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Shumate AD, Farrens DL. A rapid, tag-free way to purify functional GPCRs. J Biol Chem 2024; 300:105558. [PMID: 38097184 PMCID: PMC10820827 DOI: 10.1016/j.jbc.2023.105558] [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: 05/12/2023] [Revised: 12/01/2023] [Accepted: 12/05/2023] [Indexed: 01/14/2024] Open
Abstract
G protein-coupled receptors (GPCRs) play diverse signaling roles and represent major pharmaceutical targets. Consequently, they are the focus of intense study, and numerous advances have been made in their handling and analysis. However, a universal way to purify GPCRs has remained elusive, in part because of their inherent instability when isolated from cells. To address this, we have developed a general, rapid, and tag-free way to purify GPCRs. The method uses short peptide analogs of the Gα subunit C terminus (Gα-CT) that are attached to chromatography beads (Gα-CT resin). Because the Gα-CT peptides bind active GPCRs with high affinity, the Gα-CT resin selectively purifies only active functional receptors. We use this method to purify both rhodopsin and the β2-adrenergic receptor and show they can be purified in either active conformations or inactive conformations, simply by varying elution conditions. While simple in concept-leveraging the conserved GPCR-Gα-CT binding interaction for the purpose of GPCR purification-we think this approach holds excellent potential to isolate functional receptors for a myriad of uses, from structural biology to proteomics.
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Affiliation(s)
- Anthony D Shumate
- Department of Chemical Biology and Physiology, Oregon Health and Science University, Portland, Oregon, USA
| | - David L Farrens
- Department of Chemical Biology and Physiology, Oregon Health and Science University, Portland, Oregon, USA.
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2
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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: 41] [Impact Index Per Article: 20.5] [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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3
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Ortega JT, McKee AG, Roushar FJ, Penn WD, Schlebach JP, Jastrzebska B. Chromenone derivatives as novel pharmacological chaperones for retinitis pigmentosa-linked rod opsin mutants. Hum Mol Genet 2022; 31:3439-3457. [PMID: 35642742 PMCID: PMC9558842 DOI: 10.1093/hmg/ddac125] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 05/23/2022] [Accepted: 05/24/2022] [Indexed: 11/14/2022] Open
Abstract
The correct expression of folded, functional rhodopsin (Rho) is critical for visual perception. However, this seven-transmembrane helical G protein-coupled receptor is prone to mutations with pathological consequences of retinal degeneration in retinitis pigmentosa (RP) due to Rho misfolding. Pharmacological chaperones that stabilize the inherited Rho variants by assisting their folding and membrane targeting could slow the progression of RP. In this study, we employed virtual screening of synthetic compounds with a natural product scaffold in conjunction with in vitro and in vivo evaluations to discover a novel chromenone-containing small molecule with favorable pharmacological properties that stabilize rod opsin. This compound reversibly binds to unliganded bovine rod opsin with an EC50 value comparable to the 9-cis-retinal chromophore analog and partially rescued membrane trafficking of multiple RP-related rod opsin variants in vitro. Importantly, this novel ligand of rod opsin was effective in vivo in murine models, protecting photoreceptors from deterioration caused by either bright light or genetic insult. Together, our current study suggests potential broad therapeutic implications of the new chromenone-containing non-retinoid small molecule against retinal diseases associated with photoreceptor degeneration.
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Affiliation(s)
- Joseph T Ortega
- Department of Pharmacology and Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Andrew G McKee
- Department of Chemistry, Indiana University, 800 E. Kirkwood Avenue, Bloomington, IN 47405-7102, USA
| | - Francis J Roushar
- Department of Chemistry, Indiana University, 800 E. Kirkwood Avenue, Bloomington, IN 47405-7102, USA
| | - Wesley D Penn
- Department of Chemistry, Indiana University, 800 E. Kirkwood Avenue, Bloomington, IN 47405-7102, USA
| | - Jonathan P Schlebach
- To whom correspondence should be addressed at: Department of Pharmacology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 441064965, USA. Tel: +1 2163685683; Fax: +1 2163681300; (Beata Jastrzebska); Department of Chemistry, Indiana University, 800 E. Kirkwood Avenue, Bloomington, IN 47405-7102, USA. Tel: +1 812-855-6779; Fax: +1 812-855-8300; (Jonathan P. Schlebach)
| | - Beata Jastrzebska
- To whom correspondence should be addressed at: Department of Pharmacology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 441064965, USA. Tel: +1 2163685683; Fax: +1 2163681300; (Beata Jastrzebska); Department of Chemistry, Indiana University, 800 E. Kirkwood Avenue, Bloomington, IN 47405-7102, USA. Tel: +1 812-855-6779; Fax: +1 812-855-8300; (Jonathan P. Schlebach)
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4
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Ancient whale rhodopsin reconstructs dim-light vision over a major evolutionary transition: Implications for ancestral diving behavior. Proc Natl Acad Sci U S A 2022; 119:e2118145119. [PMID: 35759662 PMCID: PMC9271160 DOI: 10.1073/pnas.2118145119] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Cetaceans are fully aquatic mammals that descended from terrestrial ancestors, an iconic evolutionary transition characterized by adaptations for underwater foraging via breath-hold diving. Although the evolutionary history of this specialized behavior is challenging to reconstruct, coevolving sensory systems may offer valuable clues. The dim-light visual pigment, rhodopsin, which initiates phototransduction in the rod photoreceptors of the eye, has provided insight into the visual ecology of depth in several aquatic vertebrate lineages. Here, we use ancestral sequence reconstruction and protein resurrection experiments to quantify light-activation metrics in rhodopsin pigments from ancestors bracketing the cetacean terrestrial-to-aquatic transition. By comparing multiple reconstruction methods on a broadly sampled cetartiodactyl species tree, we generated highly robust ancestral sequence estimates. Our experimental results provide direct support for a blue-shift in spectral sensitivity along the branch separating cetaceans from terrestrial relatives. This blue-shift was 14 nm, resulting in a deep-sea signature (λmax = 486 nm) similar to many mesopelagic-dwelling fish. We also discovered that the decay rates of light-activated rhodopsin increased in ancestral cetaceans, which may indicate an accelerated dark adaptation response typical of deeper-diving mammals. Because slow decay rates are thought to help sequester cytotoxic photoproducts, this surprising result could reflect an ecological trade-off between rod photoprotection and dark adaptation. Taken together, these ancestral shifts in rhodopsin function suggest that some of the first fully aquatic cetaceans could dive into the mesopelagic zone (>200 m). Moreover, our reconstructions indicate that this behavior arose before the divergence of toothed and baleen whales.
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5
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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: 18] [Impact Index Per Article: 6.0] [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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6
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Tian H, Gunnison KM, Kazmi MA, Sakmar TP, Huber T. FRET sensors reveal the retinal entry pathway in the G protein-coupled receptor rhodopsin. iScience 2022; 25:104060. [PMID: 35355518 PMCID: PMC8958324 DOI: 10.1016/j.isci.2022.104060] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 01/11/2022] [Accepted: 03/04/2022] [Indexed: 11/26/2022] Open
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7
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Schafer CT, Shumate A, Farrens DL. Novel fluorescent GPCR biosensor detects retinal equilibrium binding to opsin and active G protein and arrestin signaling conformations. J Biol Chem 2020; 295:17486-17496. [PMID: 33453993 DOI: 10.1074/jbc.ra120.014631] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 09/25/2020] [Indexed: 01/14/2023] Open
Abstract
Rhodopsin is a canonical class A photosensitive G protein-coupled receptor (GPCR), yet relatively few pharmaceutical agents targeting this visual receptor have been identified, in part due to the unique characteristics of its light-sensitive, covalently bound retinal ligands. Rhodopsin becomes activated when light isomerizes 11-cis-retinal into an agonist, all-trans-retinal (ATR), which enables the receptor to activate its G protein. We have previously demonstrated that, despite being covalently bound, ATR can display properties of equilibrium binding, yet how this is accomplished is unknown. Here, we describe a new approach for both identifying compounds that can activate and attenuate rhodopsin and testing the hypothesis that opsin binds retinal in equilibrium. Our method uses opsin-based fluorescent sensors, which directly report the formation of active receptor conformations by detecting the binding of G protein or arrestin fragments that have been fused onto the receptor's C terminus. We show that these biosensors can be used to monitor equilibrium binding of the agonist, ATR, as well as the noncovalent binding of β-ionone, an antagonist for G protein activation. Finally, we use these novel biosensors to observe ATR release from an activated, unlabeled receptor and its subsequent transfer to the sensor in real time. Taken together, these data support the retinal equilibrium binding hypothesis. The approach we describe should prove directly translatable to other GPCRs, providing a new tool for ligand discovery and mutant characterization.
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Affiliation(s)
- Christopher T Schafer
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, Oregon, USA
| | - Anthony Shumate
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, Oregon, USA
| | - David L Farrens
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, Oregon, USA.
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8
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Ma N, Lee S, Vaidehi N. Activation Microswitches in Adenosine Receptor A 2A Function as Rheostats in the Cell Membrane. Biochemistry 2020; 59:4059-4071. [PMID: 33054162 PMCID: PMC8526178 DOI: 10.1021/acs.biochem.0c00626] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Although multiple components of the cell membrane modulate the stability and activation of G protein-coupled receptors (GPCRs), insights into the dynamics of GPCR structures come from biophysical studies conducted in detergents. This is because of the challenges of studying activation in a multicomponent lipid bilayer. To understand the role of cellular membrane lipids and cations in GPCR activation, we performed multiscale molecular dynamics simulations (56 μs) on three different conformational states of adenosine receptor A2AR, in both the cell membrane-like lipid bilayer and in detergent micelles. Molecular dynamics (MD) simulations show that the phosphatidylinositol bisphosphate (PIP2) interacts with the basic residues in the intracellular regions of A2AR, thereby reducing the flexibility of the receptor in the inactive state and limiting the transition to the active-intermediate state. In the G protein-coupled fully active state, PIP2 stabilizes the GPCR:G protein complex. Such stiffening effects are absent in non-ionic detergent micelles, and therefore, more transitions have been observed in detergents. The inter-residue distances that change significantly upon GPCR activation are known as activation microswitches. The activation microswitches show different levels of activation in the cell membrane, in the pure POPC bilayer, and in detergents. Thus, the temporal heat map of different activation microswitches calculated from the MD simulations suggests a rheostat model of GPCR activation microswitches rather than the binary switch model. These simulation results connect the chemistry of cell membrane lipids to receptor activity, which is useful for the design of detergents mimicking the cell membrane.
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Affiliation(s)
- Ning Ma
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, 1500 E Duarte Road, Duarte, CA-91010
| | - Sangbae Lee
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, 1500 E Duarte Road, Duarte, CA-91010
| | - Nagarajan Vaidehi
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, 1500 E Duarte Road, Duarte, CA-91010
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9
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Srinivasan S, Guixà-González R, Cordomí A, Garriga P. Ligand Binding Mechanisms in Human Cone Visual Pigments. Trends Biochem Sci 2019; 44:629-639. [PMID: 30853245 DOI: 10.1016/j.tibs.2019.02.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 02/04/2019] [Accepted: 02/07/2019] [Indexed: 12/13/2022]
Abstract
Vertebrate vision starts with light absorption by visual pigments in rod and cone photoreceptor cells of the retina. Rhodopsin, in rod cells, responds to dim light, whereas three types of cone opsins (red, green, and blue) function under bright light and mediate color vision. Cone opsins regenerate with retinal much faster than rhodopsin, but the molecular mechanism of regeneration is still unclear. Recent advances in the area pinpoint transient intermediate opsin conformations, and a possible secondary retinal-binding site, as determinant factors for regeneration. In this Review, we compile previous and recent findings to discuss possible mechanisms of ligand entry in cone opsins, involving a secondary binding site, which may have relevant functional and evolutionary implications.
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Affiliation(s)
- Sundaramoorthy Srinivasan
- Grup de Biotecnologia Molecular i Industrial, Centre de Biotecnologia Molecular, Departament d'Enginyeria Química, Universitat Politècnica de Catalunya-Barcelona Tech, Rambla de Sant Nebridi 22, 08222 Terrassa, Spain
| | - Ramon Guixà-González
- Laboratori de Medicina Computational, Universitat Autonòma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Arnau Cordomí
- Laboratori de Medicina Computational, Universitat Autonòma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Pere Garriga
- Grup de Biotecnologia Molecular i Industrial, Centre de Biotecnologia Molecular, Departament d'Enginyeria Química, Universitat Politècnica de Catalunya-Barcelona Tech, Rambla de Sant Nebridi 22, 08222 Terrassa, Spain.
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10
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Bender BJ, Vortmeier G, Ernicke S, Bosse M, Kaiser A, Els-Heindl S, Krug U, Beck-Sickinger A, Meiler J, Huster D. Structural Model of Ghrelin Bound to its G Protein-Coupled Receptor. Structure 2019; 27:537-544.e4. [PMID: 30686667 DOI: 10.1016/j.str.2018.12.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 09/14/2018] [Accepted: 12/05/2018] [Indexed: 12/27/2022]
Abstract
The peptide ghrelin targets the growth hormone secretagogue receptor 1a (GHSR) to signal changes in cell metabolism and is a sought-after therapeutic target, although no structure is known to date. To investigate the structural basis of ghrelin binding to GHSR, we used solid-state nuclear magnetic resonance (NMR) spectroscopy, site-directed mutagenesis, and Rosetta modeling. The use of saturation transfer difference NMR identified key residues in the peptide for receptor binding beyond the known motif. This information combined with assignment of the secondary structure of ghrelin in its receptor-bound state was incorporated into Rosetta using an approach that accounts for flexible binding partners. The NMR data and models revealed an extended binding surface that was confirmed via mutagenesis. Our results agree with a growing evidence of peptides interacting via two sites at G protein-coupled receptors.
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Affiliation(s)
- Brian Joseph Bender
- Department of Pharmacology and Center for Structural Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Gerrit Vortmeier
- Institute for Medical Physics and Biophysics, Medical Department, Leipzig University, Härtelstrasse 16-18, 04107 Leipzig, Germany
| | - Stefan Ernicke
- Institute of Biochemistry, Faculty of Life Sciences, Leipzig University, Brüderstrasse 34, 04103 Leipzig, Germany
| | - Mathias Bosse
- Institute for Medical Physics and Biophysics, Medical Department, Leipzig University, Härtelstrasse 16-18, 04107 Leipzig, Germany
| | - Anette Kaiser
- Institute of Biochemistry, Faculty of Life Sciences, Leipzig University, Brüderstrasse 34, 04103 Leipzig, Germany
| | - Sylvia Els-Heindl
- Institute of Biochemistry, Faculty of Life Sciences, Leipzig University, Brüderstrasse 34, 04103 Leipzig, Germany
| | - Ulrike Krug
- Institute for Medical Physics and Biophysics, Medical Department, Leipzig University, Härtelstrasse 16-18, 04107 Leipzig, Germany
| | - Annette Beck-Sickinger
- Institute of Biochemistry, Faculty of Life Sciences, Leipzig University, Brüderstrasse 34, 04103 Leipzig, Germany
| | - Jens Meiler
- Department of Pharmacology and Center for Structural Biology, Vanderbilt University, Nashville, TN 37232, USA.
| | - Daniel Huster
- Institute for Medical Physics and Biophysics, Medical Department, Leipzig University, Härtelstrasse 16-18, 04107 Leipzig, Germany.
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11
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Castiglione GM, Chang BS. Functional trade-offs and environmental variation shaped ancient trajectories in the evolution of dim-light vision. eLife 2018; 7:35957. [PMID: 30362942 PMCID: PMC6203435 DOI: 10.7554/elife.35957] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 09/09/2018] [Indexed: 12/11/2022] Open
Abstract
Trade-offs between protein stability and activity can restrict access to evolutionary trajectories, but widespread epistasis may facilitate indirect routes to adaptation. This may be enhanced by natural environmental variation, but in multicellular organisms this process is poorly understood. We investigated a paradoxical trajectory taken during the evolution of tetrapod dim-light vision, where in the rod visual pigment rhodopsin, E122 was fixed 350 million years ago, a residue associated with increased active-state (MII) stability but greatly diminished rod photosensitivity. Here, we demonstrate that high MII stability could have likely evolved without E122, but instead, selection appears to have entrenched E122 in tetrapods via epistatic interactions with nearby coevolving sites. In fishes by contrast, selection may have exploited these epistatic effects to explore alternative trajectories, but via indirect routes with low MII stability. Our results suggest that within tetrapods, E122 and high MII stability cannot be sacrificed-not even for improvements to rod photosensitivity.
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Affiliation(s)
- Gianni M Castiglione
- Department of Cell and Systems Biology, University of Toronto, Toronto, Canada.,Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Canada
| | - Belinda Sw Chang
- Department of Cell and Systems Biology, University of Toronto, Toronto, Canada.,Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Canada.,Centre for the Analysis of Genome Evolution and Function, University of Toronto, Toronto, Canada
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12
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Maeda R, Hiroshima M, Yamashita T, Wada A, Sako Y, Shichida Y, Imamoto Y. Shift in Conformational Equilibrium Induces Constitutive Activity of G-Protein-Coupled Receptor, Rhodopsin. J Phys Chem B 2018; 122:4838-4843. [DOI: 10.1021/acs.jpcb.8b02819] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ryo Maeda
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
- Cellular Informatics Laboratory, RIKEN, Wako, Saitama, Japan
| | - Michio Hiroshima
- Cellular Informatics Laboratory, RIKEN, Wako, Saitama, Japan
- Laboratory for Cell Signaling Dynamics, RIKEN Quantitative Biology Center, Suita, Osaka, Japan
| | - Takahiro Yamashita
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Akimori Wada
- Laboratory of Organic Chemistry for Life Science, Kobe Pharmaceutical University, Kobe, Hyogo, Japan
| | - Yasushi Sako
- Cellular Informatics Laboratory, RIKEN, Wako, Saitama, Japan
| | - Yoshinori Shichida
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
- Research Organization for Science and Technology, Ritsumeikan University, Kusatsu, Shiga, Japan
| | - Yasushi Imamoto
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
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13
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Mattle D, Kuhn B, Aebi J, Bedoucha M, Kekilli D, Grozinger N, Alker A, Rudolph MG, Schmid G, Schertler GFX, Hennig M, Standfuss J, Dawson RJP. Ligand channel in pharmacologically stabilized rhodopsin. Proc Natl Acad Sci U S A 2018; 115:3640-3645. [PMID: 29555765 PMCID: PMC5889642 DOI: 10.1073/pnas.1718084115] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
In the degenerative eye disease retinitis pigmentosa (RP), protein misfolding leads to fatal consequences for cell metabolism and rod and cone cell survival. To stop disease progression, a therapeutic approach focuses on stabilizing inherited protein mutants of the G protein-coupled receptor (GPCR) rhodopsin using pharmacological chaperones (PC) that improve receptor folding and trafficking. In this study, we discovered stabilizing nonretinal small molecules by virtual and thermofluor screening and determined the crystal structure of pharmacologically stabilized opsin at 2.4 Å resolution using one of the stabilizing hits (S-RS1). Chemical modification of S-RS1 and further structural analysis revealed the core binding motif of this class of rhodopsin stabilizers bound at the orthosteric binding site. Furthermore, previously unobserved conformational changes are visible at the intradiscal side of the seven-transmembrane helix bundle. A hallmark of this conformation is an open channel connecting the ligand binding site with the membrane and the intradiscal lumen of rod outer segments. Sufficient in size, the passage permits the exchange of hydrophobic ligands such as retinal. The results broaden our understanding of rhodopsin's conformational flexibility and enable therapeutic drug intervention against rhodopsin-related retinitis pigmentosa.
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Affiliation(s)
- Daniel Mattle
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, 4070 Basel, Switzerland
- Laboratory of Biomolecular Research, Department of Biology and Chemistry, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Bernd Kuhn
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, 4070 Basel, Switzerland
| | - Johannes Aebi
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, 4070 Basel, Switzerland
| | - Marc Bedoucha
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, 4070 Basel, Switzerland
| | - Demet Kekilli
- Laboratory of Biomolecular Research, Department of Biology and Chemistry, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Nathalie Grozinger
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, 4070 Basel, Switzerland
| | - Andre Alker
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, 4070 Basel, Switzerland
| | - Markus G Rudolph
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, 4070 Basel, Switzerland
| | - Georg Schmid
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, 4070 Basel, Switzerland
| | - Gebhard F X Schertler
- Laboratory of Biomolecular Research, Department of Biology and Chemistry, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
- Department of Biology, ETH Zurich, 8093 Zurich, Switzerland
| | - Michael Hennig
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, 4070 Basel, Switzerland
| | - Jörg Standfuss
- Laboratory of Biomolecular Research, Department of Biology and Chemistry, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland;
| | - Roger J P Dawson
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, 4070 Basel, Switzerland;
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Srinivasan S, Fernández-Sampedro MA, Morillo M, Ramon E, Jiménez-Rosés M, Cordomí A, Garriga P. Human Blue Cone Opsin Regeneration Involves Secondary Retinal Binding with Analog Specificity. Biophys J 2018; 114:1285-1294. [PMID: 29590586 PMCID: PMC5883618 DOI: 10.1016/j.bpj.2018.01.032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 01/22/2018] [Accepted: 01/29/2018] [Indexed: 12/16/2022] Open
Abstract
Human color vision is mediated by the red, green, and blue cone visual pigments. Cone opsins are G-protein-coupled receptors consisting of an opsin apoprotein covalently linked to the 11-cis-retinal chromophore. All visual pigments share a common evolutionary origin, and red and green cone opsins exhibit a higher homology, whereas blue cone opsin shows more resemblance to the dim light receptor rhodopsin. Here we show that chromophore regeneration in photoactivated blue cone opsin exhibits intermediate transient conformations and a secondary retinoid binding event with slower binding kinetics. We also detected a fine-tuning of the conformational change in the photoactivated blue cone opsin binding site that alters the retinal isomer binding specificity. Furthermore, the molecular models of active and inactive blue cone opsins show specific molecular interactions in the retinal binding site that are not present in other opsins. These findings highlight the differential conformational versatility of human cone opsin pigments in the chromophore regeneration process, particularly compared to rhodopsin, and point to relevant functional, unexpected roles other than spectral tuning for the cone visual pigments.
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Affiliation(s)
| | | | | | - Eva Ramon
- Universitat Politècnica de Catalunya, Terrassa, Spain
| | - Mireia Jiménez-Rosés
- Unitat de Bioestadística Bellaterra, Laboratori de Medicina Computacional, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Arnau Cordomí
- Unitat de Bioestadística Bellaterra, Laboratori de Medicina Computacional, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Pere Garriga
- Universitat Politècnica de Catalunya, Terrassa, Spain.
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15
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Decay of an active GPCR: Conformational dynamics govern agonist rebinding and persistence of an active, yet empty, receptor state. Proc Natl Acad Sci U S A 2016; 113:11961-11966. [PMID: 27702898 DOI: 10.1073/pnas.1606347113] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Here, we describe two insights into the role of receptor conformational dynamics during agonist release (all-trans retinal, ATR) from the visual G protein-coupled receptor (GPCR) rhodopsin. First, we show that, after light activation, ATR can continually release and rebind to any receptor remaining in an active-like conformation. As with other GPCRs, we observe that this equilibrium can be shifted by either promoting the active-like population or increasing the agonist concentration. Second, we find that during decay of the signaling state an active-like, yet empty, receptor conformation can transiently persist after retinal release, before the receptor ultimately collapses into an inactive conformation. The latter conclusion is based on time-resolved, site-directed fluorescence labeling experiments that show a small, but reproducible, lag between the retinal leaving the protein and return of transmembrane helix 6 (TM6) to the inactive conformation, as determined from tryptophan-induced quenching studies. Accelerating Schiff base hydrolysis and subsequent ATR dissociation, either by addition of hydroxylamine or introduction of mutations, further increased the time lag between ATR release and TM6 movement. These observations show that rhodopsin can bind its agonist in equilibrium like a traditional GPCR, provide evidence that an active GPCR conformation can persist even after agonist release, and raise the possibility of targeting this key photoreceptor protein by traditional pharmaceutical-based treatments.
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16
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Jones Brunette AM, Sinha A, David L, Farrens DL. Evidence that the Rhodopsin Kinase (GRK1) N-Terminus and the Transducin Gα C-Terminus Interact with the Same "Hydrophobic Patch" on Rhodopsin TM5. Biochemistry 2016; 55:3123-35. [PMID: 27078130 DOI: 10.1021/acs.biochem.6b00328] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Phosphorylation of G protein-coupled receptors (GPCRs) terminates their ability to couple with and activate G proteins by increasing their affinity for arrestins. Unfortunately, detailed information regarding how GPCRs interact with the kinases responsible for their phosphorylation is still limited. Here, we purified fully functional GPCR kinase 1 (GRK1) using a rapid method and used it to gain insights into how this important kinase interacts with the GPCR rhodopsin. Specifically, we find that GRK1 uses the same site on rhodopsin as the transducin (Gt) Gtα C-terminal tail and the arrestin "finger loop", a cleft formed in the cytoplasmic face of the receptor upon activation. Our studies also show GRK1 requires two conserved residues located in this cleft (L226 and V230) that have been shown to be required for Gt activation due to their direct interactions with hydrophobic residues on the Gα C-terminal tail. Our data and modeling studies are consistent with the idea that all three proteins (Gt, GRK1, and visual arrestin) bind, at least in part, in the same site on rhodopsin and interact with the receptor through a similar hydrophobic contact-driven mechanism.
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Affiliation(s)
- Amber M Jones Brunette
- Department of Biochemistry and Molecular Biology, Oregon Health and Science University , Portland, Oregon 97239-3098, United States
| | - Abhinav Sinha
- Department of Biochemistry and Molecular Biology, Oregon Health and Science University , Portland, Oregon 97239-3098, United States
| | - Larry David
- Department of Biochemistry and Molecular Biology, Oregon Health and Science University , Portland, Oregon 97239-3098, United States
| | - David L Farrens
- Department of Biochemistry and Molecular Biology, Oregon Health and Science University , Portland, Oregon 97239-3098, United States
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17
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Ye L, Van Eps N, Zimmer M, Ernst OP, Scott Prosser R. Activation of the A2A adenosine G-protein-coupled receptor by conformational selection. Nature 2016; 533:265-8. [DOI: 10.1038/nature17668] [Citation(s) in RCA: 277] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2015] [Accepted: 03/16/2016] [Indexed: 12/22/2022]
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18
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Srinivasan S, Cordomí A, Ramon E, Garriga P. Beyond spectral tuning: human cone visual pigments adopt different transient conformations for chromophore regeneration. Cell Mol Life Sci 2016; 73:1253-63. [PMID: 26387074 PMCID: PMC11108329 DOI: 10.1007/s00018-015-2043-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 09/09/2015] [Accepted: 09/10/2015] [Indexed: 01/01/2023]
Abstract
Human red and green visual pigments are seven transmembrane receptors of cone photoreceptor cells of the retina that mediate color vision. These pigments share a very high degree of homology and have been assumed to feature analogous structural and functional properties. We report on a different regeneration mechanism among red and green cone opsins with retinal analogs using UV-Vis/fluorescence spectroscopic analyses, molecular modeling and site-directed mutagenesis. We find that photoactivated green cone opsin adopts a transient conformation which regenerates via an unprotonated Schiff base linkage with its natural chromophore, whereas red cone opsin forms a typical protonated Schiff base. The chromophore regeneration kinetics is consistent with a secondary retinal uptake by the cone pigments. Overall, our findings reveal, for the first time, structural differences in the photoactivated conformation between red and green cone pigments that may be linked to their molecular evolution, and support the proposal of secondary retinal binding to visual pigments, in addition to binding to the canonical primary site, which may serve as a regulatory mechanism of dark adaptation in the phototransduction process.
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Affiliation(s)
- Sundaramoorthy Srinivasan
- Departament d'Enginyeria Química, Centre de Biotecnologia Molecular, Universitat Politècnica de Catalunya, Rambla de Sant Nebridi 22, 08222, Terrassa, Spain
| | - Arnau Cordomí
- Laboratori de Medicina Computacional, Unitat de Bioestadística, Facultat de Medicina, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, 08193, Barcelona, Spain
| | - Eva Ramon
- Departament d'Enginyeria Química, Centre de Biotecnologia Molecular, Universitat Politècnica de Catalunya, Rambla de Sant Nebridi 22, 08222, Terrassa, Spain
| | - Pere Garriga
- Departament d'Enginyeria Química, Centre de Biotecnologia Molecular, Universitat Politècnica de Catalunya, Rambla de Sant Nebridi 22, 08222, Terrassa, Spain.
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19
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Structural dynamics and energetics underlying allosteric inactivation of the cannabinoid receptor CB1. Proc Natl Acad Sci U S A 2015; 112:8469-74. [PMID: 26100912 DOI: 10.1073/pnas.1500895112] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
G protein-coupled receptors (GPCRs) are surprisingly flexible molecules that can do much more than simply turn on G proteins. Some even exhibit biased signaling, wherein the same receptor preferentially activates different G-protein or arrestin signaling pathways depending on the type of ligand bound. Why this behavior occurs is still unclear, but it can happen with both traditional ligands and ligands that bind allosterically outside the orthosteric receptor binding pocket. Here, we looked for structural mechanisms underlying these phenomena in the marijuana receptor CB1. Our work focused on the allosteric ligand Org 27569, which has an unusual effect on CB1-it simultaneously increases agonist binding, decreases G--protein activation, and induces biased signaling. Using classical pharmacological binding studies, we find that Org 27569 binds to a unique allosteric site on CB1 and show that it can act alone (without need for agonist cobinding). Through mutagenesis studies, we find that the ability of Org 27569 to bind is related to how much receptor is in an active conformation that can couple with G protein. Using these data, we estimated the energy differences between the inactive and active states. Finally, site-directed fluorescence labeling studies show the CB1 structure stabilized by Org 27569 is different and unique from that stabilized by antagonist or agonist. Specifically, transmembrane helix 6 (TM6) movements associated with G-protein activation are blocked, but at the same time, helix 8/TM7 movements are enhanced, suggesting a possible mechanism for the ability of Org 27569 to induce biased signaling.
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20
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Mertz B, Feng J, Corcoran C, Neeley B. Explaining the mobility of retinal in activated rhodopsin and opsin. Photochem Photobiol Sci 2015; 14:1952-64. [PMID: 26248892 DOI: 10.1039/c5pp00173k] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Computational studies reveal flexibility of the rhodopsin cofactor, retinal, within the protein binding pocket that play a key role in the activated state and regeneration of rhodopsin.
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Affiliation(s)
- Blake Mertz
- The C. Eugene Bennett Department of Chemistry
- West Virginia University
- Morgantown
- USA
| | - Jun Feng
- The C. Eugene Bennett Department of Chemistry
- West Virginia University
- Morgantown
- USA
| | - Conor Corcoran
- The C. Eugene Bennett Department of Chemistry
- West Virginia University
- Morgantown
- USA
| | - Brandon Neeley
- The C. Eugene Bennett Department of Chemistry
- West Virginia University
- Morgantown
- USA
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