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Xiao Y, Zeng B, Berner N, Frishman D, Langosch D, George Teese M. Experimental determination and data-driven prediction of homotypic transmembrane domain interfaces. Comput Struct Biotechnol J 2020; 18:3230-3242. [PMID: 33209210 PMCID: PMC7649602 DOI: 10.1016/j.csbj.2020.09.035] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Revised: 09/22/2020] [Accepted: 09/24/2020] [Indexed: 12/22/2022] Open
Abstract
Homotypic TMD interfaces identified by different techniques share strong similarities. The GxxxG motif is the feature most strongly associated with interfaces. Other features include conservation, polarity, coevolution, and depth in the membrane The role of each of each feature strongly depends on the individual protein. Machine-learning helps predict interfaces from evolutionary sequence data
Interactions between their transmembrane domains (TMDs) frequently support the assembly of single-pass membrane proteins to non-covalent complexes. Yet, the TMD-TMD interactome remains largely uncharted. With a view to predicting homotypic TMD-TMD interfaces from primary structure, we performed a systematic analysis of their physical and evolutionary properties. To this end, we generated a dataset of 50 self-interacting TMDs. This dataset contains interfaces of nine TMDs from bitopic human proteins (Ire1, Armcx6, Tie1, ATP1B1, PTPRO, PTPRU, PTPRG, DDR1, and Siglec7) that were experimentally identified here and combined with literature data. We show that interfacial residues of these homotypic TMD-TMD interfaces tend to be more conserved, coevolved and polar than non-interfacial residues. Further, we suggest for the first time that interface positions are deficient in β-branched residues, and likely to be located deep in the hydrophobic core of the membrane. Overrepresentation of the GxxxG motif at interfaces is strong, but that of (small)xxx(small) motifs is weak. The multiplicity of these features and the individual character of TMD-TMD interfaces, as uncovered here, prompted us to train a machine learning algorithm. The resulting prediction method, THOIPA (www.thoipa.org), excels in the prediction of key interface residues from evolutionary sequence data.
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Affiliation(s)
- Yao Xiao
- Center for Integrated Protein Science Munich (CIPSM) at the Lehrstuhl für Chemie der Biopolymere, Technische Universität München, Weihenstephaner Berg 3, 85354 Freising, Germany
| | - Bo Zeng
- Department of Bioinformatics, Wissenschaftszentrum, Weihenstephan, Maximus-von-Imhof-Forum 3, Freising 85354, Germany
| | - Nicola Berner
- Center for Integrated Protein Science Munich (CIPSM) at the Lehrstuhl für Chemie der Biopolymere, Technische Universität München, Weihenstephaner Berg 3, 85354 Freising, Germany
| | - Dmitrij Frishman
- Department of Bioinformatics, Wissenschaftszentrum, Weihenstephan, Maximus-von-Imhof-Forum 3, Freising 85354, Germany.,Department of Bioinformatics, Peter the Great Saint Petersburg Polytechnic University, St. Petersburg 195251, Russian Federation
| | - Dieter Langosch
- Center for Integrated Protein Science Munich (CIPSM) at the Lehrstuhl für Chemie der Biopolymere, Technische Universität München, Weihenstephaner Berg 3, 85354 Freising, Germany
| | - Mark George Teese
- Center for Integrated Protein Science Munich (CIPSM) at the Lehrstuhl für Chemie der Biopolymere, Technische Universität München, Weihenstephaner Berg 3, 85354 Freising, Germany.,TNG Technology Consulting GmbH, Beta-Straße 13a, 85774 Unterföhring, Germany
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2
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Groeneweg S, van den Berge A, Lima de Souza EC, Meima ME, Peeters RP, Visser WE. Insights Into the Mechanism of MCT8 Oligomerization. J Endocr Soc 2020; 4:bvaa080. [PMID: 32724870 PMCID: PMC7375341 DOI: 10.1210/jendso/bvaa080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 06/12/2020] [Indexed: 12/03/2022] Open
Abstract
Mutations in the thyroid hormone transporter monocarboxylate transporter 8 (MCT8) result in MCT8 deficiency, characterized by severe intellectual and motor disability. The MCT8 protein is predicted to have 12 transmembrane domains (TMDs) and is expressed as monomers, homodimers, and homo-oligomers. This study aimed to delineate the mechanism of MCT8 oligomerization. Coimmunoprecipitation studies demonstrated that lithium dodecyl sulfate effectively disrupts MCT8 protein complexes, indicating the involvement of non-covalent interactions. Successive C-terminal truncations of the MCT8 protein altered the oligomerization pattern only if introduced in the N-terminal half of the protein (TMD1-6). The truncation at extracellular loop 1 (E206X) still allowed homodimerization, but completely abrogated homo-oligomerization, whereas both were preserved by the C231X mutant (at TMD2), suggesting that the minimally required oligomerization sites are located proximal of Cys231. However, mutant constructs lacking the intracellular N-terminus or TMD1 and 2 were still capable to form homo-oligomers. Therefore, other domains distal of Cys231 are also likely to be involved in the formation of extensive multidomain interactions. This hypothesis was supported by structural modeling. Despite multiple approaches, MCT8 oligomerization could not be fully abrogated unless a substantial part of the protein was removed, precluding detailed studies into its functional role. Together, our findings suggest that MCT8 oligomerization involves extensive noncovalent interactions between the N-terminal halves of MCT8 proteins. Most mutations identified in patients with MCT8 deficiency have only minor effects on MCT8 oligomerization and, thus, impaired oligomerization does not appear to be an important pathogenic mechanism.
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Affiliation(s)
- Stefan Groeneweg
- Academic Center for Thyroid Diseases, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Amanda van den Berge
- Academic Center for Thyroid Diseases, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Elaine C Lima de Souza
- Academic Center for Thyroid Diseases, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Marcel E Meima
- Academic Center for Thyroid Diseases, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Robin P Peeters
- Academic Center for Thyroid Diseases, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, the Netherlands
| | - W Edward Visser
- Academic Center for Thyroid Diseases, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, the Netherlands
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3
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Chai M, Liu B, Sun F, Zhu Z, Xu L, Luo SZ. The dimerization of PSGL-1 is driven by the transmembrane domain via a leucine zipper motif. Proteins 2018; 86:844-852. [PMID: 29569285 DOI: 10.1002/prot.25498] [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: 11/07/2017] [Revised: 02/11/2018] [Accepted: 03/19/2018] [Indexed: 11/11/2022]
Abstract
P-selectin glycoprotein ligand-1 (PSGL-1) is a homodimeric mucin ligand that is important to mediate the earliest adhesive event during an inflammatory response by rapidly forming and dissociating the selectin-ligand adhesive bonds. Recent research indicates that the noncovalent associations between the PSGL-1 transmembrane domains (TMDs) can substitute for the C320-dependent covalent bond to mediate the dimerization of PSGL-1. In this article, we combined TOXCAT assays and molecular dynamics (MD) simulations to probe the mechanism of PSGL-1 dimerization. The results of TOXCAT assays and Martini coarse-grained molecular dynamics (CG MD) simulations demonstrated that PSGL-1 TMDs strongly dimerized in a natural membrane and a leucine zipper motif was responsible for the noncovalent dimerization of PSGL-1 TMD since mutations of the residues that occupied a or d positions in an (abcdefg)n leucine heptad repeat motif significantly reduced the dimer activity. Furthermore, we studied the effects of the disulfide bond on the PSGL-1 dimer using MD simulations. The disulfide bond was critical to form the leucine zipper structure, by which the disulfide bond further improved the stability of the PSGL-1 dimer. These findings provide insights to understand the transmembrane association of PSGL-1 that is an important structural basis for PSGL-1 preferentially binding to P-selectin to achieve its biochemical and biophysical functions.
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Affiliation(s)
- Mengya Chai
- Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, People's Republic of China
| | - Bo Liu
- Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, People's Republic of China
| | - Fude Sun
- Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, People's Republic of China
| | - Zhentai Zhu
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, People's Republic of China
| | - Lida Xu
- Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, People's Republic of China
| | - Shi-Zhong Luo
- Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, People's Republic of China
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4
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Grau B, Javanainen M, García-Murria MJ, Kulig W, Vattulainen I, Mingarro I, Martínez-Gil L. The role of hydrophobic matching on transmembrane helix packing in cells. Cell Stress 2017; 1:90-106. [PMID: 31225439 PMCID: PMC6551820 DOI: 10.15698/cst2017.11.111] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Folding and packing of membrane proteins are highly influenced by the lipidic component of the membrane. Here, we explore how the hydrophobic mismatch (the difference between the hydrophobic span of a transmembrane protein region and the hydrophobic thickness of the lipid membrane around the protein) influences transmembrane helix packing in a cellular environment. Using a ToxRED assay in Escherichia coli and a Bimolecular Fluorescent Complementation approach in human-derived cells complemented by atomistic molecular dynamics simulations we analyzed the dimerization of Glycophorin A derived transmembrane segments. We concluded that, biological membranes can accommodate transmembrane homo-dimers with a wide range of hydrophobic lengths. Hydrophobic mismatch and its effects on dimerization are found to be considerably weaker than those previously observed in model membranes, or under in vitro conditions, indicating that biological membranes (particularly eukaryotic membranes) can adapt to structural deformations through compensatory mechanisms that emerge from their complex structure and composition to alleviate membrane stress. Results based on atomistic simulations support this view, as they revealed that Glycophorin A dimers remain stable, despite of poor hydrophobic match, using mechanisms based on dimer tilting or local membrane thickness perturbations. Furthermore, hetero-dimers with large length disparity between their monomers are also tolerated in cells, and the conclusions that one can draw are essentially similar to those found with homo-dimers. However, large differences between transmembrane helices length hinder the monomer/dimer equilibrium, confirming that, the hydrophobic mismatch has, nonetheless, biologically relevant effects on helix packing in vivo.
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Affiliation(s)
- Brayan Grau
- Departamento de Bioquímica y Biología Molecular, ERI BioTecMed, Universitat de València, E-46100 Burjassot, Spain
| | - Matti Javanainen
- Laboratory of Physics, Tampere University of Technology, FI-33101 Tampere, Finland.,Department of Physics, University of Helsinki, POB 64, FI-00014 Helsinki, Finland
| | - Maria Jesús García-Murria
- Departamento de Bioquímica y Biología Molecular, ERI BioTecMed, Universitat de València, E-46100 Burjassot, Spain
| | - Waldemar Kulig
- Laboratory of Physics, Tampere University of Technology, FI-33101 Tampere, Finland.,Department of Physics, University of Helsinki, POB 64, FI-00014 Helsinki, Finland
| | - Ilpo Vattulainen
- Laboratory of Physics, Tampere University of Technology, FI-33101 Tampere, Finland.,Department of Physics, University of Helsinki, POB 64, FI-00014 Helsinki, Finland.,MEMPHYS - Centre for Biomembrane Physics
| | - Ismael Mingarro
- Departamento de Bioquímica y Biología Molecular, ERI BioTecMed, Universitat de València, E-46100 Burjassot, Spain
| | - Luis Martínez-Gil
- Departamento de Bioquímica y Biología Molecular, ERI BioTecMed, Universitat de València, E-46100 Burjassot, Spain
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5
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Anderson SM, Mueller BK, Lange EJ, Senes A. Combination of Cα-H Hydrogen Bonds and van der Waals Packing Modulates the Stability of GxxxG-Mediated Dimers in Membranes. J Am Chem Soc 2017; 139:15774-15783. [PMID: 29028318 PMCID: PMC5927632 DOI: 10.1021/jacs.7b07505] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The GxxxG motif is frequently found at the dimerization interface of a transmembrane structural motif called GASright, which is characterized by a short interhelical distance and a right-handed crossing angle between the helices. In GASright dimers, such as glycophorin A (GpA), BNIP3, and members of the ErbB family, the backbones of the helices are in contact, and they invariably display networks of 4 to 8 weak hydrogen bonds between Cα-H carbon donors and carbonyl acceptors on opposing helices (Cα-H···O═C hydrogen bonds). These networks of weak hydrogen bonds at the helix-helix interface are presumably stabilizing, but their energetic contribution to dimerization has yet to be determined experimentally. Here, we present a computational and experimental structure-based analysis of GASright dimers of different predicted stabilities, which show that a combination of van der Waals packing and Cα-H hydrogen bonding predicts the experimental trend of dimerization propensities. This finding provides experimental support for the hypothesis that the networks of Cα-H hydrogen bonds are major contributors to the free energy of association of GxxxG-mediated dimers. The structural comparison between groups of GASright dimers of different stabilities reveals distinct sequence as well as conformational preferences. Stability correlates with shorter interhelical distances, narrower crossing angles, better packing, and the formation of larger networks of Cα-H hydrogen bonds. The identification of these structural rules provides insight on how nature could modulate stability in GASright and finely tune dimerization to support biological function.
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Affiliation(s)
- Samantha M Anderson
- Department of Biochemistry, University of Wisconsin-Madison , 433 Babcock Drive, Madison, Wisconsin 53706, United States
| | - Benjamin K Mueller
- Department of Biochemistry, University of Wisconsin-Madison , 433 Babcock Drive, Madison, Wisconsin 53706, United States
| | - Evan J Lange
- Department of Biochemistry, University of Wisconsin-Madison , 433 Babcock Drive, Madison, Wisconsin 53706, United States
| | - Alessandro Senes
- Department of Biochemistry, University of Wisconsin-Madison , 433 Babcock Drive, Madison, Wisconsin 53706, United States
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6
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Chai M, Liu B, Sun F, Wei P, Chen P, Xu L, Luo SZ. Insights into the transmembrane helix associations of kit ligand by molecular dynamics simulation and TOXCAT. Proteins 2017; 85:1362-1370. [DOI: 10.1002/prot.25297] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2016] [Revised: 02/18/2017] [Accepted: 03/27/2017] [Indexed: 12/24/2022]
Affiliation(s)
- Mengya Chai
- Beijing Key Laboratory of Bioprocess College of Life Science and Technology; Beijing, University of Chemical Technology; Beijing 100029 China
| | - Bo Liu
- Beijing Key Laboratory of Bioprocess College of Life Science and Technology; Beijing, University of Chemical Technology; Beijing 100029 China
| | - Fude Sun
- Beijing Key Laboratory of Bioprocess College of Life Science and Technology; Beijing, University of Chemical Technology; Beijing 100029 China
| | - Peng Wei
- Beijing Key Laboratory of Bioprocess College of Life Science and Technology; Beijing, University of Chemical Technology; Beijing 100029 China
- School of Basic Medical Science; Beijing University of Chinese Medicine; Beijing 100029 China
| | - Peng Chen
- Beijing Key Laboratory of Bioprocess College of Life Science and Technology; Beijing, University of Chemical Technology; Beijing 100029 China
| | - Lida Xu
- Beijing Key Laboratory of Bioprocess College of Life Science and Technology; Beijing, University of Chemical Technology; Beijing 100029 China
| | - Shi-Zhong Luo
- Beijing Key Laboratory of Bioprocess College of Life Science and Technology; Beijing, University of Chemical Technology; Beijing 100029 China
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7
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Wei P, Sun FD, Zuo LM, Qu J, Chen P, Xu LD, Luo SZ. Critical residues and motifs for homodimerization of the first transmembrane domain of the plasma membrane glycoprotein CD36. J Biol Chem 2017; 292:8683-8693. [PMID: 28336533 DOI: 10.1074/jbc.m117.779595] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 03/09/2017] [Indexed: 12/19/2022] Open
Abstract
The plasma transmembrane (TM) glycoprotein CD36 is critically involved in many essential signaling processes, especially the binding/uptake of long-chain fatty acids and oxidized low-density lipoproteins. The association of CD36 potentially activates cytosolic protein tyrosine kinases that are thought to associate with the C-terminal cytoplasmic tail of CD36. To understand the mechanisms by which CD36 mediates ligand binding and signal transduction, we have characterized the homo-oligomeric interaction of CD36 TM domains in membrane environments and with molecular dynamics (MD) simulations. Analysis of pyrene- and coumarin-labeled TM1 peptides in SDS by FRET confirmed the homodimerization of the CD36 TM1 peptide. Homodimerization assays of CD36 TM domains with the TOXCAT technique showed that its first TM (TM1) domain, but not the second TM (TM2) domain, could homodimerize in a cell membrane. Small-residue, site-specific mutation scanning revealed that the CD36 TM1 dimerization is mediated by the conserved small residues Gly12, Gly16, Ala20, and Gly23 Furthermore, molecular dynamics (MD) simulation studies demonstrated that CD36 TM1 exhibited a switching dimerization with two right-handed packing modes driven by the 12GXXXGXXXA20 and 20AXXG23 motifs, and the mutational effect of G16I and G23I revealed these representative conformations of CD36 TM1. This packing switch pattern of CD36 TM1 homodimer was further examined and confirmed by FRET analysis of monobromobimane (mBBr)-labeled CD36 TM1 peptides. Overall, this work provides a structural basis for understanding the role of TM association in regulating signal transduction via CD36.
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Affiliation(s)
- Peng Wei
- From the Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China.,the School of Basic Medical Science, Beijing University of Chinese Medicine, Beijing 100029, China, and
| | - Fu-de Sun
- From the Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China
| | - Li-Min Zuo
- the Institute of Medicinal Biotechnology, Chinese Academy of Medical Science, Beijing 100050, China
| | - Jing Qu
- From the Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China
| | - Peng Chen
- From the Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China
| | - Li-da Xu
- From the Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China
| | - Shi-Zhong Luo
- From the Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China,
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8
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Screening for transmembrane association in divisome proteins using TOXGREEN, a high-throughput variant of the TOXCAT assay. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:2573-2583. [PMID: 27453198 DOI: 10.1016/j.bbamem.2016.07.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Revised: 07/15/2016] [Accepted: 07/19/2016] [Indexed: 11/21/2022]
Abstract
TOXCAT is a widely used genetic assay to study interactions of transmembrane helices within the inner membrane of the bacterium Escherichia coli. TOXCAT is based on a fusion construct that links a transmembrane domain of interest with a cytoplasmic DNA-binding domain from the Vibrio cholerae ToxR protein. Interaction driven by the transmembrane domain results in dimerization of the ToxR domain, which, in turn, activates the expression of the reporter gene chloramphenicol acetyl transferase (CAT). Quantification of CAT is used as a measure of the ability of the transmembrane domain to self-associate. Because the quantification of CAT is relatively laborious, we developed a high-throughput variant of the assay, TOXGREEN, based on the expression of super-folded GFP and detection of fluorescence directly in unprocessed cell cultures. Careful side-by-side comparison of TOXCAT and TOXGREEN demonstrates that the methods have comparable response, dynamic range, sensitivity and intrinsic variability both in LB and minimal media. The greatly enhanced workflow makes TOXGREEN much more scalable and ideal for screening, since hundreds of constructs can be rapidly assessed in 96 well plates. Even for small scale investigations, TOXGREEN significantly reduces time, labor and cost associated with the procedure. We demonstrate applicability with a large screening for self-association among the transmembrane domains of bitopic proteins of the divisome (FtsL, FtsB, FtsQ, FtsI, FtsN, ZipA and EzrA) belonging to 11 bacterial species. The analysis confirms a previously reported tendency for FtsB to self-associate, and suggests that the transmembrane domains of ZipA, EzrA and FtsN may also possibly oligomerize.
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9
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Sun F, Xu L, Chen P, Wei P, Qu J, Chen J, Luo SZ. Insights into the Packing Switching of the EphA2 Transmembrane Domain by Molecular Dynamic Simulations. J Phys Chem B 2015; 119:7816-24. [PMID: 26022644 DOI: 10.1021/acs.jpcb.5b01116] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Receptor tyrosine kinases play an important role in mediating cell migration and adhesion associated with various biology processes. With a single-span transmembrane domain (TMD), the activities of the receptors are regulated by the definite packing configurations of the TMDs. For the EphA2 receptor, increasing studies have been conducted to investigate the packing domains that induce its switching TMD dimerization. However, the inherent transformation mechanisms including the interrelations among the involved packing domains remain unclear. Herein, we applied multiple simulation methods to explore the underlying packing mechanisms within the EphA2 TMD dimer. Our results demonstrated that the G(540)xxxG(544) contributed to the formation of the right-handed configuration while the heptad repeat L(535)xxxG(539)xxA(542)xxxV(546)xxL(549)xxxG(553) motif together with the FFxH(559) region mediated the parallel mode. Furthermore, the FF(557) residues packing mutually as rigid riveting structures were found comparable to the heptad repeat motif in maintaining the parallel configuration. In addition, the H(559) residue associated definitely with the lower bilayer leaflet, which was proved to stabilize the parallel mode significantly. The simulations provide a full range of insights into the essential packing motifs or residues involved in the switching TMD dimer configurations, which can enrich our comprehension toward the EphA2 receptor.
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Affiliation(s)
- Fude Sun
- Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China
| | - Lida Xu
- Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China
| | - Peng Chen
- Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China
| | - Peng Wei
- Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China
| | - Jing Qu
- Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China
| | - Jialin Chen
- Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China
| | - Shi-Zhong Luo
- Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China
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10
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The membrane- and soluble-protein helix-helix interactome: similar geometry via different interactions. Structure 2015; 23:527-541. [PMID: 25703378 DOI: 10.1016/j.str.2015.01.009] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 12/17/2014] [Accepted: 01/06/2015] [Indexed: 12/25/2022]
Abstract
α Helices are a basic unit of protein secondary structure and therefore the interaction between helices is crucial to understanding tertiary and higher-order folds. Comparing subtle variations in the structural and sequence motifs between membrane and soluble proteins sheds light on the different constraints faced by each environment and elucidates the complex puzzle of membrane protein folding. Here, we demonstrate that membrane and water-soluble helix pairs share a small number of similar folds with various interhelical distances. The composition of the residues that pack at the interface between corresponding motifs shows that hydrophobic residues tend to be more enriched in the water-soluble class of structures and small residues in the transmembrane class. The latter group facilitates packing via sidechain- and backbone-mediated hydrogen bonds within the low-dielectric membrane milieu. The helix-helix interactome space, with its associated sequence preferences and accompanying hydrogen-bonding patterns, should be useful for engineering, prediction, and design of protein structure.
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11
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Ziani W, Maillard AP, Petit-Härtlein I, Garnier N, Crouzy S, Girard E, Covès J. The X-ray structure of NccX from Cupriavidus metallidurans 31A illustrates potential dangers of detergent solubilization when generating and interpreting crystal structures of membrane proteins. J Biol Chem 2014; 289:31160-72. [PMID: 25258316 DOI: 10.1074/jbc.m114.586537] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The x-ray structure of NccX, a type II transmembrane metal sensor, from Cupriavidus metallidurans 31A has been determined at a resolution of 3.12 Å. This was achieved after solubilization by dodecylphosphocholine and purification in the presence of the detergent. NccX crystal structure did not match the model based on the extensively characterized periplasmic domain of its closest homologue CnrX. Instead, the periplasmic domains of NccX appeared collapsed against the hydrophobic transmembrane segments, leading to an aberrant topology incompatible with membrane insertion. This was explained by a detergent-induced redistribution of the hydrophobic interactions among the transmembrane helices and a pair of hydrophobic patches keeping the periplasmic domains together in the native dimer. Molecular dynamics simulations performed with the full-length protein or with the transmembrane segments were used along with in vivo homodimerization assays (TOXCAT) to evaluate the determinants of the interactions between NccX protomers. Taken as a whole, computational and experimental results are in agreement with the structural model of CnrX where a cradle-shaped periplasmic metal sensor domain is anchored into the inner membrane by two N-terminal helices. In addition, they show that the main determinant of NccX dimerization is the periplasmic soluble domain and that the interaction between transmembrane segments is highly dynamic. The present work introduces a new crystal structure for a transmembrane protein and, in line with previous studies, substantiates the use of complementary theoretical and in vivo investigations to rationalize a three-dimensional structure obtained in non-native conditions.
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Affiliation(s)
- Widade Ziani
- From the Institut de Biologie Structurale, UMR 5075 CNRS-Commissariat à l'Energie Atomique (CEA)-Université Grenoble-Alpes, 71 Avenue des Martyrs, 38044 Grenoble Cedex 9, France
| | - Antoine P Maillard
- From the Institut de Biologie Structurale, UMR 5075 CNRS-Commissariat à l'Energie Atomique (CEA)-Université Grenoble-Alpes, 71 Avenue des Martyrs, 38044 Grenoble Cedex 9, France
| | - Isabelle Petit-Härtlein
- From the Institut de Biologie Structurale, UMR 5075 CNRS-Commissariat à l'Energie Atomique (CEA)-Université Grenoble-Alpes, 71 Avenue des Martyrs, 38044 Grenoble Cedex 9, France
| | - Norbert Garnier
- Centre de Biophysique Moléculaire, CNRS UPR4301 affiliated to the University of Orléans, Rue Charles Sadron, 45071 Orléans Cedex 2, France, and
| | - Serge Crouzy
- Laboratoire de Chimie et Biologie des Métaux, UMR 5249, CEA-Grenoble, 17 Avenue des Martyrs, 38054 Grenoble Cedex 09, France
| | - Eric Girard
- From the Institut de Biologie Structurale, UMR 5075 CNRS-Commissariat à l'Energie Atomique (CEA)-Université Grenoble-Alpes, 71 Avenue des Martyrs, 38044 Grenoble Cedex 9, France
| | - Jacques Covès
- From the Institut de Biologie Structurale, UMR 5075 CNRS-Commissariat à l'Energie Atomique (CEA)-Université Grenoble-Alpes, 71 Avenue des Martyrs, 38044 Grenoble Cedex 9, France,
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Reuven EM, Fink A, Shai Y. Regulation of innate immune responses by transmembrane interactions: lessons from the TLR family. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:1586-93. [PMID: 24480409 DOI: 10.1016/j.bbamem.2014.01.020] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Revised: 01/15/2014] [Accepted: 01/18/2014] [Indexed: 02/06/2023]
Abstract
The mammalian innate immune response is responsible for the early stages of defense against invading pathogens. One of the major receptor families facilitating innate immune activation is the Toll-like receptor (TLR) family. These receptors are type 1 membrane proteins spanning the membrane with a single transmembrane domain (TMD). All TLRs form homo- and hetero-dimers within membranes and new data suggest that the single transmembrane domain of some of these receptors is involved in their dimerization and function. Newly identified TLR dimers are continuously reported but only little is known about the importance of the TMDs for their dimer assembly and signaling regulation. Uncontrolled or untimely activation of TLRs is related to a large number of pathologies ranging from cystic fibrosis to sepsis and cancer. In this review we will focus on the contribution of the TMDs of innate immune receptors - specifically TLR2-to their regulation and function. In addition, we will address the current issues remaining to be solved regarding the mechanistic insights of this regulation. This article is part of a Special Issue entitled: Membrane Structure and Function: Relevance in the Cell's Physiology, Pathology and Therapy.
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Affiliation(s)
- Eliran Moshe Reuven
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Avner Fink
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Yechiel Shai
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel.
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Zhou L, Yang W, Li R. Analysis of inter-subunit contacts reveals the structural malleability of extracellular domains in platelet glycoprotein Ib-IX complex. J Thromb Haemost 2014; 12:82-9. [PMID: 24406065 PMCID: PMC4137403 DOI: 10.1111/jth.12437] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Indexed: 11/28/2022]
Abstract
BACKGROUND The glycoprotein (GP)Ib-IX complex is critical to hemostasis and thrombosis. Its proper assembly is closely correlated with its surface expression level and requires cooperative interactions among extracellular and transmembrane domains of Ibα, Ibβ and IX subunits. Two interfaces have been previously identified between the extracellular domains of Ibβ and IX. OBJECTIVE To understand how extracellular domains interact in GPIb-IX. METHODS The Ibβ extracellular domain (IbβE ) or the IX counterpart (IXE ) in GPIb-IX was replaced with a well-folded IbβE /IXE chimera called IbβEabc , and the effect of domain replacement on assembly and expression of the receptor complex in transiently transfected Chinese hamster ovary cells was analyzed. RESULTS Replacing IXE with IbβEabc in GPIb-IX retained interface 1 but not interface 2 between the extracellular domains. While this domain replacement preserved complex integrity, the expression levels of Ibβ and Ibα were significantly reduced. Additional domain replacement with IbβEabc or IbβE in GPIb-IX produced the complex at disparate expression levels that cannot be simply explained by two separate interfaces. In particular, when IbβE in GPIb-IX was replaced by IbβEabc , Ibα and IX were expressed at approximately 70% of the wild-type level. Their levels were not reduced when IXE was changed further to IbβE . CONCLUSIONS Our results demonstrate the importance of the association between Ibβ and IX extracellular domains for complex assembly and efficient expression, and provide evidence for the structural malleability of these domains that may accommodate and propagate conformational changes therein.
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Affiliation(s)
- L Zhou
- Department of Pediatrics, Aflac Cancer and Blood Disorders Center, Emory University School of Medicine, Atlanta, GA, USA
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Wei P, Zheng BK, Guo PR, Kawakami T, Luo SZ. The association of polar residues in the DAP12 homodimer: TOXCAT and molecular dynamics simulation studies. Biophys J 2013; 104:1435-44. [PMID: 23561520 DOI: 10.1016/j.bpj.2013.01.054] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Revised: 01/18/2013] [Accepted: 01/24/2013] [Indexed: 01/09/2023] Open
Abstract
Dimerization of the transmembrane (TM) adaptor protein DAP12 plays a key role in mediating activation signals through TM-TM association with cell-surface receptors. Herein, we apply the TOXCAT assay and molecular dynamics simulation to analyze dynamics and dimerization of the TM helix of DAP12 in the membrane bilayer. In the TOXCAT assay, we performed site-specific mutagenesis of potential dimerization motifs in the DAP12 TM domain. Instead of the common GxxxG dimerization motif, mutating either of the polar residues Asp-50 and Thr-54 significantly decreased the TOXCAT signal for the dimerization of DAP12 TM domain. Furthermore, through the conformational difference between wild-type and mutant DAP12 TM homodimers, a combined coarse-grained and atomistic molecular dynamics simulation has identified both Asp-50 and Thr-54 at the dimerization interface. The experimental and computational results of the DAP12 TM dimer are in excellent agreement with the previously reported NMR structure obtained in detergent micelles. Such a combination of dynamics simulation and cell-based experiments can be applied to produce insights at the molecular level into the TM-TM association of many other transmembrane proteins.
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Affiliation(s)
- Peng Wei
- Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, People's Republic of China
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Prasanna X, Praveen PJ, Sengupta D. Sequence dependent lipid-mediated effects modulate the dimerization of ErbB2 and its associative mutants. Phys Chem Chem Phys 2013; 15:19031-41. [DOI: 10.1039/c3cp52447g] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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