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Abstract
Sphingosine-1-phosphate (S1P) receptors are valid therapeutic targets to treat autoimmune diseases, such as relapsing multiple sclerosis and ulcerative colitis. Particularly, S1PR1 is well characterized because of its nonredundant functions on T and B cells’ egress. However, the activation mechanism of S1PR1 is still poorly understood. Therefore, we determined active S1PR1–Gi complex structures bound to distinct agonists. Phosphorylated Fingolimod [(S)-FTY720-P] could modulate lymphocyte trafficking and treat multiple sclerosis. The nonlipid-like agonist CBP-307 is currently being evaluated in a global phase 2 clinical study in moderate to severe ulcerative colitis and Crohn’s disease. Meanwhile, two binding poses of CBP-307 and the unoccupied subpocket we observed may provide opportunities to improve further the efficacy and specificity of CBP-307 targeting different S1P receptors. As a critical sphingolipid metabolite, sphingosine-1-phosphate (S1P) plays an essential role in immune and vascular systems. There are five S1P receptors, designated as S1PR1 to S1PR5, encoded in the human genome, and their activities are governed by endogenous S1P, lipid-like S1P mimics, or nonlipid-like therapeutic molecules. Among S1PRs, S1PR1 stands out due to its nonredundant functions, such as the egress of T and B cells from the thymus and secondary lymphoid tissues, making it a potential therapeutic target. However, the structural basis of S1PR1 activation and regulation by various agonists remains unclear. Here, we report four atomic resolution cryo-electron microscopy (cryo-EM) structures of Gi-coupled human S1PR1 complexes: bound to endogenous agonist d18:1 S1P, benchmark lipid-like S1P mimic phosphorylated Fingolimod [(S)-FTY720-P], or nonlipid-like therapeutic molecule CBP-307 in two binding modes. Our results revealed the similarities and differences of activation of S1PR1 through distinct ligands binding to the amphiphilic orthosteric pocket. We also proposed a two-step “shallow to deep” transition process of CBP-307 for S1PR1 activation. Both binding modes of CBP-307 could activate S1PR1, but from shallow to deep transition may trigger the rotation of the N-terminal helix of Gαi and further stabilize the complex by increasing the Gαi interaction with the cell membrane. We combine with extensive biochemical analysis and molecular dynamic simulations to suggest key steps of S1P binding and receptor activation. The above results decipher the common feature of the S1PR1 agonist recognition and activation mechanism and will firmly promote the development of therapeutics targeting S1PRs.
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2
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Krishna Deepak RNV, Verma RK, Hartono YD, Yew WS, Fan H. Recent Advances in Structure, Function, and Pharmacology of Class A Lipid GPCRs: Opportunities and Challenges for Drug Discovery. Pharmaceuticals (Basel) 2021; 15:12. [PMID: 35056070 PMCID: PMC8779880 DOI: 10.3390/ph15010012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/17/2021] [Accepted: 12/17/2021] [Indexed: 01/01/2023] Open
Abstract
Great progress has been made over the past decade in understanding the structural, functional, and pharmacological diversity of lipid GPCRs. From the first determination of the crystal structure of bovine rhodopsin in 2000, much progress has been made in the field of GPCR structural biology. The extraordinary progress in structural biology and pharmacology of GPCRs, coupled with rapid advances in computational approaches to study receptor dynamics and receptor-ligand interactions, has broadened our comprehension of the structural and functional facets of the receptor family members and has helped usher in a modern age of structure-based drug design and development. First, we provide a primer on lipid mediators and lipid GPCRs and their role in physiology and diseases as well as their value as drug targets. Second, we summarize the current advancements in the understanding of structural features of lipid GPCRs, such as the structural variation of their extracellular domains, diversity of their orthosteric and allosteric ligand binding sites, and molecular mechanisms of ligand binding. Third, we close by collating the emerging paradigms and opportunities in targeting lipid GPCRs, including a brief discussion on current strategies, challenges, and the future outlook.
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Affiliation(s)
- R. N. V. Krishna Deepak
- Bioinformatics Institute, A*STAR, 30 Biopolis Street, Matrix #07-01, Singapore 138671, Singapore; (R.K.V.); (Y.D.H.)
| | - Ravi Kumar Verma
- Bioinformatics Institute, A*STAR, 30 Biopolis Street, Matrix #07-01, Singapore 138671, Singapore; (R.K.V.); (Y.D.H.)
| | - Yossa Dwi Hartono
- Bioinformatics Institute, A*STAR, 30 Biopolis Street, Matrix #07-01, Singapore 138671, Singapore; (R.K.V.); (Y.D.H.)
- Synthetic Biology Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, 14 Medical Drive, Singapore 117599, Singapore;
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 8 Medical Drive, Singapore 117597, Singapore
| | - Wen Shan Yew
- Synthetic Biology Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, 14 Medical Drive, Singapore 117599, Singapore;
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 8 Medical Drive, Singapore 117597, Singapore
| | - Hao Fan
- Bioinformatics Institute, A*STAR, 30 Biopolis Street, Matrix #07-01, Singapore 138671, Singapore; (R.K.V.); (Y.D.H.)
- Synthetic Biology Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, 14 Medical Drive, Singapore 117599, Singapore;
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3
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Bueren-Calabuig JA, G Bage M, Cowling VH, Pisliakov AV. Mechanism of allosteric activation of human mRNA cap methyltransferase (RNMT) by RAM: insights from accelerated molecular dynamics simulations. Nucleic Acids Res 2019; 47:8675-8692. [PMID: 31329932 PMCID: PMC7145595 DOI: 10.1093/nar/gkz613] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 07/01/2019] [Accepted: 07/08/2019] [Indexed: 02/04/2023] Open
Abstract
The RNA guanine-N7 methyltransferase (RNMT) in complex with RNMT-activating miniprotein (RAM) catalyses the formation of a N7-methylated guanosine cap structure on the 5' end of nascent RNA polymerase II transcripts. The mRNA cap protects the primary transcript from exonucleases and recruits cap-binding complexes that mediate RNA processing, export and translation. By using microsecond standard and accelerated molecular dynamics simulations, we provide for the first time a detailed molecular mechanism of allosteric regulation of RNMT by RAM. We show that RAM selects the RNMT active site conformations that are optimal for binding of substrates (AdoMet and the cap), thus enhancing their affinity. Furthermore, our results strongly suggest the likely scenario in which the cap binding promotes the subsequent AdoMet binding, consistent with the previously suggested cooperative binding model. By employing the network community analyses, we revealed the underlying long-range allosteric networks and paths that are crucial for allosteric regulation by RAM. Our findings complement and explain previous experimental data on RNMT activity. Moreover, this study provides the most complete description of the cap and AdoMet binding poses and interactions within the enzyme's active site. This information is critical for the drug discovery efforts that consider RNMT as a promising anti-cancer target.
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Affiliation(s)
- Juan A Bueren-Calabuig
- Computational Biology, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Marcus G Bage
- Computational Biology, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Victoria H Cowling
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Andrei V Pisliakov
- Computational Biology, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK.,Physics, School of Science and Engineering, University of Dundee, Dundee, DD1 4HN, UK
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4
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Abstract
Sphingosine-1-phosphate (S1P) is a lipidic mediator in mammals that functions either as a second messenger or as a ligand. In the latter case, it is transported by its HDL-associated apoM carrier and circulated in blood where it binds to specific S1P receptors on cell membranes and induces downstream reactions. Although S1P signaling pathways are essential for many biological processes, they are poorly understood at the molecular level. Here, the solved crystal structures of the S1P1 receptor were used to evaluate molecular dynamics (MD) simulations to generate greater detailed molecular insights into the mechanism of S1P signaling. The MD simulations provided observations at the coarse-grained and atomic levels indicating that S1P may access the receptor binding pocket directly from solvents. Lifting of the bulky N-terminal cap region of the receptor precedes initial S1P binding. Glu1213.29 guides S1P penetration, and together with Arg2927.34 is responsible for the stabilization of S1P in the binding pocket, which is consistent with experimental predictions. The complete binding of S1P is followed by receptor activation, wherein Trp2696.48 moves toward the transmembrane helix (TM) 7, resulting in the formation of an enhanced hydrogen bond network in the lower region of TM7. The distance between TM3 and TM6 is subsequently increased, resulting in the opening of the intracellular binding pocket that enables G protein binding. Further analysis of the force distribution network in the receptor yielded a detailed molecular understanding of the signal transmission network that is activated upon agonist binding.
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Díaz Ó, Dalton JAR, Giraldo J. Revealing the Mechanism of Agonist-Mediated Cannabinoid Receptor 1 (CB1) Activation and Phospholipid-Mediated Allosteric Modulation. J Med Chem 2019; 62:5638-5654. [DOI: 10.1021/acs.jmedchem.9b00612] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Óscar Díaz
- Instituto de Salud Carlos III, Centro de Investigación Biomédica en Red de Salud Mental, CIBERSAM, 08193 Bellaterra, Spain
| | - James A. R. Dalton
- Instituto de Salud Carlos III, Centro de Investigación Biomédica en Red de Salud Mental, CIBERSAM, 08193 Bellaterra, Spain
| | - Jesús Giraldo
- Instituto de Salud Carlos III, Centro de Investigación Biomédica en Red de Salud Mental, CIBERSAM, 08193 Bellaterra, Spain
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Manna M, Nieminen T, Vattulainen I. Understanding the Role of Lipids in Signaling Through Atomistic and Multiscale Simulations of Cell Membranes. Annu Rev Biophys 2019; 48:421-439. [DOI: 10.1146/annurev-biophys-052118-115553] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cell signaling controls essentially all cellular processes. While it is often assumed that proteins are the key architects coordinating cell signaling, recent studies have shown more and more clearly that lipids are also involved in signaling processes in a number of ways. Lipids do, for instance, act as messengers, modulate membrane receptor conformation and dynamics, and control membrane receptor partitioning. Further, through structural modifications such as oxidation, the functions of lipids as part of signaling processes can be modified. In this context, in this article we discuss the understanding recently revealed by atomistic and coarse-grained computer simulations of nanoscale processes and underlying physicochemical principles related to lipids’ functions in cellular signaling.
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Affiliation(s)
- Moutusi Manna
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal, Madhya Pradesh 462 066, India
| | - Tuomo Nieminen
- Computational Physics Laboratory, Tampere University, FI-33014 Tampere, Finland
| | - Ilpo Vattulainen
- Computational Physics Laboratory, Tampere University, FI-33014 Tampere, Finland
- Department of Physics, University of Helsinki, FI-00014 Helsinki, Finland
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7
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Current status of multiscale simulations on GPCRs. Curr Opin Struct Biol 2019; 55:93-103. [DOI: 10.1016/j.sbi.2019.02.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2018] [Revised: 02/19/2019] [Accepted: 02/27/2019] [Indexed: 01/14/2023]
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Corradi V, Sejdiu BI, Mesa-Galloso H, Abdizadeh H, Noskov SY, Marrink SJ, Tieleman DP. Emerging Diversity in Lipid-Protein Interactions. Chem Rev 2019; 119:5775-5848. [PMID: 30758191 PMCID: PMC6509647 DOI: 10.1021/acs.chemrev.8b00451] [Citation(s) in RCA: 245] [Impact Index Per Article: 49.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
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Membrane
lipids interact with proteins in a variety of ways, ranging
from providing a stable membrane environment for proteins to being
embedded in to detailed roles in complicated and well-regulated protein
functions. Experimental and computational advances are converging
in a rapidly expanding research area of lipid–protein interactions.
Experimentally, the database of high-resolution membrane protein structures
is growing, as are capabilities to identify the complex lipid composition
of different membranes, to probe the challenging time and length scales
of lipid–protein interactions, and to link lipid–protein
interactions to protein function in a variety of proteins. Computationally,
more accurate membrane models and more powerful computers now enable
a detailed look at lipid–protein interactions and increasing
overlap with experimental observations for validation and joint interpretation
of simulation and experiment. Here we review papers that use computational
approaches to study detailed lipid–protein interactions, together
with brief experimental and physiological contexts, aiming at comprehensive
coverage of simulation papers in the last five years. Overall, a complex
picture of lipid–protein interactions emerges, through a range
of mechanisms including modulation of the physical properties of the
lipid environment, detailed chemical interactions between lipids and
proteins, and key functional roles of very specific lipids binding
to well-defined binding sites on proteins. Computationally, despite
important limitations, molecular dynamics simulations with current
computer power and theoretical models are now in an excellent position
to answer detailed questions about lipid–protein interactions.
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Affiliation(s)
- Valentina Corradi
- Centre for Molecular Simulation and Department of Biological Sciences , University of Calgary , 2500 University Drive NW , Calgary , Alberta T2N 1N4 , Canada
| | - Besian I Sejdiu
- Centre for Molecular Simulation and Department of Biological Sciences , University of Calgary , 2500 University Drive NW , Calgary , Alberta T2N 1N4 , Canada
| | - Haydee Mesa-Galloso
- Centre for Molecular Simulation and Department of Biological Sciences , University of Calgary , 2500 University Drive NW , Calgary , Alberta T2N 1N4 , Canada
| | - Haleh Abdizadeh
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials , University of Groningen , Nijenborgh 7 , 9747 AG Groningen , The Netherlands
| | - Sergei Yu Noskov
- Centre for Molecular Simulation and Department of Biological Sciences , University of Calgary , 2500 University Drive NW , Calgary , Alberta T2N 1N4 , Canada
| | - Siewert J Marrink
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials , University of Groningen , Nijenborgh 7 , 9747 AG Groningen , The Netherlands
| | - D Peter Tieleman
- Centre for Molecular Simulation and Department of Biological Sciences , University of Calgary , 2500 University Drive NW , Calgary , Alberta T2N 1N4 , Canada
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Song W, Yen HY, Robinson CV, Sansom MSP. State-dependent Lipid Interactions with the A2a Receptor Revealed by MD Simulations Using In Vivo-Mimetic Membranes. Structure 2019; 27:392-403.e3. [PMID: 30581046 PMCID: PMC7031699 DOI: 10.1016/j.str.2018.10.024] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 10/02/2018] [Accepted: 10/25/2018] [Indexed: 01/01/2023]
Abstract
Membranes are known to have modulatory effects on G protein-coupled receptors (GPCRs) via specific lipid interactions. However, the mechanisms of such modulations in physiological conditions and how they influence GPCR functions remain unclear. Here we report coarse-grained molecular dynamics simulations on the Adenosine A2a receptor in different conformational states embedded in an in vivo-mimetic membrane model. Nine lipid interaction sites were revealed. The strength of lipid interactions with these sites showed a degree of dependence on the conformational states of the receptor, suggesting that these lipids may regulate the conformational dynamics of the receptor. In particular, we revealed a dual role of PIP2 on A2aR activation that involves both stabilization of the characteristic outward tilt of TM6 and enhancement of A2aR-mini-Gs association. Our results demonstrated that the bound lipids allosterically regulate the functional properties of GPCRs. These protein-lipid interactions provide a springboard for design of allosteric modulators of GPCRs.
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Affiliation(s)
- Wanling Song
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Hsin-Yung Yen
- Chemical Research Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QY, UK
| | - Carol V Robinson
- Chemical Research Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QY, UK
| | - Mark S P Sansom
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK.
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Blaho VA, Chun J. 'Crystal' Clear? Lysophospholipid Receptor Structure Insights and Controversies. Trends Pharmacol Sci 2018; 39:953-966. [PMID: 30343728 PMCID: PMC6201317 DOI: 10.1016/j.tips.2018.08.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Revised: 08/11/2018] [Accepted: 08/27/2018] [Indexed: 12/29/2022]
Abstract
Lysophospholipids (LPLs), particularly sphingosine 1-phosphate (S1P) and lysophosphatidic acid (LPA), are bioactive lipid modulators of cellular homeostasis and pathology. The discovery and characterization of five S1P- and six LPA-specific G protein-coupled receptors (GPCRs), S1P1-5 and LPA1-6, have expanded their known involvement in all mammalian physiological systems. Resolution of the S1P1, LPA1, and LPA6 crystal structures has fueled the growing interest in these receptors and their ligands as targets for pharmacological manipulation. In this review, we have attempted to provide an integrated overview of the three crystallized LPL GPCRs with biochemical and physiological structure-function data. Finally, we provide a novel discussion of how chaperones for LPLs may be considered when extrapolating crystallographic and computational data toward understanding actual biological interactions and phenotypes.
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Affiliation(s)
- Victoria A Blaho
- Sanford Burnham Prebys Medical Discovery Institute, Degenerative Diseases Program, La Jolla, CA 92037, USA.
| | - Jerold Chun
- Sanford Burnham Prebys Medical Discovery Institute, Degenerative Diseases Program, La Jolla, CA 92037, USA.
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