1
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Lihan M, Tajkhorshid E. Improved Highly Mobile Membrane Mimetic Model for Investigating Protein-Cholesterol Interactions. J Chem Inf Model 2024; 64:4822-4834. [PMID: 38844760 DOI: 10.1021/acs.jcim.4c00619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/25/2024]
Abstract
Cholesterol (CHL) plays an integral role in modulating the function and activity of various mammalian membrane proteins. Due to the slow dynamics of lipids, conventional computational studies of protein-CHL interactions rely on either long-time scale atomistic simulations or coarse-grained approximations to sample the process. A highly mobile membrane mimetic (HMMM) has been developed to enhance lipid diffusion and thus used to facilitate the investigation of lipid interactions with peripheral membrane proteins and, with customized in silico solvents to replace phospholipid tails, with integral membrane proteins. Here, we report an updated HMMM model that is able to include CHL, a nonphospholipid component of the membrane, henceforth called HMMM-CHL. To this end, we had to optimize the effect of the customized solvents on CHL behavior in the membrane. Furthermore, the new solvent is compatible with simulations using force-based switching protocols. In the HMMM-CHL, both improved CHL dynamics and accelerated lipid diffusion are integrated. To test the updated model, we have applied it to the characterization of protein-CHL interactions in two membrane protein systems, the human β2-adrenergic receptor (β2AR) and the mitochondrial voltage-dependent anion channel 1 (VDAC-1). Our HMMM-CHL simulations successfully identified CHL binding sites and captured detailed CHL interactions in excellent consistency with experimental data as well as other simulation results, indicating the utility of the improved model in applications where an enhanced sampling of protein-CHL interactions is desired.
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Affiliation(s)
- Muyun Lihan
- Center for Biophysics and Quantitative Biology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
- NIH Center for Macromolecular Modeling and Visualization, Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Emad Tajkhorshid
- Center for Biophysics and Quantitative Biology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
- NIH Center for Macromolecular Modeling and Visualization, Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
- Department of Biochemistry, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
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2
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Inan T, Flinko R, Lewis GK, MacKerell AD, Kurkcuoglu O. Identifying and Assessing Putative Allosteric Sites and Modulators for CXCR4 Predicted through Network Modeling and Site Identification by Ligand Competitive Saturation. J Phys Chem B 2024; 128:5157-5174. [PMID: 38647430 PMCID: PMC11139592 DOI: 10.1021/acs.jpcb.4c00925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Revised: 04/04/2024] [Accepted: 04/08/2024] [Indexed: 04/25/2024]
Abstract
The chemokine receptor CXCR4 is a critical target for the treatment of several cancer types and HIV-1 infections. While orthosteric and allosteric modulators have been developed targeting its extracellular or transmembrane regions, the intramembrane region of CXCR4 may also include allosteric binding sites suitable for the development of allosteric drugs. To investigate this, we apply the Gaussian Network Model (GNM) to the monomeric and dimeric forms of CXCR4 to identify residues essential for its local and global motions located in the hinge regions of the protein. Residue interaction network (RIN) analysis suggests hub residues that participate in allosteric communication throughout the receptor. Mutual residues from the network models reside in regions with a high capacity to alter receptor dynamics upon ligand binding. We then investigate the druggability of these potential allosteric regions using the site identification by ligand competitive saturation (SILCS) approach, revealing two putative allosteric sites on the monomer and three on the homodimer. Two screening campaigns with Glide and SILCS-Monte Carlo docking using FDA-approved drugs suggest 20 putative hit compounds including antifungal drugs, anticancer agents, HIV protease inhibitors, and antimalarial drugs. In vitro assays considering mAB 12G5 and CXCL12 demonstrate both positive and negative allosteric activities of these compounds, supporting our computational approach. However, in vivo functional assays based on the recruitment of β-arrestin to CXCR4 do not show significant agonism and antagonism at a single compound concentration. The present computational pipeline brings a new perspective to computer-aided drug design by combining conformational dynamics based on network analysis and cosolvent analysis based on the SILCS technology to identify putative allosteric binding sites using CXCR4 as a showcase.
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Affiliation(s)
- Tugce Inan
- Department
of Chemical Engineering, Istanbul Technical
University, Istanbul 34469, Turkey
| | - Robin Flinko
- Institute
of Human Virology, University of Maryland
School of Medicine, Baltimore, Maryland 21201, United States
| | - George K. Lewis
- Institute
of Human Virology, University of Maryland
School of Medicine, Baltimore, Maryland 21201, United States
| | - Alexander D. MacKerell
- University
of Maryland Computer-Aided Drug Design Center, Department of Pharmaceutical
Sciences, School of Pharmacy, University
of Maryland, Baltimore, Maryland 21201, United States
| | - Ozge Kurkcuoglu
- Department
of Chemical Engineering, Istanbul Technical
University, Istanbul 34469, Turkey
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3
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Gorostiola González M, Rakers PRJ, Jespers W, IJzerman AP, Heitman LH, van Westen GJP. Computational Characterization of Membrane Proteins as Anticancer Targets: Current Challenges and Opportunities. Int J Mol Sci 2024; 25:3698. [PMID: 38612509 PMCID: PMC11011372 DOI: 10.3390/ijms25073698] [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: 02/21/2024] [Revised: 03/21/2024] [Accepted: 03/21/2024] [Indexed: 04/14/2024] Open
Abstract
Cancer remains a leading cause of mortality worldwide and calls for novel therapeutic targets. Membrane proteins are key players in various cancer types but present unique challenges compared to soluble proteins. The advent of computational drug discovery tools offers a promising approach to address these challenges, allowing for the prioritization of "wet-lab" experiments. In this review, we explore the applications of computational approaches in membrane protein oncological characterization, particularly focusing on three prominent membrane protein families: receptor tyrosine kinases (RTKs), G protein-coupled receptors (GPCRs), and solute carrier proteins (SLCs). We chose these families due to their varying levels of understanding and research data availability, which leads to distinct challenges and opportunities for computational analysis. We discuss the utilization of multi-omics data, machine learning, and structure-based methods to investigate aberrant protein functionalities associated with cancer progression within each family. Moreover, we highlight the importance of considering the broader cellular context and, in particular, cross-talk between proteins. Despite existing challenges, computational tools hold promise in dissecting membrane protein dysregulation in cancer. With advancing computational capabilities and data resources, these tools are poised to play a pivotal role in identifying and prioritizing membrane proteins as personalized anticancer targets.
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Affiliation(s)
- Marina Gorostiola González
- Leiden Academic Centre of Drug Research, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands; (M.G.G.); (P.R.J.R.); (W.J.); (A.P.I.); (L.H.H.)
- Oncode Institute, 2333 CC Leiden, The Netherlands
| | - Pepijn R. J. Rakers
- Leiden Academic Centre of Drug Research, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands; (M.G.G.); (P.R.J.R.); (W.J.); (A.P.I.); (L.H.H.)
| | - Willem Jespers
- Leiden Academic Centre of Drug Research, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands; (M.G.G.); (P.R.J.R.); (W.J.); (A.P.I.); (L.H.H.)
| | - Adriaan P. IJzerman
- Leiden Academic Centre of Drug Research, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands; (M.G.G.); (P.R.J.R.); (W.J.); (A.P.I.); (L.H.H.)
| | - Laura H. Heitman
- Leiden Academic Centre of Drug Research, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands; (M.G.G.); (P.R.J.R.); (W.J.); (A.P.I.); (L.H.H.)
- Oncode Institute, 2333 CC Leiden, The Netherlands
| | - Gerard J. P. van Westen
- Leiden Academic Centre of Drug Research, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands; (M.G.G.); (P.R.J.R.); (W.J.); (A.P.I.); (L.H.H.)
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4
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Naglekar A, Chattopadhyay A, Sengupta D. Palmitoylation of the Glucagon-like Peptide-1 Receptor Modulates Cholesterol Interactions at the Receptor-Lipid Microenvironment. J Phys Chem B 2023; 127:11000-11010. [PMID: 38111968 DOI: 10.1021/acs.jpcb.3c05930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2023]
Abstract
The G protein-coupled receptor (GPCR) superfamily of cell surface receptors has been shown to be functionally modulated by post-translational modifications. The glucagon-like peptide receptor-1 (GLP-1R), which is a drug target in diabetes and obesity, undergoes agonist-dependent palmitoyl tail conjugation. The palmitoylation in the C-terminal domain of GLP-1R has been suggested to modulate the receptor-lipid microenvironment. In this work, we have performed coarse-grain molecular dynamics simulations of palmitoylated and nonpalmitoylated GLP-1R to analyze the differential receptor-lipid interactions. Interestingly, the placement and dynamics of the C-terminal domain of GLP-1R are found to be directly dependent on the palmitoyl tail. We observe that both cholesterol and phospholipids interact with the receptor but display differential interactions in the presence and absence of the palmitoyl tail. We characterize important cholesterol-binding sites and validate sites that have been previously reported in experimentally resolved structures of the receptor. We show that the receptor acts like a conduit for cholesterol flip-flop by stabilizing cholesterol in the membrane core. Taken together, our work represents an important step in understanding the molecular effects of lipid modifications in GPCRs.
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Affiliation(s)
- Amit Naglekar
- CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Amitabha Chattopadhyay
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500007, India
| | - Durba Sengupta
- CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
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5
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Di Marino D, Conflitti P, Motta S, Limongelli V. Structural basis of dimerization of chemokine receptors CCR5 and CXCR4. Nat Commun 2023; 14:6439. [PMID: 37833254 PMCID: PMC10575954 DOI: 10.1038/s41467-023-42082-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Accepted: 09/28/2023] [Indexed: 10/15/2023] Open
Abstract
G protein-coupled receptors (GPCRs) are prominent drug targets responsible for extracellular-to-intracellular signal transduction. GPCRs can form functional dimers that have been poorly characterized so far. Here, we show the dimerization mechanism of the chemokine receptors CCR5 and CXCR4 by means of an advanced free-energy technique named coarse-grained metadynamics. Our results reproduce binding events between the GPCRs occurring in the minute timescale, revealing a symmetric and an asymmetric dimeric structure for each of the three investigated systems, CCR5/CCR5, CXCR4/CXCR4, and CCR5/CXCR4. The transmembrane helices TM4-TM5 and TM6-TM7 are the preferred binding interfaces for CCR5 and CXCR4, respectively. The identified dimeric states differ in the access to the binding sites of the ligand and G protein, indicating that dimerization may represent a fine allosteric mechanism to regulate receptor activity. Our study offers structural basis for the design of ligands able to modulate the formation of CCR5 and CXCR4 dimers and in turn their activity, with therapeutic potential against HIV, cancer, and immune-inflammatory diseases.
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Affiliation(s)
- Daniele Di Marino
- Department of Life and Environmental Sciences - New York-Marche Structural Biology Centre (NY-MaSBiC), Polytechnic University of Marche, Via Brecce Bianche, 60131, Ancona, Italy
- Neuronal Death and Neuroprotection Unit, Department of Neuroscience, Mario Negri Institute for Pharmacological Research-IRCCS, Via Mario Negri 2, 20156, Milan, Italy
- National Biodiversity Future Center (NBFC), Palermo, Italy
| | - Paolo Conflitti
- Università della Svizzera italiana (USI), Faculty of Biomedical Sciences, Euler Institute, Via G. Buffi 13, CH-6900, Lugano, Switzerland
| | - Stefano Motta
- Department of Earth and Environmental Sciences, University of Milano-Bicocca, Piazza della Scienza 1, 20126, Milan, Italy
| | - Vittorio Limongelli
- Università della Svizzera italiana (USI), Faculty of Biomedical Sciences, Euler Institute, Via G. Buffi 13, CH-6900, Lugano, Switzerland.
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6
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Wachlmayr J, Fläschner G, Pluhackova K, Sandtner W, Siligan C, Horner A. Entropic barrier of water permeation through single-file channels. Commun Chem 2023; 6:135. [PMID: 37386127 DOI: 10.1038/s42004-023-00919-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 06/02/2023] [Indexed: 07/01/2023] Open
Abstract
Facilitated water permeation through narrow biological channels is fundamental for all forms of life. Despite its significance in health and disease as well as for biotechnological applications, the energetics of water permeation are still elusive. Gibbs free energy of activation is composed of an enthalpic and an entropic component. Whereas the enthalpic contribution is readily accessible via temperature dependent water permeability measurements, estimation of the entropic contribution requires information on the temperature dependence of the rate of water permeation. Here, we estimate, by means of accurate activation energy measurements of water permeation through Aquaporin-1 and by determining the accurate single channel permeability, the entropic barrier of water permeation through a narrow biological channel. Thereby the calculated value for [Formula: see text] = 2.01 ± 0.82 J/(mol·K) links the activation energy of 3.75 ± 0.16 kcal/mol with its efficient water conduction rate of ~1010 water molecules/second. This is a first step in understanding the energetic contributions in various biological and artificial channels exhibiting vastly different pore geometries.
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Affiliation(s)
- Johann Wachlmayr
- Institute of Biophysics, Johannes Kepler University Linz, Linz, Austria
| | - Gotthold Fläschner
- Department of Biosystems Science and Engineering, Eidgenössiche Technische Hochschule (ETH) Zürich, Basel, Switzerland
| | - Kristyna Pluhackova
- Stuttgart Center for Simulation Science, Cluster of Excellence EXC 2075, University of Stuttgart, Universitätsstr. 32, 70569, Stuttgart, Germany
| | - Walter Sandtner
- Center of Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, Schwarzspanierstr. 17A, 1090, Vienna, Austria
| | - Christine Siligan
- Institute of Biophysics, Johannes Kepler University Linz, Linz, Austria
| | - Andreas Horner
- Institute of Biophysics, Johannes Kepler University Linz, Linz, Austria.
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7
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Antonello P, Pizzagalli DU, Foglierini M, Melgrati S, Radice E, Thelen S, Thelen M. ACKR3 promotes CXCL12/CXCR4-mediated cell-to-cell-induced lymphoma migration through LTB4 production. Front Immunol 2023; 13:1067885. [PMID: 36713377 PMCID: PMC9878562 DOI: 10.3389/fimmu.2022.1067885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 12/22/2022] [Indexed: 01/14/2023] Open
Abstract
Chemotaxis is an essential physiological process, often harnessed by tumors for metastasis. CXCR4, its ligand CXCL12 and the atypical receptor ACKR3 are overexpressed in many human cancers. Interfering with this axis by ACKR3 deletion impairs lymphoma cell migration towards CXCL12. Here, we propose a model of how ACKR3 controls the migration of the diffused large B-cell lymphoma VAL cells in vitro and in vivo in response to CXCL12. VAL cells expressing full-length ACKR3, but not a truncated version missing the C-terminus, can support the migration of VAL cells lacking ACKR3 (VAL-ko) when allowed to migrate together. This migration of VAL-ko cells is pertussis toxin-sensitive suggesting the involvement of a Gi-protein coupled receptor. RNAseq analysis indicate the expression of chemotaxis-mediating LTB4 receptors in VAL cells. We found that LTB4 acts synergistically with CXCL12 in stimulating the migration of VAL cells. Pharmacologic or genetic inhibition of BLT1R markedly reduces chemotaxis towards CXCL12 suggesting that LTB4 enhances in a contact-independent manner the migration of lymphoma cells. The results unveil a novel mechanism of cell-to-cell-induced migration of lymphoma.
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Affiliation(s)
- Paola Antonello
- Faculty of Biomedical Sciences, Institute for Research in Biomedicine, Università della Svizzera italiana, Bellinzona, Switzerland
- Graduate School of Cellular and Molecular Sciences, University of Bern, Bern, Switzerland
| | - Diego U. Pizzagalli
- Faculty of Biomedical Sciences, Institute for Research in Biomedicine, Università della Svizzera italiana, Bellinzona, Switzerland
- Università della Svizzera italiana, Euler Institute, Lugano-Viganello, Switzerland
| | - Mathilde Foglierini
- Faculty of Biomedical Sciences, Institute for Research in Biomedicine, Università della Svizzera italiana, Bellinzona, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Serena Melgrati
- Faculty of Biomedical Sciences, Institute for Research in Biomedicine, Università della Svizzera italiana, Bellinzona, Switzerland
- Graduate School of Cellular and Molecular Sciences, University of Bern, Bern, Switzerland
| | - Egle Radice
- Faculty of Biomedical Sciences, Institute for Research in Biomedicine, Università della Svizzera italiana, Bellinzona, Switzerland
| | - Sylvia Thelen
- Faculty of Biomedical Sciences, Institute for Research in Biomedicine, Università della Svizzera italiana, Bellinzona, Switzerland
| | - Marcus Thelen
- Faculty of Biomedical Sciences, Institute for Research in Biomedicine, Università della Svizzera italiana, Bellinzona, Switzerland
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8
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Yekefallah M, Rasberry CA, van Aalst EJ, Browning HP, Amani R, Versteeg DB, Wylie BJ. Mutational Insight into Allosteric Regulation of Kir Channel Activity. ACS OMEGA 2022; 7:43621-43634. [PMID: 36506180 PMCID: PMC9730464 DOI: 10.1021/acsomega.2c04456] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 11/10/2022] [Indexed: 06/08/2023]
Abstract
Potassium (K+) channels are regulated in part by allosteric communication between the helical bundle crossing, or inner gate, and the selectivity filter, or outer gate. This network is triggered by gating stimuli. In concert, there is an allosteric network which is a conjugated set of interactions which correlate long-range structural rearrangements necessary for channel function. Inward-rectifier K+ (Kir) channels favor inward K+ conductance, are ligand-gated, and help establish resting membrane potentials. KirBac1.1 is a bacterial Kir (KirBac) channel homologous to human Kir (hKir) channels. Additionally, KirBac1.1 is gated by the anionic phospholipid ligand phosphatidylglycerol (PG). In this study, we use site-directed mutagenesis to investigate residues involved in the KirBac1.1 gating mechanism and allosteric network we previously proposed using detailed solid-state NMR (SSNMR) measurements. Using fluorescence-based K+ and sodium (Na+) flux assays, we identified channel mutants with impaired function that do not alter selectivity of the channel. In tandem, we performed coarse grain molecular dynamics simulations, observing changes in PG-KirBac1.1 interactions correlated with mutant channel activity and contacts between the two transmembrane helices and pore helix tied to this behavior. Lipid affinity is closely tied to the proximity of two tryptophan residues on neighboring subunits which lure anionic lipids to a cationic pocket formed by a cluster of arginine residues. Thus, these simulations establish a structural and functional basis for the role of each mutated site in the proposed allosteric network. The experimental and simulated data provide insight into key functional residues involved in gating and lipid allostery of K+ channels. Our findings also have direct implications on the physiology of hKir channels due to conservation of many of the residues identified in this work from KirBac1.1.
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9
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Kluge C, Pöhnl M, Böckmann RA. Spontaneous local membrane curvature induced by transmembrane proteins. Biophys J 2022; 121:671-683. [PMID: 35122737 PMCID: PMC8943716 DOI: 10.1016/j.bpj.2022.01.029] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Revised: 01/13/2022] [Accepted: 01/28/2022] [Indexed: 11/26/2022] Open
Abstract
The (local) curvature of cellular membranes acts as a driving force for the targeting of membrane-associated proteins to specific membrane domains, as well as a sorting mechanism for transmembrane proteins, e.g., by accumulation in regions of matching spontaneous curvature. The latter measure was previously experimentally employed to study the curvature induced by the potassium channel KvAP and by aquaporin AQP0. However, the direction of the reported spontaneous curvature levels as well as the molecular driving forces governing the membrane curvature induced by these integral transmembrane proteins could not be addressed experimentally. Here, using both coarse-grained and atomistic molecular dynamics (MD) simulations, we report induced spontaneous curvature values for the homologous potassium channel Kv 1.2/2.1 Chimera (KvChim) and AQP0 embedded in unrestrained lipid bicelles that are in very good agreement with experiment. Importantly, the direction of curvature could be directly assessed from our simulations: KvChim induces a strong positive membrane curvature (≈0.036 nm-1) whereas AQP0 causes a comparably small negative curvature (≈-0.019 nm-1). Analyses of protein-lipid interactions within the bicelle revealed that the potassium channel shapes the surrounding membrane via structural determinants. Differences in shape of the protein-lipid interface of the voltage-gating domains between the extracellular and cytosolic membrane leaflets induce membrane stress and thereby promote a protein-proximal membrane curvature. In contrast, the water pore AQP0 displayed a high structural stability and an only faint effect on the surrounding membrane environment that is connected to its wedge-like shape.
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Affiliation(s)
- Christoph Kluge
- Computational Biology, Department of Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Matthias Pöhnl
- Computational Biology, Department of Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Rainer A. Böckmann
- Computational Biology, Department of Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany,National Center for High-Performance Computing Erlangen (NHR@FAU), Erlangen, Germany,Corresponding author
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10
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Evolution of CCR5 and CCR2 Genes in Bats Showed Multiple Independent Gene Conversion Events. Viruses 2022; 14:v14020169. [PMID: 35215768 PMCID: PMC8877049 DOI: 10.3390/v14020169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 01/12/2022] [Accepted: 01/15/2022] [Indexed: 11/16/2022] Open
Abstract
Chemokine receptors are an important determinant for the infectiousness of different pathogens, which are able to target the host cells by binding to the extracellular domains of these proteins. This is the mechanism of infection of HIV-1, among other concerning human diseases. Over the past years, it has been shown that two chemokine receptors, CCR2 and CCR5, have been shaped by events of gene conversion in different mammalian lineages, which has been linked to a possible selective advantage against pathogens. Here, by taking advantage of available bat genomes, we present the first insight of CCR2 and CCR5 evolution within the Chiroptera order. In total, four independent events of recombination between CCR2 and CCR5 were detected: two in a single species, Miniopterus natalensis; one in two species from the Rhinolophoidea superfamily; and one in four species from the Pteropodidae family. The regions affected by the gene conversions were generally extensive and always encompassed extracellular domains. Overall, we demonstrate that CCR2 and CCR5 have been subject to extensive gene conversion in multiple species of bats. Considering that bats are known to be large reservoirs of virus in nature, these results might indicate that chimeric CCR2-CCR5 genes might grant some bat species a selective advantage against viruses that rely in the extracellular portions of either CCR2 or CCR5 as gateways into the cell.
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11
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Pluhackova K, Wilhelm FM, Müller DJ. Lipids and Phosphorylation Conjointly Modulate Complex Formation of β 2-Adrenergic Receptor and β-arrestin2. Front Cell Dev Biol 2022; 9:807913. [PMID: 35004696 PMCID: PMC8733679 DOI: 10.3389/fcell.2021.807913] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 11/30/2021] [Indexed: 01/14/2023] Open
Abstract
G protein-coupled receptors (GPCRs) are the largest class of human membrane proteins that bind extracellular ligands at their orthosteric binding pocket to transmit signals to the cell interior. Ligand binding evokes conformational changes in GPCRs that trigger the binding of intracellular interaction partners (G proteins, G protein kinases, and arrestins), which initiate diverse cellular responses. It has become increasingly evident that the preference of a GPCR for a certain intracellular interaction partner is modulated by a diverse range of factors, e.g., ligands or lipids embedding the transmembrane receptor. Here, by means of molecular dynamics simulations of the β2-adrenergic receptor and β-arrestin2, we study how membrane lipids and receptor phosphorylation regulate GPCR-arrestin complex conformation and dynamics. We find that phosphorylation drives the receptor’s intracellular loop 3 (ICL3) away from a native negatively charged membrane surface to interact with arrestin. If the receptor is embedded in a neutral membrane, the phosphorylated ICL3 attaches to the membrane surface, which widely opens the receptor core. This opening, which is similar to the opening in the G protein-bound state, weakens the binding of arrestin. The loss of binding specificity is manifested by shallower arrestin insertion into the receptor core and higher dynamics of the receptor-arrestin complex. Our results show that receptor phosphorylation and the local membrane composition cooperatively fine-tune GPCR-mediated signal transduction. Moreover, the results suggest that deeper understanding of complex GPCR regulation mechanisms is necessary to discover novel pathways of pharmacological intervention.
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Affiliation(s)
- Kristyna Pluhackova
- Department of Biosystems Science and Engineering, Eidgenössische Technische Hochschule (ETH) Zurich, Basel, Switzerland
| | - Florian M Wilhelm
- Department of Biosystems Science and Engineering, Eidgenössische Technische Hochschule (ETH) Zurich, Basel, Switzerland
| | - Daniel J Müller
- Department of Biosystems Science and Engineering, Eidgenössische Technische Hochschule (ETH) Zurich, Basel, Switzerland
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12
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Song W, Duncan AL, Sansom MSP. Modulation of adenosine A2a receptor oligomerization by receptor activation and PIP 2 interactions. Structure 2021; 29:1312-1325.e3. [PMID: 34270937 PMCID: PMC8581623 DOI: 10.1016/j.str.2021.06.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 05/28/2021] [Accepted: 06/25/2021] [Indexed: 11/23/2022]
Abstract
GPCRs have been shown to form oligomers, which generate distinctive signaling outcomes. However, the structural nature of the oligomerization process remains uncertain. We have characterized oligomeric configurations of the adenosine A2a receptor (A2aR) by combining large-scale molecular dynamics simulations with Markov state models. These oligomeric structures may also serve as templates for studying oligomerization of other class A GPCRs. Our simulation data revealed that receptor activation results in enhanced oligomerization, more diverse oligomer populations, and a more connected oligomerization network. The active state conformation of the A2aR shifts protein-protein association interfaces to those involving intracellular loop ICL3 and transmembrane helix TM6. Binding of PIP2 to A2aR stabilizes protein-protein interactions via PIP2-mediated association interfaces. These results indicate that A2aR oligomerization is responsive to the local membrane lipid environment. This, in turn, suggests a modulatory effect on A2aR whereby a given oligomerization profile favors the dynamic formation of specific supramolecular signaling complexes.
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Affiliation(s)
- Wanling Song
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Anna L Duncan
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Mark S P Sansom
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK.
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13
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Tse LH, Wong YH. Modeling the Heterodimer Interfaces of Melatonin Receptors. Front Cell Neurosci 2021; 15:725296. [PMID: 34690701 PMCID: PMC8529217 DOI: 10.3389/fncel.2021.725296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 08/16/2021] [Indexed: 11/16/2022] Open
Abstract
Melatonin receptors are Class A G protein-coupled receptors (GPCRs) that regulate a plethora of physiological activities in response to the rhythmic secretion of melatonin from the pineal gland. Melatonin is a key regulator in the control of circadian rhythm and has multiple functional roles in retinal physiology, memory, immunomodulation and tumorigenesis. The two subtypes of human melatonin receptors, termed MT1 and MT2, utilize overlapping signaling pathways although biased signaling properties have been reported in some cellular systems. With the emerging concept of GPCR dimerization, melatonin receptor heterodimers have been proposed to participate in system-biased signaling. Here, we used computational approaches to map the dimerization interfaces of known heterodimers of melatonin receptors, including MT1/MT2, MT1/GPR50, MT2/GPR50, and MT2/5-HT2C. By homology modeling and membrane protein docking analyses, we have identified putative preferred interface interactions within the different pairs of melatonin receptor dimers and provided plausible structural explanations for some of the unique pharmacological features of specific heterodimers previously reported. A thorough understanding of the molecular basis of melatonin receptor heterodimers may enable the development of new therapeutic approaches against aliments involving these heterodimeric receptors.
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Affiliation(s)
- Lap Hang Tse
- Division of Life Science and the Biotechnology Research Institute, Hong Kong University of Science and Technology, Hong Kong, SAR China
| | - Yung Hou Wong
- Division of Life Science and the Biotechnology Research Institute, Hong Kong University of Science and Technology, Hong Kong, SAR China.,State Key Laboratory of Molecular Neuroscience, Molecular Neuroscience Center, Hong Kong University of Science and Technology, Hong Kong, SAR China.,Hong Kong Center for Neurodegenerative Diseases, Hong Kong Science Park, Hong Kong, SAR China
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14
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CXCR4-CCR7 Heterodimerization Is a Driver of Breast Cancer Progression. Life (Basel) 2021; 11:life11101049. [PMID: 34685420 PMCID: PMC8538406 DOI: 10.3390/life11101049] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 10/01/2021] [Accepted: 10/02/2021] [Indexed: 01/11/2023] Open
Abstract
Metastatic breast cancer has one of the highest mortality rates among women in western society. Chemokine receptors CXCR4 and CCR7 have been shown to be linked to the metastatic spread of breast cancer, however, their precise function and underlying molecular pathways leading to the acquisition of the pro-metastatic properties remain poorly understood. We demonstrate here that the CXCR4 and CCR7 receptor ligands, CXCL12 and CCL19, cooperatively bind and selectively elicit synergistic signalling responses in invasive breast cancer cell lines as well as primary mammary human tumour cells. Furthermore, for the first time, we have documented the presence of CXCR4-CCR7 heterodimers in advanced primary mammary mouse and human tumours where number of CXCR4-CCR7 complexes directly correlate with the severity of the disease. The functional significance of the CXCR4-CCR7 association was also demonstrated when their forced heterodimerization led to the acquisition of invasive phenotype in non-metastatic breast cancer cells. Taken together, our data establish the CXCR4-CCR7 receptor complex as a new functional unit, which is responsible for the acquisition of breast cancer cell metastatic phenotype and which may serve as a novel biomarker for invasive mammary tumours.
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15
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Sokkar P, Harms M, Stürzel C, Gilg A, Kizilsavas G, Raasholm M, Preising N, Wagner M, Kirchhoff F, Ständker L, Weidinger G, Mayer B, Münch J, Sanchez-Garcia E. Computational modeling and experimental validation of the EPI-X4/CXCR4 complex allows rational design of small peptide antagonists. Commun Biol 2021; 4:1113. [PMID: 34552197 PMCID: PMC8458281 DOI: 10.1038/s42003-021-02638-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 08/31/2021] [Indexed: 11/13/2022] Open
Abstract
EPI-X4, a 16-mer fragment of albumin, is a specific endogenous antagonist and inverse agonist of the CXC-motif-chemokine receptor 4 (CXCR4) and thus a key regulator of CXCR4 function. Accordingly, activity-optimized synthetic derivatives of EPI-X4 are promising leads for the therapy of CXCR4-linked disorders such as cancer or inflammatory diseases. We investigated the binding of EPI-X4 to CXCR4, which so far remained unclear, by means of biomolecular simulations combined with experimental mutagenesis and activity studies. We found that EPI-X4 interacts through its N-terminal residues with CXCR4 and identified its key interaction motifs, explaining receptor antagonization. Using this model, we developed shortened EPI-X4 derivatives (7-mers) with optimized receptor antagonizing properties as new leads for the development of CXCR4 inhibitors. Our work reveals the molecular details and mechanism by which the first endogenous peptide antagonist of CXCR4 interacts with its receptor and provides a foundation for the rational design of improved EPI-X4 derivatives.
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Affiliation(s)
- Pandian Sokkar
- Computational Biochemistry, Center of Medical Biotechnology, University of Duisburg-Essen, Essen, Germany
- Faculty of Allied Health Sciences, Chettinad Hospital and Research Institute, Chettinad Academy of Research and Education, Kelambakkam, Tamil Nadu, 603103, India
| | - Mirja Harms
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Christina Stürzel
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Andrea Gilg
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | | | - Martina Raasholm
- Institute of Biochemistry and Molecular Biology, Ulm University, Ulm, 89081, Germany
| | - Nico Preising
- Core Facility Functional Peptidomics, Ulm University Medical Center, Ulm, 89081, Germany
| | - Manfred Wagner
- Max Planck Institute for Polymer Research, Mainz, Germany
| | - Frank Kirchhoff
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Ludger Ständker
- Core Facility Functional Peptidomics, Ulm University Medical Center, Ulm, 89081, Germany
| | - Gilbert Weidinger
- Institute of Biochemistry and Molecular Biology, Ulm University, Ulm, 89081, Germany
| | - Benjamin Mayer
- Institute for Epidemiology and Medical Biometry, Ulm University, Ulm, 89075, Germany
| | - Jan Münch
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany.
- Core Facility Functional Peptidomics, Ulm University Medical Center, Ulm, 89081, Germany.
| | - Elsa Sanchez-Garcia
- Computational Biochemistry, Center of Medical Biotechnology, University of Duisburg-Essen, Essen, Germany.
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16
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van Aalst E, Wylie BJ. Cholesterol Is a Dose-Dependent Positive Allosteric Modulator of CCR3 Ligand Affinity and G Protein Coupling. Front Mol Biosci 2021; 8:724603. [PMID: 34490352 PMCID: PMC8417553 DOI: 10.3389/fmolb.2021.724603] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Accepted: 07/14/2021] [Indexed: 01/14/2023] Open
Abstract
Cholesterol as an allosteric modulator of G protein-coupled receptor (GPCR) function is well documented. This quintessential mammalian lipid facilitates receptor–ligand interactions and multimerization states. Functionally, this introduces a complicated mechanism for the homeostatic modulation of GPCR signaling. Chemokine receptors are Class A GPCRs responsible for immune cell trafficking through the binding of endogenous peptide ligands. CCR3 is a CC motif chemokine receptor expressed by eosinophils and basophils. It traffics these cells by transducing the signal stimulated by the CC motif chemokine primary messengers 11, 24, and 26. These behaviors are close to the human immunoresponse. Thus, CCR3 is implicated in cancer metastasis and inflammatory conditions. However, there is a paucity of experimental evidence linking the functional states of CCR3 to the molecular mechanisms of cholesterol–receptor cooperativity. In this vein, we present a means to combine codon harmonization and a maltose-binding protein fusion tag to produce CCR3 from E. coli. This technique yields ∼2.6 mg of functional GPCR per liter of minimal media. We leveraged this protein production capability to investigate the effects of cholesterol on CCR3 function in vitro. We found that affinity for the endogenous ligand CCL11 increases in a dose-dependent manner with cholesterol concentration in both styrene:maleic acid lipid particles (SMALPs) and proteoliposomes. This heightened receptor activation directly translates to increased signal transduction as measured by the GTPase activity of the bound G-protein α inhibitory subunit 3 (Gαi3). This work represents a critical step forward in understanding the role of cholesterol-GPCR allostery in regulation of signal transduction.
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Affiliation(s)
- Evan van Aalst
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX, United States
| | - Benjamin J Wylie
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX, United States
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17
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van Aalst E, Koneri J, Wylie BJ. In Silico Identification of Cholesterol Binding Motifs in the Chemokine Receptor CCR3. MEMBRANES 2021; 11:570. [PMID: 34436333 PMCID: PMC8401243 DOI: 10.3390/membranes11080570] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Revised: 07/21/2021] [Accepted: 07/22/2021] [Indexed: 01/14/2023]
Abstract
CC motif chemokine receptor 3 (CCR3) is a Class A G protein-coupled receptor (GPCR) mainly responsible for the cellular trafficking of eosinophils. As such, it plays key roles in inflammatory conditions, such as asthma and arthritis, and the metastasis of many deadly forms of cancer. However, little is known about how CCR3 functionally interacts with its bilayer environment. Here, we investigate cholesterol binding sites in silico through Coarse-Grained Molecular Dynamics (MD) and Pylipid analysis using an extensively validated homology model based on the crystal structure of CCR5. These simulations identified several cholesterol binding sites containing Cholesterol Recognition/Interaction Amino Acid Consensus motif (CRAC) and its inversion CARC motifs in CCR3. One such site, a CARC site in TM1, in conjunction with aliphatic residues in TM7, emerged as a candidate for future investigation based on the cholesterol residency time within the binding pocket. This site forms the core of a cholesterol binding site previously observed in computational studies of CCR2 and CCR5. Most importantly, these cholesterol binding sites are conserved in other chemokine receptors and may provide clues to cholesterol regulation mechanisms in this subfamily of Class A GPCRs.
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Affiliation(s)
| | | | - Benjamin J. Wylie
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79423, USA; (E.v.A.); (J.K.)
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18
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Jaworski JP, Urrutia M, Dascal E, Jaita G, Peluffo MC. C-C motif chemokine receptor 2 as a novel intermediate in the ovulatory cascade. Mol Hum Reprod 2021; 26:289-300. [PMID: 32159806 DOI: 10.1093/molehr/gaaa020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Revised: 02/28/2020] [Indexed: 12/12/2022] Open
Abstract
Expression of immune function genes within follicle cells has been reported in ovaries from many species. Recent work from our laboratory showed a direct effect of the monocyte chemoattractant protein 1/C-C motif chemokine receptor 2 system within the feline cumulus oocyte complex, by increasing the mRNA levels of key genes involved in the ovulatory cascade in vitro. Studies were designed to evaluate if C-C motif chemokine receptor 2 acts as a novel mediator of the ovulatory cascade in vitro. Therefore, feline cumulus oocyte complexes were cultured in the presence or absence of a highly selective C-C motif chemokine receptor 2 antagonist together with known inducers of cumulus-oocyte expansion and/or oocyte maturation to assess mRNA expression of key genes related to periovulatory events in other species as well as oocyte maturation. Also, the effects of recombinant monocyte chemoattractant protein 1 on spontaneous or gonadotrophin-induced oocyte maturation were assessed. This is an in vitro system using isolated cumulus oocyte complexes from feline ovaries. The present study reveals the modulation of several key ovulatory genes by a highly selective C-C motif chemokine receptor 2 antagonist. However, this antagonist was not enough to block the oocyte maturation induced by gonadotropins or amphiregulin. Nonetheless, recombinant monocyte chemoattractant protein 1 had a significant effect on spontaneous oocyte maturation, increasing the percentage of metaphase II stage oocytes in comparison to the control. This is the first study in any species to establish C-C motif chemokine receptor 2 as a mediator of some actions of the mid-cycle gonadotrophin surge.
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Affiliation(s)
- J P Jaworski
- Instituto de Virología, INTA (National Institute of Agricultural Technology-Instituto Nacional de Tecnología Agropecuaria)-CONICET, Argentina. Las Cabañas y Los Reseros s/n, Las Cabañas y Los Reseros 10 s/n, Castelar, Argentina
| | - M Urrutia
- Centro de Investigaciones Endocrinológicas "Dr. César Bergadá" (CEDIE), CONICET - FEI - División de Endocrinología, Hospital de Niños Ricardo Gutiérrez, Gallo 1330, C1425EFD Ciudad Autónoma de Buenos Aires, Argentina
| | - E Dascal
- Centro de Investigaciones Endocrinológicas "Dr. César Bergadá" (CEDIE), CONICET - FEI - División de Endocrinología, Hospital de Niños Ricardo Gutiérrez, Gallo 1330, C1425EFD Ciudad Autónoma de Buenos Aires, Argentina
| | - G Jaita
- Instituto de Investigaciones Biomédicas (INBIOMED), Facultad de Medicina CONICET, Universidad de Buenos Aires, Paraguay 2155, C1121ABG Ciudad Autónoma de Buenos Aires, Argentina.,Departamento de Biología Celular e Histología, Facultad de Medicina, Universidad de Buenos Aires Buenos, Paraguay 2155, C1121ABG Ciudad Autónoma de Buenos Aires, Argentina
| | - M C Peluffo
- Centro de Investigaciones Endocrinológicas "Dr. César Bergadá" (CEDIE), CONICET - FEI - División de Endocrinología, Hospital de Niños Ricardo Gutiérrez, Gallo 1330, C1425EFD Ciudad Autónoma de Buenos Aires, Argentina
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19
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Latest update on chemokine receptors as therapeutic targets. Biochem Soc Trans 2021; 49:1385-1395. [PMID: 34060588 PMCID: PMC8286821 DOI: 10.1042/bst20201114] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 04/19/2021] [Accepted: 04/23/2021] [Indexed: 12/12/2022]
Abstract
The chemokine system plays a fundamental role in a diverse range of physiological processes, such as homeostasis and immune responses. Dysregulation in the chemokine system has been linked to inflammatory diseases and cancer, which renders chemokine receptors to be considered as therapeutic targets. In the past two decades, around 45 drugs targeting chemokine receptors have been developed, yet only three are clinically approved. The challenging factors include the limited understanding of aberrant chemokine signalling in malignant diseases, high redundancy of the chemokine system, differences between cell types and non-specific binding of the chemokine receptor antagonists due to the broad ligand-binding pockets. In recent years, emerging studies attempt to characterise the chemokine ligand–receptor interactions and the downstream signalling protein–protein interactions, aiming to fine tuning to the promiscuous interplay of the chemokine system for the development of precision medicine. This review will outline the updates on the mechanistic insights in the chemokine system and propose some potential strategies in the future development of targeted therapy.
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20
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Pluhackova K, Horner A. Native-like membrane models of E. coli polar lipid extract shed light on the importance of lipid composition complexity. BMC Biol 2021; 19:4. [PMID: 33441107 PMCID: PMC7807449 DOI: 10.1186/s12915-020-00936-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 11/27/2020] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Lipid-protein interactions stabilize protein oligomers, shape their structure, and modulate their function. Whereas in vitro experiments already account for the functional importance of lipids by using natural lipid extracts, in silico methods lack behind by embedding proteins in single component lipid bilayers. However, to accurately complement in vitro experiments with molecular details at very high spatio-temporal resolution, molecular dynamics simulations have to be performed in natural(-like) lipid environments. RESULTS To enable more accurate MD simulations, we have prepared four membrane models of E. coli polar lipid extract, a typical model organism, each at all-atom (CHARMM36) and coarse-grained (Martini3) representations. These models contain all main lipid headgroup types of the E. coli inner membrane, i.e., phosphatidylethanolamines, phosphatidylglycerols, and cardiolipins, symmetrically distributed between the membrane leaflets. The lipid tail (un)saturation and propanylation stereochemistry represent the bacterial lipid tail composition of E. coli grown at 37∘C until 3/4 of the log growth phase. The comparison of the Simple three lipid component models to the complex 14-lipid component model Avanti over a broad range of physiologically relevant temperatures revealed that the balance of lipid tail unsaturation and propanylation in different positions and inclusion of lipid tails of various length maintain realistic values for lipid mobility, membrane area compressibility, lipid ordering, lipid volume and area, and the bilayer thickness. The only Simple model that was able to satisfactory reproduce most of the structural properties of the complex Avanti model showed worse agreement of the activation energy of basal water permeation with the here performed measurements. The Martini3 models reflect extremely well both experimental and atomistic behavior of the E. coli polar lipid extract membranes. Aquaporin-1 embedded in our native(-like) membranes causes partial lipid ordering and membrane thinning in its vicinity. Moreover, aquaporin-1 attracts and temporarily binds negatively charged lipids, mainly cardiolipins, with a distinct cardiolipin binding site in the crevice at the contact site between two monomers, most probably stabilizing the tetrameric protein assembly. CONCLUSIONS The here prepared and validated membrane models of E. coli polar lipids extract revealed that lipid tail complexity, in terms of double bond and cyclopropane location and varying lipid tail length, is key to stabilize membrane properties over a broad temperature range. In addition, they build a solid basis for manifold future simulation studies on more realistic lipid membranes bridging the gap between simulations and experiments.
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Affiliation(s)
- Kristyna Pluhackova
- Department of Biosystems Science and Engineering, Eidgenössiche Technische Hochschule (ETH) Zürich, Mattenstr. 26, Basel, 4058, Switzerland.
| | - Andreas Horner
- Institute of Biophysics, Johannes Kepler University Linz, Gruberstr. 40, Linz, 4020, Austria
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21
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Kurth M, Lolicato F, Sandoval-Perez A, Amaya-Espinosa H, Teslenko A, Sinning I, Beck R, Brügger B, Aponte-Santamaría C. Cholesterol Localization around the Metabotropic Glutamate Receptor 2. J Phys Chem B 2020; 124:9061-9078. [PMID: 32954729 DOI: 10.1021/acs.jpcb.0c05264] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The metabotropic glutamate receptor (mGluR) 2 plays a key role in the central nervous system. mGluR2 has been shown to be regulated by its surrounding lipid environment, especially by cholesterol, by an unknown mechanism. Here, using a combination of biochemical approaches, photo-cross-linking experiments, and molecular dynamics simulations we show the interaction of cholesterol with at least two, but potentially five more, preferential sites on the mGluR2 transmembrane domain. Our simulations demonstrate that surface matching, rather than electrostatic interactions with specific amino acids, is the main factor defining cholesterol localization. Moreover, the cholesterol localization observed here is similar to the sterol-binding pattern previously described in silico for other members of the mGluR family. Biochemical assays suggest little influence of cholesterol on trafficking or dimerization of mGluR2. Nevertheless, simulations revealed a significant reduction of residue-residue contacts together with an alteration in the internal mechanical stress at the cytoplasmic side of the helical bundle when cholesterol was present in the membrane. These alterations may be related to destabilization of the basal state of mGluR2. Due to the high sequence conservation of the transmembrane domains of mGluRs, the molecular interaction of cholesterol and mGluR2 described here is also likely to be relevant for other members of the mGLuR family.
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Affiliation(s)
- Markus Kurth
- Biochemistry Center (BZH), Heidelberg University, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Fabio Lolicato
- Biochemistry Center (BZH), Heidelberg University, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Angelica Sandoval-Perez
- Max Planck Tandem Group in Computational Biophysics, University of Los Andes, Bogotá, Colombia
| | - Helman Amaya-Espinosa
- Max Planck Tandem Group in Computational Biophysics, University of Los Andes, Bogotá, Colombia
| | - Alexandra Teslenko
- Biochemistry Center (BZH), Heidelberg University, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Irmgard Sinning
- Biochemistry Center (BZH), Heidelberg University, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Rainer Beck
- Biochemistry Center (BZH), Heidelberg University, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Britta Brügger
- Biochemistry Center (BZH), Heidelberg University, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Camilo Aponte-Santamaría
- Max Planck Tandem Group in Computational Biophysics, University of Los Andes, Bogotá, Colombia.,Interdisciplinary Center for Scientific Computing, University of Heidelberg, Heidelberg, Germany
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22
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Kharche SA, Sengupta D. Dynamic protein interfaces and conformational landscapes of membrane protein complexes. Curr Opin Struct Biol 2020; 61:191-197. [DOI: 10.1016/j.sbi.2020.01.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 12/30/2019] [Accepted: 01/01/2020] [Indexed: 12/15/2022]
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23
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Gahbauer S, Böckmann RA. Comprehensive Characterization of Lipid-Guided G Protein-Coupled Receptor Dimerization. J Phys Chem B 2020; 124:2823-2834. [DOI: 10.1021/acs.jpcb.0c00062] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Stefan Gahbauer
- Computational Biology, Friedrich-Alexander-University Erlangen-Nüremberg, Erlangen, Germany
| | - Rainer A. Böckmann
- Computational Biology, Friedrich-Alexander-University Erlangen-Nüremberg, Erlangen, Germany
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24
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D'Agostino G, García-Cuesta EM, Gomariz RP, Rodríguez-Frade JM, Mellado M. The multilayered complexity of the chemokine receptor system. Biochem Biophys Res Commun 2020; 528:347-358. [PMID: 32145914 DOI: 10.1016/j.bbrc.2020.02.120] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 02/17/2020] [Accepted: 02/20/2020] [Indexed: 01/08/2023]
Abstract
The chemokines receptor family are membrane-expressed class A-specific seven-transmembrane receptors linked to G proteins. Through interaction with the corresponding ligands, the chemokines, they induce a wide variety of cellular responses including cell polarization, movement, immune and inflammatory responses, as well as the prevention of HIV-1 infection. Like a Russian matryoshka doll, the chemokine receptor system is more complex than initially envisaged. This review focuses on the mechanisms that contribute to this dazzling complexity and how they modulate the signaling events triggered by chemokines. The chemokines and their receptors exist as monomers, dimers and oligomers, their expression pattern is highly regulated, and the ligands can bind distinct receptors with similar affinities. The use of novel imaging-based technologies, particularly real-time imaging modalities, has shed new light on the very dynamic conformations that chemokine receptors adopt depending on the cellular context, and that affect chemokine-mediated responses. This complex scenario presents both challenging and exciting opportunities for drug discovery.
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Affiliation(s)
- Gianluca D'Agostino
- Dept. Immunology and Oncology, Centro Nacional de Biotecnología/CSIC, Darwin 3, Campus Cantoblanco, E-28049, Madrid, Spain
| | - Eva M García-Cuesta
- Dept. Immunology and Oncology, Centro Nacional de Biotecnología/CSIC, Darwin 3, Campus Cantoblanco, E-28049, Madrid, Spain
| | - Rosa P Gomariz
- Dept. Cell Biology, Complutense University of Madrid, Research Institute Hospital 12 de Octubre (i+12), E-28041, Madrid, Spain
| | - José Miguel Rodríguez-Frade
- Dept. Immunology and Oncology, Centro Nacional de Biotecnología/CSIC, Darwin 3, Campus Cantoblanco, E-28049, Madrid, Spain
| | - Mario Mellado
- Dept. Immunology and Oncology, Centro Nacional de Biotecnología/CSIC, Darwin 3, Campus Cantoblanco, E-28049, Madrid, Spain.
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25
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Role of cholesterol-mediated effects in GPCR heterodimers. Chem Phys Lipids 2019; 227:104852. [PMID: 31866438 DOI: 10.1016/j.chemphyslip.2019.104852] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 12/16/2019] [Accepted: 12/16/2019] [Indexed: 12/19/2022]
Abstract
G protein-coupled receptors (GPCRs) are transmembrane receptors that mediate a large number of cellular responses. The organization of GPCRs into dimers and higher-order oligomers is known to allow a larger repertoire of downstream signaling events. In this context, a crosstalk between the adenosine and dopamine receptors has been reported, indicating the presence of heterodimers that are functionally relevant. In this paper, we explored the effect of membrane cholesterol on the adenosine2A (A2A) and dopamine D3 (D3) receptors using coarse-grain molecular dynamics simulations. We analyzed cholesterol interaction sites on the A2A receptor and were able to reproduce the sites indicated by crystallography and previous atomistic simulations. We predict novel cholesterol interaction sites on the D3 receptor that could be important in the reported cholesterol sensitivity in receptor function. Further, we analyzed the formation of heterodimers between the two receptors. Our results suggest that membrane cholesterol modulates the relative population of several co-existing heterodimer conformations. Both direct receptor-cholesterol interaction and indirect membrane effects contribute toward the modulation of heterodimer conformations. These results constitute one of the first examples of modulation of GPCR hetero-dimerization by membrane cholesterol, and could prove to be useful in designing better therapeutic strategies.
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26
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Calmet P, Cullin C, Cortès S, Vang M, Caudy N, Baccouch R, Dessolin J, Maamar NT, Lecomte S, Tillier B, Alves ID. Cholesterol impacts chemokine CCR5 receptor ligand-binding activity. FEBS J 2019; 287:2367-2385. [PMID: 31738467 DOI: 10.1111/febs.15145] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 09/27/2019] [Accepted: 11/16/2019] [Indexed: 01/03/2023]
Abstract
The chemokine CCR5 receptor is target of maraviroc, a negative allosteric modulator of CCR5 that blocks the HIV protein gp120 from associating with the receptor, thereby inhibiting virus cellular entry. As noted with other G-protein-coupled receptor family members, the role of the lipid environment in CCR5 signaling remains obscure and very modestly investigated. Controversial literature on the impact of cholesterol (Chol) depletion in HIV infection and CCR5 signaling, including the hypothesis that Chol depletion could inhibit HIV infection, lead us to focus on the understanding of Chol impact in the first stages of receptor activation. To address this aim, the approach chosen was to employ reconstituted model lipid systems of controlled lipid composition containing CCR5 from two distinct expression systems: Pichia pastoris and cell-free expression. The characterization of receptor/ligand interaction in terms of total binding or competition binding assays was independently performed by plasmon waveguide resonance and fluorescence anisotropy, respectively. Maraviroc, a potent receptor antagonist, was the ligand investigated. Additionally, coarse-grained molecular dynamics simulation was employed to investigate Chol impact in the receptor-conformational flexibility and dynamics. Results obtained with receptor produced by different expression systems and using different biophysical approaches clearly demonstrate a considerable impact of Chol in the binding affinity of maraviroc to the receptor and receptor-conformational dynamics. Chol considerably decreases maraviroc binding affinity to the CCR5 receptor. The mechanisms by which this effect occurs seem to involve the adoption of distinct receptor-conformational states with restrained structural dynamics and helical motions in the presence of Chol.
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Affiliation(s)
- Pierre Calmet
- CBMN, UMR 5248 CNRS, University of Bordeaux, Pessac, France
| | | | | | - Maylou Vang
- CBMN, UMR 5248 CNRS, University of Bordeaux, Pessac, France
| | - Nada Caudy
- CBMN, UMR 5248 CNRS, University of Bordeaux, Pessac, France
| | - Rim Baccouch
- CBMN, UMR 5248 CNRS, University of Bordeaux, Pessac, France
| | - Jean Dessolin
- CBMN, UMR 5248 CNRS, University of Bordeaux, Pessac, France
| | | | - Sophie Lecomte
- CBMN, UMR 5248 CNRS, University of Bordeaux, Pessac, France
| | | | - Isabel D Alves
- CBMN, UMR 5248 CNRS, University of Bordeaux, Pessac, France
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27
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Khan AO, White CW, Pike JA, Yule J, Slater A, Hill SJ, Poulter NS, Thomas SG, Morgan NV. Optimised insert design for improved single-molecule imaging and quantification through CRISPR-Cas9 mediated knock-in. Sci Rep 2019; 9:14219. [PMID: 31578415 PMCID: PMC6775134 DOI: 10.1038/s41598-019-50733-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 09/18/2019] [Indexed: 12/29/2022] Open
Abstract
The use of CRISPR-Cas9 genome editing to introduce endogenously expressed tags has the potential to address a number of the classical limitations of single molecule localisation microscopy. In this work we present the first systematic comparison of inserts introduced through CRISPR-knock in, with the aim of optimising this approach for single molecule imaging. We show that more highly monomeric and codon optimised variants of mEos result in improved expression at the TubA1B locus, despite the use of identical guides, homology templates, and selection strategies. We apply this approach to target the G protein-coupled receptor (GPCR) CXCR4 and show a further insert dependent effect on expression and protein function. Finally, we show that compared to over-expressed CXCR4, endogenously labelled samples allow for accurate single molecule quantification on ligand treatment. This suggests that despite the complications evident in CRISPR mediated labelling, the development of CRISPR-PALM has substantial quantitative benefits.
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Affiliation(s)
- Abdullah O Khan
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK.
| | - Carl W White
- Centre of Membrane and Protein and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK
- Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research, Nedlands, WA, Australia
- Centre for Medical Research, The University of Western Australia, Crawley, WA, Australia
| | - Jeremy A Pike
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
- Centre of Membrane and Protein and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK
| | - Jack Yule
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
- Centre of Membrane and Protein and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK
| | - Alexandre Slater
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - Stephen J Hill
- Centre of Membrane and Protein and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK
| | - Natalie S Poulter
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
- Centre of Membrane and Protein and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK
| | - Steven G Thomas
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK.
- Centre of Membrane and Protein and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK.
| | - Neil V Morgan
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK.
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28
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Marrink SJ, Corradi V, Souza PC, Ingólfsson HI, Tieleman DP, Sansom MS. Computational Modeling of Realistic Cell Membranes. Chem Rev 2019; 119:6184-6226. [PMID: 30623647 PMCID: PMC6509646 DOI: 10.1021/acs.chemrev.8b00460] [Citation(s) in RCA: 410] [Impact Index Per Article: 82.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Indexed: 12/15/2022]
Abstract
Cell membranes contain a large variety of lipid types and are crowded with proteins, endowing them with the plasticity needed to fulfill their key roles in cell functioning. The compositional complexity of cellular membranes gives rise to a heterogeneous lateral organization, which is still poorly understood. Computational models, in particular molecular dynamics simulations and related techniques, have provided important insight into the organizational principles of cell membranes over the past decades. Now, we are witnessing a transition from simulations of simpler membrane models to multicomponent systems, culminating in realistic models of an increasing variety of cell types and organelles. Here, we review the state of the art in the field of realistic membrane simulations and discuss the current limitations and challenges ahead.
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Affiliation(s)
- Siewert J. Marrink
- Groningen
Biomolecular Sciences and Biotechnology Institute & Zernike Institute
for Advanced Materials, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Valentina Corradi
- Centre
for Molecular Simulation and Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
| | - Paulo C.T. Souza
- Groningen
Biomolecular Sciences and Biotechnology Institute & Zernike Institute
for Advanced Materials, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Helgi I. Ingólfsson
- Biosciences
and Biotechnology Division, Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States
| | - D. Peter Tieleman
- Centre
for Molecular Simulation and Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
| | - Mark S.P. Sansom
- Department
of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, U.K.
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29
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Muller MP, Jiang T, Sun C, Lihan M, Pant S, Mahinthichaichan P, Trifan A, Tajkhorshid E. Characterization of Lipid-Protein Interactions and Lipid-Mediated Modulation of Membrane Protein Function through Molecular Simulation. Chem Rev 2019; 119:6086-6161. [PMID: 30978005 PMCID: PMC6506392 DOI: 10.1021/acs.chemrev.8b00608] [Citation(s) in RCA: 133] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The cellular membrane constitutes one of the most fundamental compartments of a living cell, where key processes such as selective transport of material and exchange of information between the cell and its environment are mediated by proteins that are closely associated with the membrane. The heterogeneity of lipid composition of biological membranes and the effect of lipid molecules on the structure, dynamics, and function of membrane proteins are now widely recognized. Characterization of these functionally important lipid-protein interactions with experimental techniques is however still prohibitively challenging. Molecular dynamics (MD) simulations offer a powerful complementary approach with sufficient temporal and spatial resolutions to gain atomic-level structural information and energetics on lipid-protein interactions. In this review, we aim to provide a broad survey of MD simulations focusing on exploring lipid-protein interactions and characterizing lipid-modulated protein structure and dynamics that have been successful in providing novel insight into the mechanism of membrane protein function.
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Affiliation(s)
- Melanie P. Muller
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- Center for Biophysics and Quantitative Biology
- College of Medicine
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Tao Jiang
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- Center for Biophysics and Quantitative Biology
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Chang Sun
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Muyun Lihan
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- Center for Biophysics and Quantitative Biology
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Shashank Pant
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- Center for Biophysics and Quantitative Biology
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Paween Mahinthichaichan
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Anda Trifan
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- Center for Biophysics and Quantitative Biology
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Emad Tajkhorshid
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- Center for Biophysics and Quantitative Biology
- College of Medicine
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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30
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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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31
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Friess MD, Pluhackova K, Böckmann RA. Structural Model of the mIgM B-Cell Receptor Transmembrane Domain From Self-Association Molecular Dynamics Simulations. Front Immunol 2018; 9:2947. [PMID: 30619307 PMCID: PMC6304377 DOI: 10.3389/fimmu.2018.02947] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 11/30/2018] [Indexed: 12/11/2022] Open
Abstract
Antigen binding to B-cell antigen receptors (BCRs) followed by signaling initiates the humoral immune response. The signaling is intimately coupled to nanoclustering of BCRs and their sorting to specific membrane domains, a process that is ruled by interactions between the BCR transmembrane domain and lipids. While the structure of the extracellular domains of BCRs has been resolved, little is known about the configuration of the constituting four immunoglobulin domains spanning the membrane. Here, we modeled the structure of the transmembrane (TM) domain of the IgM B-cell receptor using self-assembly coarse-grained molecular dynamics simulations. The obtained quaternary structure was validated against available experimental data and atomistic simulations. The IgM-BCR-TM domain configuration shows a 1:1 stoichiometry between the homodimeric membrane-bound domain of IgM (mIgM) and a Ig-α/Ig-β heterodimer. The mIgM homodimer is based on an asymmetric association of two mIgM domains. We show that a specific site of the Ig-α/Ig-β heterodimer is responsible for the association of IgM-BCRs with lipid rafts. Our results further suggest that this site is blocked in small-sized IgM-BCR clusters. The BCR TM structure provides a molecular basis for the previously suggested dissociation activation model of B-cell receptors. Self-assembly molecular dynamics simulations at the coarse-grained scale here proved as a versatile tool in the study of receptor complexes.
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Affiliation(s)
- Mario D Friess
- Department of Biology, Computational Biology, Friedrich-Alexander University of Erlangen-Nürnberg, Erlangen, Germany
| | - Kristyna Pluhackova
- Department of Biology, Computational Biology, Friedrich-Alexander University of Erlangen-Nürnberg, Erlangen, Germany
| | - Rainer A Böckmann
- Department of Biology, Computational Biology, Friedrich-Alexander University of Erlangen-Nürnberg, Erlangen, Germany
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32
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GPCR homo-oligomerization. Curr Opin Cell Biol 2018; 57:40-47. [PMID: 30453145 PMCID: PMC7083226 DOI: 10.1016/j.ceb.2018.10.007] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 10/22/2018] [Accepted: 10/23/2018] [Indexed: 12/21/2022]
Abstract
G protein-coupled receptors (GPCRs) are an extensive class of trans-plasma membrane proteins that function to regulate a wide range of physiological functions. Despite a general perception that GPCRs exist as monomers an extensive literature has examined whether GPCRs can also form dimers and even higher-order oligomers, and if such organization influences various aspects of GPCR function, including cellular trafficking, ligand binding, G protein coupling and signalling. Here we focus on recent studies that employ approaches ranging from computational methods to single molecule tracking and both quantal brightness and fluorescence fluctuation measurements to assess the organization, stability and potential functional significance of dimers and oligomers within the class A, rhodopsin-like GPCR family.
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