1
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Sahoo AR, Souza PCT, Meng Z, Buck M. Transmembrane dimers of type 1 receptors sample alternate configurations: MD simulations using coarse grain Martini 3 versus AlphaFold2 Multimer. Structure 2023; 31:735-745.e2. [PMID: 37075749 PMCID: PMC10833135 DOI: 10.1016/j.str.2023.03.014] [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: 10/06/2022] [Revised: 02/07/2023] [Accepted: 03/23/2023] [Indexed: 04/21/2023]
Abstract
Structures and dynamics of transmembrane (TM) receptor regions are key to understanding their signaling mechanism across membranes. Here we examine configurations of TM region dimers, assembled using the recent Martini 3 force field for coarse-grain (CG) molecular dynamics simulations. At first glance, our results show only a reasonable agreement with ab initio predictions using PREDDIMER and AlphaFold2 Multimer and with nuclear magnetic resonance (NMR)-derived structures. 5 of 11 CG TM structures are similar to the NMR structures (within <3.5 Å root-mean-square deviation [RMSD]) compared with 10 and 9 using PREDDIMER and AlphaFold2, respectively (with 8 structures of the later within 1.5 Å). Surprisingly, AlphaFold2 predictions are closer to NMR structures when the 2001 instead of 2020 database is used for training. The CG simulations reveal that alternative configurations of TM dimers readily interconvert with a predominant population. The implications for transmembrane signaling are discussed, including for the development of peptide-based pharmaceuticals.
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Affiliation(s)
- Amita R Sahoo
- Department of Physiology and Biophysics, Case Western Reserve University, School of Medicine, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Paulo C T Souza
- Molecular Microbiology and Structural Biochemistry (MMSB, UMR 5086), CNRS & University of Lyon, 7 Passage du Vercors, 69007 Lyon, France
| | - Zhiyuan Meng
- Department of Physiology and Biophysics, Case Western Reserve University, School of Medicine, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Matthias Buck
- Department of Physiology and Biophysics, Case Western Reserve University, School of Medicine, 10900 Euclid Avenue, Cleveland, OH 44106, USA.
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2
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Keller F, Alavizargar A, Wedlich-Söldner R, Heuer A. The impact of bilayer composition on the dimerization properties of the Slg1 stress sensor TMD from a multiscale analysis. Phys Chem Chem Phys 2023; 25:1299-1309. [PMID: 36533706 DOI: 10.1039/d2cp03497b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The impact of mutual interactions between the transmembrane domains of membrane proteins and lipids on bilayer properties has gained major attraction. Most simulation studies of membranes rely on the Martini force field, which has proven extremely helpful in providing molecular insights into realistic systems. Accordingly, an evaluation of the accuracy of the Martini force field is crucial to be able to correctly interpret the reported data. In this study, we combine atomistic and coarse-grained Martini simulations to investigate the properties of transmembrane domains (TMDs) in a model yeast membrane. The results show that the TMD binding state (monomeric and dimeric with positive or negative crossing angle) and the membrane composition significantly influence the properties around the TMDs and change TMD-TMD and TMD-lipid affinities. Furthermore, ergosterol (ERG) exhibits a strong affinity to TMD dimers. Importantly, the right-handed TMD dimer configuration is stabilized via TMD-TMD contacts by the addition of asymmetric anionic phosphatidylserine (PS). The coarse-grained simulations corroborate many of these findings, with two notable exceptions: a systematic overestimation of TMD-ERG interaction and lack of stabilization of the right-handed TMD dimers with the addition of PS.
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Affiliation(s)
- Fabian Keller
- Institut für Physikalische Chemie, Corrensstraße 28, Münster, Germany.
| | | | | | - Andreas Heuer
- Institut für Physikalische Chemie, Corrensstraße 28, Münster, Germany.
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3
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Díaz Vázquez G, Cui Q, Senes A. Thermodynamic analysis of the GAS right transmembrane motif supports energetic model of dimerization. Biophys J 2023; 122:143-155. [PMID: 36371634 PMCID: PMC9822795 DOI: 10.1016/j.bpj.2022.11.018] [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: 07/12/2022] [Revised: 09/12/2022] [Accepted: 11/09/2022] [Indexed: 11/13/2022] Open
Abstract
The GASright motif, best known as the fold of the glycophorin A transmembrane dimer, is one of the most common dimerization motifs in membrane proteins, characterized by its hallmark GxxxG-like sequence motifs (GxxxG, AxxxG, GxxxS, and similar). Structurally, GASright displays a right-handed crossing angle and short interhelical distance. Contact between the helical backbones favors the formation of networks of weak hydrogen bonds between Cα-H carbon donors and carbonyl acceptors on opposing helices (Cα-H···O=C). To understand the factors that modulate the stability of GASright, we previously presented a computational and experimental structure-based analysis of 26 predicted dimers. We found that the contributions of van der Waals packing and Cα-H hydrogen bonding to stability, as inferred from the structural models, correlated well with relative dimerization propensities estimated experimentally with the in vivo assay TOXCAT. Here we test this model with a quantitative thermodynamic analysis. We used Förster resonance energy transfer (FRET) to determine the free energy of dimerization of a representative subset of seven of the 26 original TOXCAT dimers using FRET. To overcome the technical issue arising from limited sampling of the dimerization isotherm, we introduced a globally fitting strategy across a set of constructs comprising a wide range of stabilities. This strategy yielded precise thermodynamic data that show strikingly good agreement between the original propensities and ΔG° of association in detergent, suggesting that TOXCAT is a thermodynamically driven process. From the correlation between TOXCAT and thermodynamic stability, the predicted free energy for all the 26 GASright dimers was calculated. These energies correlate with the in silico ΔE scores of dimerization that were computed on the basis of their predicted structure. These findings corroborate our original model with quantitative thermodynamic evidence, strengthening the hypothesis that van der Waals and Cα-H hydrogen bond interactions are the key modulators of GASright stability.
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Affiliation(s)
- Gladys Díaz Vázquez
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin; Biophysics Graduate Program, University of Wisconsin-Madison, Madison, Wisconsin
| | - Qiang Cui
- Department of Chemistry, Boston University, Boston, Massachusetts
| | - Alessandro Senes
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin.
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4
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Jackson V, Hermann J, Tynan CJ, Rolfe DJ, Corey RA, Duncan AL, Noriega M, Chu A, Kalli AC, Jones EY, Sansom MSP, Martin-Fernandez ML, Seiradake E, Chavent M. The guidance and adhesion protein FLRT2 dimerizes in cis via dual small-X 3-small transmembrane motifs. Structure 2022; 30:1354-1365.e5. [PMID: 35700726 DOI: 10.1016/j.str.2022.05.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 03/03/2022] [Accepted: 05/18/2022] [Indexed: 10/18/2022]
Abstract
Fibronectin Leucine-rich Repeat Transmembrane (FLRT 1-3) proteins are a family of broadly expressed single-spanning transmembrane receptors that play key roles in development. Their extracellular domains mediate homotypic cell-cell adhesion and heterotypic protein interactions with other receptors to regulate cell adhesion and guidance. These in trans FLRT interactions determine the formation of signaling complexes of varying complexity and function. Whether FLRTs also interact at the surface of the same cell, in cis, remains unknown. Here, molecular dynamics simulations reveal two dimerization motifs in the FLRT2 transmembrane helix. Single particle tracking experiments show that these Small-X3-Small motifs synergize with a third dimerization motif encoded in the extracellular domain to permit the cis association and co-diffusion patterns of FLRT2 receptors on cells. These results may point to a competitive switching mechanism between in cis and in trans interactions, which suggests that homotypic FLRT interaction mirrors the functionalities of classic adhesion molecules.
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Affiliation(s)
- Verity Jackson
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 5RJ, UK
| | - Julia Hermann
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 5RJ, UK
| | - Christopher J Tynan
- Central Laser Facility, Research Complex at Harwell, Science and Technology Facilities Council, Harwell Campus, Didcot, OX11 0FA, UK
| | - Daniel J Rolfe
- Central Laser Facility, Research Complex at Harwell, Science and Technology Facilities Council, Harwell Campus, Didcot, OX11 0FA, UK
| | - Robin A Corey
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 5RJ, UK
| | - Anna L Duncan
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 5RJ, UK
| | - Maxime Noriega
- Institut de Pharmacologie et Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, 205 route de Narbonne, 31400 Toulouse, France
| | - Amy Chu
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 5RJ, UK
| | - Antreas C Kalli
- Leeds Institute of Cardiovascular and Metabolic Medicine, School of Medicine and Astbury Center for Structural Molecular Biology, University of Leeds, Leeds, LS2 9NL, UK
| | - E Yvonne Jones
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, OX3 7BN, UK
| | - Mark S P Sansom
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 5RJ, UK
| | - Marisa L Martin-Fernandez
- Central Laser Facility, Research Complex at Harwell, Science and Technology Facilities Council, Harwell Campus, Didcot, OX11 0FA, UK.
| | - Elena Seiradake
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 5RJ, UK.
| | - Matthieu Chavent
- Institut de Pharmacologie et Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, 205 route de Narbonne, 31400 Toulouse, France.
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5
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You X, Thakur N, Ray AP, Eddy MT, Baiz CR. A comparative study of interfacial environments in lipid nanodiscs and vesicles. BIOPHYSICAL REPORTS 2022; 2. [PMID: 36176716 PMCID: PMC9518727 DOI: 10.1016/j.bpr.2022.100066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Membrane protein conformations and dynamics are driven by the protein-lipid interactions occurring within the local environment of the membrane. These environments remain challenging to accurately capture in structural and biophysical experiments using bilayers. Consequently, there is an increasing need for realistic cell-membrane mimetics for in vitro studies. Lipid nanodiscs provide certain advantages over vesicles for membrane protein studies. Nanodiscs are increasingly used for structural and spectroscopic characterization of membrane proteins. Despite the common use of nanodiscs, the interfacial environments of lipids confined to a ~10-nm diameter area have remained relatively underexplored. Here, we use ultrafast two-dimensional infrared spectroscopy and temperature-dependent infrared absorption measurements of the ester carbonyls to compare the interfacial hydrogen bond structure and dynamics in lipid nanodiscs of varying lipid compositions and sizes with ~100-nm vesicles. We examine the effects of lipid composition and nanodisc size. We found that nanodiscs and vesicles share largely similar lipid-water H-bond environments and interfacial dynamics. Differences in measured enthalpies of H-bonding suggest that H-bond dynamics in nanodiscs are modulated by the interaction between the annular lipids and the scaffold protein.
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6
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Sofińska K, Lupa D, Chachaj-Brekiesz A, Czaja M, Kobierski J, Seweryn S, Skirlińska-Nosek K, Szymonski M, Wilkosz N, Wnętrzak A, Lipiec E. Revealing local molecular distribution, orientation, phase separation, and formation of domains in artificial lipid layers: Towards comprehensive characterization of biological membranes. Adv Colloid Interface Sci 2022; 301:102614. [PMID: 35190313 DOI: 10.1016/j.cis.2022.102614] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 01/28/2022] [Accepted: 02/01/2022] [Indexed: 01/01/2023]
Abstract
Lipids, together with molecules such as DNA and proteins, are one of the most relevant systems responsible for the existence of life. Selected lipids are able to assembly into various organized structures, such as lipid membranes. The unique properties of lipid membranes determine their complex functions, not only to separate biological environments, but also to participate in regulatory functions, absorption of nutrients, cell-cell communication, endocytosis, cell signaling, and many others. Despite numerous scientific efforts, still little is known about the reason underlying the variability within lipid membranes, and its biochemical significance. In this review, we discuss the structural complexity of lipid membranes, as well as the importance to simplify studied systems in order to understand phenomena occurring in natural, complex membranes. Such systems require a model interface to be analyzed. Therefore, here we focused on analytical studies of artificial systems at various interfaces. The molecular structure of lipid membranes, specifically the nanometric thickens of molecular bilayer, limits in a major extent the choice of highly sensitive methods suitable to study such structures. Therefore, we focused on methods that combine high sensitivity, and/or chemical selectivity, and/or nanometric spatial resolution, such as atomic force microscopy, nanospectroscopy (tip-enhanced Raman spectroscopy, infrared nanospectroscopy), phase modulation infrared reflection-absorption spectroscopy, sum-frequency generation spectroscopy. We summarized experimental and theoretical approaches providing information about molecular structure and composition, lipid spatial distribution (phase separation), organization (domain shape, molecular orientation) of lipid membranes, and real-time visualization of the influence of various molecules (proteins, drugs) on their integrity. An integral part of this review discusses the latest achievements in the field of lipid layer-based biosensors.
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7
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Stopp M, Steinmetz PA, Unden G. Properties of transmembrane helix TM1 of the DcuS sensor kinase of Escherichia coli, the stator for TM2 piston signaling. Biol Chem 2021; 402:1239-1246. [PMID: 34355547 DOI: 10.1515/hsz-2021-0254] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Accepted: 07/05/2021] [Indexed: 11/15/2022]
Abstract
The sensor kinase DcuS of Escherichia coli perceives extracellular fumarate by a periplasmic PASP sensor domain. Transmembrane (TM) helix TM2, present as TM2-TM2' homo-dimer, transmits fumarate activation in a piston-slide across the membrane. The second TM helix of DcuS, TM1, is known to lack piston movement. Structural and functional properties of TM1 were analyzed. Oxidative Cys-crosslinking (CL) revealed homo-dimerization of TM1 over the complete membrane, but only the central part showed α-helical +3/+4 spacing of the CL maxima. The GALLEX bacterial two-hybrid system indicates TM1/TM1' interaction, and the presence of a TM1-TM1' homo-dimer is suggested. The peripheral TM1 regions presented CL in a spacing atypical for α-helical arrangement. On the periplasmic side the deviation extended over 11 AA residues (V32-S42) between the α-helical part of TM1 and the onset of PASP. In the V32-S42 region, CL efficiency decreased in the presence of fumarate. Therefore, TM1 exists as a homo-dimer with α-helical arrangement in the central membrane region, and non-α-helical arrangement in the connector to PASP. The fumarate induced structural response in the V32-S42 region is suggested to represent a structural adaptation to the shift of TM2 in the TM1-TM1'/TM2-TM2' four-helical bundle.
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Affiliation(s)
- Marius Stopp
- Microbiology and Wine Research, Institute for Molecular Physiology, Johannes Gutenberg University Mainz, BZ II, Hanns-Dieter-Hüsch-Weg 17, D-55128 Mainz, Germany
| | - Philipp A Steinmetz
- Microbiology and Wine Research, Institute for Molecular Physiology, Johannes Gutenberg University Mainz, BZ II, Hanns-Dieter-Hüsch-Weg 17, D-55128 Mainz, Germany
| | - Gottfried Unden
- Microbiology and Wine Research, Institute for Molecular Physiology, Johannes Gutenberg University Mainz, BZ II, Hanns-Dieter-Hüsch-Weg 17, D-55128 Mainz, Germany
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8
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Small Residues Inhibit Homo-Dimerization of the Human Carbonic Anhydrase XII Transmembrane Domain. MEMBRANES 2021; 11:membranes11070512. [PMID: 34357162 PMCID: PMC8307134 DOI: 10.3390/membranes11070512] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 06/17/2021] [Accepted: 06/29/2021] [Indexed: 12/03/2022]
Abstract
Amino acids with small side chains and motifs of small residues in a distance of four are rather abundant in human single-span transmembrane helices. While interaction of such helices appears to be common, the role of the small residues in mediating and/or stabilizing transmembrane helix oligomers remains mostly elusive. Yet, the mere existence of (small)xxx(small) motifs in transmembrane helices is frequently used to model dimeric TM helix structures. The single transmembrane helix of the human carbonic anhydrases XII contains a large number of amino acids with small side chains, and critical involvement of these small amino acids in dimerization of the transmembrane domain has been suggested. Using the GALLEX assay, we show here that the transmembrane domain indeed forms a strong transmembrane helix oligomer within a biological membrane. However, single or multiple mutations of small residue(s) to isoleucine almost always increased, rather than decreased, the interaction propensities. Reduction of helix flexibility and of protein–lipid contacts caused by a reduced lipid accessible surface area likely results in stabilization of helix–helix interactions within the membrane.
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9
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Nakano M, Hanashima S, Hara T, Kabayama K, Asahina Y, Hojo H, Komura N, Ando H, Nyholm TKM, Slotte JP, Murata M. FRET detects lateral interaction between transmembrane domain of EGF receptor and ganglioside GM3 in lipid bilayers. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2021; 1863:183623. [PMID: 33933428 DOI: 10.1016/j.bbamem.2021.183623] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 04/03/2021] [Accepted: 04/05/2021] [Indexed: 12/16/2022]
Abstract
Ganglioside GM3 in the plasma membranes suppresses cell growth by preventing the autophosphorylation of the epidermal growth factor receptor (EGFR). Biological studies have suggested that GM3 interacts with the transmembrane segment of EGFR. Further biophysical experiments are particularly important for quantitative evaluation of the peptide-glycolipid interplay in bilayer membranes using a simple reconstituted system. To examine these interactions in this way, we synthesized the transmembrane segment of EGFR bearing a nitrobenzoxadiazole fluorophore (NBD-TM) at the N-terminus. The affinity between EGFR and GM3 was evaluated based on Förster resonance energy transfer (FRET) between NBD-TM and ATTO594-labeled GM3 in bilayers where their non-specific interaction due to lateral proximity was subtracted by using NBD-labeled phospholipid. This method for selectively detecting the specific lipid-peptide interactions in model lipid bilayers disclosed that the lateral interaction between GM3 and the transmembrane segment of EGFR plays a certain role in disturbing the formation of active EGFR dimers.
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Affiliation(s)
- Mikito Nakano
- Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka 560-0043, Japan
| | - Shinya Hanashima
- Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka 560-0043, Japan.
| | - Toshiaki Hara
- Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka 560-0043, Japan; ERATO, Lipid Active Structure Project, Japan Science and Technology Agency, Graduate School of Science, Osaka University, Osaka 560-0043, Japan
| | - Kazuya Kabayama
- Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka 560-0043, Japan
| | - Yuya Asahina
- Institute for Protein Research, Osaka University, Yamadaoka 3-2, Suita 565-0871, Japan
| | - Hironobu Hojo
- Institute for Protein Research, Osaka University, Yamadaoka 3-2, Suita 565-0871, Japan
| | - Naoko Komura
- Center for Highly Advanced Integration of Nano and Life Sciences (G-CHAIN), Gifu University, Gifu 501-1193, Japan; Institute for Glyco-core Research (iGCORE), Gifu University, Gifu 501-1193, Japan
| | - Hiromune Ando
- Center for Highly Advanced Integration of Nano and Life Sciences (G-CHAIN), Gifu University, Gifu 501-1193, Japan; Institute for Glyco-core Research (iGCORE), Gifu University, Gifu 501-1193, Japan
| | - Thomas K M Nyholm
- Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, 20520 Turku, Finland
| | - J Peter Slotte
- Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, 20520 Turku, Finland
| | - Michio Murata
- Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka 560-0043, Japan; ERATO, Lipid Active Structure Project, Japan Science and Technology Agency, Graduate School of Science, Osaka University, Osaka 560-0043, Japan.
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10
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Beytur S. Marker residue types at the structural regions of transmembrane alpha-helical and beta-barrel interfaces. Proteins 2021; 89:1145-1157. [PMID: 33890696 DOI: 10.1002/prot.26087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 04/13/2021] [Accepted: 04/16/2021] [Indexed: 11/11/2022]
Abstract
Membrane proteins play a variety of biological functions to the survival of organisms and functionalities of these proteins are often due to their homo- or hetero-complexation. Encoded by ~30% of the genome in most organisms, they represent the target of over half of nowadays drugs. Spanning the entirety of the cell membrane, transmembrane proteins are the most common type of membrane proteins and can be classified by secondary structures: alpha-helical and beta-barrel structures. Protein-protein interaction (PPI) have been widely studied for globular proteins and many computational tools are available for predicting PPI sites and construct models of complexes. Here, the structural regions of a non-redundant set of 232 alpha-helical and 37 beta-barrel transmembrane complexes and their interfaces are analyzed. Using the residue composition, frequency and propensity, this study brings the light on the marker residue types located at the structural regions of alpha-helical and beta-barrel transmembrane homomeric protein complexes and of their interfaces. This study also shows the necessity to relate the frequency to the composition into a ratio for immediately figuring out residue types presenting high frequencies at the interface and/or at one of its structural regions despite being a minor contributor compared to other residue types to that location's residue composition.
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Affiliation(s)
- Sercan Beytur
- Faculty of Engineering and Natural Sciences, Department of Bioinformatics and Genetics, Kadir Has University, Istanbul, Turkey
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11
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SMIM1, carrier of the Vel blood group, is a tail-anchored transmembrane protein and readily forms homodimers in a cell-free system. Biosci Rep 2021; 40:222673. [PMID: 32301496 PMCID: PMC7953501 DOI: 10.1042/bsr20200318] [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: 02/05/2020] [Revised: 03/17/2020] [Accepted: 03/24/2020] [Indexed: 01/05/2023] Open
Abstract
Antibodies to the Vel blood group antigen can cause adverse hemolytic reactions unless Vel-negative blood units are transfused. Since the genetic background of Vel-negativity was discovered in 2013, DNA-based typing of the 17-bp deletion causing the phenotype has facilitated identification of Vel-negative blood donors. SMIM1, the gene underlying Vel, encodes a 78-amino acid erythroid transmembrane protein of unknown function. The transmembrane orientation of SMIM1 has been debated since experimental data supported both the N- and C-termini being extracellular. Likewise, computational predictions of its orientation were divided and potential alternatives such as monotopic or dual-topology have been discussed but not investigated. We used a cell-free system to explore the topology of SMIM1 when synthesized in the endoplasmic reticulum (ER). SMIM1 was tagged with an opsin-derived N-glycosylation reporter at either the N- or C-terminus and synthesized in vitro using rabbit reticulocyte lysate supplemented with canine pancreatic microsomes as a source of ER membrane. SMIM1 topology was then determined by assessing the N-glycosylation of its N- or C-terminal tags. Complementary experiments were carried out by expressing the same SMIM1 variants in HEK293T/17 cells and establishing their membrane orientation by immunoblotting and flow cytometry. Our data consistently indicate that SMIM1 has its short C-terminus located extracellularly and that it most likely belongs to the tail-anchored class of membrane proteins with the bulk of the polypeptide located in the cytoplasm. Having established its membrane orientation in an independent model system, future work can now focus on functional aspects of SMIM1 as a potential regulator of erythropoiesis.
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Pawar AB, Sengupta D. Role of Cholesterol in Transmembrane Dimerization of the ErbB2 Growth Factor Receptor. J Membr Biol 2021; 254:301-310. [PMID: 33506276 DOI: 10.1007/s00232-021-00168-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 01/05/2021] [Indexed: 11/28/2022]
Abstract
The association of ErbB2 growth factor receptors is critical for cell growth and potentiates tumor proliferation in several cancer types. An important aspect in ErbB2 association is the role of lipids such as cholesterol, especially since their metabolism is often reprogrammed in cancer cells. Here, we have coupled metadynamics with coarse-grain simulations to identify cholesterol effects in the transmembrane dimerization of ErbB2 receptors. Overall, cholesterol interactions are observed with the receptor that directly tunes the association energetics. Several dimer conformations are identified both in the presence and absence of cholesterol, although the dimer regime appears to be more favorable in the presence of cholesterol. We observe an overall modulation of the underlying energy profile and the symmetric active and inactive conformational states are not distinguished in the presence of cholesterol. We show that cholesterol binds to the receptor transmembrane domain at a site (CRAC motif) that overlaps with the dimer interface (SmXXXSm motif). The competition between the transmembrane interactions and cholesterol interactions decides the final conformational landscape. Our work is an important step toward characterizing cholesterol effects in ErbB2 membrane receptor function.
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Affiliation(s)
- Aiswarya B Pawar
- CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune, 411008, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, 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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13
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Stopp M, Steinmetz PA, Schubert C, Griesinger C, Schneider D, Unden G. Transmembrane signaling and cytoplasmic signal conversion by dimeric transmembrane helix 2 and a linker domain of the DcuS sensor kinase. J Biol Chem 2020; 296:100148. [PMID: 33277358 PMCID: PMC7857512 DOI: 10.1074/jbc.ra120.015999] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 11/30/2020] [Accepted: 12/04/2020] [Indexed: 01/16/2023] Open
Abstract
Transmembrane (TM) signaling is a key process of membrane-bound sensor kinases. The C4-dicarboxylate (fumarate) responsive sensor kinase DcuS of Escherichia coli is anchored by TM helices TM1 and TM2 in the membrane. Signal transmission across the membrane relies on the piston-type movement of the periplasmic part of TM2. To define the role of TM2 in TM signaling, we use oxidative Cys cross-linking to demonstrate that TM2 extends over the full distance of the membrane and forms a stable TM homodimer in both the inactive and fumarate-activated state of DcuS. An S186xxxGxxxG194 motif is required for the stability and function of the TM2 homodimer. The TM2 helix further extends on the periplasmic side into the α6-helix of the sensory PASP domain and on the cytoplasmic side into the α1-helix of PASC. PASC has to transmit the signal to the C-terminal kinase domain. A helical linker on the cytoplasmic side connecting TM2 with PASC contains an LxxxLxxxL sequence. The dimeric state of the linker was relieved during fumarate activation of DcuS, indicating structural rearrangements in the linker. Thus, DcuS contains a long α-helical structure reaching from the sensory PASP (α6) domain across the membrane to α1(PASC). Taken together, the results suggest piston-type TM signaling by the TM2 homodimer from PASP across the full TM region, whereas the fumarate-destabilized linker dimer converts the signal on the cytoplasmic side for PASC and kinase regulation.
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Affiliation(s)
- Marius Stopp
- Microbiology and Wine Research, Institute for Molecular Physiology, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Philipp Aloysius Steinmetz
- Microbiology and Wine Research, Institute for Molecular Physiology, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Christopher Schubert
- Microbiology and Wine Research, Institute for Molecular Physiology, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Christian Griesinger
- Department of NMR-based Structural Biology, Max Planck Institute for Biophysical Chemistry, Gottingen, Germany
| | - Dirk Schneider
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Gottfried Unden
- Microbiology and Wine Research, Institute for Molecular Physiology, Johannes Gutenberg University Mainz, Mainz, Germany.
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14
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The Interplay among Subunit Composition, Cardiolipin Content, and Aggregation State of Bovine Heart Cytochrome c Oxidase. Cells 2020; 9:cells9122588. [PMID: 33287231 PMCID: PMC7761698 DOI: 10.3390/cells9122588] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 11/24/2020] [Accepted: 12/01/2020] [Indexed: 02/07/2023] Open
Abstract
Mitochondrial cytochrome c oxidase (CcO) is a multisubunit integral membrane complex consisting of 13 dissimilar subunits, as well as three to four tightly bound molecules of cardiolipin (CL). The monomeric unit of CcO is able to form a dimer and participate in the formation of supercomplexes in the inner mitochondrial membrane. The structural and functional integrity of the enzyme is crucially dependent on the full subunit complement and the presence of unperturbed bound CL. A direct consequence of subunit loss, CL removal, or its oxidative modification is the destabilization of the quaternary structure, loss of the activity, and the inability to dimerize. Thus, the intimate interplay between individual components of the complex is imperative for regulation of the CcO aggregation state. While it appears that the aggregation state of CcO might affect its conformational stability, the functional role of the aggregation remains unclear as both monomeric and dimeric forms of CcO seem to be fully active. Here, we review the current status of our knowledge with regard to the role of dimerization in the function and stability of CcO and factors, such as subunit composition, amphiphilic environment represented by phospholipids/detergents, and posttranslational modifications that play a role in the regulation of the CcO aggregation state.
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15
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Leveraging a gain-of-function allele of Caenorhabditis elegans paqr-1 to elucidate membrane homeostasis by PAQR proteins. PLoS Genet 2020; 16:e1008975. [PMID: 32750056 PMCID: PMC7428288 DOI: 10.1371/journal.pgen.1008975] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 08/14/2020] [Accepted: 07/01/2020] [Indexed: 12/12/2022] Open
Abstract
The C. elegans proteins PAQR-2 (a homolog of the human seven-transmembrane domain AdipoR1 and AdipoR2 proteins) and IGLR-2 (a homolog of the mammalian LRIG proteins characterized by a single transmembrane domain and the presence of immunoglobulin domains and leucine-rich repeats in their extracellular portion) form a complex that protects against plasma membrane rigidification by promoting the expression of fatty acid desaturases and the incorporation of polyunsaturated fatty acids into phospholipids, hence increasing membrane fluidity. In the present study, we leveraged a novel gain-of-function allele of PAQR-1, a PAQR-2 paralog, to carry out structure-function studies. We found that the transmembrane domains of PAQR-2 are responsible for its functional requirement for IGLR-2, that PAQR-1 does not require IGLR-2 but acts via the same pathway as PAQR-2, and that the divergent N-terminal cytoplasmic domains of the PAQR-1 and PAQR-2 proteins serve a regulatory function and may regulate access to the catalytic site of these proteins. We also show that overexpression of human AdipoR1 or AdipoR2 alone is sufficient to confer increased palmitic acid resistance in HEK293 cells, and thus act in a manner analogous to the PAQR-1 gain-of-function allele.
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16
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Gopal SM, Pawar AB, Wassenaar TA, Sengupta D. Lipid-dependent conformational landscape of the ErbB2 growth factor receptor dimers. Chem Phys Lipids 2020; 230:104911. [PMID: 32353357 DOI: 10.1016/j.chemphyslip.2020.104911] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 03/04/2020] [Accepted: 03/27/2020] [Indexed: 01/31/2023]
Abstract
Altered lipid metabolism has been linked to cancer development and progression. Several roles have been attributed to the increased saturation and length of lipid acyl tails observed in tumors, but its effect on signaling receptors is still emerging. In this work, we have analyzed the lipid dependence of the ErbB2 growth factor receptor dimerization that plays an important role in the pathogenesis of breast cancer. We have performed coarse-grain ensemble molecular dynamics simulations to comprehensively sample the ErbB2 monomer-dimer association. Our results indicate a dynamic dimer state with a complex conformational landscape that is modulated with increasing lipid tail length. We resolve the native N-terminal "active" and C-terminal "inactive" conformations in all membrane compositions. However, the relative population of the N-terminal and C-terminal conformers is dependent on length of the saturated lipid tails. In short-tail membranes, additional non-specific dimers are observed which are reduced or absent in long-tailed bilayers. Our results indicate that the relative population as well as the structure of the dimer state is modulated by membrane composition. We have correlated these differences to local perturbations of the membrane around the receptor. Our work is an important step in characterizing ErbB dimers in healthy and diseased states and emphasize the importance of sampling lipid dynamics in understanding receptor association.
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Affiliation(s)
- Srinivasa M Gopal
- CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411 008, India; Lehrstuhl fur Theoretische Chemie, Ruhr University Bochum, D-44780 Bochum, Germany
| | - Aiswarya B Pawar
- CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411 008, India; AcSIR, Mathura Road, New Delhi, 110 025, India
| | - Tsjerk A Wassenaar
- Molecular Dynamics, University of Groningen, Nijenborgh 7, 9747AG Groningen, the Netherlands
| | - Durba Sengupta
- CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411 008, India; AcSIR, Mathura Road, New Delhi, 110 025, India.
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17
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Franco ML, Nadezhdin KD, Goncharuk SA, Mineev KS, Arseniev AS, Vilar M. Structural basis of the transmembrane domain dimerization and rotation in the activation mechanism of the TRKA receptor by nerve growth factor. J Biol Chem 2020; 295:275-286. [PMID: 31801826 PMCID: PMC6952603 DOI: 10.1074/jbc.ra119.011312] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 11/26/2019] [Indexed: 01/03/2023] Open
Abstract
Tropomyosin-receptor kinases (TRKs) are essential for the development of the nervous system. The molecular mechanism of TRKA activation by its ligand nerve growth factor (NGF) is still unsolved. Recent results indicate that at endogenous levels most of TRKA is in a monomer-dimer equilibrium and that the binding of NGF induces an increase of the dimeric and oligomeric forms of this receptor. An unsolved issue is the role of the TRKA transmembrane domain (TMD) in the dimerization of TRKA and the structural details of the TMD in the active dimer receptor. Here, we found that the TRKA-TMD can form dimers, identified the structural determinants of the dimer interface in the active receptor, and validated this interface through site-directed mutagenesis together with functional and cell differentiation studies. Using in vivo cross-linking, we found that the extracellular juxtamembrane region is reordered after ligand binding. Replacement of some residues in the juxtamembrane region with cysteine resulted in ligand-independent active dimers and revealed the preferred dimer interface. Moreover, insertion of leucine residues into the TMD helix induced a ligand-independent TRKA activation, suggesting that a rotation of the TMD dimers underlies NGF-induced TRKA activation. Altogether, our findings indicate that the transmembrane and juxtamembrane regions of TRKA play key roles in its dimerization and activation by NGF.
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Affiliation(s)
- María L Franco
- Molecular Basis of Neurodegeneration Unit, Institute of Biomedicine of València, Consejo Superior de Investigaciones Científicas, 46010 València, Spain
| | - Kirill D Nadezhdin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russian Federation; Moscow Institute of Physics and Technology (State University), Institutskiy Pereulok 9, Dolgoprudny, Moscow Region 141700, Russian Federation
| | - Sergey A Goncharuk
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russian Federation; Moscow Institute of Physics and Technology (State University), Institutskiy Pereulok 9, Dolgoprudny, Moscow Region 141700, Russian Federation
| | - Konstantin S Mineev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russian Federation; Moscow Institute of Physics and Technology (State University), Institutskiy Pereulok 9, Dolgoprudny, Moscow Region 141700, Russian Federation
| | - Alexander S Arseniev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russian Federation; Moscow Institute of Physics and Technology (State University), Institutskiy Pereulok 9, Dolgoprudny, Moscow Region 141700, Russian Federation.
| | - Marçal Vilar
- Molecular Basis of Neurodegeneration Unit, Institute of Biomedicine of València, Consejo Superior de Investigaciones Científicas, 46010 València, Spain.
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18
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Enhanced oligomerization of full-length RAGE by synergy of the interaction of its domains. Sci Rep 2019; 9:20332. [PMID: 31889156 PMCID: PMC6937306 DOI: 10.1038/s41598-019-56993-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 12/11/2019] [Indexed: 01/10/2023] Open
Abstract
The pattern recognition receptor RAGE (receptor for advanced glycation end-products) transmits proinflammatory signals in several inflammation-related pathological states, including vascular diseases, cancer, neurodegeneration and diabetes. Its oligomerization is believed to be important in signal transduction, but RAGE oligomeric structures and stoichiometries remain unclear. Different oligomerization modes have been proposed in studies involving different truncated versions of the extracellular parts of RAGE. Here, we provide basic characterization of the oligomerization patterns of full-length RAGE (including the transmembrane (TM) and cytosolic regions) and compare the results with oligomerization modes of its four truncated fragments. For this purpose, we used native mass spectrometry, analytical ultracentrifugation, and size-exclusion chromatography coupled with multi-angle light scattering. Our results confirm known oligomerization tendencies of separate domains and highlight the enhanced oligomerization properties of full-length RAGE. Mutational analyses within the GxxxG motif of the TM region show sensitivity of oligomeric distributions to the TM sequence. Using hydrogen–deuterium exchange, we mapped regions involved in TM-dependent RAGE oligomerization. Our data provide experimental evidence for the major role of the C2 and TM domains in oligomerization, underscoring synergy among different oligomerization contact regions along the RAGE sequence. These results also explain the variability of obtained oligomerization modes in RAGE fragments.
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19
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Pannwitt S, Stangl M, Schneider D. Lipid Binding Controls Dimerization of the Coat Protein p24 Transmembrane Helix. Biophys J 2019; 117:1554-1562. [PMID: 31627840 DOI: 10.1016/j.bpj.2019.09.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 09/05/2019] [Accepted: 09/09/2019] [Indexed: 10/25/2022] Open
Abstract
Coat protein (COP) I and COP II complexes are involved in the transport of proteins between the endoplasmic reticulum and the Golgi apparatus in eukaryotic cells. The formation of COP I/II complexes at membrane surfaces is an early step in vesicle formation and is mastered by p24, a type I transmembrane protein. Oligomerization of p24 monomers was suggested to be mediated and/or stabilized via interactions within the transmembrane domain, and the p24 transmembrane helix appears to selectively bind a single sphingomyelin C18:0 molecule. Furthermore, a potential cholesterol-binding sequence has also been predicted in the p24 transmembrane domain. Thus, sphingomyelin and/or cholesterol binding to the transmembrane domain might directly control the oligomeric state of p24 and, thus, COP vesicle formation. In this study, we show that sequence-specific dimerization of the p24 transmembrane helix is mediated by a LQ7 motif, with Gln187 being of special importance. Whereas cholesterol has no direct impact on p24 dimerization, binding of the sphingolipid can clearly control dimerization of p24 in rigid membrane regions. We suggest that specific binding of a sphingolipid to the p24 transmembrane helix affects p24 dimerization in membranes with increased cholesterol contents. A clearly defined p24 dimerization propensity likely is crucial for the p24 activity, which involves shuttling in between the endoplasmic reticulum and the Golgi membrane, in which cholesterol and SM C18:0 concentrations differ.
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Affiliation(s)
- Stefanie Pannwitt
- Institute of Pharmacy and Biochemistry, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Michael Stangl
- Institute of Pharmacy and Biochemistry, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Dirk Schneider
- Institute of Pharmacy and Biochemistry, Johannes Gutenberg University Mainz, Mainz, Germany.
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20
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Federman RS, Boguraev AS, Heim EN, DiMaio D. Biologically Active Ultra-Simple Proteins Reveal Principles of Transmembrane Domain Interactions. J Mol Biol 2019; 431:3753-3770. [PMID: 31301406 DOI: 10.1016/j.jmb.2019.07.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 07/02/2019] [Accepted: 07/03/2019] [Indexed: 11/30/2022]
Abstract
Specific interactions between the helical membrane-spanning domains of transmembrane proteins play central roles in the proper folding and oligomerization of these proteins. However, the relationship between the hydrophobic amino acid sequences of transmembrane domains and their functional interactions is in most cases unknown. Here, we use ultra-simple artificial proteins to systematically study the sequence basis for transmembrane domain interactions. We show that most short homopolymeric polyleucine transmembrane proteins containing single amino acid substitutions can activate the platelet-derived growth factor β receptor or the erythropoietin receptor in cultured mouse cells, resulting in cell transformation or proliferation. These proteins displayed complex patterns of activity that were markedly affected by seemingly minor sequence differences in the ultra-simple protein itself or in the transmembrane domain of the target receptor, and the effects of these sequence differences are not additive. In addition, specific leucine residues along the length of these proteins are required for activity, and the positions of these required leucines differ based on the identity and position of the central substituted amino acid. Our results suggest that these ultra-simple proteins use a variety of molecular mechanisms to activate the same target and that diversification of transmembrane domain sequences over the course of evolution minimized off-target interactions.
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Affiliation(s)
- Ross S Federman
- Department of Immunobiology, Yale School of Medicine, PO Box 208011, New Haven, CT 06520-8011, USA
| | - Anna-Sophia Boguraev
- Department of Genetics, Yale School of Medicine, PO Box 208005, New Haven, CT 06520-8005, USA
| | - Erin N Heim
- Department of Genetics, Yale School of Medicine, PO Box 208005, New Haven, CT 06520-8005, USA
| | - Daniel DiMaio
- Department of Genetics, Yale School of Medicine, PO Box 208005, New Haven, CT 06520-8005, USA; Department of Therapeutic Radiology, Yale School of Medicine, PO Box 208040, New Haven, CT 06520-8040, USA; Department of Molecular Biophysics & Biochemistry, Yale School of Medicine, PO Box 208024, New Haven, CT 06520-8024, USA; Yale Cancer Center, PO Box 208028, New Haven, CT 06520-8028, USA.
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21
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Bennett MK, Wallington-Beddoe CT, Pitson SM. Sphingolipids and the unfolded protein response. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1864:1483-1494. [PMID: 31176037 DOI: 10.1016/j.bbalip.2019.06.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 05/29/2019] [Accepted: 06/01/2019] [Indexed: 12/17/2022]
Abstract
The unfolded protein response (UPR) is a response by the endoplasmic reticulum to stress, classically caused by any disruption to cell homeostasis that results in an accumulation in unfolded proteins. However, there is an increasing body of research demonstrating that the UPR can also be activated by changes in lipid homeostasis, including changes in sphingolipid metabolism. Sphingolipids are a family of bioactive lipids with important roles in both the formation and integrity of cellular membranes, and regulation of key cellular processes, including cell proliferation and apoptosis. Bi-directional interactions between sphingolipids and the UPR have now been observed in a range of diseases, including cancer, diabetes and liver disease. Determining how these two key cellular components influence each other could play an important role in deciphering the causes of these diseases and potentially reveal new therapeutic approaches.
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Affiliation(s)
- Melissa K Bennett
- Centre for Cancer Biology, University of South Australia and SA Pathology, UniSA CRI Building, North Tce, Adelaide, SA 5001, Australia
| | - Craig T Wallington-Beddoe
- Centre for Cancer Biology, University of South Australia and SA Pathology, UniSA CRI Building, North Tce, Adelaide, SA 5001, Australia; Adelaide Medical School, University of Adelaide, Adelaide, SA 5001, Australia; Flinders Medical Centre, Bedford Park, SA 5042, Australia; College of Medicine and Public Health, Flinders University, Bedford Park, SA 5042, Australia
| | - Stuart M Pitson
- Centre for Cancer Biology, University of South Australia and SA Pathology, UniSA CRI Building, North Tce, Adelaide, SA 5001, Australia; Adelaide Medical School, University of Adelaide, Adelaide, SA 5001, Australia; School of Biological Sciences, University of Adelaide, Adelaide, SA 5000, Australia.
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22
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Marinko J, Huang H, Penn WD, Capra JA, Schlebach JP, Sanders CR. Folding and Misfolding of Human Membrane Proteins in Health and Disease: From Single Molecules to Cellular Proteostasis. Chem Rev 2019; 119:5537-5606. [PMID: 30608666 PMCID: PMC6506414 DOI: 10.1021/acs.chemrev.8b00532] [Citation(s) in RCA: 153] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Indexed: 12/13/2022]
Abstract
Advances over the past 25 years have revealed much about how the structural properties of membranes and associated proteins are linked to the thermodynamics and kinetics of membrane protein (MP) folding. At the same time biochemical progress has outlined how cellular proteostasis networks mediate MP folding and manage misfolding in the cell. When combined with results from genomic sequencing, these studies have established paradigms for how MP folding and misfolding are linked to the molecular etiologies of a variety of diseases. This emerging framework has paved the way for the development of a new class of small molecule "pharmacological chaperones" that bind to and stabilize misfolded MP variants, some of which are now in clinical use. In this review, we comprehensively outline current perspectives on the folding and misfolding of integral MPs as well as the mechanisms of cellular MP quality control. Based on these perspectives, we highlight new opportunities for innovations that bridge our molecular understanding of the energetics of MP folding with the nuanced complexity of biological systems. Given the many linkages between MP misfolding and human disease, we also examine some of the exciting opportunities to leverage these advances to address emerging challenges in the development of therapeutics and precision medicine.
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Affiliation(s)
- Justin
T. Marinko
- Department
of Biochemistry, Vanderbilt University, Nashville, Tennessee 37240, United States
- Center
for Structural Biology, Vanderbilt University, Nashville, Tennessee 37240, United States
| | - Hui Huang
- Department
of Biochemistry, Vanderbilt University, Nashville, Tennessee 37240, United States
- Center
for Structural Biology, Vanderbilt University, Nashville, Tennessee 37240, United States
| | - Wesley D. Penn
- Department
of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - John A. Capra
- Center
for Structural Biology, Vanderbilt University, Nashville, Tennessee 37240, United States
- Department
of Biological Sciences, Vanderbilt University, Nashville, Tennessee 37245, United States
| | - Jonathan P. Schlebach
- Department
of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Charles R. Sanders
- Department
of Biochemistry, Vanderbilt University, Nashville, Tennessee 37240, United States
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23
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Enkavi G, Javanainen M, Kulig W, Róg T, Vattulainen I. Multiscale Simulations of Biological Membranes: The Challenge To Understand Biological Phenomena in a Living Substance. Chem Rev 2019; 119:5607-5774. [PMID: 30859819 PMCID: PMC6727218 DOI: 10.1021/acs.chemrev.8b00538] [Citation(s) in RCA: 175] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Indexed: 12/23/2022]
Abstract
Biological membranes are tricky to investigate. They are complex in terms of molecular composition and structure, functional over a wide range of time scales, and characterized by nonequilibrium conditions. Because of all of these features, simulations are a great technique to study biomembrane behavior. A significant part of the functional processes in biological membranes takes place at the molecular level; thus computer simulations are the method of choice to explore how their properties emerge from specific molecular features and how the interplay among the numerous molecules gives rise to function over spatial and time scales larger than the molecular ones. In this review, we focus on this broad theme. We discuss the current state-of-the-art of biomembrane simulations that, until now, have largely focused on a rather narrow picture of the complexity of the membranes. Given this, we also discuss the challenges that we should unravel in the foreseeable future. Numerous features such as the actin-cytoskeleton network, the glycocalyx network, and nonequilibrium transport under ATP-driven conditions have so far received very little attention; however, the potential of simulations to solve them would be exceptionally high. A major milestone for this research would be that one day we could say that computer simulations genuinely research biological membranes, not just lipid bilayers.
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Affiliation(s)
- Giray Enkavi
- Department
of Physics, University of
Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
| | - Matti Javanainen
- Department
of Physics, University of
Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
- Institute
of Organic Chemistry and Biochemistry of the Czech Academy
of Sciences, Flemingovo naḿesti 542/2, 16610 Prague, Czech Republic
- Computational
Physics Laboratory, Tampere University, P.O. Box 692, FI-33014 Tampere, Finland
| | - Waldemar Kulig
- Department
of Physics, University of
Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
| | - Tomasz Róg
- Department
of Physics, University of
Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
- Computational
Physics Laboratory, Tampere University, P.O. Box 692, FI-33014 Tampere, Finland
| | - Ilpo Vattulainen
- Department
of Physics, University of
Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
- Computational
Physics Laboratory, Tampere University, P.O. Box 692, FI-33014 Tampere, Finland
- MEMPHYS-Center
for Biomembrane Physics
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24
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Glatzová D, Cebecauer M. Dual Role of CD4 in Peripheral T Lymphocytes. Front Immunol 2019; 10:618. [PMID: 31001252 PMCID: PMC6454155 DOI: 10.3389/fimmu.2019.00618] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 03/08/2019] [Indexed: 01/07/2023] Open
Abstract
The interaction of T-cell receptors (TCRs) with self- and non-self-peptides in the major histocompatibility complex (MHC) stimulates crucial signaling events, which in turn can activate T lymphocytes. A variety of accessory molecules further modulate T-cell signaling. Of these, the CD4 and CD8 coreceptors make the most critical contributions to T cell sensitivity in vivo. Whereas, CD4 function in T cell development is well-characterized, its role in peripheral T cells remains incompletely understood. It was originally suggested that CD4 stabilizes weak interactions between TCRs and peptides in the MHC and delivers Lck kinases to that complex. The results of numerous experiments support the latter role, indicating that the CD4-Lck complex accelerates TCR-triggered signaling and controls the availability of the kinase for TCR in the absence of the ligand. On the other hand, extremely low affinity of CD4 for MHC rules out its ability to stabilize the receptor-ligand complex. In this review, we summarize the current knowledge on CD4 in T cells, with a special emphasis on the spatio-temporal organization of early signaling events and the relevance for CD4 function. We further highlight the capacity of CD4 to interact with the MHC in the absence of TCR. It drives the adhesion of T cells to the cells that express the MHC. This process is facilitated by the CD4 accumulation in the tips of microvilli on the surface of unstimulated T cells. Based on these observations, we suggest an alternative model of CD4 role in T-cell activation.
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Affiliation(s)
- Daniela Glatzová
- Department of Biophysical Chemistry, J. Heyrovsky Institute of Physical Chemistry of the Czech Academy of Sciences, Prague, Czechia
- Laboratory of Leukocyte Signaling, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
| | - Marek Cebecauer
- Department of Biophysical Chemistry, J. Heyrovsky Institute of Physical Chemistry of the Czech Academy of Sciences, Prague, Czechia
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25
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Mitochondrial presequence import: Multiple regulatory knobs fine-tune mitochondrial biogenesis and homeostasis. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2019; 1866:930-944. [PMID: 30802482 DOI: 10.1016/j.bbamcr.2019.02.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Revised: 02/14/2019] [Accepted: 02/19/2019] [Indexed: 12/22/2022]
Abstract
Mitochondria are pivotal organelles for cellular signaling and metabolism, and their dysfunction leads to severe cellular stress. About 60-70% of the mitochondrial proteome consists of preproteins synthesized in the cytosol with an amino-terminal cleavable presequence targeting signal. The TIM23 complex transports presequence signals towards the mitochondrial matrix. Ultimately, the mature protein segments are either transported into the matrix or sorted to the inner membrane. To ensure accurate preprotein import into distinct mitochondrial sub-compartments, the TIM23 machinery adopts specific functional conformations and interacts with different partner complexes. Regulatory subunits modulate the translocase dynamics, tailoring the import reaction to the incoming preprotein. The mitochondrial membrane potential and the ATP generated via oxidative phosphorylation are key energy sources in driving the presequence import pathway. Thus, mitochondrial dysfunctions have rapid repercussions on biogenesis. Cellular mechanisms exploit the presequence import pathway to monitor mitochondrial dysfunctions and mount transcriptional and proteostatic responses to restore functionality.
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Polyansky AA, Bocharov EV, Velghe AI, Kuznetsov AS, Bocharova OV, Urban AS, Arseniev AS, Zagrovic B, Demoulin JB, Efremov RG. Atomistic mechanism of the constitutive activation of PDGFRA via its transmembrane domain. Biochim Biophys Acta Gen Subj 2018; 1863:82-95. [PMID: 30253204 DOI: 10.1016/j.bbagen.2018.09.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 09/12/2018] [Accepted: 09/16/2018] [Indexed: 12/14/2022]
Abstract
Single-point mutations in the transmembrane (TM) region of receptor tyrosine kinases (RTKs) can lead to abnormal ligand-independent activation. We use a combination of computational modeling, NMR spectroscopy and cell experiments to analyze in detail the mechanism of how TM domains contribute to the activation of wild-type (WT) PDGFRA and its oncogenic V536E mutant. Using a computational framework, we scan all positions in PDGFRA TM helix for identification of potential functional mutations for the WT and the mutant and reveal the relationship between the receptor activity and TM dimerization via different interfaces. This strategy also allows us design a novel activating mutation in the WT (I537D) and a compensatory mutation in the V536E background eliminating its constitutive activity (S541G). We show both computationally and experimentally that single-point mutations in the TM region reshape the TM dimer ensemble and delineate the structural and dynamic determinants of spontaneous activation of PDGFRA via its TM domain. Our atomistic picture of the coupling between TM dimerization and PDGFRA activation corroborates the data obtained for other RTKs and provides a foundation for developing novel modulators of the pathological activity of PDGFRA.
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Affiliation(s)
- Anton A Polyansky
- MM Shemyakin and Yu A Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya, 16/10, 117997 Moscow, Russia; Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria.
| | - Eduard V Bocharov
- MM Shemyakin and Yu A Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya, 16/10, 117997 Moscow, Russia; Moscow Institute of Physics and Technology (State University), Institutskiy Pereulok 9, Dolgoprudny, Moscow region 141700, Russia; National Research Centre "Kurchatov Institute", Akad. Kurchatova pl. 1, Moscow 123182, Russia
| | - Amélie I Velghe
- de Duve Institute, Université catholique de Louvain, Avenue Hippocrate 75, 1200 Brussels, Belgium
| | - Andrey S Kuznetsov
- MM Shemyakin and Yu A Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya, 16/10, 117997 Moscow, Russia; Moscow Institute of Physics and Technology (State University), Institutskiy Pereulok 9, Dolgoprudny, Moscow region 141700, Russia; Higher School of Economics, Myasnitskaya 20, 101000 Moscow, Russia
| | - Olga V Bocharova
- MM Shemyakin and Yu A Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya, 16/10, 117997 Moscow, Russia; Moscow Institute of Physics and Technology (State University), Institutskiy Pereulok 9, Dolgoprudny, Moscow region 141700, Russia
| | - Anatoly S Urban
- MM Shemyakin and Yu A Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya, 16/10, 117997 Moscow, Russia; Moscow Institute of Physics and Technology (State University), Institutskiy Pereulok 9, Dolgoprudny, Moscow region 141700, Russia
| | - Alexander S Arseniev
- MM Shemyakin and Yu A Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya, 16/10, 117997 Moscow, Russia; Moscow Institute of Physics and Technology (State University), Institutskiy Pereulok 9, Dolgoprudny, Moscow region 141700, Russia
| | - Bojan Zagrovic
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Jean-Baptiste Demoulin
- de Duve Institute, Université catholique de Louvain, Avenue Hippocrate 75, 1200 Brussels, Belgium.
| | - Roman G Efremov
- MM Shemyakin and Yu A Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya, 16/10, 117997 Moscow, Russia; Moscow Institute of Physics and Technology (State University), Institutskiy Pereulok 9, Dolgoprudny, Moscow region 141700, Russia; Higher School of Economics, Myasnitskaya 20, 101000 Moscow, Russia
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The Third Transmembrane Domain of EscR Is Critical for Function of the Enteropathogenic Escherichia coli Type III Secretion System. mSphere 2018; 3:3/4/e00162-18. [PMID: 30045964 PMCID: PMC6060343 DOI: 10.1128/msphere.00162-18] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Many Gram-negative bacterial pathogens that cause life-threatening diseases employ a type III secretion system (T3SS) for their virulence. The T3SS comprises several proteins that assemble into a syringe-like structure dedicated to the injection of bacterial virulence factors into the host cells. Although many T3SS proteins are transmembrane proteins, our knowledge of these proteins is limited mostly to their soluble domains. In this study, we found that the third transmembrane domain (TMD) of EscR, a central protein of the T3SS in enteropathogenic E. coli, contributes to protein self-oligomerization. Moreover, we demonstrated that a single aspartic acid residue, located at the core of this TMD, is critical for the activity of the full-length protein and the function of the entire T3SS, possibly due to its involvement in mediating TMD-TMD interactions. Our findings should encourage the mapping of the entire interactome of the T3SS components, including interactions mediated through their TMDs. Many Gram-negative bacterial pathogens utilize a specialized protein delivery system, called the type III secretion system (T3SS), to translocate effector proteins into the host cells. The translocated effectors are crucial for bacterial infection and survival. The base of the T3SS transverses both bacterial membranes and contains an export apparatus that comprises five membrane proteins. Here, we study the export apparatus of enteropathogenic Escherichia coli (EPEC) and characterize its central component, called the EscR protein. We found that the third transmembrane domain (TMD) of EscR mediates strong self-oligomerization in an isolated genetic reporter system. Replacing this TMD sequence with an alternative hydrophobic sequence within the full-length protein resulted in a complete loss of function of the T3SS, further suggesting that the EscR TMD3 sequence has another functional role in addition to its role as a membrane anchor. Moreover, we found that an aspartic acid residue, located at the core of EscR TMD3, is important for the oligomerization propensity of TMD3 and that a point mutation of this residue within the full-length protein abolishes the T3SS activity and the ability of the bacteria to translocate effectors into host cells. IMPORTANCE Many Gram-negative bacterial pathogens that cause life-threatening diseases employ a type III secretion system (T3SS) for their virulence. The T3SS comprises several proteins that assemble into a syringe-like structure dedicated to the injection of bacterial virulence factors into the host cells. Although many T3SS proteins are transmembrane proteins, our knowledge of these proteins is limited mostly to their soluble domains. In this study, we found that the third transmembrane domain (TMD) of EscR, a central protein of the T3SS in enteropathogenic E. coli, contributes to protein self-oligomerization. Moreover, we demonstrated that a single aspartic acid residue, located at the core of this TMD, is critical for the activity of the full-length protein and the function of the entire T3SS, possibly due to its involvement in mediating TMD-TMD interactions. Our findings should encourage the mapping of the entire interactome of the T3SS components, including interactions mediated through their TMDs.
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28
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Shteinfer-Kuzmine A, Amsalem Z, Arif T, Zooravlov A, Shoshan-Barmatz V. Selective induction of cancer cell death by VDAC1-based peptides and their potential use in cancer therapy. Mol Oncol 2018; 12:1077-1103. [PMID: 29698587 PMCID: PMC6026870 DOI: 10.1002/1878-0261.12313] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2017] [Revised: 03/22/2018] [Accepted: 04/15/2018] [Indexed: 01/06/2023] Open
Abstract
Mitochondrial VDAC1 mediates cross talk between the mitochondria and other parts of the cell by transporting anions, cations, ATP, Ca2+, and metabolites and serves as a key player in apoptosis. As such, VDAC1 is involved in two important hallmarks of cancer development, namely energy and metabolic reprograming and apoptotic cell death evasion. We previously developed cell‐penetrating VDAC1‐derived peptides that interact with hexokinase (HK), Bcl‐2, and Bcl‐xL to prevent the anti‐apoptotic activities of these proteins and induce cancer cell death, with a focus on leukemia and glioblastoma. In this study, we demonstrated the sensitivity of a panel of genetically characterized cancer cell lines, differing in origin and carried mutations, to VDAC1‐based peptide‐induced apoptosis. Noncancerous cell lines were less affected by the peptides. Furthermore, we constructed additional VDAC1‐based peptides with the aim of improving targeting, selectivity, and cellular stability, including R‐Tf‐D‐LP4, containing the transferrin receptor internalization sequence (Tf) that allows targeting of the peptide to cancer cells, known to overexpress the transferrin receptor. The mode of action of the VDAC1‐based peptides involves HK detachment, interfering with the action of anti‐apoptotic proteins, and thus activating multiple routes leading to an impairment of cell energy and metabolism homeostasis and the induction of apoptosis. Finally, in xenograft glioblastoma, lung, and breast cancer mouse models, R‐Tf‐D‐LP4 inhibited tumor growth while inducing massive cancer cell death, including of cancer stem cells. Thus, VDAC1‐based peptides offer an innovative new conceptual framework for cancer therapy.
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Affiliation(s)
- Anna Shteinfer-Kuzmine
- Department of Life Sciences, National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Zohar Amsalem
- Department of Life Sciences, National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Tasleem Arif
- Department of Life Sciences, National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Alexandra Zooravlov
- Department of Life Sciences, National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Varda Shoshan-Barmatz
- Department of Life Sciences, National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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Pollard AM, Sourjik V. Transmembrane region of bacterial chemoreceptor is capable of promoting protein clustering. J Biol Chem 2017; 293:2149-2158. [PMID: 29259129 DOI: 10.1074/jbc.m117.796722] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 12/06/2017] [Indexed: 11/06/2022] Open
Abstract
Many membrane proteins are known to form higher-order oligomers, but the degree to which membrane regions could facilitate protein complex assembly remains largely unclear. Clusters of chemotaxis receptors are among the most prominent structures in the bacterial cell membrane, and they play important functions in processing of chemotactic signals. Although much work has been done to elucidate mechanisms of cluster formation, it almost exclusively focused on cytoplasmic interactions among receptors and other chemotaxis proteins, whereas involvement of membrane-mediated interactions was only hypothesized. Here we used imaging of constructs composed of only a fluorescent protein and the TM helices of Tar to demonstrate that interactions between the lipid bilayer and transmembrane (TM) helices of Escherichia coli chemoreceptors alone are sufficient to mediate clustering. We found that the ability to cluster depends on the sequence or length of the TM helices, implying that certain conformations of these helices facilitate clustering, whereas others do not. Notably, observed sequence specificity was apparently consistent with differences in clustering between native E. coli receptors, with the TM sequence of better-clustering high-abundance receptors being more efficient in promoting membrane-mediated complex formation. These results indicate that being more than just membrane anchors, TM helices could play an important role in the clustering and organization of membrane proteins in bacteria.
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Affiliation(s)
- Abiola M Pollard
- From the Max Planck Institute for Terrestrial Microbiology and LOEWE Center for Synthetic Microbiology (SYNMIKRO), D-35043 Marburg, Germany
| | - Victor Sourjik
- From the Max Planck Institute for Terrestrial Microbiology and LOEWE Center for Synthetic Microbiology (SYNMIKRO), D-35043 Marburg, Germany
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30
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Excessive aggregation of membrane proteins in the Martini model. PLoS One 2017; 12:e0187936. [PMID: 29131844 PMCID: PMC5683612 DOI: 10.1371/journal.pone.0187936] [Citation(s) in RCA: 121] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Accepted: 10/27/2017] [Indexed: 11/19/2022] Open
Abstract
The coarse-grained Martini model is employed extensively to study membrane protein oligomerization. While this approach is exceptionally promising given its computational efficiency, it is alarming that a significant fraction of these studies demonstrate unrealistic protein clusters, whose formation is essentially an irreversible process. This suggests that the protein-protein interactions are exaggerated in the Martini model. If this held true, then it would limit the applicability of Martini to study multi-protein complexes, as the rapidly clustering proteins would not be able to properly sample the correct dimerization conformations. In this work we first demonstrate the excessive protein aggregation by comparing the dimerization free energies of helical transmembrane peptides obtained with the Martini model to those determined from FRET experiments. Second, we show that the predictions provided by the Martini model for the structures of transmembrane domain dimers are in poor agreement with the corresponding structures resolved using NMR. Next, we demonstrate that the first issue can be overcome by slightly scaling down the Martini protein-protein interactions in a manner, which does not interfere with the other Martini interaction parameters. By preventing excessive, irreversible, and non-selective aggregation of membrane proteins, this approach renders the consideration of lateral dynamics and protein-lipid interactions in crowded membranes by the Martini model more realistic. However, this adjusted model does not lead to an improvement in the predicted dimer structures. This implicates that the poor agreement between the Martini model and NMR structures cannot be cured by simply uniformly reducing the interactions between all protein beads. Instead, a careful amino-acid specific adjustment of the protein-protein interactions is likely required.
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31
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Bocharov EV. Alternative dimerization of receptor tyrosine kinases with signal transduction through a cellular membrane. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2017. [DOI: 10.1134/s1068162017050041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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32
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Bauer J, Bakke O, Morth JP. Overview of the membrane-associated RING-CH (MARCH) E3 ligase family. N Biotechnol 2017; 38:7-15. [DOI: 10.1016/j.nbt.2016.12.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 12/05/2016] [Accepted: 12/13/2016] [Indexed: 12/17/2022]
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33
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Conformational transitions and interactions underlying the function of membrane embedded receptor protein kinases. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:1417-1429. [DOI: 10.1016/j.bbamem.2017.01.025] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 01/06/2017] [Accepted: 01/09/2017] [Indexed: 01/08/2023]
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34
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Metola A, Bouchet AM, Alonso-Mariño M, Diercks T, Mäler L, Goñi FM, Viguera AR. Purification and characterization of the colicin A immunity protein in detergent micelles. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:2181-2192. [PMID: 28803731 DOI: 10.1016/j.bbamem.2017.08.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 08/06/2017] [Accepted: 08/09/2017] [Indexed: 11/18/2022]
Abstract
The immunity proteins against pore-forming colicins represent a family of integral membrane proteins that reside in the inner membrane of producing cells. Cai, the colicin A immunity protein, was characterized here in detergent micelles by circular dichroism (CD), size exclusion chromatography, chemical cross-linking, nuclear magnetic resonance (NMR) spectroscopy, cysteine accessibility, and colicin A binding in detergent micelles. Bile-salt derivatives induced extensive protein polymerization that precluded further investigation. The physical characterization of detergent-solubilized protein indicates that phosphate-containing detergents are more efficient in extracting, solubilizing and maintaining Cai in a monomeric state. Yet, their capacity to ensure protein activity, reconstitution, helix packing, and high-quality NMR spectra was inferior to that of milder detergents. Solvent ionic strength and composition greatly modified the solubilizing capacity of milder detergents. Most importantly, binding to the colicin A pore-forming domain (pf-ColA) occurred almost exclusively in sugar-derived detergents. The relative performance of the different detergents in each experiment depends on their impact not only on Cai structure, solubility and oligomerization state, but also on other reaction components and technical aspects. Thus, proteoliposomes were best obtained from protein in LDAO micelles, possibly also due to indirect effects on the lipidic bilayer. The compatibility of a detergent with Cai/pf-ColA complex formation is influenced by its effect on the conformational landscape of each protein, where detergent-mediated pf-ColA denaturation could also lead to negative results. The NMR spectra were greatly affected by the solubility, monodispersity, fold and dynamics of the protein-detergent complexes, and none of those tested here provided NMR spectra of sufficient quality to allow for peak assignment. Cai function could be proven in alkyl glycosides and not in those detergents that afforded the best solubility, reconstitution efficiency or spectral quality indicating that these criteria cannot be taken as unambiguous proof of nativeness without the support of direct activity measurements.
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Affiliation(s)
- Ane Metola
- Instituto Biofisika (CSIC, UPV/EHU), Parque Científico de la UPV/EHU, Barrio Sarriena s/n, 48940 Leioa, Bizkaia, Spain
| | - Ana M Bouchet
- Instituto Biofisika (CSIC, UPV/EHU), Parque Científico de la UPV/EHU, Barrio Sarriena s/n, 48940 Leioa, Bizkaia, Spain
| | - Marian Alonso-Mariño
- Instituto Biofisika (CSIC, UPV/EHU), Parque Científico de la UPV/EHU, Barrio Sarriena s/n, 48940 Leioa, Bizkaia, Spain
| | - Tammo Diercks
- Structural Biology Unit, CIC bioGUNE, Parque Tecnológico de Bizkaia Ed. 800, 48160 Derio, Spain
| | - Lena Mäler
- Department of Biochemistry and Biophysics, Center for Biomembrane Research, The Arrhenius Laboratory, Stockholm University, 10691 Stockholm, Sweden
| | - Félix M Goñi
- Instituto Biofisika (CSIC, UPV/EHU), Parque Científico de la UPV/EHU, Barrio Sarriena s/n, 48940 Leioa, Bizkaia, Spain; Departamento de Bioquímica, Universidad del País Vasco, 48940 Leioa. Spain
| | - Ana R Viguera
- Instituto Biofisika (CSIC, UPV/EHU), Parque Científico de la UPV/EHU, Barrio Sarriena s/n, 48940 Leioa, Bizkaia, Spain.
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35
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Merz D, Richter J, Gonneau M, Sanchez-Rodriguez C, Eder T, Sormani R, Martin M, Hématy K, Höfte H, Hauser MT. T-DNA alleles of the receptor kinase THESEUS1 with opposing effects on cell wall integrity signaling. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:4583-4593. [PMID: 28981771 PMCID: PMC5853656 DOI: 10.1093/jxb/erx263] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 07/04/2017] [Indexed: 05/21/2023]
Abstract
Perturbation of cellulose synthesis in plants triggers stress responses, including growth retardation, mediated by the cell wall integrity-sensing receptor-like kinase (RLK) THESEUS1 (THE1). The analysis of two alleles carrying T-DNA insertions at comparable positions has led to conflicting conclusions concerning the impact of THE1 signaling on growth. Here we confirm that, unlike the1-3 and other the1 alleles in which cellular responses to genetic or pharmacological inhibition of cellulose synthesis are attenuated, the1-4 showed enhanced responses, including growth inhibition, ectopic lignification, and stress gene expression. Both the1-3 and the1-4 express a transcript encoding a predicted membrane-associated truncated protein lacking the kinase domain. However, the1-3, in contrast to the1-4, strongly expresses antisense transcripts, which are expected to prevent the expression of the truncated protein as suggested by the genetic interactions between the two alleles. Seedlings overexpressing such a truncated protein react to isoxaben treatment similarly to the1-4 and the full-length THE overexpressor. We conclude that the1-4 is a hypermorphic allele; that THE1 signaling upon cell wall damage has a negative impact on cell expansion; and that caution is required when interpreting the phenotypic effects of T-DNA insertions in RLK genes.
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Affiliation(s)
- David Merz
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Julia Richter
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Martine Gonneau
- Institut Jean-Pierre Bourgin, INRA, Centre National pour la Recherche Scientifique, AgroParisTech, Université Paris-Saclay, Versailles Cedex, France
| | | | - Tobias Eder
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Rodnay Sormani
- Institut Jean-Pierre Bourgin, INRA, Centre National pour la Recherche Scientifique, AgroParisTech, Université Paris-Saclay, Versailles Cedex, France
| | - Marjolaine Martin
- Institut Jean-Pierre Bourgin, INRA, Centre National pour la Recherche Scientifique, AgroParisTech, Université Paris-Saclay, Versailles Cedex, France
| | - Kian Hématy
- Institut Jean-Pierre Bourgin, INRA, Centre National pour la Recherche Scientifique, AgroParisTech, Université Paris-Saclay, Versailles Cedex, France
| | - Herman Höfte
- Institut Jean-Pierre Bourgin, INRA, Centre National pour la Recherche Scientifique, AgroParisTech, Université Paris-Saclay, Versailles Cedex, France
| | - Marie-Theres Hauser
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
- Corresponding author:
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36
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Franz J, Bereau T, Pannwitt S, Anbazhagan V, Lehr A, Nubbemeyer U, Dietz U, Bonn M, Weidner T, Schneider D. Nitrated Fatty Acids Modulate the Physical Properties of Model Membranes and the Structure of Transmembrane Proteins. Chemistry 2017; 23:9690-9697. [DOI: 10.1002/chem.201702041] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Indexed: 12/12/2022]
Affiliation(s)
- Johannes Franz
- Institute for Pharmacy and BiochemistryJohannes Gutenberg University 55128 Mainz Germany
- Max Planck Institute for Polymer ResearchMolecular Spectroscopy Department 55128 Mainz Germany
| | - Tristan Bereau
- Max Planck Institute for Polymer ResearchTheory group 55128 Mainz Germany
| | - Stefanie Pannwitt
- Institute for Pharmacy and BiochemistryJohannes Gutenberg University 55128 Mainz Germany
| | - Veerappan Anbazhagan
- Institute for Pharmacy and BiochemistryJohannes Gutenberg University 55128 Mainz Germany
- Current address: School of Chemical and BiotechnologySASTRA University Thanjavur 613401, Tamil Nadu India
| | - Alexander Lehr
- Institute for Organic ChemistryJohannes Gutenberg University 55128 Mainz Germany
| | - Udo Nubbemeyer
- Institute for Organic ChemistryJohannes Gutenberg University 55128 Mainz Germany
| | | | - Mischa Bonn
- Max Planck Institute for Polymer ResearchMolecular Spectroscopy Department 55128 Mainz Germany
| | - Tobias Weidner
- Max Planck Institute for Polymer ResearchMolecular Spectroscopy Department 55128 Mainz Germany
| | - Dirk Schneider
- Institute for Pharmacy and BiochemistryJohannes Gutenberg University 55128 Mainz Germany
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37
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BLaTM 2.0, a Genetic Tool Revealing Preferred Antiparallel Interaction of Transmembrane Helix 4 of the Dual-Topology Protein EmrE. J Mol Biol 2017; 429:1630-1637. [DOI: 10.1016/j.jmb.2017.04.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 04/03/2017] [Accepted: 04/06/2017] [Indexed: 01/13/2023]
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38
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Schneider D. Border controls: Lipids control proteins and proteins control lipids. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:507-508. [DOI: 10.1016/j.bbamem.2016.12.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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39
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Schanzenbach C, Schmidt FC, Breckner P, Teese MG, Langosch D. Identifying ionic interactions within a membrane using BLaTM, a genetic tool to measure homo- and heterotypic transmembrane helix-helix interactions. Sci Rep 2017; 7:43476. [PMID: 28266525 PMCID: PMC5339904 DOI: 10.1038/srep43476] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 01/23/2017] [Indexed: 12/15/2022] Open
Abstract
The assembly of integral membrane protein complexes is frequently supported by transmembrane domain (TMD) interactions. Here, we present the BLaTM assay that measures homotypic as well as heterotypic TMD-TMD interactions in a bacterial membrane. The system is based on complementation of β-lactamase fragments genetically fused to interacting TMDs, which confers ampicillin resistance to expressing cells. We validated BLaTM by showing that the assay faithfully reports known sequence-specific interactions of both types. In a practical application, we used BLaTM to screen a focussed combinatorial library for heterotypic interactions driven by electrostatic forces. The results reveal novel patterns of ionizable amino acids within the isolated TMD pairs. Those patterns indicate that formation of heterotypic TMD pairs is most efficiently supported by closely spaced ionizable residues of opposite charge. In addition, TMD heteromerization can apparently be driven by hydrogen bonding between basic or between acidic residues.
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Affiliation(s)
- Christoph Schanzenbach
- Munich Center For Integrated Protein Science (CIPSM) at the Lehrstuhl für Chemie der Biopolymere, Technische Universität München, Weihenstephaner Berg 3, 85354 Freising, Germany
| | - Fabian C. Schmidt
- Munich Center For Integrated Protein Science (CIPSM) at the Lehrstuhl für Chemie der Biopolymere, Technische Universität München, Weihenstephaner Berg 3, 85354 Freising, Germany
| | - Patrick Breckner
- Munich Center For Integrated Protein Science (CIPSM) at the Lehrstuhl für Chemie der Biopolymere, Technische Universität München, Weihenstephaner Berg 3, 85354 Freising, Germany
| | - Mark G. Teese
- Munich Center For Integrated Protein Science (CIPSM) at the Lehrstuhl für Chemie der Biopolymere, Technische Universität München, Weihenstephaner Berg 3, 85354 Freising, Germany
| | - Dieter Langosch
- Munich Center For Integrated Protein Science (CIPSM) at the Lehrstuhl für Chemie der Biopolymere, Technische Universität München, Weihenstephaner Berg 3, 85354 Freising, Germany
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40
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Chadwick AC, Jensen DR, Hanson PJ, Lange PT, Proudfoot SC, Peterson FC, Volkman BF, Sahoo D. NMR Structure of the C-Terminal Transmembrane Domain of the HDL Receptor, SR-BI, and a Functionally Relevant Leucine Zipper Motif. Structure 2017; 25:446-457. [PMID: 28162952 DOI: 10.1016/j.str.2017.01.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 11/23/2016] [Accepted: 01/05/2017] [Indexed: 01/26/2023]
Abstract
The interaction of high-density lipoprotein (HDL) with its receptor, scavenger receptor BI (SR-BI), is critical for lowering plasma cholesterol levels and reducing the risk for cardiovascular disease. The HDL/SR-BI complex facilitates delivery of cholesterol into cells and is likely mediated by receptor dimerization. This work describes the use of nuclear magnetic resonance (NMR) spectroscopy to generate the first high-resolution structure of the C-terminal transmembrane domain of SR-BI. This region of SR-BI harbors a leucine zipper dimerization motif, which when mutated impairs the ability of the receptor to bind HDL and mediate cholesterol delivery. These losses in function correlate with the inability of SR-BI to form dimers. We also identify juxtamembrane regions of the extracellular domain of SR-BI that may interact with the lipid surface to facilitate cholesterol transport functions of the receptor.
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Affiliation(s)
- Alexandra C Chadwick
- Department of Biochemistry, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - Davin R Jensen
- Department of Biochemistry, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - Paul J Hanson
- Division of Endocrinology, Metabolism & Clinical Nutrition, Department of Medicine, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - Philip T Lange
- Division of Endocrinology, Metabolism & Clinical Nutrition, Department of Medicine, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - Sarah C Proudfoot
- Department of Biochemistry, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - Francis C Peterson
- Department of Biochemistry, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - Brian F Volkman
- Department of Biochemistry, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA.
| | - Daisy Sahoo
- Division of Endocrinology, Metabolism & Clinical Nutrition, Department of Medicine, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA; Department of Biochemistry, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA.
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41
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Steindorf D, Schneider D. In vivo selection of heterotypically interacting transmembrane helices: Complementary helix surfaces, rather than conserved interaction motifs, drive formation of transmembrane hetero-dimers. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:245-256. [DOI: 10.1016/j.bbamem.2016.11.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 11/23/2016] [Accepted: 11/29/2016] [Indexed: 11/16/2022]
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Venko K, Roy Choudhury A, Novič M. Computational Approaches for Revealing the Structure of Membrane Transporters: Case Study on Bilitranslocase. Comput Struct Biotechnol J 2017; 15:232-242. [PMID: 28228927 PMCID: PMC5312651 DOI: 10.1016/j.csbj.2017.01.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 01/19/2017] [Accepted: 01/20/2017] [Indexed: 11/23/2022] Open
Abstract
The structural and functional details of transmembrane proteins are vastly underexplored, mostly due to experimental difficulties regarding their solubility and stability. Currently, the majority of transmembrane protein structures are still unknown and this present a huge experimental and computational challenge. Nowadays, thanks to X-ray crystallography or NMR spectroscopy over 3000 structures of membrane proteins have been solved, among them only a few hundred unique ones. Due to the vast biological and pharmaceutical interest in the elucidation of the structure and the functional mechanisms of transmembrane proteins, several computational methods have been developed to overcome the experimental gap. If combined with experimental data the computational information enables rapid, low cost and successful predictions of the molecular structure of unsolved proteins. The reliability of the predictions depends on the availability and accuracy of experimental data associated with structural information. In this review, the following methods are proposed for in silico structure elucidation: sequence-dependent predictions of transmembrane regions, predictions of transmembrane helix–helix interactions, helix arrangements in membrane models, and testing their stability with molecular dynamics simulations. We also demonstrate the usage of the computational methods listed above by proposing a model for the molecular structure of the transmembrane protein bilitranslocase. Bilitranslocase is bilirubin membrane transporter, which shares similar tissue distribution and functional properties with some of the members of the Organic Anion Transporter family and is the only member classified in the Bilirubin Transporter Family. Regarding its unique properties, bilitranslocase is a potentially interesting drug target.
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Affiliation(s)
- Katja Venko
- Department of Cheminformatics, National Institute of Chemistry, Ljubljana, Slovenia
| | - A Roy Choudhury
- Department of Cheminformatics, National Institute of Chemistry, Ljubljana, Slovenia
| | - Marjana Novič
- Department of Cheminformatics, National Institute of Chemistry, Ljubljana, Slovenia
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Fischermeier E, Pospíšil P, Sayed A, Hof M, Solioz M, Fahmy K. Dipolar Relaxation Dynamics at the Active Site of an ATPase Regulated by Membrane Lateral Pressure. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201611582] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Elisabeth Fischermeier
- Helmholtz-Zentrum Dresden-Rossendorf Institute of Resource Ecology Bautzner Landstrasse 400 01328 Dresden Germany
- Technische Universität Dresden Biotechnology Center Tatzberg 47-49, 01307 Dresden Germany
- Nationales Zentrum für Tumorerkrankungen Heidelberg Im Neuenheimer Feld 460 69120 Heidelberg Germany
| | - Petr Pospíšil
- J. Heyrovský Inst. Physical Chemistry of the A.S.C.R. v.v.i. Prague Czech Republic
| | - Ahmed Sayed
- Helmholtz-Zentrum Dresden-Rossendorf Institute of Resource Ecology Bautzner Landstrasse 400 01328 Dresden Germany
- Technische Universität Dresden Biotechnology Center Tatzberg 47-49, 01307 Dresden Germany
- Institute for Experimental Physics I Universität Leipzig Linnéstrasse 5 04103 Leipzig Germany
| | - Martin Hof
- J. Heyrovský Inst. Physical Chemistry of the A.S.C.R. v.v.i. Prague Czech Republic
| | - Marc Solioz
- University of Bern Dept. of Clinical Pharmacology Murtenstrasse 35 3008 Bern Switzerland
| | - Karim Fahmy
- Helmholtz-Zentrum Dresden-Rossendorf Institute of Resource Ecology Bautzner Landstrasse 400 01328 Dresden Germany
- Technische Universität Dresden Biotechnology Center Tatzberg 47-49, 01307 Dresden Germany
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44
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Fischermeier E, Pospíšil P, Sayed A, Hof M, Solioz M, Fahmy K. Dipolar Relaxation Dynamics at the Active Site of an ATPase Regulated by Membrane Lateral Pressure. Angew Chem Int Ed Engl 2016; 56:1269-1272. [DOI: 10.1002/anie.201611582] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Indexed: 01/07/2023]
Affiliation(s)
- Elisabeth Fischermeier
- Helmholtz-Zentrum Dresden-Rossendorf Institute of Resource Ecology Bautzner Landstrasse 400 01328 Dresden Germany
- Technische Universität Dresden Biotechnology Center Tatzberg 47-49, 01307 Dresden Germany
- Nationales Zentrum für Tumorerkrankungen Heidelberg Im Neuenheimer Feld 460 69120 Heidelberg Germany
| | - Petr Pospíšil
- J. Heyrovský Inst. Physical Chemistry of the A.S.C.R. v.v.i. Prague Czech Republic
| | - Ahmed Sayed
- Helmholtz-Zentrum Dresden-Rossendorf Institute of Resource Ecology Bautzner Landstrasse 400 01328 Dresden Germany
- Technische Universität Dresden Biotechnology Center Tatzberg 47-49, 01307 Dresden Germany
- Institute for Experimental Physics I Universität Leipzig Linnéstrasse 5 04103 Leipzig Germany
| | - Martin Hof
- J. Heyrovský Inst. Physical Chemistry of the A.S.C.R. v.v.i. Prague Czech Republic
| | - Marc Solioz
- University of Bern Dept. of Clinical Pharmacology Murtenstrasse 35 3008 Bern Switzerland
| | - Karim Fahmy
- Helmholtz-Zentrum Dresden-Rossendorf Institute of Resource Ecology Bautzner Landstrasse 400 01328 Dresden Germany
- Technische Universität Dresden Biotechnology Center Tatzberg 47-49, 01307 Dresden Germany
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Del Piccolo N, Sarabipour S, Hristova K. A New Method to Study Heterodimerization of Membrane Proteins and Its Application to Fibroblast Growth Factor Receptors. J Biol Chem 2016; 292:1288-1301. [PMID: 27927983 DOI: 10.1074/jbc.m116.755777] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 12/05/2016] [Indexed: 12/30/2022] Open
Abstract
The activity of receptor tyrosine kinases (RTKs) is controlled through their lateral association in the plasma membrane. RTKs are believed to form both homodimers and heterodimers, and the different dimers are believed to play unique roles in cell signaling. However, RTK heterodimers remain poorly characterized, as compared with homodimers, because of limitations in current experimental methods. Here, we develop a FRET-based methodology to assess the thermodynamics of hetero-interactions in the plasma membrane. To demonstrate the utility of the methodology, we use it to study the hetero-interactions between three fibroblast growth factor receptors-FGFR1, FGFR2, and FGFR3-in the absence of ligand. Our results show that all possible FGFR heterodimers form, suggesting that the biological roles of FGFR heterodimers may be as significant as the homodimer roles. We further investigate the effect of two pathogenic point mutations in FGFR3 (A391E and G380R) on heterodimerization. We show that each of these mutations stabilize most of the heterodimers, with the largest effects observed for FGFR3 wild-type/mutant heterodimers. We thus demonstrate that the methodology presented here can yield new knowledge about RTK interactions and can further our understanding of signal transduction across the plasma membrane.
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Affiliation(s)
- Nuala Del Piccolo
- From the Department of Materials Science & Engineering, The Johns Hopkins University, Baltimore, Maryland 21218
| | - Sarvenaz Sarabipour
- From the Department of Materials Science & Engineering, The Johns Hopkins University, Baltimore, Maryland 21218
| | - Kalina Hristova
- From the Department of Materials Science & Engineering, The Johns Hopkins University, Baltimore, Maryland 21218
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46
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Qureshi T, Goto NK. Impact of Differential Detergent Interactions on Transmembrane Helix Dimerization Affinities. ACS OMEGA 2016; 1:277-285. [PMID: 31457129 PMCID: PMC6640775 DOI: 10.1021/acsomega.6b00138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 08/18/2016] [Indexed: 06/10/2023]
Abstract
Interactions between transmembrane (TM) helices play a critical role in the fundamental processes required for cells to communicate and exchange materials with their surroundings. Our understanding of the factors that promote TM helix interactions has greatly benefited from our ability to study these interactions in the solution phase through the use of membrane-mimetic micelles. However, less is known about the potential influence of juxtamembrane regions flanking the interacting TM helices that may modulate dimerization affinities, even when the interacting surface itself is not altered. To investigate this question, we used solution NMR to quantitate the dimerization affinity of the major coat protein from the M13 bacteriophage in sodium dodecyl sulfate (SDS), a well-characterized model of a single-spanning self-associating TM protein. Here, we showed that a shorter construct lacking the N-terminal amphipathic helix has a higher dimerization affinity relative to that of the full-length protein, with no change in the helical structure between the monomeric and dimeric states in both cases. Although this translated into a 0.6 kcal/mol difference in free energy when the SDS solvent was approximated as a continuous phase, there were deviations from this model at high protein to detergent ratios. Instead, the equilibria were better fit to a model that treats the empty micelle as an active participant in the reaction, giving rise to standard free energies of association that were the same for both full-length and TM-segment constructs. According to this model, the higher apparent affinity of the shorter peptide could be completely explained by the enhanced detergent binding by the monomer relative to that bound by the dimer. Therefore, differential detergent binding between the monomeric and dimeric states provides a mechanism by which TM helix interactions can be modulated by noninteracting juxtamembrane regions.
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47
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Lelimousin M, Limongelli V, Sansom MSP. Conformational Changes in the Epidermal Growth Factor Receptor: Role of the Transmembrane Domain Investigated by Coarse-Grained MetaDynamics Free Energy Calculations. J Am Chem Soc 2016; 138:10611-22. [PMID: 27459426 PMCID: PMC5010359 DOI: 10.1021/jacs.6b05602] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
![]()
The epidermal growth
factor receptor (EGFR) is a dimeric membrane
protein that regulates key aspects of cellular function. Activation
of the EGFR is linked to changes in the conformation of the transmembrane
(TM) domain, brought about by changes in interactions of the TM helices
of the membrane lipid bilayer. Using an advanced computational approach
that combines Coarse-Grained molecular dynamics and well-tempered
MetaDynamics (CG-MetaD), we characterize the large-scale motions
of the TM helices, simulating multiple association and dissociation
events between the helices in membrane, thus leading to a free energy
landscape of the dimerization process. The lowest energy state of
the TM domain is a right-handed dimer structure in which the TM helices
interact through the N-terminal small-X3-small sequence
motif. In addition to this state, which is thought to correspond to
the active form of the receptor, we have identified further low-energy
states that allow us to integrate with a high level of detail a range
of previous experimental observations. These conformations may lead
to the active state via two possible activation pathways, which involve
pivoting and rotational motions of the helices, respectively. Molecular
dynamics also reveals correlation between the conformational changes
of the TM domains and of the intracellular juxtamembrane domains,
paving the way for a comprehensive understanding of EGFR signaling
at the cell membrane.
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Affiliation(s)
- Mickaël Lelimousin
- Department of Biochemistry, University of Oxford , South Parks Road, Oxford OX1 3QU, U.K.,CERMAV, Université Grenoble Alpes and CNRS , BP 53, F-38041 Grenoble Cedex 9, France
| | - Vittorio Limongelli
- Università della Svizzera Italiana (USI), Faculty of Informatics, Institute of Computational Science - Center for Computational Medicine in Cardiology , via G. Buffi 13, CH-6900 Lugano, Switzerland.,Department of Pharmacy, University of Naples "Federico II" , via D. Montesano 49, I-80131 Naples, Italy
| | - Mark S P Sansom
- Department of Biochemistry, University of Oxford , South Parks Road, Oxford OX1 3QU, U.K
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Trenker R, Call MJ, Call ME. Progress and prospects for structural studies of transmembrane interactions in single-spanning receptors. Curr Opin Struct Biol 2016; 39:115-123. [DOI: 10.1016/j.sbi.2016.07.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 06/20/2016] [Accepted: 07/01/2016] [Indexed: 11/28/2022]
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49
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Ho CS, Khadka NK, She F, Cai J, Pan J. Influenza M2 Transmembrane Domain Senses Membrane Heterogeneity and Enhances Membrane Curvature. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:6730-6738. [PMID: 27285399 PMCID: PMC5131574 DOI: 10.1021/acs.langmuir.6b00150] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Targeting host cell membranes by M2 of influenza A virus is important for virus invasion and replication. We study the transmembrane domain of M2 (M2TM) interacting with mica-supported planar bilayers and free-standing giant unilamellar vesicles (GUVs). Using solution atomic force microscopy (AFM), we show that the size of M2TM oligomers is dependent on lipid composition. The addition of M2TM to lipid bilayers containing liquid-ordered (Lo) and liquid-disordered (Ld) phases reveals that M2TM preferentially partitions into the Ld phase; phase-dependent partitioning results in a larger rigidity of the Ld phase. We next use fluorescence microscopy to study the effects of M2TM on phase-coexisting GUVs. In particular, M2TM is found to increase GUVs' miscibility transition temperature Tmix. The augmented thermodynamic stability can be accounted for by considering an enhanced energy barrier of lipid mixing between coexisting phases. Our GUV study also shows that M2TM can elicit an array of vesicle shapes mimicking virus budding. M2TM enhanced membrane curvature is consistent with our AFM data, which show altered membrane rigidity and consequently line tension at domain edges. Together, our results highlight that in addition to conducting protons, M2TM can actively regulate membrane heterogeneity and augment membrane curvature.
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Affiliation(s)
- Chian Sing Ho
- Department of Physics, University of South Florida, Tampa, FL 33620, United States
| | - Nawal K. Khadka
- Department of Physics, University of South Florida, Tampa, FL 33620, United States
| | - Fengyu She
- Department of Chemistry, University of South Florida, Tampa, FL 33620, United States
| | - Jianfeng Cai
- Department of Chemistry, University of South Florida, Tampa, FL 33620, United States
| | - Jianjun Pan
- Department of Physics, University of South Florida, Tampa, FL 33620, United States
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50
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The Rap1-RIAM-talin axis of integrin activation and blood cell function. Blood 2016; 128:479-87. [PMID: 27207789 DOI: 10.1182/blood-2015-12-638700] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 05/07/2016] [Indexed: 12/14/2022] Open
Abstract
Integrin adhesion receptors mediate the adhesion of blood cells, such as leukocytes, to other cells, such as endothelial cells. Integrins also are critical for anchorage of hematopoietic precursors to the extracellular matrix. Blood cells can dynamically regulate the affinities of integrins for their ligands ("activation"), an event central to their functions. Here we review recent progress in understanding the mechanisms of integrin activation with a focus on the functions of blood cells. We discuss how talin binding to the integrin β cytoplasmic domain, in conjunction with the plasma membrane, induces long-range allosteric rearrangements that lead to integrin activation. Second, we review our understanding of how signaling events, particularly those involving Rap1 small guanosine triphosphate (GTP)hydrolases, can regulate the talin-integrin interaction and resulting activation. Third, we review recent findings that highlight the role of the Rap1-GTP-interacting adapter molecule (RIAM), encoded by the APBB1IP gene, in leukocyte integrin activation and consequently in leukocyte trafficking.
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