likely confer both rapidity and specificity to GPCR signaling. These findings may provide new strategies to pharmaceutically modulate GPCR function, which might eventually pave the way to innovative drugs for common diseases such as diabetes or heart failure.
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Affiliation(s)
- Davide Calebiro
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom; Centre of Membrane Proteins and Receptors (COMPARE), Universities of Nottingham and Birmingham, Birmingham, United Kingdom
| | - Zsombor Koszegi
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom; Centre of Membrane Proteins and Receptors (COMPARE), Universities of Nottingham and Birmingham, Birmingham, United Kingdom
| | - Yann Lanoiselée
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom; Centre of Membrane Proteins and Receptors (COMPARE), Universities of Nottingham and Birmingham, Birmingham, United Kingdom
| | - Tamara Miljus
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom; Centre of Membrane Proteins and Receptors (COMPARE), Universities of Nottingham and Birmingham, Birmingham, United Kingdom
| | - Shannon O'Brien
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom; Centre of Membrane Proteins and Receptors (COMPARE), Universities of Nottingham and Birmingham, Birmingham, United Kingdom
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Capturing Peptide-GPCR Interactions and Their Dynamics. Molecules 2020; 25:molecules25204724. [PMID: 33076289 PMCID: PMC7587574 DOI: 10.3390/molecules25204724] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 10/08/2020] [Accepted: 10/09/2020] [Indexed: 12/16/2022] Open
Abstract
Many biological functions of peptides are mediated through G protein-coupled receptors (GPCRs). Upon ligand binding, GPCRs undergo conformational changes that facilitate the binding and activation of multiple effectors. GPCRs regulate nearly all physiological processes and are a favorite pharmacological target. In particular, drugs are sought after that elicit the recruitment of selected effectors only (biased ligands). Understanding how ligands bind to GPCRs and which conformational changes they induce is a fundamental step toward the development of more efficient and specific drugs. Moreover, it is emerging that the dynamic of the ligand–receptor interaction contributes to the specificity of both ligand recognition and effector recruitment, an aspect that is missing in structural snapshots from crystallography. We describe here biochemical and biophysical techniques to address ligand–receptor interactions in their structural and dynamic aspects, which include mutagenesis, crosslinking, spectroscopic techniques, and mass-spectrometry profiling. With a main focus on peptide receptors, we present methods to unveil the ligand–receptor contact interface and methods that address conformational changes both in the ligand and the GPCR. The presented studies highlight a wide structural heterogeneity among peptide receptors, reveal distinct structural changes occurring during ligand binding and a surprisingly high dynamics of the ligand–GPCR complexes.
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Chang CC, Liou JW, Dass KTP, Li YT, Jiang SJ, Pan SF, Yeh YC, Hsu HJ. Internal water channel formation in CXCR4 is crucial for G i-protein coupling upon activation by CXCL12. Commun Chem 2020; 3:133. [PMID: 36703316 PMCID: PMC9814148 DOI: 10.1038/s42004-020-00383-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 09/15/2020] [Indexed: 01/29/2023] Open
Abstract
Chemokine receptor CXCR4 is a major drug target for numerous diseases because of its involvement in the regulation of cell migration and the developmental process. In this study, atomic-level molecular dynamics simulations were used to determine the activation mechanism and internal water formation of CXCR4 in complex with chemokine CXCL12 and Gi-protein. The results indicated that CXCL12-bound CXCR4 underwent transmembrane 6 (TM6) outward movement and a decrease in tyrosine toggle switch by eliciting the breakage of hydrophobic layer to form a continuous internal water channel. In the GDP-bound Gαi-protein state, the rotation and translation of the α5-helix of Gαi-protein toward the cytoplasmic pocket of CXCR4 induced an increase in interdomain distance for GDP leaving. Finally, an internal water channel formation model was proposed based on our simulations for CXCL12-bound CXCR4 in complex with Gαi-protein upon activation for downstream signaling. This model could be useful in anticancer drug development.
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Affiliation(s)
- Chun-Chun Chang
- Department of Laboratory Medicine, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, 97004, Taiwan
- Department of Laboratory Medicine and Biotechnology, College of Medicine, Tzu Chi University, Hualien, 97004, Taiwan
| | - Je-Wen Liou
- Department of Biochemistry, School of Medicine, Tzu Chi University, Hualien, 97004, Taiwan
| | | | - Ya-Tzu Li
- Department of Biochemistry, School of Medicine, Tzu Chi University, Hualien, 97004, Taiwan
| | - Shinn-Jong Jiang
- Department of Biochemistry, School of Medicine, Tzu Chi University, Hualien, 97004, Taiwan
| | - Sheng-Feng Pan
- Department of Biochemistry, School of Medicine, Tzu Chi University, Hualien, 97004, Taiwan
| | - Yu-Chen Yeh
- Department of Biochemistry, School of Medicine, Tzu Chi University, Hualien, 97004, Taiwan
- Department of Life Sciences, Tzu Chi University, Hualien, 97004, Taiwan
| | - Hao-Jen Hsu
- Department of Biochemistry, School of Medicine, Tzu Chi University, Hualien, 97004, Taiwan.
- Department of Life Sciences, Tzu Chi University, Hualien, 97004, Taiwan.
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Valdez-Lopez JC, Petr ST, Donohue MP, Bailey RJ, Gebreeziabher M, Cameron EG, Wolf JB, Szalai VA, Robinson PR. The C-Terminus and Third Cytoplasmic Loop Cooperatively Activate Mouse Melanopsin Phototransduction. Biophys J 2020; 119:389-401. [PMID: 32621866 PMCID: PMC7376183 DOI: 10.1016/j.bpj.2020.06.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 05/28/2020] [Accepted: 06/10/2020] [Indexed: 11/30/2022] Open
Abstract
Melanopsin, an atypical vertebrate visual pigment, mediates non-image-forming light responses including circadian photoentrainment and pupillary light reflexes and contrast detection for image formation. Melanopsin-expressing intrinsically photosensitive retinal ganglion cells are characterized by sluggish activation and deactivation of their light responses. The molecular determinants of mouse melanopsin's deactivation have been characterized (i.e., C-terminal phosphorylation and β-arrestin binding), but a detailed analysis of melanopsin's activation is lacking. We propose that an extended third cytoplasmic loop is adjacent to the proximal C-terminal region of mouse melanopsin in the inactive conformation, which is stabilized by the ionic interaction of these two regions. This model is supported by site-directed spin labeling and electron paramagnetic resonance spectroscopy of melanopsin, the results of which suggests a high degree of steric freedom at the third cytoplasmic loop, which is increased upon C-terminus truncation, supporting the idea that these two regions are close in three-dimensional space in wild-type melanopsin. To test for a functionally critical C-terminal conformation, calcium imaging of melanopsin mutants including a proximal C-terminus truncation (at residue 365) and proline mutation of this proximal region (H377P, L380P, Y382P) delayed melanopsin's activation rate. Mutation of all potential phosphorylation sites, including a highly conserved tyrosine residue (Y382), into alanines also delayed the activation rate. A comparison of mouse melanopsin with armadillo melanopsin-which has substitutions of various potential phosphorylation sites and a substitution of the conserved tyrosine-indicates that substitution of these potential phosphorylation sites and the tyrosine residue result in dramatically slower activation kinetics, a finding that also supports the role of phosphorylation in signaling activation. We therefore propose that melanopsin's C-terminus is proximal to intracellular loop 3, and C-terminal phosphorylation permits the ionic interaction between these two regions, thus forming a stable structural conformation that is critical for initiating G-protein signaling.
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Affiliation(s)
- Juan C Valdez-Lopez
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland
| | - Stephen T Petr
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland
| | - Matthew P Donohue
- Center for Nanoscale and Technology, National Institutes of Standards and Technology, Gaithersburg, Maryland; Maryland NanoCenter, University of Maryland College Park, College Park, Maryland
| | - Robin J Bailey
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland
| | - Meheret Gebreeziabher
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland
| | - Evan G Cameron
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland
| | - Julia B Wolf
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland
| | - Veronika A Szalai
- Center for Nanoscale and Technology, National Institutes of Standards and Technology, Gaithersburg, Maryland
| | - Phyllis R Robinson
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland.
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39
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Rojas G, Orellana I, Rosales-Rojas R, García-Olivares J, Comer J, Vergara-Jaque A. Structural Determinants of the Dopamine Transporter Regulation Mediated by G Proteins. J Chem Inf Model 2020; 60:3577-3586. [PMID: 32525311 DOI: 10.1021/acs.jcim.0c00236] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Dopamine clearance in the brain is controlled by the dopamine transporter (DAT), a protein residing in the plasma membrane, which drives reuptake of extracellular dopamine into presynaptic neurons. Studies have revealed that the βγ subunits of heterotrimeric G proteins modulate DAT function through a physical association with the C-terminal region of the transporter. Regulation of neurotransmitter transporters by Gβγ subunits is unprecedented in the literature; therefore, it is interesting to investigate the structural details of this particular protein-protein interaction. Here, we refined the crystal structure of the Drosophila melanogaster DAT (dDAT), modeling de novo the N- and C-terminal domains; subsequently, we used the full-length dDAT structure to generate a comparative model of human DAT (hDAT). Both proteins were assembled with Gβ1γ2 subunits employing protein-protein docking, and subsequent molecular dynamics simulations were run to identify the specific interactions governing the formation of the hDAT:Gβγ and dDAT:Gβγ complexes. A [L/F]R[Q/E]R sequence motif containing the residues R588 in hDAT and R587 in dDAT was found as key to bind the Gβγ subunits through electrostatic interactions with a cluster of negatively charged residues located at the top face of the Gβ subunit. Alterations of DAT function have been associated with multiple devastating neuropathological conditions; therefore, this work represents a step toward better understanding DAT regulation by signaling proteins, allowing us to predict therapeutic target regions.
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Affiliation(s)
- Genoveva Rojas
- Center for Bioinformatics and Molecular Simulation, Faculty of Engineering, Universidad de Talca, 2 Norte 685, Talca, Chile
| | - Ivana Orellana
- Center for Bioinformatics and Molecular Simulation, Faculty of Engineering, Universidad de Talca, 2 Norte 685, Talca, Chile
| | - Roberto Rosales-Rojas
- Center for Bioinformatics and Molecular Simulation, Faculty of Engineering, Universidad de Talca, 2 Norte 685, Talca, Chile
| | - Jennie García-Olivares
- Supernus Pharmaceuticals, 9715 Key West Avenue, Rockville, Maryland 20850, United States
| | - Jeffrey Comer
- Institute of Computational Comparative Medicine, Nanotechnology Innovation Center of Kansas State, Kansas State University, Manhattan, Kansas 66506, United States
| | - Ariela Vergara-Jaque
- Center for Bioinformatics and Molecular Simulation, Faculty of Engineering, Universidad de Talca, 2 Norte 685, Talca, Chile.,Millennium Nucleus of Ion Channels-associated Diseases (MiNICAD), Santiago, Chile
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40
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Wasilko DJ, Johnson ZL, Ammirati M, Che Y, Griffor MC, Han S, Wu H. Structural basis for chemokine receptor CCR6 activation by the endogenous protein ligand CCL20. Nat Commun 2020; 11:3031. [PMID: 32541785 PMCID: PMC7295996 DOI: 10.1038/s41467-020-16820-6] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Accepted: 05/27/2020] [Indexed: 01/08/2023] Open
Abstract
Chemokines are important protein-signaling molecules that regulate various immune responses by activating chemokine receptors which belong to the G protein-coupled receptor (GPCR) superfamily. Despite the substantial progression of our structural understanding of GPCR activation by small molecule and peptide agonists, the molecular mechanism of GPCR activation by protein agonists remains unclear. Here, we present a 3.3-Å cryo-electron microscopy structure of the human chemokine receptor CCR6 bound to its endogenous ligand CCL20 and an engineered Go. CCL20 binds in a shallow extracellular pocket, making limited contact with the core 7-transmembrane (TM) bundle. The structure suggests that this mode of binding induces allosterically a rearrangement of a noncanonical toggle switch and the opening of the intracellular crevice for G protein coupling. Our results demonstrate that GPCR activation by a protein agonist does not always require substantial interactions between ligand and the 7TM core region. Chemokine receptors are GPCRs involved in immune responses and regulated by small protein ligands known as chemokines. A structural study of the human CCR6/CCL20–Go complex reveals that CCL20 binds in a shallow extracellular pocket, and suggests that activation of CCR6 by CCL20 binding involves an allosteric effect on a noncanonical toggle switch.
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Affiliation(s)
- David Jonathan Wasilko
- Discovery Sciences, Medicine Design, Pfizer Worldwide Research and Development, Groton, CT, 06340, USA
| | - Zachary Lee Johnson
- Discovery Sciences, Medicine Design, Pfizer Worldwide Research and Development, Groton, CT, 06340, USA
| | - Mark Ammirati
- Discovery Sciences, Medicine Design, Pfizer Worldwide Research and Development, Groton, CT, 06340, USA
| | - Ye Che
- Discovery Sciences, Medicine Design, Pfizer Worldwide Research and Development, Groton, CT, 06340, USA
| | - Matthew C Griffor
- Discovery Sciences, Medicine Design, Pfizer Worldwide Research and Development, Groton, CT, 06340, USA
| | - Seungil Han
- Discovery Sciences, Medicine Design, Pfizer Worldwide Research and Development, Groton, CT, 06340, USA
| | - Huixian Wu
- Discovery Sciences, Medicine Design, Pfizer Worldwide Research and Development, Groton, CT, 06340, USA.
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41
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Wang J, Hua T, Liu ZJ. Structural features of activated GPCR signaling complexes. Curr Opin Struct Biol 2020; 63:82-89. [PMID: 32485565 DOI: 10.1016/j.sbi.2020.04.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 04/16/2020] [Accepted: 04/18/2020] [Indexed: 12/22/2022]
Abstract
G protein-coupled receptors (GPCRs) couple to diverse heterotrimeric G protein subtypes and then activate downstream signaling pathways in classical GPCR activation. It has also been found that GPCRs transduce signals through different regulatory proteins, such as arrestins. Recently, owing to the breakthroughs in cryo-electron macroscopy (Cryo-EM), numerous structures of GPCR-G protein or GPCR-arrestin complexes have been deciphered. In this review, we summarize most of reported GPCR signaling complex structures, with an emphasis on the structural features of rhodopsin-like GPCR activation and G protein-binding/arrestin-binding modes, to illustrate the activation and signaling mechanism of rhodopsin-like GPCRs.
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Affiliation(s)
- Jingjing Wang
- iHuman Institute, ShanghaiTech University, Shanghai 201210, China; School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Tian Hua
- iHuman Institute, ShanghaiTech University, Shanghai 201210, China.
| | - Zhi-Jie Liu
- iHuman Institute, ShanghaiTech University, Shanghai 201210, China; School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China.
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42
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Errey JC, Fiez-Vandal C. Production of membrane proteins in industry: The example of GPCRs. Protein Expr Purif 2020; 169:105569. [DOI: 10.1016/j.pep.2020.105569] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 01/07/2020] [Accepted: 01/12/2020] [Indexed: 01/08/2023]
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43
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Akbar S, Mozumder S, Sengupta J. Retrospect and Prospect of Single Particle Cryo-Electron Microscopy: The Class of Integral Membrane Proteins as an Example. J Chem Inf Model 2020; 60:2448-2457. [DOI: 10.1021/acs.jcim.9b01015] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Shirin Akbar
- Structural Biology and Bioinformatics Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Jadavpur, Kolkata 700032, India
| | - Sukanya Mozumder
- Structural Biology and Bioinformatics Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Jadavpur, Kolkata 700032, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Jayati Sengupta
- Structural Biology and Bioinformatics Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Jadavpur, Kolkata 700032, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
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44
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Ma S, Shen Q, Zhao LH, Mao C, Zhou XE, Shen DD, de Waal PW, Bi P, Li C, Jiang Y, Wang MW, Sexton PM, Wootten D, Melcher K, Zhang Y, Xu HE. Molecular Basis for Hormone Recognition and Activation of Corticotropin-Releasing Factor Receptors. Mol Cell 2020; 77:669-680.e4. [PMID: 32004470 DOI: 10.1016/j.molcel.2020.01.013] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Revised: 10/07/2019] [Accepted: 01/07/2020] [Indexed: 01/13/2023]
Abstract
Corticotropin-releasing factor (CRF) and the three related peptides urocortins 1-3 (UCN1-UCN3) are endocrine hormones that control the stress responses by activating CRF1R and CRF2R, two members of class B G-protein-coupled receptors (GPCRs). Here, we present two cryoelectron microscopy (cryo-EM) structures of UCN1-bound CRF1R and CRF2R with the stimulatory G protein. In both structures, UCN1 adopts a single straight helix with its N terminus dipped into the receptor transmembrane bundle. Although the peptide-binding residues in CRF1R and CRF2R are different from other members of class B GPCRs, the residues involved in receptor activation and G protein coupling are conserved. In addition, both structures reveal bound cholesterol molecules to the receptor transmembrane helices. Our structures define the basis of ligand-binding specificity in the CRF receptor-hormone system, establish a common mechanism of class B GPCR activation and G protein coupling, and provide a paradigm for studying membrane protein-lipid interactions for class B GPCRs.
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Affiliation(s)
- Shanshan Ma
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qingya Shen
- Department of Biophysics, and Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Li-Hua Zhao
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China.
| | - Chunyou Mao
- Department of Biophysics, and Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - X Edward Zhou
- Center for Cancer and Cell Biology, Program for Structural Biology, Van Andel Research Institute, Grand Rapids, MI, USA
| | - Dan-Dan Shen
- Department of Biophysics, and Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Parker W de Waal
- Center for Cancer and Cell Biology, Program for Structural Biology, Van Andel Research Institute, Grand Rapids, MI, USA
| | - Peng Bi
- Department of Biophysics, and Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Chuntao Li
- Department of Biophysics, and Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Yi Jiang
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Ming-Wei Wang
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; School of Pharmacy, Fudan University, Shanghai 201203, China
| | - Patrick M Sexton
- Drug Discovery Biology and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052 VIC, Australia
| | - Denise Wootten
- Drug Discovery Biology and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052 VIC, Australia
| | - Karsten Melcher
- Center for Cancer and Cell Biology, Program for Structural Biology, Van Andel Research Institute, Grand Rapids, MI, USA
| | - Yan Zhang
- Department of Biophysics, and Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China.
| | - H Eric Xu
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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45
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Smrcka AV, Fisher I. G-protein βγ subunits as multi-functional scaffolds and transducers in G-protein-coupled receptor signaling. Cell Mol Life Sci 2019; 76:4447-4459. [PMID: 31435698 PMCID: PMC6842434 DOI: 10.1007/s00018-019-03275-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 08/05/2019] [Accepted: 08/12/2019] [Indexed: 02/08/2023]
Abstract
G-protein βγ subunits are key participants in G-protein signaling. These subunits facilitate interactions between receptors and G proteins that are critical for the G protein activation cycle at the plasma membrane. In addition, they play roles in directly transducing signals to an ever expanding range of downstream targets, including integral membrane and cytosolic proteins. Emerging data indicate that Gβγ may play additional roles at intracellular compartments including endosomes, the Golgi apparatus, and the nucleus. Here, we discuss the molecular and structural basis for their ability to coordinate this wide range of cellular activities.
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Affiliation(s)
- Alan V Smrcka
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, 48104, USA.
| | - Isaac Fisher
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, 48104, USA
- Department of Pharmacology and Physiology, University of Rochester School of Medicine, Rochester, NY, 14629, USA
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46
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Development of "Plug and Play" Fiducial Marks for Structural Studies of GPCR Signaling Complexes by Single-Particle Cryo-EM. Structure 2019; 27:1862-1874.e7. [PMID: 31669042 DOI: 10.1016/j.str.2019.10.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 08/26/2019] [Accepted: 10/07/2019] [Indexed: 12/12/2022]
Abstract
"Universal" synthetic antibody (sAB)-based fiducial marks have been generated by customized phage display selections to facilitate the rapid structure determination of G protein-coupled receptor (GPCR) signaling complexes by single-particle cryo-electron microscopy (SP cryo-EM). sABs were generated to the two major G protein subclasses: trimeric Gi and Gs, as well as mini-Gs, and were tested to ensure binding in the context of their cognate GPCRs. Epitope binning revealed that multiple distinct epitopes exist for each G(αβγ) protein. Several Gβγ-specific sABs, cross-reactive between trimeric Gi and Gs, were identified suggesting they could be used across all subclasses in a "plug and play" fashion. sABs were also generated to a representative of another class of GPCR signaling partner, G protein receptor kinase 1 (GRK1) and evaluated further, supporting the generalizability of the approach. EM data suggested that the subclass-specific sABs provide effective single and dual fiducials for multiple GPCR signaling complexes.
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