1
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Mihalič F, Arcila D, Pettersson ME, Farkhondehkish P, Andersson E, Andersson L, Betancur-R R, Jemth P. Conservation of Affinity Rather Than Sequence Underlies a Dynamic Evolution of the Motif-Mediated p53/MDM2 Interaction in Ray-Finned Fishes. Mol Biol Evol 2024; 41:msae018. [PMID: 38301272 PMCID: PMC10901556 DOI: 10.1093/molbev/msae018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 12/12/2023] [Accepted: 01/22/2024] [Indexed: 02/03/2024] Open
Abstract
The transcription factor and cell cycle regulator p53 is marked for degradation by the ubiquitin ligase MDM2. The interaction between these 2 proteins is mediated by a conserved binding motif in the disordered p53 transactivation domain (p53TAD) and the folded SWIB domain in MDM2. The conserved motif in p53TAD from zebrafish displays a 20-fold weaker interaction with MDM2, compared to the interaction in human and chicken. To investigate this apparent difference, we tracked the molecular evolution of the p53TAD/MDM2 interaction among ray-finned fishes (Actinopterygii), the largest vertebrate clade. Intriguingly, phylogenetic analyses, ancestral sequence reconstructions, and binding experiments showed that different loss-of-affinity changes in the canonical binding motif within p53TAD have occurred repeatedly and convergently in different fish lineages, resulting in relatively low extant affinities (KD = 0.5 to 5 μM). However, for 11 different fish p53TAD/MDM2 interactions, nonconserved regions flanking the canonical motif increased the affinity 4- to 73-fold to be on par with the human interaction. Our findings suggest that compensating changes at conserved and nonconserved positions within the motif, as well as in flanking regions of low conservation, underlie a stabilizing selection of "functional affinity" in the p53TAD/MDM2 interaction. Such interplay complicates bioinformatic prediction of binding and calls for experimental validation. Motif-mediated protein-protein interactions involving short binding motifs and folded interaction domains are very common across multicellular life. It is likely that the evolution of affinity in motif-mediated interactions often involves an interplay between specific interactions made by conserved motif residues and nonspecific interactions by nonconserved disordered regions.
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Affiliation(s)
- Filip Mihalič
- Department of Medical Biochemistry and Microbiology, Uppsala University, BMC, Uppsala SE-75123, Sweden
| | - Dahiana Arcila
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093, USA
| | - Mats E Pettersson
- Department of Medical Biochemistry and Microbiology, Uppsala University, BMC, Uppsala SE-75123, Sweden
| | - Pouria Farkhondehkish
- Department of Medical Biochemistry and Microbiology, Uppsala University, BMC, Uppsala SE-75123, Sweden
| | - Eva Andersson
- Department of Medical Biochemistry and Microbiology, Uppsala University, BMC, Uppsala SE-75123, Sweden
| | - Leif Andersson
- Department of Medical Biochemistry and Microbiology, Uppsala University, BMC, Uppsala SE-75123, Sweden
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX 77483, USA
| | - Ricardo Betancur-R
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093, USA
| | - Per Jemth
- Department of Medical Biochemistry and Microbiology, Uppsala University, BMC, Uppsala SE-75123, Sweden
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2
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Mohanty P, Rizuan A, Kim YC, Fawzi NL, Mittal J. A complex network of interdomain interactions underlies the conformational ensemble of monomeric TDP-43 and modulates its phase behavior. Protein Sci 2024; 33:e4891. [PMID: 38160320 PMCID: PMC10804676 DOI: 10.1002/pro.4891] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 12/07/2023] [Accepted: 12/28/2023] [Indexed: 01/03/2024]
Abstract
TAR DNA-binding protein 43 (TDP-43) is a multidomain protein involved in the regulation of RNA metabolism, and its aggregates have been observed in neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Numerous studies indicate TDP-43 can undergo liquid-liquid phase separation (LLPS) in vitro and is a component of biological condensates. Homo-oligomerization via the folded N-terminal domain (aa:1-77) and the conserved helical region (aa:319-341) of the disordered, C-terminal domain is found to be an important driver of TDP-43 phase separation. However, a comprehensive molecular view of TDP-43 phase separation, particularly regarding the nature of heterodomain interactions, is lacking due to the challenges associated with its stability and purification. Here, we utilize all-atom and coarse-grained (CG) molecular dynamics (MD) simulations to uncover the network of interdomain interactions implicated in TDP-43 phase separation. All-atom simulations uncovered the presence of transient, interdomain interactions involving flexible linkers, RNA-recognition motif (RRM) domains and a charged segment of disordered C-terminal domain (CTD). CG simulations indicate these inter-domain interactions which affect the conformational landscape of TDP-43 in the dilute phase are also prevalent in the condensed phase. Finally, sequence and surface charge distribution analysis coupled with all-atom simulations (at high salt) confirmed that the transient interdomain contacts are predominantly electrostatic in nature. Overall, our findings from multiscale simulations lead to a greater appreciation of the complex interaction network underlying the structural landscape and phase separation of TDP-43.
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Affiliation(s)
- Priyesh Mohanty
- Artie McFerrin Department of Chemical EngineeringTexas A&M UniversityCollege StationTexasUSA
| | - Azamat Rizuan
- Artie McFerrin Department of Chemical EngineeringTexas A&M UniversityCollege StationTexasUSA
| | - Young C. Kim
- Naval Research LaboratoryCenter for Materials Physics and TechnologyWashingtonDistrict of ColumbiaUSA
| | - Nicolas L. Fawzi
- Department of Molecular Biology, Cell Biology and BiochemistryProvidenceRhode IslandUSA
| | - Jeetain Mittal
- Artie McFerrin Department of Chemical EngineeringTexas A&M UniversityCollege StationTexasUSA
- Department of ChemistryTexas A&M UniversityCollege StationTexasUSA
- Interdisciplinary Graduate Program in Genetics and GenomicsTexas A&M UniversityCollege StationTexasUSA
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3
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Krishnamohan A, Hamilton GL, Goutam R, Sanabria H, Morcos F. Coevolution and smFRET Enhances Conformation Sampling and FRET Experimental Design in Tandem PDZ1-2 Proteins. J Phys Chem B 2023; 127:884-898. [PMID: 36693159 PMCID: PMC9900596 DOI: 10.1021/acs.jpcb.2c06720] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The structural flexibility of proteins is crucial for their functions. Many experimental and computational approaches can probe protein dynamics across a range of time and length-scales. Integrative approaches synthesize the complementary outputs of these techniques and provide a comprehensive view of the dynamic conformational space of proteins, including the functionally relevant limiting conformational states and transition pathways between them. Here, we introduce an integrative paradigm to model the conformational states of multidomain proteins. As a model system, we use the first two tandem PDZ domains of postsynaptic density protein 95. First, we utilize available sequence information collected from genomic databases to identify potential amino acid interactions in the PDZ1-2 tandem that underlie modeling of the functionally relevant conformations maintained through evolution. This was accomplished through combination of coarse-grained structural modeling with outputs from direct coupling analysis measuring amino acid coevolution, a hybrid approach called SBM+DCA. We recapitulated five distinct, experimentally derived PDZ1-2 tandem conformations. In addition, SBM+DCA unveiled an unidentified, twisted conformation of the PDZ1-2 tandem. Finally, we implemented an integrative framework for the design of single-molecule Förster resonance energy transfer (smFRET) experiments incorporating the outputs of SBM+DCA with simulated FRET observables. This resulting FRET network is designed to mutually resolve the predicted limiting state conformations through global analysis. Using simulated FRET observables, we demonstrate that structural modeling with the newly designed FRET network is expected to outperform a previously used empirical FRET network at resolving all states simultaneously. Integrative approaches to experimental design have the potential to provide a new level of detail in characterizing the evolutionarily conserved conformational landscapes of proteins, and thus new insights into functional relevance of protein dynamics in biological function.
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Affiliation(s)
- Aishwarya Krishnamohan
- Departments of Biological Sciences and Bioengineering, University of Texas at Dallas, Richardson, Texas75080, United States
| | - George L Hamilton
- Department of Physics and Astronomy, Clemson University, Clemson, South Carolina29634, United States
| | - Rajen Goutam
- Department of Physics and Astronomy, Clemson University, Clemson, South Carolina29634, United States
| | - Hugo Sanabria
- Department of Physics and Astronomy, Clemson University, Clemson, South Carolina29634, United States
| | - Faruck Morcos
- Departments of Biological Sciences and Bioengineering, University of Texas at Dallas, Richardson, Texas75080, United States.,Center for Systems Biology, University of Texas at Dallas, Richardson, Texas75080, United States
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4
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Ibanes S, El-Alaoui F, Lai-Kee-Him J, Cazevieille C, Hoh F, Lyonnais S, Bron P, Cipelletti L, Picas L, Piatti S. The Syp1/FCHo2 protein induces septin filament bundling through its intrinsically disordered domain. Cell Rep 2022; 41:111765. [PMID: 36476870 DOI: 10.1016/j.celrep.2022.111765] [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: 03/07/2022] [Revised: 09/30/2022] [Accepted: 11/10/2022] [Indexed: 12/12/2022] Open
Abstract
The septin collar of budding yeast is an ordered array of septin filaments that serves a scaffolding function for the cytokinetic machinery at the bud neck and compartmentalizes the membrane between mother and daughter cell. How septin architecture is aided by septin-binding proteins is largely unknown. Syp1 is an endocytic protein that was implicated in the timely recruitment of septins to the newly forming collar through an unknown mechanism. Using advanced microscopy and in vitro reconstitution assays, we show that Syp1 is able to align laterally and tightly pack septin filaments, thereby forming flat bundles or sheets. This property is shared by the Syp1 mammalian counterpart FCHo2, thus emphasizing conserved protein functions. Interestingly, the septin-bundling activity of Syp1 resides mainly in its intrinsically disordered region. Our data uncover the mechanism through which Syp1 promotes septin collar assembly and offer another example of functional diversity of unstructured protein domains.
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Affiliation(s)
- Sandy Ibanes
- CRBM (Centre de Recherche en Biologie cellulaire de Montpellier), University of Montpellier, CNRS UMR 5237, 1919 Route de Mende, 34293 Montpellier, France
| | - Fatima El-Alaoui
- IRIM (Institut de Recherche en Infectiologie de Montpellier), University of Montpellier, CNRS UMR 9004, 1919 Route de Mende, 34293 Montpellier, France
| | - Joséphine Lai-Kee-Him
- CBS (Centre de Biologie Structurale), University of Montpellier, CNRS UMR 5048, INSERM U 1054, 29 Rue de Navacelles, 34090 Montpellier, France
| | - Chantal Cazevieille
- COMET Electron Microscopy Platform, INM (Institute for Neurosciences of Montpellier), University of Montpellier, INSERM U 1298, 80 Rue Augustin Fliche, 34091 Montpellier, France
| | - François Hoh
- CBS (Centre de Biologie Structurale), University of Montpellier, CNRS UMR 5048, INSERM U 1054, 29 Rue de Navacelles, 34090 Montpellier, France
| | - Sébastien Lyonnais
- CEMIPAI (Centre d'Etudes des Maladies Infectieuses et Pharmacologie Anti-Infectieuse), University of Montpellier, UAR 3725 CNRS, Montpellier, France
| | - Patrick Bron
- CBS (Centre de Biologie Structurale), University of Montpellier, CNRS UMR 5048, INSERM U 1054, 29 Rue de Navacelles, 34090 Montpellier, France
| | - Luca Cipelletti
- L2C (Laboratoire Charles Coulomb), University of Montpellier, CNRS, Place E. Bataillon, 34095 Montpellier, France; IUF (Institut Universitaire de France), Paris, France
| | - Laura Picas
- IRIM (Institut de Recherche en Infectiologie de Montpellier), University of Montpellier, CNRS UMR 9004, 1919 Route de Mende, 34293 Montpellier, France
| | - Simonetta Piatti
- CRBM (Centre de Recherche en Biologie cellulaire de Montpellier), University of Montpellier, CNRS UMR 5237, 1919 Route de Mende, 34293 Montpellier, France.
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5
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Laursen L, Inturi R, Østergaard S, Jemth P. Determinants of affinity, specificity, and phase separation in a supramodule from Post-synaptic density protein 95. iScience 2022; 25:105069. [PMID: 36157580 PMCID: PMC9490041 DOI: 10.1016/j.isci.2022.105069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 07/01/2022] [Accepted: 08/30/2022] [Indexed: 11/26/2022] Open
Abstract
The post-synaptic density (PSD) is a phase-separated membraneless compartment of proteins including PSD-95 that undergoes morphological alteration in response to synaptic activity. Here, we investigated the interactome of a three-domain supramodule, PDZ3-SH3-GK (PSG) from PSD-95 using bioinformatics to identify potential binding partners, and biophysical methods to characterize the interaction with peptides from these proteins. PSG and the single PDZ3 domain bound similar peptides, but with different specificity. Furthermore, we found that the protein ADGRB1 formed liquid droplets with the PSG supramodule, extending the model for PSD formation. Moreover, certain mutations, introduced outside of the binding pocket in PDZ3, increased the affinity and specificity of the interaction and the size of liquid droplets. Other mutations within the ligand binding pocket lead to a new binding motif specificity. Our results show how the context in terms of supertertiary structure modulates affinity, specificity, and phase separation, and how these properties can evolve by point mutation. Identification of potential binding partners for PSD-95 in the post-synaptic density ADGRB1 and PSD-95 undergo liquid-liquid phase separation (LLPS) Single domain PDZ3 cannot induce LLPS and binds weakly to ADGRB1 and SynGap Supertertiary structure alters the affinity, specificity, and phase separation
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Affiliation(s)
- Louise Laursen
- Department of Medical Biochemistry and Microbiology, Uppsala University, BMC Box 582, 75123 Uppsala, Sweden
| | - Raviteja Inturi
- Department of Medical Biochemistry and Microbiology, Uppsala University, BMC Box 582, 75123 Uppsala, Sweden
| | - Søren Østergaard
- Global Research Technology, Novo Nordisk A/S, Novo Nordisk Research Park, 2760 Maalov, Denmark
| | - Per Jemth
- Department of Medical Biochemistry and Microbiology, Uppsala University, BMC Box 582, 75123 Uppsala, Sweden
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6
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Handa T, Kundu D, Dubey VK. Perspectives on evolutionary and functional importance of intrinsically disordered proteins. Int J Biol Macromol 2022; 224:243-255. [DOI: 10.1016/j.ijbiomac.2022.10.120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 10/08/2022] [Accepted: 10/10/2022] [Indexed: 11/05/2022]
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7
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Hamilton GL, Saikia N, Basak S, Welcome FS, Wu F, Kubiak J, Zhang C, Hao Y, Seidel CAM, Ding F, Sanabria H, Bowen ME. Fuzzy supertertiary interactions within PSD-95 enable ligand binding. eLife 2022; 11:e77242. [PMID: 36069777 PMCID: PMC9581536 DOI: 10.7554/elife.77242] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 09/06/2022] [Indexed: 11/13/2022] Open
Abstract
The scaffold protein PSD-95 links postsynaptic receptors to sites of presynaptic neurotransmitter release. Flexible linkers between folded domains in PSD-95 enable a dynamic supertertiary structure. Interdomain interactions within the PSG supramodule, formed by PDZ3, SH3, and Guanylate Kinase domains, regulate PSD-95 activity. Here we combined discrete molecular dynamics and single molecule Förster resonance energy transfer (FRET) to characterize the PSG supramodule, with time resolution spanning picoseconds to seconds. We used a FRET network to measure distances in full-length PSD-95 and model the conformational ensemble. We found that PDZ3 samples two conformational basins, which we confirmed with disulfide mapping. To understand effects on activity, we measured binding of the synaptic adhesion protein neuroligin. We found that PSD-95 bound neuroligin well at physiological pH while truncated PDZ3 bound poorly. Our hybrid structural models reveal how the supertertiary context of PDZ3 enables recognition of this critical synaptic ligand.
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Affiliation(s)
- George L Hamilton
- Department of Physics and Astronomy, Clemson UniversityClemsonUnited States
| | - Nabanita Saikia
- Department of Physics and Astronomy, Clemson UniversityClemsonUnited States
| | - Sujit Basak
- Department of Physiology and Biophysics, Stony Brook UniversityStony BrookUnited States
| | - Franceine S Welcome
- Department of Physiology and Biophysics, Stony Brook UniversityStony BrookUnited States
| | - Fang Wu
- Department of Physiology and Biophysics, Stony Brook UniversityStony BrookUnited States
| | - Jakub Kubiak
- Molecular Physical Chemistry, Heinrich Heine UniversityDüsseldorfGermany
| | - Changcheng Zhang
- Department of Physiology and Biophysics, Stony Brook UniversityStony BrookUnited States
| | - Yan Hao
- Department of Physiology and Biophysics, Stony Brook UniversityStony BrookUnited States
| | - Claus AM Seidel
- Molecular Physical Chemistry, Heinrich Heine UniversityDüsseldorfGermany
| | - Feng Ding
- Department of Physics and Astronomy, Clemson UniversityClemsonUnited States
| | - Hugo Sanabria
- Department of Physics and Astronomy, Clemson UniversityClemsonUnited States
| | - Mark E Bowen
- Department of Physiology and Biophysics, Stony Brook UniversityStony BrookUnited States
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8
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Dominguez MJ, McCord JJ, Sutton RB. Redefining the architecture of ferlin proteins: Insights into multi-domain protein structure and function. PLoS One 2022; 17:e0270188. [PMID: 35901179 PMCID: PMC9333456 DOI: 10.1371/journal.pone.0270188] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 06/07/2022] [Indexed: 11/18/2022] Open
Abstract
Ferlins are complex, multi-domain proteins, involved in membrane trafficking, membrane repair, and exocytosis. The large size of ferlin proteins and the lack of consensus regarding domain boundaries have slowed progress in understanding molecular-level details of ferlin protein structure and function. However, in silico protein folding techniques have significantly enhanced our understanding of the complex ferlin family domain structure. We used RoseTTAFold to assemble full-length models for the six human ferlin proteins (dysferlin, myoferlin, otoferlin, Fer1L4, Fer1L5, and Fer1L6). Our full-length ferlin models were used to obtain objective domain boundaries, and these boundaries were supported by AlphaFold2 predictions. Despite the differences in amino acid sequence between the ferlin proteins, the domain ranges and distinct subdomains in the ferlin domains are remarkably consistent. Further, the RoseTTAFold/AlphaFold2 in silico boundary predictions allowed us to describe and characterize a previously unknown C2 domain, ubiquitous in all human ferlins, which we refer to as C2-FerA. At present, the ferlin domain-domain interactions implied by the full-length in silico models are predicted to have a low accuracy; however, the use of RoseTTAFold and AlphaFold2 as a domain finder has proven to be a powerful research tool for understanding ferlin structure.
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Affiliation(s)
- Matthew J. Dominguez
- Department of Cell Physiology and Molecular Biophysics, Texas Tech University Health Sciences Center, Lubbock, TX, United States of America
| | - Jon J. McCord
- Department of Cell Physiology and Molecular Biophysics, Texas Tech University Health Sciences Center, Lubbock, TX, United States of America
| | - R. Bryan Sutton
- Department of Cell Physiology and Molecular Biophysics, Texas Tech University Health Sciences Center, Lubbock, TX, United States of America
- Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, TX, United States of America
- * E-mail:
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9
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Dionne U, Percival LJ, Chartier FJM, Landry CR, Bisson N. SRC homology 3 domains: multifaceted binding modules. Trends Biochem Sci 2022; 47:772-784. [PMID: 35562294 DOI: 10.1016/j.tibs.2022.04.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/30/2022] [Accepted: 04/11/2022] [Indexed: 12/15/2022]
Abstract
The assembly of complexes following the detection of extracellular signals is often controlled by signaling proteins comprising multiple peptide binding modules. The SRC homology (SH)3 family represents the archetypical modular protein interaction module, with ~300 annotated SH3 domains in humans that regulate an impressive array of signaling processes. We review recent findings regarding the allosteric contributions of SH3 domains host protein context, their phosphoregulation, and their roles in phase separation that challenge the simple model in which SH3s are considered to be portable domains binding to specific proline-rich peptide motifs.
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Affiliation(s)
- Ugo Dionne
- Centre de recherche sur le cancer et Centre de recherche du CHU de Québec - Université Laval, QC, Canada; Quebec Network for Research on Protein Function, Engineering, and Applications (PROTEO), QC, Canada
| | - Lily J Percival
- Centre de recherche sur le cancer et Centre de recherche du CHU de Québec - Université Laval, QC, Canada; Quebec Network for Research on Protein Function, Engineering, and Applications (PROTEO), QC, Canada; School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, The Michael Smith Building, Manchester, UK
| | - François J M Chartier
- Centre de recherche sur le cancer et Centre de recherche du CHU de Québec - Université Laval, QC, Canada; Quebec Network for Research on Protein Function, Engineering, and Applications (PROTEO), QC, Canada
| | - Christian R Landry
- Quebec Network for Research on Protein Function, Engineering, and Applications (PROTEO), QC, Canada; Institute of Integrative and Systems Biology, Université Laval, Quebec, QC, Canada; Department of Biochemistry, Microbiology and Bioinformatics, Université Laval, Quebec, QC, Canada; Department of Biology, Université Laval, Quebec, QC, Canada.
| | - Nicolas Bisson
- Centre de recherche sur le cancer et Centre de recherche du CHU de Québec - Université Laval, QC, Canada; Quebec Network for Research on Protein Function, Engineering, and Applications (PROTEO), QC, Canada; Department of Molecular Biology, Medical Biochemistry and Pathology, Université Laval, Quebec, QC, Canada.
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10
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Basak S, Sakia N, Dougherty L, Guo Z, Wu F, Mindlin F, Lary JW, Cole JL, Ding F, Bowen ME. Probing Interdomain Linkers and Protein Supertertiary Structure In Vitro and in Live Cells with Fluorescent Protein Resonance Energy Transfer. J Mol Biol 2021; 433:166793. [PMID: 33388290 DOI: 10.1016/j.jmb.2020.166793] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 12/03/2020] [Accepted: 12/21/2020] [Indexed: 12/23/2022]
Abstract
Many proteins are composed of independently-folded domains connected by flexible linkers. The primary sequence and length of such linkers can set the effective concentration for the tethered domains, which impacts rates of association and enzyme activity. The length of such linkers can be sensitive to environmental conditions, which raises questions as to how studies in dilute buffer relate to the highly-crowded cellular environment. To examine the role of linkers in domain separation, we measured Fluorescent Protein-Fluorescence Resonance Energy Transfer (FP-FRET) for a series of tandem FPs that varied in the length of their interdomain linkers. We used discrete molecular dynamics to map the underlying conformational distribution, which revealed intramolecular contact states that we confirmed with single molecule FRET. Simulations found that attached FPs increased linker length and slowed conformational dynamics relative to the bare linkers. This makes the CLYs poor sensors of inherent linker properties. However, we also showed that FP-FRET in CLYs was sensitive to solvent quality and macromolecular crowding making them potent environmental sensors. Finally, we targeted the same proteins to the plasma membrane of living mammalian cells to measure FP-FRET in cellulo. The measured FP-FRET when tethered to the plasma membrane was the same as that in dilute buffer. While caveats remain regarding photophysics, this suggests that the supertertiary conformational ensemble of these CLY proteins may not be affected by this specific cellular environment.
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Affiliation(s)
- Sujit Basak
- Department of Physiology & Biophysics, Stony Brook University, Stony Brook, NY 11794-8661, USA
| | - Nabanita Sakia
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634-0978, USA
| | - Laura Dougherty
- Department of Physiology & Biophysics, Stony Brook University, Stony Brook, NY 11794-8661, USA
| | - Zhuojun Guo
- Department of Physiology & Biophysics, Stony Brook University, Stony Brook, NY 11794-8661, USA
| | - Fang Wu
- Department of Physiology & Biophysics, Stony Brook University, Stony Brook, NY 11794-8661, USA
| | - Frank Mindlin
- Department of Physiology & Biophysics, Stony Brook University, Stony Brook, NY 11794-8661, USA
| | - Jeffrey W Lary
- National Analytical Ultracentrifugation Facility, University of Connecticut, Storrs, CT 06269, USA
| | - James L Cole
- National Analytical Ultracentrifugation Facility, University of Connecticut, Storrs, CT 06269, USA; Department of Molecular and Cell Biology, and Department of Chemistry, University of Connecticut, Storrs, CT 06269, USA
| | - Feng Ding
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634-0978, USA
| | - Mark E Bowen
- Department of Physiology & Biophysics, Stony Brook University, Stony Brook, NY 11794-8661, USA.
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11
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Laursen L, Karlsson E, Gianni S, Jemth P. Functional interplay between protein domains in a supramodular structure involving the postsynaptic density protein PSD-95. J Biol Chem 2019; 295:1992-2000. [PMID: 31831623 DOI: 10.1074/jbc.ra119.011050] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 12/12/2019] [Indexed: 11/06/2022] Open
Abstract
Cell scaffolding and signaling are governed by protein-protein interactions. Although a particular interaction is often defined by two specific domains binding to each other, this interaction often occurs in the context of other domains in multidomain proteins. How such adjacent domains form supertertiary structures and modulate protein-protein interactions has only recently been addressed and is incompletely understood. The postsynaptic density protein PSD-95 contains a three-domain supramodule, denoted PSG, which consists of PDZ, Src homology 3 (SH3), and guanylate kinase-like domains. The PDZ domain binds to the C terminus of its proposed natural ligand, CXXC repeat-containing interactor of PDZ3 domain (CRIPT), and results from previous experiments using only the isolated PDZ domain are consistent with the simplest scenario for a protein-protein interaction; namely, a two-state mechanism. Here we analyzed the binding kinetics of the PSG supramodule with CRIPT. We show that PSG binds CRIPT via a more complex mechanism involving two conformational states interconverting on the second timescale. Both conformational states bound a CRIPT peptide with similar affinities but with different rates, and the distribution of the two conformational states was slightly shifted upon CRIPT binding. Our results are consistent with recent structural findings of conformational changes in PSD-95 and demonstrate how conformational transitions in supertertiary structures can shape the ligand-binding energy landscape and modulate protein-protein interactions.
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Affiliation(s)
- Louise Laursen
- Department of Medical Biochemistry and Microbiology, Uppsala University, BMC Box 582, 75123 Uppsala, Sweden
| | - Elin Karlsson
- Department of Medical Biochemistry and Microbiology, Uppsala University, BMC Box 582, 75123 Uppsala, Sweden
| | - Stefano Gianni
- Istituto Pasteur-Fondazione Cenci Bolognetti and Istituto di Biologia e Patologia Molecolari del CNR, Dipartimento di Scienze Biochimiche "A. Rossi Fanelli," Sapienza Università di Roma, 00185 Rome, Italy.
| | - Per Jemth
- Department of Medical Biochemistry and Microbiology, Uppsala University, BMC Box 582, 75123 Uppsala, Sweden.
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12
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Han JY, Choi TS, Heo CE, Son MK, Kim HI. Gas-phase conformations of intrinsically disordered proteins and their complexes with ligands: Kinetically trapped states during transfer from solution to the gas phase. MASS SPECTROMETRY REVIEWS 2019; 38:483-500. [PMID: 31021441 DOI: 10.1002/mas.21596] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 04/10/2019] [Indexed: 06/09/2023]
Abstract
Flexible structures of intrinsically disordered proteins (IDPs) are crucial for versatile functions in living organisms, which involve interaction with diverse partners. Electrospray ionization ion mobility mass spectrometry (ESI-IM-MS) has been widely applied for structural characterization of apo-state and ligand-associated IDPs via two-dimensional separation in the gas phase. Gas-phase IDP structures have been regarded as kinetically trapped states originated from conformational features in solution. However, an implication of the states remains elusive in the structural characterization of IDPs, because it is unclear what structural property of IDPs is preserved. Recent studies have indicated that the conformational features of IDPs in solution are not fully reproduced in the gas phase. Nevertheless, the molecular interactions captured in the gas phase amplify the structural differences between IDP conformers. Therefore, an IDP conformational change that is not observed in solution is observable in the gas-phase structures obtained by ESI-IM-MS. Herein, we have presented up-to-date researches on the key implications of kinetically trapped states in the gas phase with a brief summary of the structural dynamics of IDPs in ESI-IM-MS.
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Affiliation(s)
- Jong Yoon Han
- Department of Chemistry, Korea University, Seoul, 02841, Republic of Korea
| | - Tae Su Choi
- Department of Chemistry, Korea University, Seoul, 02841, Republic of Korea
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, 92093
| | - Chae Eun Heo
- Department of Chemistry, Korea University, Seoul, 02841, Republic of Korea
| | - Myung Kook Son
- Department of Chemistry, Korea University, Seoul, 02841, Republic of Korea
| | - Hugh I Kim
- Department of Chemistry, Korea University, Seoul, 02841, Republic of Korea
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13
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Vaughan RM, Dickson BM, Cornett EM, Harrison JS, Kuhlman B, Rothbart SB. Comparative biochemical analysis of UHRF proteins reveals molecular mechanisms that uncouple UHRF2 from DNA methylation maintenance. Nucleic Acids Res 2019; 46:4405-4416. [PMID: 29506131 PMCID: PMC5961305 DOI: 10.1093/nar/gky151] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 02/21/2018] [Indexed: 12/30/2022] Open
Abstract
UHRF1 is a histone- and DNA-binding E3 ubiquitin ligase that functions with DNMT1 to maintain mammalian DNA methylation. UHRF1 facilitates DNMT1 recruitment to replicating chromatin through a coordinated mechanism involving histone and DNA recognition and histone ubiquitination. UHRF2 shares structural homology with UHRF1, but surprisingly lacks functional redundancy to facilitate DNA methylation maintenance. Molecular mechanisms uncoupling UHRF2 from DNA methylation maintenance are poorly defined. Through comprehensive and comparative biochemical analysis of recombinant human UHRF1 and UHRF2 reader and writer activities, we reveal conserved modes of histone PTM recognition but divergent DNA binding properties. While UHRF1 and UHRF2 diverge in their affinities toward hemi-methylated DNA, we surprisingly show that both hemi-methylated and hemi-hydroxymethylated DNA oligonucleotides stimulate UHRF2 ubiquitin ligase activity toward histone H3 peptide substrates. This is the first example of an E3 ligase allosterically regulated by DNA hydroxymethylation. However, UHRF2 is not a productive histone E3 ligase toward purified mononucleosomes, suggesting UHRF2 has an intra-domain architecture distinct from UHRF1 that is conformationally constrained when bound to chromatin. Collectively, our studies reveal that uncoupling of UHRF2 from the DNA methylation maintenance program is linked to differences in the molecular readout of chromatin signatures that connect UHRF1 to ubiquitination of histone H3.
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Affiliation(s)
- Robert M Vaughan
- Center for Epigenetics, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | - Bradley M Dickson
- Center for Epigenetics, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | - Evan M Cornett
- Center for Epigenetics, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | - Joseph S Harrison
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, NC 27599, USA.,Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, NC 27599, USA
| | - Brian Kuhlman
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, NC 27599, USA.,Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, NC 27599, USA
| | - Scott B Rothbart
- Center for Epigenetics, Van Andel Research Institute, Grand Rapids, MI 49503, USA
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14
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Davey NE. The functional importance of structure in unstructured protein regions. Curr Opin Struct Biol 2019; 56:155-163. [DOI: 10.1016/j.sbi.2019.03.009] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 03/01/2019] [Accepted: 03/07/2019] [Indexed: 12/15/2022]
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15
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Abstract
A sizeable proportion of active protein sequences lack structural motifs making them irresolvable by NMR and crystallography. Such intrinsically disordered proteins (IDPs) or regions (IDRs) play a major role in biological mechanisms. They are often involved in cell regulation processes, and by extension can be the perpetrator or signifier of disease. In light of their importance and the shortcomings of conventional methods of biophysical analysis to identify them and to describe their conformational variance, IDPs and IDRs have been termed "the dark proteome." In this chapter we describe the use of ion mobility-mass spectrometry (IM-MS) coupled with electrospray ionization to analyze the conformational diversity of IDPs. Using the LEA protein COR15A as an exemplar system and contrasting it with the behavior of myoglobin, we outline the methods for analyzing an IDP using nanoelectrospray ionization coupled with IM-MS, covering sample preparation, purification; optimization of mass spectrometry conditions and tuning parameters; data collection and analysis. Following this, we detail the use of a "toy" model that provides a predictive framework for the study of all proteins with ESI-IM-MS.
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16
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Hardouin P, Velours C, Bou-Nader C, Assrir N, Laalami S, Putzer H, Durand D, Golinelli-Pimpaneau B. Dissociation of the Dimer of the Intrinsically Disordered Domain of RNase Y upon Antibody Binding. Biophys J 2018; 115:2102-2113. [PMID: 30447990 DOI: 10.1016/j.bpj.2018.10.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 09/17/2018] [Accepted: 10/17/2018] [Indexed: 12/12/2022] Open
Abstract
Although RNase Y acts as the key enzyme initiating messenger RNA decay in Bacillus subtilis and likely in many other Gram-positive bacteria, its three-dimensional structure remains unknown. An antibody belonging to the rare immunoglobulin G (IgG) 2b λx isotype was raised against a 12-residue conserved peptide from the N-terminal noncatalytic domain of B. subtilis RNase Y (BsRNaseY) that is predicted to be intrinsically disordered. Here, we show that this domain can be produced as a stand-alone protein called Nter-BsRNaseY that undergoes conformational changes between monomeric and dimeric forms. Circular dichroism and size exclusion chromatography coupled with multiangle light scattering or with small angle x-ray scattering indicate that the Nter-BsRNaseY dimer displays an elongated form and a high content of α-helices, in agreement with the existence of a central coiled-coil structure appended with flexible ends, and that the monomeric state of Nter-BsRNaseY is favored upon binding the fragment antigen binding (Fab) of the antibody. The dissociation constants of the IgG/BsRNaseY, IgG/Nter-BsRNaseY, and IgG/peptide complexes indicate that the affinity of the IgG for Nter-BsRNaseY is in the nM range and suggest that the peptide is less accessible in BsRNaseY than in Nter-BsRNaseY. The crystal structure of the Fab in complex with the peptide antigen shows that the peptide adopts an elongated U-shaped conformation in which the unique hydrophobic residue of the peptide, Leu6, is completely buried. The peptide/Fab complex may mimic the interaction of a microdomain of the N-terminal domain of BsRNaseY with one of its cellular partners within the degradosome complex. Altogether, our results suggest that BsRNaseY may become accessible for protein interaction upon dissociation of its N-terminal domain into the monomeric form.
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Affiliation(s)
- Pierre Hardouin
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, Collège de France, Université Pierre et Marie Curie, Paris CEDEX 05, France
| | - Christophe Velours
- Institute for Integrative Biology of the Cell, CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette CEDEX, France
| | - Charles Bou-Nader
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, Collège de France, Université Pierre et Marie Curie, Paris CEDEX 05, France
| | - Nadine Assrir
- Structural Chemistry and Biology Team, Institut de Chimie des Substances Naturelles, CNRS UPR 2301, Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Soumaya Laalami
- CNRS UMR8261-Université Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, Paris, France
| | - Harald Putzer
- CNRS UMR8261-Université Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, Paris, France
| | - Dominique Durand
- Institute for Integrative Biology of the Cell, CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette CEDEX, France
| | - Béatrice Golinelli-Pimpaneau
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, Collège de France, Université Pierre et Marie Curie, Paris CEDEX 05, France.
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17
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Yanez Orozco IS, Mindlin FA, Ma J, Wang B, Levesque B, Spencer M, Rezaei Adariani S, Hamilton G, Ding F, Bowen ME, Sanabria H. Identifying weak interdomain interactions that stabilize the supertertiary structure of the N-terminal tandem PDZ domains of PSD-95. Nat Commun 2018; 9:3724. [PMID: 30214057 PMCID: PMC6137104 DOI: 10.1038/s41467-018-06133-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 08/16/2018] [Indexed: 01/01/2023] Open
Abstract
Previous studies of the N-terminal PDZ tandem from PSD-95 produced divergent models and failed to identify interdomain contacts stabilizing the structure. We used ensemble and single-molecule FRET along with replica-exchange molecular dynamics to fully characterize the energy landscape. Simulations and experiments identified two conformations: an open-like conformation with a small contact interface stabilized by salt bridges, and a closed-like conformation with a larger contact interface stabilized by surface-exposed hydrophobic residues. Both interfaces were confirmed experimentally. Proximity of interdomain contacts to the binding pockets may explain the observed coupling between conformation and binding. The low-energy barrier between conformations allows submillisecond dynamics, which were time-averaged in previous NMR and FRET studies. Moreover, the small contact interfaces were likely overridden by lattice contacts as crystal structures were rarely sampled in simulations. Our hybrid approach can identify transient interdomain interactions, which are abundant in multidomain proteins yet often obscured by dynamic averaging.
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Affiliation(s)
| | - Frank A Mindlin
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, NY, USA
| | - Junyan Ma
- Department of Chemistry, Clemson University, Clemson, SC, USA
- Center for Optical Materials Science and Engineering Technology, Clemson, SC, USA
| | - Bo Wang
- Department of Physics and Astronomy, Clemson University, Clemson, SC, USA
| | - Brie Levesque
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, NY, USA
| | - Matheu Spencer
- Department of Physics and Astronomy, Clemson University, Clemson, SC, USA
| | | | - George Hamilton
- Department of Physics and Astronomy, Clemson University, Clemson, SC, USA
| | - Feng Ding
- Department of Physics and Astronomy, Clemson University, Clemson, SC, USA.
| | - Mark E Bowen
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, NY, USA.
| | - Hugo Sanabria
- Department of Physics and Astronomy, Clemson University, Clemson, SC, USA.
- Center for Optical Materials Science and Engineering Technology, Clemson, SC, USA.
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18
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Chromatin structure and its chemical modifications regulate the ubiquitin ligase substrate selectivity of UHRF1. Proc Natl Acad Sci U S A 2018; 115:8775-8780. [PMID: 30104358 PMCID: PMC6126761 DOI: 10.1073/pnas.1806373115] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
DNA methylation and histone posttranslational modifications are key epigenetic marks that contribute to the fine-tuned regulation of gene expression and other chromatin-templated biological processes. Here, we build artificial chromatin templates and reveal key chromatin structural features and epigenetic marks that coordinately regulate the binding and enzymatic activity of the DNA methylation regulator UHRF1. Studying activities of epigenetic regulators in the context of defined chromatin templates, particularly for multidomain histone and DNA binding proteins such as UHRF1, is critical for understanding molecular mechanisms of epigenetic crosstalk and mechanics regulating epigenetic signaling, and for determining how epigenetic dysregulation contributes to human disease. Mitotic inheritance of DNA methylation patterns is facilitated by UHRF1, a DNA- and histone-binding E3 ubiquitin ligase that helps recruit the maintenance DNA methyltransferase DNMT1 to replicating chromatin. The DNA methylation maintenance function of UHRF1 is dependent on its ability to bind chromatin, where it facilitates monoubiquitination of histone H3 at lysines 18 and 23, a docking site for DNMT1. Because of technical limitations, this model of UHRF1-dependent DNA methylation inheritance has been constructed largely based on genetics and biochemical observations querying methylated DNA oligonucleotides, synthetic histone peptides, and heterogeneous chromatin extracted from cells. Here, we construct semisynthetic mononucleosomes harboring defined histone and DNA modifications and perform rigorous analysis of UHRF1 binding and enzymatic activity with these reagents. We show that multivalent engagement of nucleosomal linker DNA and dimethylated lysine 9 on histone H3 directs UHRF1 ubiquitin ligase activity toward histone substrates. Notably, we reveal a molecular switch, stimulated by recognition of hemimethylated DNA, which redirects UHRF1 ubiquitin ligase activity away from histones in favor of robust autoubiquitination. Our studies support a noncompetitive model for UHRF1 and DNMT1 chromatin recruitment to replicating chromatin and define a role for hemimethylated linker DNA as a regulator of UHRF1 ubiquitin ligase substrate selectivity.
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19
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Bood M, Füchtbauer AF, Wranne MS, Ro JJ, Sarangamath S, El-Sagheer AH, Rupert DLM, Fisher RS, Magennis SW, Jones AC, Höök F, Brown T, Kim BH, Dahlén A, Wilhelmsson LM, Grøtli M. Pentacyclic adenine: a versatile and exceptionally bright fluorescent DNA base analogue. Chem Sci 2018; 9:3494-3502. [PMID: 29780479 PMCID: PMC5934695 DOI: 10.1039/c7sc05448c] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Accepted: 03/01/2018] [Indexed: 12/16/2022] Open
Abstract
A highly fluorescent, non-perturbing, pentacyclic adenine analog was designed, synthesized, incorporated into DNA and photophysical evaluated.
Emissive base analogs are powerful tools for probing nucleic acids at the molecular level. Herein we describe the development and thorough characterization of pentacyclic adenine (pA), a versatile base analog with exceptional fluorescence properties. When incorporated into DNA, pA pairs selectively with thymine without perturbing the B-form structure and is among the brightest nucleobase analogs reported so far. Together with the recently established base analog acceptor qAnitro, pA allows accurate distance and orientation determination via Förster resonance energy transfer (FRET) measurements. The high brightness at emission wavelengths above 400 nm also makes it suitable for fluorescence microscopy, as demonstrated by imaging of single liposomal constructs coated with cholesterol-anchored pA–dsDNA, using total internal reflection fluorescence microscopy. Finally, pA is also highly promising for two-photon excitation at 780 nm, with a brightness (5.3 GM) that is unprecedented for a base analog.
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Affiliation(s)
- Mattias Bood
- Department of Chemistry and Molecular Biology , University of Gothenburg , SE-412 96 Gothenburg , Sweden .
| | - Anders F Füchtbauer
- Department of Chemistry and Chemical Engineering, Chemistry and Biochemistry , Chalmers University of Technology , SE-412 96 Gothenburg , Sweden .
| | - Moa S Wranne
- Department of Chemistry and Chemical Engineering, Chemistry and Biochemistry , Chalmers University of Technology , SE-412 96 Gothenburg , Sweden .
| | - Jong Jin Ro
- Department of Chemistry , Division of Advanced Materials Science , Pohang University of Science and Technology (POSTECH) , Pohang 37673 , South Korea
| | - Sangamesh Sarangamath
- Department of Chemistry and Chemical Engineering, Chemistry and Biochemistry , Chalmers University of Technology , SE-412 96 Gothenburg , Sweden .
| | - Afaf H El-Sagheer
- Chemistry Branch , Faculty of Petroleum and Mining Engineering , Suez University , Suez 43721 , Egypt
| | - Déborah L M Rupert
- Division of Biological Physics , Department of Physics , Chalmers University of Technology , SE-412 96 Gothenburg , Sweden
| | - Rachel S Fisher
- School of Chemistry , University of Edinburgh , The King's Buildings , Edinburgh EH9 3JJ , UK
| | - Steven W Magennis
- WestCHEM , School of Chemistry , University of Glasgow , Glasgow , G12 8QQ , UK
| | - Anita C Jones
- School of Chemistry , University of Edinburgh , The King's Buildings , Edinburgh EH9 3JJ , UK
| | - Fredrik Höök
- Division of Biological Physics , Department of Physics , Chalmers University of Technology , SE-412 96 Gothenburg , Sweden
| | - Tom Brown
- Department of Chemistry , Chemistry Research Laboratory , University of Oxford , Oxford , OX1 3TA , UK
| | - Byeang Hyean Kim
- Department of Chemistry , Division of Advanced Materials Science , Pohang University of Science and Technology (POSTECH) , Pohang 37673 , South Korea
| | - Anders Dahlén
- AstraZeneca R&D , Innovative Medicines , Cardiovascular & Metabolic Diseases (CVMD) , Pepparedsleden 1, SE-431 83 Mölndal , Gothenburg , Sweden
| | - L Marcus Wilhelmsson
- Department of Chemistry and Chemical Engineering, Chemistry and Biochemistry , Chalmers University of Technology , SE-412 96 Gothenburg , Sweden .
| | - Morten Grøtli
- Department of Chemistry and Molecular Biology , University of Gothenburg , SE-412 96 Gothenburg , Sweden .
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20
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Stuchfield D, Barran P. Unique insights to intrinsically disordered proteins provided by ion mobility mass spectrometry. Curr Opin Chem Biol 2018; 42:177-185. [DOI: 10.1016/j.cbpa.2018.01.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 01/10/2018] [Accepted: 01/13/2018] [Indexed: 02/05/2023]
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21
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Kilic S, Felekyan S, Doroshenko O, Boichenko I, Dimura M, Vardanyan H, Bryan LC, Arya G, Seidel CAM, Fierz B. Single-molecule FRET reveals multiscale chromatin dynamics modulated by HP1α. Nat Commun 2018; 9:235. [PMID: 29339721 PMCID: PMC5770380 DOI: 10.1038/s41467-017-02619-5] [Citation(s) in RCA: 92] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 12/11/2017] [Indexed: 01/17/2023] Open
Abstract
The dynamic architecture of chromatin fibers, a key determinant of genome regulation, is poorly understood. Here, we employ multimodal single-molecule Förster resonance energy transfer studies to reveal structural states and their interconversion kinetics in chromatin fibers. We show that nucleosomes engage in short-lived (micro- to milliseconds) stacking interactions with one of their neighbors. This results in discrete tetranucleosome units with distinct interaction registers that interconvert within hundreds of milliseconds. Additionally, we find that dynamic chromatin architecture is modulated by the multivalent architectural protein heterochromatin protein 1α (HP1α), which engages methylated histone tails and thereby transiently stabilizes stacked nucleosomes. This compacted state nevertheless remains dynamic, exhibiting fluctuations on the timescale of HP1α residence times. Overall, this study reveals that exposure of internal DNA sites and nucleosome surfaces in chromatin fibers is governed by an intrinsic dynamic hierarchy from micro- to milliseconds, allowing the gene regulation machinery to access compact chromatin. Chromatin fibers undergo continuous structural rearrangements but their dynamic architecture is poorly understood. Here, the authors use single-molecule FRET to determine the structural states and interconversion kinetics of chromatin fibers, monitoring their effector protein-dependent dynamic motions.
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Affiliation(s)
- Sinan Kilic
- Laboratory of Biophysical Chemistry of Macromolecules, Institute of Chemical Sciences and Engineering (ISIC), Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland.,Department of Molecular Mechanisms of Disease, University of Zurich, 8057, Zurich, Switzerland
| | - Suren Felekyan
- Institut für Physikalische Chemie, Lehrstuhl für Molekulare Physikalische Chemie, Heinrich-Heine-Universität, Universitätsstraße 1, 40225, Düsseldorf, Germany
| | - Olga Doroshenko
- Institut für Physikalische Chemie, Lehrstuhl für Molekulare Physikalische Chemie, Heinrich-Heine-Universität, Universitätsstraße 1, 40225, Düsseldorf, Germany
| | - Iuliia Boichenko
- Laboratory of Biophysical Chemistry of Macromolecules, Institute of Chemical Sciences and Engineering (ISIC), Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
| | - Mykola Dimura
- Institut für Physikalische Chemie, Lehrstuhl für Molekulare Physikalische Chemie, Heinrich-Heine-Universität, Universitätsstraße 1, 40225, Düsseldorf, Germany
| | - Hayk Vardanyan
- Institut für Physikalische Chemie, Lehrstuhl für Molekulare Physikalische Chemie, Heinrich-Heine-Universität, Universitätsstraße 1, 40225, Düsseldorf, Germany
| | - Louise C Bryan
- Laboratory of Biophysical Chemistry of Macromolecules, Institute of Chemical Sciences and Engineering (ISIC), Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
| | - Gaurav Arya
- Pratt School of Engineering, Duke University, 144 Hudson Hall, Box 90300, Durham, NC, 27708, USA
| | - Claus A M Seidel
- Institut für Physikalische Chemie, Lehrstuhl für Molekulare Physikalische Chemie, Heinrich-Heine-Universität, Universitätsstraße 1, 40225, Düsseldorf, Germany.
| | - Beat Fierz
- Laboratory of Biophysical Chemistry of Macromolecules, Institute of Chemical Sciences and Engineering (ISIC), Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland.
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22
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Muller P, Chan JM, Simoncik O, Fojta M, Lane DP, Hupp T, Vojtesek B. Evidence for allosteric effects on p53 oligomerization induced by phosphorylation. Protein Sci 2017; 27:523-530. [PMID: 29124793 DOI: 10.1002/pro.3344] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 10/22/2017] [Accepted: 11/07/2017] [Indexed: 11/06/2022]
Abstract
p53 is a tetrameric protein with a thermodynamically unstable deoxyribonucleic acid (DNA)-binding domain flanked by intrinsically disordered regulatory domains that control its activity. The unstable and disordered segments of p53 allow high flexibility as it interacts with binding partners and permits a rapid on/off switch to control its function. The p53 tetramer can exist in multiple conformational states, any of which can be stabilized by a particular modification. Here, we apply the allostery model to p53 to ask whether evidence can be found that the "activating" C-terminal phosphorylation of p53 stabilizes a specific conformation of the protein in the absence of DNA. We take advantage of monoclonal antibodies for p53 that measure indirectly the following conformations: unfolded, folded, and tetrameric. A double antibody capture enzyme linked-immunosorbent assay was used to observe evidence of conformational changes of human p53 upon phosphorylation by casein kinase 2 in vitro. It was demonstrated that oligomerization and stabilization of p53 wild-type conformation results in differential exposure of conformational epitopes PAb1620, PAb240, and DO12 that indicates a reduction in the "unfolded" conformation and increases in the folded conformation coincide with increases in its oligomerization state. These data highlight that the oligomeric conformation of p53 can be stabilized by an activating enzyme and further highlight the utility of the allostery model when applied to understanding the regulation of unstable and intrinsically disordered proteins.
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Affiliation(s)
- Petr Muller
- RECAMO, Masaryk Memorial Cancer Institute, Brno, 65653, Czech Republic
| | - Juliana M Chan
- p53 Laboratory (A*STAR), Singapore, 138648, Singapore.,School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore, 637457, Singapore
| | - Oliver Simoncik
- RECAMO, Masaryk Memorial Cancer Institute, Brno, 65653, Czech Republic
| | - Miroslav Fojta
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, 612 65, Czech Republic
| | - David P Lane
- p53 Laboratory (A*STAR), Singapore, 138648, Singapore
| | - Ted Hupp
- RECAMO, Masaryk Memorial Cancer Institute, Brno, 65653, Czech Republic.,Institute of Genetics and Molecular Medicine, Edinburgh Cancer Research Centre Cell Signaling Unit, University of Edinburgh, Edinburgh, EH4 2XR, United Kingdom
| | - Borivoj Vojtesek
- RECAMO, Masaryk Memorial Cancer Institute, Brno, 65653, Czech Republic
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23
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Pauwels K, Lebrun P, Tompa P. To be disordered or not to be disordered: is that still a question for proteins in the cell? Cell Mol Life Sci 2017; 74:3185-3204. [PMID: 28612216 PMCID: PMC11107661 DOI: 10.1007/s00018-017-2561-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 06/01/2017] [Indexed: 12/26/2022]
Abstract
There is ample evidence that many proteins or regions of proteins lack a well-defined folded structure under native-like conditions. These are called intrinsically disordered proteins (IDPs) or intrinsically disordered regions (IDRs). Whether this intrinsic disorder is also their main structural characteristic in living cells has been a matter of intense debate. The structural analysis of IDPs became an important challenge also because of their involvement in a plethora of human diseases, which made IDPs attractive targets for therapeutic development. Therefore, biophysical approaches are increasingly being employed to probe the structural and dynamical state of proteins, not only in isolation in a test tube, but also in a complex biological environment and even within intact cells. Here, we survey direct and indirect evidence that structural disorder is in fact the physiological state of many proteins in the proteome. The paradigmatic case of α-synuclein is used to illustrate the controversial nature of this topic.
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Affiliation(s)
- Kris Pauwels
- VIB-VUB Center for Structural Biology (CSB), Vlaams Instituut voor Biotechnologie (VIB), Brussels, Belgium
- Structural Biology Brussels (SBB), Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Pierre Lebrun
- VIB-VUB Center for Structural Biology (CSB), Vlaams Instituut voor Biotechnologie (VIB), Brussels, Belgium
- Structural Biology Brussels (SBB), Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Peter Tompa
- VIB-VUB Center for Structural Biology (CSB), Vlaams Instituut voor Biotechnologie (VIB), Brussels, Belgium.
- Structural Biology Brussels (SBB), Vrije Universiteit Brussel (VUB), Brussels, Belgium.
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary.
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24
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Linking functions: an additional role for an intrinsically disordered linker domain in the transcriptional coactivator CBP. Sci Rep 2017; 7:4676. [PMID: 28680062 PMCID: PMC5498717 DOI: 10.1038/s41598-017-04611-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 05/17/2017] [Indexed: 12/25/2022] Open
Abstract
The multi-domain transcriptional coactivators CBP/p300 integrate a multitude of signaling inputs, interacting with more than 400 proteins via one or more of their globular domains. While CBP/p300 function is typically considered in terms of these structured domains, about half of the protein consists of intrinsically disordered regions (IDRs) of varying length. However, these IDRs have only been thought of as linkers that allow flexible spatial arrangement of the structured domains, but recent studies have shown that similar IDRs mediate specific and critical interactions in other proteins. To examine the roles of IDRs in CBP, we performed yeast-two-hybrid screenings of placenta and lung cancer cDNA libraries, which demonstrated that the long IDR linking the KIX domain and bromodomain of CBP (termed ID3) can potentially bind to several proteins. The RNA-binding Zinc-finger protein 106 (ZFP106) detected in both libraries was identified as a novel substrate for CBP-mediated acetylation. Nuclear magnetic resonance (NMR) spectroscopy combined with cross-linking experiments and competition-binding assays showed that the fully disordered isolated ID3 transiently interacts with an IDR of ZFP106 in a fashion that disorder of both regions is maintained. These findings demonstrate that beside the linking function, ID3 can also interact with acetylation substrates of CBP.
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Füchtbauer AF, Preus S, Börjesson K, McPhee SA, Lilley DMJ, Wilhelmsson LM. Fluorescent RNA cytosine analogue - an internal probe for detailed structure and dynamics investigations. Sci Rep 2017; 7:2393. [PMID: 28539582 PMCID: PMC5443824 DOI: 10.1038/s41598-017-02453-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 04/10/2017] [Indexed: 12/22/2022] Open
Abstract
The bright fluorescent cytosine analogue tCO stands out among fluorescent bases due to its virtually unquenched fluorescence emission in duplex DNA. However, like most reported base analogues, it has not been thoroughly characterized in RNA. We here report on the first synthesis and RNA-incorporation of tCO, and characterize its base-mimicking and fluorescence properties in RNA. As in DNA, we find a high quantum yield inside RNA duplexes (<ΦF> = 0.22) that is virtually unaffected by the neighbouring bases (ΦF = 0.20-0.25), resulting in an average brightness of 1900 M-1 cm-1. The average fluorescence lifetime in RNA duplexes is 4.3 ns and generally two lifetimes are required to fit the exponential decays. Fluorescence properties in ssRNA are defined by a small increase in average quantum yield (<ΦF > = 0.24) compared to dsRNA, with a broader distribution (ΦF = 0.17-0.34) and slightly shorter average lifetimes. Using circular dichroism, we find that the tCO-modified RNA duplexes form regular A-form helices and in UV-melting experiments the stability of the duplexes is only slightly higher than that of the corresponding natural RNA (<ΔT m> = + 2.3 °C). These properties make tCO a highly interesting fluorescent RNA base analogue for detailed FRET-based structural measurements, as a bright internal label in microscopy, and for fluorescence anisotropy measurements of RNA dynamics.
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Affiliation(s)
- Anders Foller Füchtbauer
- Chemistry and Chemical Engineering/Chemistry and Biochemistry, Chalmers University of Technology, Gothenburg, SE-41296, Sweden
| | - Søren Preus
- Department of Chemistry, University of Copenhagen, Copenhagen, DK-2100, Denmark
| | - Karl Börjesson
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, SE-41296, Sweden
| | - Scott A McPhee
- Cancer Research UK Nucleic Acid Structure Research Group, MSI/WTB Complex, The University of Dundee, Dow Street, Dundee, DD1 5EH, UK
| | - David M J Lilley
- Cancer Research UK Nucleic Acid Structure Research Group, MSI/WTB Complex, The University of Dundee, Dow Street, Dundee, DD1 5EH, UK
| | - L Marcus Wilhelmsson
- Chemistry and Chemical Engineering/Chemistry and Biochemistry, Chalmers University of Technology, Gothenburg, SE-41296, Sweden.
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26
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Antonov LD, Olsson S, Boomsma W, Hamelryck T. Bayesian inference of protein ensembles from SAXS data. Phys Chem Chem Phys 2017; 18:5832-8. [PMID: 26548662 DOI: 10.1039/c5cp04886a] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The inherent flexibility of intrinsically disordered proteins (IDPs) and multi-domain proteins with intrinsically disordered regions (IDRs) presents challenges to structural analysis. These macromolecules need to be represented by an ensemble of conformations, rather than a single structure. Small-angle X-ray scattering (SAXS) experiments capture ensemble-averaged data for the set of conformations. We present a Bayesian approach to ensemble inference from SAXS data, called Bayesian ensemble SAXS (BE-SAXS). We address two issues with existing methods: the use of a finite ensemble of structures to represent the underlying distribution, and the selection of that ensemble as a subset of an initial pool of structures. This is achieved through the formulation of a Bayesian posterior of the conformational space. BE-SAXS modifies a structural prior distribution in accordance with the experimental data. It uses multi-step expectation maximization, with alternating rounds of Markov-chain Monte Carlo simulation and empirical Bayes optimization. We demonstrate the method by employing it to obtain a conformational ensemble of the antitoxin PaaA2 and comparing the results to a published ensemble.
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Affiliation(s)
- L D Antonov
- Bioinformatics Centre, Department of Biology, University of Copenhagen, Ole Maaloes Vej 5, DK-2200 Copenhagen N, Denmark.
| | - S Olsson
- Laboratory of Physical Chemistry, Swiss Federal Institute of Technology, ETH-Hönggerberg, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland and Institute for Research in Biomedicine, Università della Svizzera Italiana, Via Vincenzo Vela 6, CH-6500 Bellinzona, Switzerland
| | - W Boomsma
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaloes Vej 5, DK-2200 Copenhagen N, Denmark
| | - T Hamelryck
- Bioinformatics Centre, Department of Biology, University of Copenhagen, Ole Maaloes Vej 5, DK-2200 Copenhagen N, Denmark.
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27
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Dimura M, Peulen TO, Hanke CA, Prakash A, Gohlke H, Seidel CA. Quantitative FRET studies and integrative modeling unravel the structure and dynamics of biomolecular systems. Curr Opin Struct Biol 2016; 40:163-185. [PMID: 27939973 DOI: 10.1016/j.sbi.2016.11.012] [Citation(s) in RCA: 113] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 11/11/2016] [Accepted: 11/11/2016] [Indexed: 01/11/2023]
Abstract
Förster Resonance Energy Transfer (FRET) combined with single-molecule spectroscopy probes macromolecular structure and dynamics and identifies coexisting conformational states. We review recent methodological developments in integrative structural modeling by satisfying spatial restraints on networks of FRET pairs (hybrid-FRET). We discuss procedures to incorporate prior structural knowledge and to obtain optimal distance networks. Finally, a workflow for hybrid-FRET is presented that automates integrative structural modeling and experiment planning to put hybrid-FRET on rails. To test this workflow, we simulate realistic single-molecule experiments and resolve three protein conformers, exchanging at 30μs and 10ms, with accuracies of 1-3Å RMSD versus the target structure. Incorporation of data from other spectroscopies and imaging is also discussed.
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Affiliation(s)
- Mykola Dimura
- Chair for Molecular Physical Chemistry, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; Institute for Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany
| | - Thomas O Peulen
- Chair for Molecular Physical Chemistry, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany
| | - Christian A Hanke
- Chair for Molecular Physical Chemistry, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany
| | - Aiswaria Prakash
- Chair for Molecular Physical Chemistry, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany
| | - Holger Gohlke
- Institute for Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany
| | - Claus Am Seidel
- Chair for Molecular Physical Chemistry, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany.
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28
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Scholl ZN, Li Q, Yang W, Marszalek PE. Single-molecule Force Spectroscopy Reveals the Calcium Dependence of the Alternative Conformations in the Native State of a βγ-Crystallin Protein. J Biol Chem 2016; 291:18263-75. [PMID: 27378818 DOI: 10.1074/jbc.m116.729525] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Indexed: 12/30/2022] Open
Abstract
Although multidomain proteins predominate the proteome of all organisms and are expected to display complex folding behaviors and significantly greater structural dynamics as compared with single-domain proteins, their conformational heterogeneity and its impact on their interaction with ligands are poorly understood due to a lack of experimental techniques. The multidomain calcium-binding βγ-crystallin proteins are particularly important because their deterioration and misfolding/aggregation are associated with melanoma tumors and cataracts. Here we investigate the mechanical stability and conformational dynamics of a model calcium-binding βγ-crystallin protein, Protein S, and elaborate on its interactions with calcium. We ask whether domain interactions and calcium binding affect Protein S folding and potential structural heterogeneity. Our results from single-molecule force spectroscopy show that the N-terminal (but not the C-terminal) domain is in equilibrium with an alternative conformation in the absence of Ca(2+), which is mechanically stable in contrast to other proteins that were observed to sample a molten globule under similar conditions. Mutagenesis experiments and computer simulations reveal that the alternative conformation of the N-terminal domain is caused by structural instability produced by the high charge density of a calcium binding site. We find that this alternative conformation in the N-terminal domain is diminished in the presence of calcium and can also be partially eliminated with a hitherto unrecognized compensatory mechanism that uses the interaction of the C-terminal domain to neutralize the electronegative site. We find that up to 1% of all identified multidomain calcium-binding proteins contain a similarly highly charged site and therefore may exploit a similar compensatory mechanism to prevent structural instability in the absence of ligand.
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Affiliation(s)
| | - Qing Li
- the Department of Mechanical Engineering and Materials Science, and
| | - Weitao Yang
- the Department of Chemistry, Duke University, Durham, North Carolina 27708
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29
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Khan SN, Charlier C, Augustyniak R, Salvi N, Déjean V, Bodenhausen G, Lequin O, Pelupessy P, Ferrage F. Distribution of Pico- and Nanosecond Motions in Disordered Proteins from Nuclear Spin Relaxation. Biophys J 2016; 109:988-99. [PMID: 26331256 PMCID: PMC4564687 DOI: 10.1016/j.bpj.2015.06.069] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 05/15/2015] [Accepted: 06/23/2015] [Indexed: 11/30/2022] Open
Abstract
Intrinsically disordered proteins and intrinsically disordered regions (IDRs) are ubiquitous in the eukaryotic proteome. The description and understanding of their conformational properties require the development of new experimental, computational, and theoretical approaches. Here, we use nuclear spin relaxation to investigate the distribution of timescales of motions in an IDR from picoseconds to nanoseconds. Nitrogen-15 relaxation rates have been measured at five magnetic fields, ranging from 9.4 to 23.5 T (400-1000 MHz for protons). This exceptional wealth of data allowed us to map the spectral density function for the motions of backbone NH pairs in the partially disordered transcription factor Engrailed at 11 different frequencies. We introduce an approach called interpretation of motions by a projection onto an array of correlation times (IMPACT), which focuses on an array of six correlation times with intervals that are equidistant on a logarithmic scale between 21 ps and 21 ns. The distribution of motions in Engrailed varies smoothly along the protein sequence and is multimodal for most residues, with a prevalence of motions around 1 ns in the IDR. We show that IMPACT often provides better quantitative agreement with experimental data than conventional model-free or extended model-free analyses with two or three correlation times. We introduce a graphical representation that offers a convenient platform for a qualitative discussion of dynamics. Even when relaxation data are only acquired at three magnetic fields that are readily accessible, the IMPACT analysis gives a satisfactory characterization of spectral density functions, thus opening the way to a broad use of this approach.
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Affiliation(s)
- Shahid N Khan
- Département de Chimie, École Normale Supérieure-PSL Research University, Paris, France; Sorbonne Universités, UPMC Univ Paris 06, LBM, Paris, France; Centre National de la Recherche Scientifique, UMR 7203 LBM, Paris, France
| | - Cyril Charlier
- Département de Chimie, École Normale Supérieure-PSL Research University, Paris, France; Sorbonne Universités, UPMC Univ Paris 06, LBM, Paris, France; Centre National de la Recherche Scientifique, UMR 7203 LBM, Paris, France
| | - Rafal Augustyniak
- Département de Chimie, École Normale Supérieure-PSL Research University, Paris, France; Sorbonne Universités, UPMC Univ Paris 06, LBM, Paris, France; Centre National de la Recherche Scientifique, UMR 7203 LBM, Paris, France
| | - Nicola Salvi
- Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne, BCH, Lausanne, Switzerland
| | - Victoire Déjean
- Département de Chimie, École Normale Supérieure-PSL Research University, Paris, France; Sorbonne Universités, UPMC Univ Paris 06, LBM, Paris, France; Centre National de la Recherche Scientifique, UMR 7203 LBM, Paris, France
| | - Geoffrey Bodenhausen
- Département de Chimie, École Normale Supérieure-PSL Research University, Paris, France; Sorbonne Universités, UPMC Univ Paris 06, LBM, Paris, France; Centre National de la Recherche Scientifique, UMR 7203 LBM, Paris, France; Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne, BCH, Lausanne, Switzerland
| | - Olivier Lequin
- Département de Chimie, École Normale Supérieure-PSL Research University, Paris, France; Sorbonne Universités, UPMC Univ Paris 06, LBM, Paris, France; Centre National de la Recherche Scientifique, UMR 7203 LBM, Paris, France
| | - Philippe Pelupessy
- Département de Chimie, École Normale Supérieure-PSL Research University, Paris, France; Sorbonne Universités, UPMC Univ Paris 06, LBM, Paris, France; Centre National de la Recherche Scientifique, UMR 7203 LBM, Paris, France
| | - Fabien Ferrage
- Département de Chimie, École Normale Supérieure-PSL Research University, Paris, France; Sorbonne Universités, UPMC Univ Paris 06, LBM, Paris, France; Centre National de la Recherche Scientifique, UMR 7203 LBM, Paris, France.
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30
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Rajasekaran N, Gopi S, Narayan A, Naganathan AN. Quantifying Protein Disorder through Measures of Excess Conformational Entropy. J Phys Chem B 2016; 120:4341-50. [PMID: 27111521 DOI: 10.1021/acs.jpcb.6b00658] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Intrinsically disordered proteins (IDPs) and proteins with a large degree of disorder are abundant in the proteomes of eukaryotes and viruses, and play a vital role in cellular homeostasis and disease. One fundamental question that has been raised on IDPs is the process by which they offset the entropic penalty involved in transitioning from a heterogeneous ensemble of conformations to a much smaller collection of binding-competent states. However, this has been a difficult problem to address, as the effective entropic cost of fixing residues in a folded-like conformation from disordered amino acid neighborhoods is itself not known. Moreover, there are several examples where the sequence complexity of disordered regions is as high as well-folded regions. Disorder in such cases therefore arises from excess conformational entropy determined entirely by correlated sequence effects, an entropic code that is yet to be identified. Here, we explore these issues by exploiting the order-disorder transitions of a helix in Pbx-Homeodomain together with a dual entropy statistical mechanical model to estimate the magnitude and sign of the excess conformational entropy of residues in disordered regions. We find that a mere 2.1-fold increase in the number of allowed conformations per residue (∼0.7kBT favoring the unfolded state) relative to a well-folded sequence, or ∼2(N) additional conformations for a N-residue sequence, is sufficient to promote disorder under physiological conditions. We show that this estimate is quite robust and helps in rationalizing the thermodynamic signatures of disordered regions in important regulatory proteins, modeling the conformational folding-binding landscapes of IDPs, quantifying the stability effects characteristic of disordered protein loops and their subtle roles in determining the partitioning of folding flux in ordered domains. In effect, the dual entropy model we propose provides a statistical thermodynamic basis for the relative conformational propensities of amino acids in folded and disordered environments in proteins. Our work thus lays the foundation for understanding and quantifying protein disorder through measures of excess conformational entropy.
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Affiliation(s)
- Nandakumar Rajasekaran
- Department of Biotechnology, Bhupat & Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras , Chennai 600036, India
| | - Soundhararajan Gopi
- Department of Biotechnology, Bhupat & Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras , Chennai 600036, India
| | - Abhishek Narayan
- Department of Biotechnology, Bhupat & Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras , Chennai 600036, India
| | - Athi N Naganathan
- Department of Biotechnology, Bhupat & Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras , Chennai 600036, India
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31
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Posttranslational Modifications Regulate the Postsynaptic Localization of PSD-95. Mol Neurobiol 2016; 54:1759-1776. [PMID: 26884267 DOI: 10.1007/s12035-016-9745-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 01/22/2016] [Indexed: 01/08/2023]
Abstract
The postsynaptic density (PSD) consists of a lattice-like array of interacting proteins that organizes and stabilizes synaptic receptors, ion channels, structural proteins, and signaling molecules required for normal synaptic transmission and synaptic function. The scaffolding and hub protein postsynaptic density protein-95 (PSD-95) is a major element of central chemical synapses and interacts with glutamate receptors, cell adhesion molecules, and cytoskeletal elements. In fact, PSD-95 can regulate basal synaptic stability as well as the activity-dependent structural plasticity of the PSD and, therefore, of the excitatory chemical synapse. Several studies have shown that PSD-95 is highly enriched at excitatory synapses and have identified multiple protein structural domains and protein-protein interactions that mediate PSD-95 function and trafficking to the postsynaptic region. PSD-95 is also a target of several signaling pathways that induce posttranslational modifications, including palmitoylation, phosphorylation, ubiquitination, nitrosylation, and neddylation; these modifications determine the synaptic stability and function of PSD-95 and thus regulate the fates of individual dendritic spines in the nervous system. In the present work, we review the posttranslational modifications that regulate the synaptic localization of PSD-95 and describe their functional consequences. We also explore the signaling pathways that induce such changes.
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32
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Guharoy M, Bhowmick P, Tompa P. Design Principles Involving Protein Disorder Facilitate Specific Substrate Selection and Degradation by the Ubiquitin-Proteasome System. J Biol Chem 2016; 291:6723-31. [PMID: 26851277 DOI: 10.1074/jbc.r115.692665] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The ubiquitin-proteasome system (UPS) regulates diverse cellular pathways by the timely removal (or processing) of proteins. Here we review the role of structural disorder and conformational flexibility in the different aspects of degradation. First, we discuss post-translational modifications within disordered regions that regulate E3 ligase localization, conformation, and enzymatic activity, and also the role of flexible linkers in mediating ubiquitin transfer and reaction processivity. Next we review well studied substrates and discuss that substrate elements (degrons) recognized by E3 ligases are highly disordered: short linear motifs recognized by many E3s constitute an important class of degrons, and these are almost always present in disordered regions. Substrate lysines targeted for ubiquitination are also often located in neighboring regions of the E3 docking motifs and are therefore part of the disordered segment. Finally, biochemical experiments and predictions show that initiation of degradation at the 26S proteasome requires a partially unfolded region to facilitate substrate entry into the proteasomal core.
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Affiliation(s)
- Mainak Guharoy
- From the VIB Structural Biology Research Center (SBRC), Vlaams Instituut voor Biotechnologie, 1050 Brussel, Belgium, the Structural Biology Brussels (SBB), Vrije Universiteit Brussel, 1050 Brussels, Belgium, and
| | - Pallab Bhowmick
- From the VIB Structural Biology Research Center (SBRC), Vlaams Instituut voor Biotechnologie, 1050 Brussel, Belgium, the Structural Biology Brussels (SBB), Vrije Universiteit Brussel, 1050 Brussels, Belgium, and
| | - Peter Tompa
- From the VIB Structural Biology Research Center (SBRC), Vlaams Instituut voor Biotechnologie, 1050 Brussel, Belgium, the Structural Biology Brussels (SBB), Vrije Universiteit Brussel, 1050 Brussels, Belgium, and the Institute of Enzymology, Research Centre for Natural Sciences of the Hungarian Academy of Sciences, 1117 Budapest, Hungary
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Abstract
Specific conformations of signaling proteins can serve as “signals” in signal transduction by being recognized by receptors.
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Affiliation(s)
- Peter Tompa
- VIB Structural Biology Research Center (SBRC)
- Brussels
- Belgium
- Vrije Universiteit Brussel
- Brussels
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34
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Borysik AJ, Kovacs D, Guharoy M, Tompa P. Ensemble Methods Enable a New Definition for the Solution to Gas-Phase Transfer of Intrinsically Disordered Proteins. J Am Chem Soc 2015; 137:13807-17. [DOI: 10.1021/jacs.5b06027] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Antoni J. Borysik
- King’s College London, Department of Chemistry,
Britannia House, 7 Trinity
Street, London SE1 1DB, U.K
| | - Denes Kovacs
- VIB
Structural Biology Research Centre (SBRC), Vrije Universiteit Brussel, Pleinlaan 2, Brussels B-1050, Belgium
| | - Mainak Guharoy
- VIB
Structural Biology Research Centre (SBRC), Vrije Universiteit Brussel, Pleinlaan 2, Brussels B-1050, Belgium
| | - Peter Tompa
- VIB
Structural Biology Research Centre (SBRC), Vrije Universiteit Brussel, Pleinlaan 2, Brussels B-1050, Belgium
- Institute
of Enzymology, Research Centre for Natural Sciences of
the Hungarian Academy of Sciences, 1117 Budapest, Hungary
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Varadi M, Vranken W, Guharoy M, Tompa P. Computational approaches for inferring the functions of intrinsically disordered proteins. Front Mol Biosci 2015; 2:45. [PMID: 26301226 PMCID: PMC4525029 DOI: 10.3389/fmolb.2015.00045] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 07/21/2015] [Indexed: 01/09/2023] Open
Abstract
Intrinsically disordered proteins (IDPs) are ubiquitously involved in cellular processes and often implicated in human pathological conditions. The critical biological roles of these proteins, despite not adopting a well-defined fold, encouraged structural biologists to revisit their views on the protein structure-function paradigm. Unfortunately, investigating the characteristics and describing the structural behavior of IDPs is far from trivial, and inferring the function(s) of a disordered protein region remains a major challenge. Computational methods have proven particularly relevant for studying IDPs: on the sequence level their dependence on distinct characteristics determined by the local amino acid context makes sequence-based prediction algorithms viable and reliable tools for large scale analyses, while on the structure level the in silico integration of fundamentally different experimental data types is essential to describe the behavior of a flexible protein chain. Here, we offer an overview of the latest developments and computational techniques that aim to uncover how protein function is connected to intrinsic disorder.
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Affiliation(s)
- Mihaly Varadi
- Flemish Institute of Biotechnology Brussels, Belgium ; Department of Structural Biology, VIB, Vrije Universiteit Brussels Brussels, Belgium
| | - Wim Vranken
- Flemish Institute of Biotechnology Brussels, Belgium ; Department of Structural Biology, VIB, Vrije Universiteit Brussels Brussels, Belgium ; ULB-VUB - Interuniversity Institute of Bioinformatics in Brussels (IB)2 Brussels, Belgium
| | - Mainak Guharoy
- Flemish Institute of Biotechnology Brussels, Belgium ; Department of Structural Biology, VIB, Vrije Universiteit Brussels Brussels, Belgium
| | - Peter Tompa
- Flemish Institute of Biotechnology Brussels, Belgium ; Department of Structural Biology, VIB, Vrije Universiteit Brussels Brussels, Belgium
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36
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Potempa LA, Yao ZY, Ji SR, Filep JG, Wu Y. Solubilization and purification of recombinant modified C-reactive protein from inclusion bodies using reversible anhydride modification. BIOPHYSICS REPORTS 2015; 1:18-33. [PMID: 26942216 PMCID: PMC4762138 DOI: 10.1007/s41048-015-0003-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2015] [Accepted: 03/26/2015] [Indexed: 02/07/2023] Open
Abstract
The precise function of C-reactive protein (CRP) as a regulator of inflammation in health and disease continues to evolve. The true understanding of its role in host defense responses has been hampered by numerous reports of comparable systems with contradictory interpretations of CRP as a stimulator, suppressor, or benign contributor to such processes. These discrepancies may be explained in part by the existence of a naturally occurring CRP isoform, termed modified CRP (i.e., mCRP), that is expressed when CRP subunits are dissociated into monomeric structures. The free mCRP subunit undergoes a non-proteolytic conformational change that has unique solubility, antigenicity, and bioactivity compared to the subunits that remain associated in the native, pentameric CRP molecule (i.e., pCRP). As specific reagents have been developed to identify and quantify mCRP, it has become apparent that this isoform can be formed spontaneously in calcium-free solutions. Furthermore, mCRP can be expressed on perturbed cell membranes with as little as 24–48 h incubation in tissue culture. Because mCRP has the same size as pCRP subunits as evaluated by SDS-PAGE, its presence in a pCRP reagent would not be apparent using this technique to evaluate purity. Finally, because many antibody reagents purported to be specific for “CRP” contains some, or substantial specificity to mCRP, antigen-detection techniques using such reagents may fail to distinguish the specific CRP isoform detected. All these caveats concerning CRP structures and measurements suggest that the aforementioned contradictory studies may reflect to some extent on distinctive bioactivities of mCRP rather than on pCRP. To provide a reliable, abundant supply of mCRP for separate and comparable studies, a recombinant protein was engineered and expressed in E. coli (i.e., recombinant mCRP or rmCRP). Synthesized protein was produced as inclusion bodies which proved difficult to solubilize for purification and characterization. Herein, we describe a method using anhydride reagents to effectively solubilize rmCRP and allow for chromatographic purification in high yield and free of contaminating endotoxin. Furthermore, the purified rmCRP reagent represents an excellent comparable protein to the biologically produced mCRP and as a distinctive reagent from pCRP. Deciphering the true function of CRP in both health and disease requires a knowledge, understanding, and reliable supply of each of its structures so to define the distinctive effects of each on the body’s response to tissue damaging events.
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Affiliation(s)
| | - Zhen-Yu Yao
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000 People's Republic of China
| | - Shang-Rong Ji
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000 People's Republic of China
| | - János G Filep
- Research Center, Maisonneuve-Rosemont Hospital, University of Montréal, Montréal, QC Canada
| | - Yi Wu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000 People's Republic of China ; Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Lanzhou University, Lanzhou, 730000 People's Republic of China
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Hertig S, Goddard TD, Johnson GT, Ferrin TE. Multidomain Assembler (MDA) Generates Models of Large Multidomain Proteins. Biophys J 2015; 108:2097-102. [PMID: 25954868 PMCID: PMC4423039 DOI: 10.1016/j.bpj.2015.03.051] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Revised: 03/17/2015] [Accepted: 03/26/2015] [Indexed: 11/17/2022] Open
Abstract
Homology modeling predicts protein structures using known structures of related proteins as templates. We developed MULTIDOMAIN ASSEMBLER (MDA) to address the special problems that arise when modeling proteins with large numbers of domains, such as fibronectin with 30 domains, as well as cases with hundreds of templates. These problems include how to spatially arrange nonoverlapping template structures, and how to get the best template coverage when some sequence regions have hundreds of available structures while other regions have a few distant homologs. MDA automates the tasks of template searching, visualization, and selection followed by multidomain model generation, and is part of the widely used molecular graphics package UCSF CHIMERA (University of California, San Francisco). We demonstrate applications and discuss MDA's benefits and limitations.
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Affiliation(s)
- Samuel Hertig
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, California; Resource for Biocomputing, Visualization, and Informatics, University of California, San Francisco, San Francisco, California
| | - Thomas D Goddard
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, California; Resource for Biocomputing, Visualization, and Informatics, University of California, San Francisco, San Francisco, California
| | - Graham T Johnson
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, California; Resource for Biocomputing, Visualization, and Informatics, University of California, San Francisco, San Francisco, California; California Institute for Quantitative Biosciences (QB3), University of California, San Francisco, San Francisco, California
| | - Thomas E Ferrin
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, California; Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, California; Resource for Biocomputing, Visualization, and Informatics, University of California, San Francisco, San Francisco, California; California Institute for Quantitative Biosciences (QB3), University of California, San Francisco, San Francisco, California.
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38
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Healy AR, Houston DR, Remnant L, Huart AS, Brychtova V, Maslon MM, Meers O, Muller P, Krejci A, Blackburn EA, Vojtesek B, Hernychova L, Walkinshaw MD, Westwood NJ, Hupp TR. Discovery of a novel ligand that modulates the protein-protein interactions of the AAA+ superfamily oncoprotein reptin. Chem Sci 2015; 6:3109-3116. [PMID: 28706685 PMCID: PMC5490336 DOI: 10.1039/c4sc03885a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 03/20/2015] [Indexed: 12/31/2022] Open
Abstract
Developing approaches to discover protein-protein interactions (PPIs) remains a fundamental challenge. A chemical biology platform is applied here to identify novel PPIs for the AAA+ superfamily oncoprotein reptin. An in silico screen coupled with chemical optimization provided Liddean, a nucleotide-mimetic which modulates reptin's oligomerization status, protein-binding activity and global conformation. Combinatorial peptide phage library screening of Liddean-bound reptin with next generation sequencing identified interaction motifs including a novel reptin docking site on the p53 tumor suppressor protein. Proximity ligation assays demonstrated that endogenous reptin forms a predominantly cytoplasmic complex with its paralog pontin in cancer cells and Liddean promotes a shift of this complex to the nucleus. An emerging view of PPIs in higher eukaryotes is that they occur through a striking diversity of linear peptide motifs. The discovery of a compound that alters reptin's protein interaction landscape potentially leads to novel avenues for therapeutic development.
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Affiliation(s)
- Alan R Healy
- School of Chemistry & Biomedical Sciences Research Complex , University of St Andrews & EaStCHEM , North Haugh, St Andrews , KY16 9ST , UK .
| | - Douglas R Houston
- Centre for Chemical Biology , University of Edinburgh , EH9 3JG , UK .
| | - Lucy Remnant
- Edinburgh Cancer Research Centre , Cell Signalling Unit , University of Edinburgh , EH4 2XR , UK .
| | - Anne-Sophie Huart
- Edinburgh Cancer Research Centre , Cell Signalling Unit , University of Edinburgh , EH4 2XR , UK .
| | - Veronika Brychtova
- RECAMO , Masaryk Memorial Cancer Institute , 656 53 Brno , Czech Republic
| | - Magda M Maslon
- Edinburgh Cancer Research Centre , Cell Signalling Unit , University of Edinburgh , EH4 2XR , UK .
| | - Olivia Meers
- Edinburgh Cancer Research Centre , Cell Signalling Unit , University of Edinburgh , EH4 2XR , UK .
| | - Petr Muller
- RECAMO , Masaryk Memorial Cancer Institute , 656 53 Brno , Czech Republic
| | - Adam Krejci
- RECAMO , Masaryk Memorial Cancer Institute , 656 53 Brno , Czech Republic
| | | | - Borek Vojtesek
- RECAMO , Masaryk Memorial Cancer Institute , 656 53 Brno , Czech Republic
| | - Lenka Hernychova
- RECAMO , Masaryk Memorial Cancer Institute , 656 53 Brno , Czech Republic
| | | | - Nicholas J Westwood
- School of Chemistry & Biomedical Sciences Research Complex , University of St Andrews & EaStCHEM , North Haugh, St Andrews , KY16 9ST , UK .
| | - Ted R Hupp
- Edinburgh Cancer Research Centre , Cell Signalling Unit , University of Edinburgh , EH4 2XR , UK .
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39
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Tria G, Mertens HDT, Kachala M, Svergun DI. Advanced ensemble modelling of flexible macromolecules using X-ray solution scattering. IUCRJ 2015; 2:207-17. [PMID: 25866658 PMCID: PMC4392415 DOI: 10.1107/s205225251500202x] [Citation(s) in RCA: 440] [Impact Index Per Article: 48.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Accepted: 01/30/2015] [Indexed: 05/19/2023]
Abstract
Dynamic ensembles of macromolecules mediate essential processes in biology. Understanding the mechanisms driving the function and molecular interactions of 'unstructured' and flexible molecules requires alternative approaches to those traditionally employed in structural biology. Small-angle X-ray scattering (SAXS) is an established method for structural characterization of biological macromolecules in solution, and is directly applicable to the study of flexible systems such as intrinsically disordered proteins and multi-domain proteins with unstructured regions. The Ensemble Optimization Method (EOM) [Bernadó et al. (2007 ▶). J. Am. Chem. Soc. 129, 5656-5664] was the first approach introducing the concept of ensemble fitting of the SAXS data from flexible systems. In this approach, a large pool of macromolecules covering the available conformational space is generated and a sub-ensemble of conformers coexisting in solution is selected guided by the fit to the experimental SAXS data. This paper presents a series of new developments and advancements to the method, including significantly enhanced functionality and also quantitative metrics for the characterization of the results. Building on the original concept of ensemble optimization, the algorithms for pool generation have been redesigned to allow for the construction of partially or completely symmetric oligomeric models, and the selection procedure was improved to refine the size of the ensemble. Quantitative measures of the flexibility of the system studied, based on the characteristic integral parameters of the selected ensemble, are introduced. These improvements are implemented in the new EOM version 2.0, and the capabilities as well as inherent limitations of the ensemble approach in SAXS, and of EOM 2.0 in particular, are discussed.
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Affiliation(s)
- Giancarlo Tria
- European Molecular Biology Laboratory, Hamburg Outstation, c/o DESY, Notkestrasse 85, Hamburg, 22603, Germany
| | - Haydyn D. T. Mertens
- European Molecular Biology Laboratory, Hamburg Outstation, c/o DESY, Notkestrasse 85, Hamburg, 22603, Germany
| | - Michael Kachala
- European Molecular Biology Laboratory, Hamburg Outstation, c/o DESY, Notkestrasse 85, Hamburg, 22603, Germany
| | - Dmitri I. Svergun
- European Molecular Biology Laboratory, Hamburg Outstation, c/o DESY, Notkestrasse 85, Hamburg, 22603, Germany
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40
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Kachala M, Valentini E, Svergun DI. Application of SAXS for the Structural Characterization of IDPs. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 870:261-89. [PMID: 26387105 DOI: 10.1007/978-3-319-20164-1_8] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Small-angle X-ray scattering (SAXS) is a powerful structural method allowing one to study the structure, folding state and flexibility of native particles and complexes in solution and to rapidly analyze structural changes in response to variations in external conditions. New high brilliance sources and novel data analysis methods significantly enhanced resolution and reliability of structural models provided by the technique. Automation of the SAXS experiment, data processing and interpretation make solution SAXS a streamline tool for large scale structural studies in molecular biology. The method provides low resolution macromolecular shapes ab initio and is readily combined with other structural and biochemical techniques in integrative studies. Very importantly, SAXS is sensitive to macromolecular flexibility being one of the few structural techniques applicable to flexible systems and intrinsically disordered proteins (IDPs). A major recent development is the use of SAXS to study particle dynamics in solution by ensemble approaches, which allow one to quantitatively characterize flexible systems. Of special interest is the joint use of SAXS with solution NMR, given that both methods yield highly complementary structural information, in particular, for IDPs. In this chapter, we present the basics of SAXS and also consider protocols of the experiment and data analysis for different scenarios depending on the type of the studied object. These include ab initio shape reconstruction, validation of available high resolution structures and rigid body modelling for folded macromolecules and also characterisation of flexible proteins with the ensemble methods. The methods are illustrated by examples of recent applications and further perspectives of the integrative use of SAXS with NMR in the studies of IDPs are discussed.
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Affiliation(s)
- Michael Kachala
- Hamburg Outstation, European Molecular Biology Laboratory, c/o DESY, Notkestrasse 85, 22603, Hamburg, Germany. .,Department of Chemistry, Hamburg University, Martin-Luther-King Platz 6, 20146, Hamburg, Germany.
| | - Erica Valentini
- Hamburg Outstation, European Molecular Biology Laboratory, c/o DESY, Notkestrasse 85, 22603, Hamburg, Germany.,Department of Chemistry, Hamburg University, Martin-Luther-King Platz 6, 20146, Hamburg, Germany
| | - Dmitri I Svergun
- Hamburg Outstation, European Molecular Biology Laboratory, c/o DESY, Notkestrasse 85, 22603, Hamburg, Germany.
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41
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van der Lee R, Buljan M, Lang B, Weatheritt RJ, Daughdrill GW, Dunker AK, Fuxreiter M, Gough J, Gsponer J, Jones D, Kim PM, Kriwacki R, Oldfield CJ, Pappu RV, Tompa P, Uversky VN, Wright P, Babu MM. Classification of intrinsically disordered regions and proteins. Chem Rev 2014; 114:6589-631. [PMID: 24773235 PMCID: PMC4095912 DOI: 10.1021/cr400525m] [Citation(s) in RCA: 1436] [Impact Index Per Article: 143.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Indexed: 12/11/2022]
Affiliation(s)
- Robin van der Lee
- MRC
Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
- Centre
for Molecular and Biomolecular Informatics, Radboud University Medical Centre, 6500 HB Nijmegen, The
Netherlands
| | - Marija Buljan
- MRC
Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - Benjamin Lang
- MRC
Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - Robert J. Weatheritt
- MRC
Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - Gary W. Daughdrill
- Department
of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, 3720 Spectrum Boulevard, Suite 321, Tampa, Florida 33612, United States
| | - A. Keith Dunker
- Department
of Biochemistry and Molecular Biology, Indiana
University School of Medicine, Indianapolis, Indiana 46202, United States
| | - Monika Fuxreiter
- MTA-DE
Momentum Laboratory of Protein Dynamics, Department of Biochemistry
and Molecular Biology, University of Debrecen, H-4032 Debrecen, Nagyerdei krt 98, Hungary
| | - Julian Gough
- Department
of Computer Science, University of Bristol, The Merchant Venturers Building, Bristol BS8 1UB, United Kingdom
| | - Joerg Gsponer
- Department
of Biochemistry and Molecular Biology, Centre for High-Throughput
Biology, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - David
T. Jones
- Bioinformatics
Group, Department of Computer Science, University
College London, London, WC1E 6BT, United Kingdom
| | - Philip M. Kim
- Terrence Donnelly Centre for Cellular and Biomolecular Research, Department of Molecular
Genetics, and Department of Computer Science, University
of Toronto, Toronto, Ontario M5S 3E1, Canada
| | - Richard
W. Kriwacki
- Department
of Structural Biology, St. Jude Children’s
Research Hospital, Memphis, Tennessee 38105, United States
| | - Christopher J. Oldfield
- Department
of Biochemistry and Molecular Biology, Indiana
University School of Medicine, Indianapolis, Indiana 46202, United States
| | - Rohit V. Pappu
- Department
of Biomedical Engineering and Center for Biological Systems Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Peter Tompa
- VIB Department
of Structural Biology, Vrije Universiteit
Brussel, Brussels, Belgium
- Institute
of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Vladimir N. Uversky
- Department
of Molecular Medicine and USF Health Byrd Alzheimer’s Research
Institute, Morsani College of Medicine, University of South Florida, Tampa, Florida 33612, United States
- Institute for Biological Instrumentation,
Russian Academy of Sciences, Pushchino,
Moscow Region, Russia
| | - Peter
E. Wright
- Department
of Integrative Structural and Computational Biology and Skaggs Institute
of Chemical Biology, The Scripps Research
Institute, 10550 North
Torrey Pines Road, La Jolla, California 92037, United States
| | - M. Madan Babu
- MRC
Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
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42
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Murciano-Calles J, Marin-Argany M, Cobos ES, Villegas S, Martinez JC. The impact of extra-domain structures and post-translational modifications in the folding/misfolding behaviour of the third PDZ domain of MAGUK neuronal protein PSD-95. PLoS One 2014; 9:e98124. [PMID: 24845085 PMCID: PMC4028313 DOI: 10.1371/journal.pone.0098124] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Accepted: 04/28/2014] [Indexed: 01/02/2023] Open
Abstract
The modulation of binding affinities and specificities by post-translational modifications located out from the binding pocket of the third PDZ domain of PSD-95 (PDZ3) has been reported recently. It is achieved through an intra-domain electrostatic network involving some charged residues in the β2–β3 loop (were a succinimide modification occurs), the α3 helix (an extra-structural element that links the PDZ3 domain with the following SH3 domain in PSD-95, and contains the phosphorylation target Tyr397), and the ligand peptide. Here, we have investigated the main structural and thermodynamic aspects that these structural elements and their related post-translational modifications display in the folding/misfolding pathway of PDZ3 by means of site-directed mutagenesis combined with calorimetry and spectroscopy. We have found that, although all the assayed mutations generate proteins more prone to aggregation than the wild-type PDZ3, those directly affecting the α3 helix, like the E401R substitution or the truncation of the whole α3 helix, increase the population of the DSC-detected intermediate state and the misfolding kinetics, by organizing the supramacromolecular structures at the expense of the two β-sheets present in the PDZ3 fold. However, those mutations affecting the β2–β3 loop, included into the prone-to-aggregation region composed by a single β-sheet comprising β2 to β4 chains, stabilize the trimeric intermediate previously shown in the wild-type PDZ3 and slow-down aggregation, also making it partly reversible. These results strongly suggest that the α3 helix protects to some extent the PDZ3 domain core from misfolding. This might well constitute the first example where an extra-element, intended to link the PDZ3 domain to the following SH3 in PSD-95 and in other members of the MAGUK family, not only regulates the binding abilities of this domain but it also protects PDZ3 from misfolding and aggregation. The influence of the post-translational modifications in this regulatory mechanism is also discussed.
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Affiliation(s)
- Javier Murciano-Calles
- Departamento de Química Física e Instituto de Biotecnología, Facultad de Ciencias, Universidad de Granada, Granada, Spain
| | - Marta Marin-Argany
- Departament de Bioquímica i Biología Molecular, Facultat de Biociències, Universitat Autónoma de Barcelona, Barcelona, Spain
| | - Eva S. Cobos
- Departamento de Química Física e Instituto de Biotecnología, Facultad de Ciencias, Universidad de Granada, Granada, Spain
| | - Sandra Villegas
- Departament de Bioquímica i Biología Molecular, Facultat de Biociències, Universitat Autónoma de Barcelona, Barcelona, Spain
- * E-mail: (SV); (JCM)
| | - Jose C. Martinez
- Departamento de Química Física e Instituto de Biotecnología, Facultad de Ciencias, Universidad de Granada, Granada, Spain
- * E-mail: (SV); (JCM)
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43
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Sterckx YGJ, Volkov AN, Vranken WF, Kragelj J, Jensen MR, Buts L, Garcia-Pino A, Jové T, Van Melderen L, Blackledge M, van Nuland NAJ, Loris R. Small-angle X-ray scattering- and nuclear magnetic resonance-derived conformational ensemble of the highly flexible antitoxin PaaA2. Structure 2014; 22:854-65. [PMID: 24768114 DOI: 10.1016/j.str.2014.03.012] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Revised: 03/14/2014] [Accepted: 03/15/2014] [Indexed: 11/26/2022]
Abstract
Antitoxins from prokaryotic type II toxin-antitoxin modules are characterized by a high degree of intrinsic disorder. The description of such highly flexible proteins is challenging because they cannot be represented by a single structure. Here, we present a combination of SAXS and NMR data to describe the conformational ensemble of the PaaA2 antitoxin from the human pathogen E. coli O157. The method encompasses the use of SAXS data to filter ensembles out of a pool of conformers generated by a custom NMR structure calculation protocol and the subsequent refinement by a block jackknife procedure. The final ensemble obtained through the method is validated by an established residual dipolar coupling analysis. We show that the conformational ensemble of PaaA2 is highly compact and that the protein exists in solution as two preformed helices, connected by a flexible linker, that probably act as molecular recognition elements for toxin inhibition.
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Affiliation(s)
- Yann G J Sterckx
- Structural Biology Brussels, Department of Biotechnology, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium; Molecular Recognition Unit and Jean Jeener NMR Centre, Structural Biology Research Center, VIB, Pleinlaan 2, B-1050 Brussels, Belgium
| | - Alexander N Volkov
- Structural Biology Brussels, Department of Biotechnology, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium; Molecular Recognition Unit and Jean Jeener NMR Centre, Structural Biology Research Center, VIB, Pleinlaan 2, B-1050 Brussels, Belgium
| | - Wim F Vranken
- Structural Biology Brussels, Department of Biotechnology, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium; Molecular Recognition Unit and Jean Jeener NMR Centre, Structural Biology Research Center, VIB, Pleinlaan 2, B-1050 Brussels, Belgium
| | - Jaka Kragelj
- Protein Dynamics and Flexibility, Institut de Biologie Structurale Jean-Pierre Ebel CNRS-CEA-UJF UMR 5075, 41 Rue Jules Horowitz, 38027 Grenoble Cedex, France
| | - Malene Ringkjøbing Jensen
- Protein Dynamics and Flexibility, Institut de Biologie Structurale Jean-Pierre Ebel CNRS-CEA-UJF UMR 5075, 41 Rue Jules Horowitz, 38027 Grenoble Cedex, France
| | - Lieven Buts
- Structural Biology Brussels, Department of Biotechnology, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium; Molecular Recognition Unit and Jean Jeener NMR Centre, Structural Biology Research Center, VIB, Pleinlaan 2, B-1050 Brussels, Belgium
| | - Abel Garcia-Pino
- Structural Biology Brussels, Department of Biotechnology, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium; Molecular Recognition Unit and Jean Jeener NMR Centre, Structural Biology Research Center, VIB, Pleinlaan 2, B-1050 Brussels, Belgium
| | - Thomas Jové
- Laboratoire de Génétique et Physiologie Bactérienne, Institut de Biologie et de Médecine Moléculaires Faculté des Sciences, Université Libre de Bruxelles, 12 Rue des Professeurs Jeener et Brachet, B-6041 Gosselies, Belgium
| | - Laurence Van Melderen
- Laboratoire de Génétique et Physiologie Bactérienne, Institut de Biologie et de Médecine Moléculaires Faculté des Sciences, Université Libre de Bruxelles, 12 Rue des Professeurs Jeener et Brachet, B-6041 Gosselies, Belgium
| | - Martin Blackledge
- Protein Dynamics and Flexibility, Institut de Biologie Structurale Jean-Pierre Ebel CNRS-CEA-UJF UMR 5075, 41 Rue Jules Horowitz, 38027 Grenoble Cedex, France
| | - Nico A J van Nuland
- Structural Biology Brussels, Department of Biotechnology, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium; Molecular Recognition Unit and Jean Jeener NMR Centre, Structural Biology Research Center, VIB, Pleinlaan 2, B-1050 Brussels, Belgium.
| | - Remy Loris
- Structural Biology Brussels, Department of Biotechnology, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium; Molecular Recognition Unit and Jean Jeener NMR Centre, Structural Biology Research Center, VIB, Pleinlaan 2, B-1050 Brussels, Belgium.
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44
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Forman-Kay JD, Mittag T. From sequence and forces to structure, function, and evolution of intrinsically disordered proteins. Structure 2014; 21:1492-9. [PMID: 24010708 DOI: 10.1016/j.str.2013.08.001] [Citation(s) in RCA: 166] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 08/02/2013] [Accepted: 08/06/2013] [Indexed: 01/27/2023]
Abstract
Intrinsically disordered proteins (IDPs), which lack persistent structure, are a challenge to structural biology due to the inapplicability of standard methods for characterization of folded proteins as well as their deviation from the dominant structure/function paradigm. Their widespread presence and involvement in biological function, however, has spurred the growing acceptance of the importance of IDPs and the development of new tools for studying their structure, dynamics, and function. The interplay of folded and disordered domains or regions for function and the existence of a continuum of protein states with respect to conformational energetics, motional timescales, and compactness are shaping a unified understanding of structure-dynamics-disorder/function relationships. In the 20(th) anniversary of Structure, we provide a historical perspective on the investigation of IDPs and summarize the sequence features and physical forces that underlie their unique structural, functional, and evolutionary properties.
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Affiliation(s)
- Julie D Forman-Kay
- Molecular Structure and Function, Hospital for Sick Children, Toronto, ON, M5G 1X8, Canada; Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada.
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45
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Nicholson J, Scherl A, Way L, Blackburn EA, Walkinshaw MD, Ball KL, Hupp TR. A systems wide mass spectrometric based linear motif screen to identify dominant in-vivo interacting proteins for the ubiquitin ligase MDM2. Cell Signal 2014; 26:1243-57. [PMID: 24583282 DOI: 10.1016/j.cellsig.2014.02.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Accepted: 02/21/2014] [Indexed: 12/24/2022]
Abstract
Linear motifs mediate protein-protein interactions (PPI) that allow expansion of a target protein interactome at a systems level. This study uses a proteomics approach and linear motif sub-stratifications to expand on PPIs of MDM2. MDM2 is a multi-functional protein with over one hundred known binding partners not stratified by hierarchy or function. A new linear motif based on a MDM2 interaction consensus is used to select novel MDM2 interactors based on Nutlin-3 responsiveness in a cell-based proteomics screen. MDM2 binds a subset of peptide motifs corresponding to real proteins with a range of allosteric responses to MDM2 ligands. We validate cyclophilin B as a novel protein with a consensus MDM2 binding motif that is stabilised by Nutlin-3 in vivo, thus identifying one of the few known interactors of MDM2 that is stabilised by Nutlin-3. These data invoke two modes of peptide binding at the MDM2 N-terminus that rely on a consensus core motif to control the equilibrium between MDM2 binding proteins. This approach stratifies MDM2 interacting proteins based on the linear motif feature and provides a new biomarker assay to define clinically relevant Nutlin-3 responsive MDM2 interactors.
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Affiliation(s)
- Judith Nicholson
- Edinburgh Cancer Research Centre, Cell Signalling Unit, University of Edinburgh, EH4 2XR, United Kingdom; Department of Radiation Oncology and Biology, University of Oxford, OX3 7DQ, United Kingdom
| | - Alex Scherl
- Proteomics Core Facility, University of Geneva, Switzerland
| | - Luke Way
- Edinburgh Cancer Research Centre, Cell Signalling Unit, University of Edinburgh, EH4 2XR, United Kingdom
| | - Elizabeth A Blackburn
- Edinburgh Centre for Chemical Biology, University of Edinburgh, EH9 3JG, United Kingdom
| | - Malcolm D Walkinshaw
- Edinburgh Centre for Chemical Biology, University of Edinburgh, EH9 3JG, United Kingdom
| | - Kathryn L Ball
- Edinburgh Cancer Research Centre, Cell Signalling Unit, University of Edinburgh, EH4 2XR, United Kingdom
| | - Ted R Hupp
- Edinburgh Cancer Research Centre, Cell Signalling Unit, University of Edinburgh, EH4 2XR, United Kingdom.
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46
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Post-translational modifications modulate ligand recognition by the third PDZ domain of the MAGUK protein PSD-95. PLoS One 2014; 9:e90030. [PMID: 24587199 PMCID: PMC3935999 DOI: 10.1371/journal.pone.0090030] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 01/31/2014] [Indexed: 12/20/2022] Open
Abstract
The relative promiscuity of hub proteins such as postsynaptic density protein-95 (PSD-95) can be achieved by alternative splicing, allosteric regulation, and post-translational modifications, the latter of which is the most efficient method of accelerating cellular responses to environmental changes in vivo. Here, a mutational approach was used to determine the impact of phosphorylation and succinimidation post-translational modifications on the binding affinity of the postsynaptic density protein-95/discs large/zonula occludens-1 (PDZ3) domain of PSD-95. Molecular dynamics simulations revealed that the binding affinity of this domain is influenced by an interplay between salt-bridges linking the α3 helix, the β2–β3 loop and the positively charged Lys residues in its high-affinity hexapeptide ligand KKETAV. The α3 helix is an extra structural element that is not present in other PDZ domains, which links PDZ3 with the following SH3 domain in the PSD-95 protein. This regulatory mechanism was confirmed experimentally via thermodynamic and NMR chemical shift perturbation analyses, discarding intra-domain long-range effects. Taken together, the results presented here reveal the molecular basis of the regulatory role of the α3 extra-element and the effects of post-translational modifications of PDZ3 on its binding affinity, both energetically and dynamically.
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47
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Tompa P. Multisteric Regulation by Structural Disorder in Modular Signaling Proteins: An Extension of the Concept of Allostery. Chem Rev 2013; 114:6715-32. [DOI: 10.1021/cr4005082] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Peter Tompa
- VIB Department of Structural
Biology, Vrije Universiteit Brussel, 1050 Brussels, Belgium
- Institute of Enzymology, Biological Research Center, Hungarian Academy
of Sciences, Budapest H-1113, Hungary
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Kosol S, Contreras-Martos S, Cedeño C, Tompa P. Structural characterization of intrinsically disordered proteins by NMR spectroscopy. Molecules 2013; 18:10802-28. [PMID: 24008243 PMCID: PMC6269831 DOI: 10.3390/molecules180910802] [Citation(s) in RCA: 128] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Revised: 08/19/2013] [Accepted: 08/30/2013] [Indexed: 01/25/2023] Open
Abstract
Recent advances in NMR methodology and techniques allow the structural investigation of biomolecules of increasing size with atomic resolution. NMR spectroscopy is especially well-suited for the study of intrinsically disordered proteins (IDPs) and intrinsically disordered regions (IDRs) which are in general highly flexible and do not have a well-defined secondary or tertiary structure under functional conditions. In the last decade, the important role of IDPs in many essential cellular processes has become more evident as the lack of a stable tertiary structure of many protagonists in signal transduction, transcription regulation and cell-cycle regulation has been discovered. The growing demand for structural data of IDPs required the development and adaption of methods such as 13C-direct detected experiments, paramagnetic relaxation enhancements (PREs) or residual dipolar couplings (RDCs) for the study of ‘unstructured’ molecules in vitro and in-cell. The information obtained by NMR can be processed with novel computational tools to generate conformational ensembles that visualize the conformations IDPs sample under functional conditions. Here, we address NMR experiments and strategies that enable the generation of detailed structural models of IDPs.
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Affiliation(s)
- Simone Kosol
- VIB Department of Structural Biology, Vrije Universiteit Brussel, Brussels 1050, Belgium; E-Mails: (S.C.M.); (C.C.)
- Authors to whom correspondence should be addressed; E-Mails: (S.K.); (P.T.)
| | - Sara Contreras-Martos
- VIB Department of Structural Biology, Vrije Universiteit Brussel, Brussels 1050, Belgium; E-Mails: (S.C.M.); (C.C.)
| | - Cesyen Cedeño
- VIB Department of Structural Biology, Vrije Universiteit Brussel, Brussels 1050, Belgium; E-Mails: (S.C.M.); (C.C.)
| | - Peter Tompa
- VIB Department of Structural Biology, Vrije Universiteit Brussel, Brussels 1050, Belgium; E-Mails: (S.C.M.); (C.C.)
- Institute of Enzymology, Biological Research Center, Hungarian Academy of Sciences, Budapest 1518, Hungary
- Authors to whom correspondence should be addressed; E-Mails: (S.K.); (P.T.)
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Carotenuto M, Pedone E, Diana D, de Antonellis P, Džeroski S, Marino N, Navas L, Di Dato V, Scoppettuolo MN, Cimmino F, Correale S, Pirone L, Monti SM, Bruder E, Zenko B, Slavkov I, Pastorino F, Ponzoni M, Schulte JH, Schramm A, Eggert A, Westermann F, Arrigoni G, Accordi B, Basso G, Saviano M, Fattorusso R, Zollo M. Neuroblastoma tumorigenesis is regulated through the Nm23-H1/h-Prune C-terminal interaction. Sci Rep 2013; 3:1351. [PMID: 23448979 PMCID: PMC3584926 DOI: 10.1038/srep01351] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Accepted: 02/12/2013] [Indexed: 12/21/2022] Open
Abstract
Nm23-H1 is one of the most interesting candidate genes for a relevant role in Neuroblastoma pathogenesis. H-Prune is the most characterized Nm23-H1 binding partner, and its overexpression has been shown in different human cancers. Our study focuses on the role of the Nm23-H1/h-Prune protein complex in Neuroblastoma. Using NMR spectroscopy, we performed a conformational analysis of the h-Prune C-terminal to identify the amino acids involved in the interaction with Nm23-H1. We developed a competitive permeable peptide (CPP) to impair the formation of the Nm23-H1/h-Prune complex and demonstrated that CPP causes impairment of cell motility, substantial impairment of tumor growth and metastases formation. Meta-analysis performed on three Neuroblastoma cohorts showed Nm23-H1 as the gene highly associated to Neuroblastoma aggressiveness. We also identified two other proteins (PTPRA and TRIM22) with expression levels significantly affected by CPP. These data suggest a new avenue for potential clinical application of CPP in Neuroblastoma treatment.
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Huang W, Greene GL, Ravikumar KM, Yang S. Cross-talk between the ligand- and DNA-binding domains of estrogen receptor. Proteins 2013; 81:1900-9. [PMID: 23737157 DOI: 10.1002/prot.24331] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Revised: 04/22/2013] [Accepted: 05/09/2013] [Indexed: 11/11/2022]
Abstract
Estrogen receptor alpha (ERα) is a hormone-responsive transcription factor that contains several discrete functional domains, including a ligand-binding domain (LBD) and a DNA-binding domain (DBD). Despite a wealth of knowledge about the behaviors of individual domains, the molecular mechanisms of cross-talk between LBD and DBD during signal transduction from hormone to DNA-binding of ERα remain elusive. Here, we apply a multiscale approach combining coarse-grained (CG) and atomistically detailed simulations to characterize this cross-talk mechanism via an investigation of the ERα conformational landscape. First, a CG model of ERα is built based on crystal structures of individual LBDs and DBDs, with more emphasis on their interdomain interactions. Second, molecular dynamics simulations are implemented and enhanced sampling is achieved via the "push-pull-release" strategy in the search for different LBD-DBD orientations. Third, multiple energetically stable ERα conformations are identified on the landscape. A key finding is that estradiol-bound LBDs utilize the well-described activation helix H12 to pack and stabilize LBD-DBD interactions. Our results suggest that the estradiol-bound LBDs can serve as a scaffold to position and stabilize the DBD-DNA complex, consistent with experimental observations of enhanced DNA binding with the LBD. Final assessment using atomic-level simulations shows that these CG-predicted models are significantly stable within a 15-ns simulation window and that specific pairs of lysine residues in close proximity at the domain interfaces could serve as candidate sites for chemical cross-linking studies. Together, these simulation results provide a molecular view of the role of ERα domain interactions in response to hormone binding.
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Affiliation(s)
- Wei Huang
- Center for Proteomics and Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, 44106-4988
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