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Abstract
Intrinsically disordered proteins (IDPs) can adopt a range of conformations from globules to swollen coils. This large range of conformational preferences for different IDPs raises the question of how conformational preferences are encoded by sequence. Global compositional features of a sequence such as the fraction of charged residues and the net charge per residue engender certain conformational biases. However, more specific sequence features such as the patterning of oppositely charged residues, expansion driving residues, or residues that can undergo posttranslational modifications can also influence the conformational ensembles of an IDP. Here, we outline how to calculate important global compositional features and patterning metrics that can be used to classify IDPs into different conformational classes and predict relative changes in conformation for sequences with the same amino acid composition. Although increased effort has been devoted to determining conformational properties of IDPs in recent years, quantitative predictions of conformation directly from sequence remain difficult and often inaccurate. Thus, if quantitative predictions of conformational properties are desired, then sequence-specific simulations must be performed.
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Affiliation(s)
- Kiersten M Ruff
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA.
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52
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Schuler B, Borgia A, Borgia MB, Heidarsson PO, Holmstrom ED, Nettels D, Sottini A. Binding without folding - the biomolecular function of disordered polyelectrolyte complexes. Curr Opin Struct Biol 2019; 60:66-76. [PMID: 31874413 DOI: 10.1016/j.sbi.2019.12.006] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 11/29/2019] [Accepted: 12/05/2019] [Indexed: 12/16/2022]
Abstract
Recent evidence shows that oppositely charged intrinsically disordered proteins (IDPs) can form high-affinity complexes that involve neither the formation of secondary or tertiary structure nor site-specific interactions between individual residues. Similar electrostatically dominated interactions have also been identified for positively charged IDPs binding to nucleic acids. These highly disordered polyelectrolyte complexes constitute an extreme case within the spectrum of biomolecular interactions involving disorder. Such interactions are likely to be widespread, since sequence analysis predicts proteins with highly charged disordered regions to be surprisingly numerous. Here, we summarize the insights that have emerged from the highly disordered polyelectrolyte complexes identified so far, and we highlight recent developments and future challenges in (i) establishing models for the underlying highly dynamic structural ensembles, (ii) understanding the novel binding mechanisms associated with them, and (iii) identifying the functional consequences.
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Affiliation(s)
- Benjamin Schuler
- Department of Biochemistry, University of Zurich, Switzerland; Department of Physics, University of Zurich, Switzerland.
| | - Alessandro Borgia
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Madeleine B Borgia
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Pétur O Heidarsson
- Department of Biochemistry, Science Institute, University of Iceland, Dunhagi 3, 107 Reykjavík, Iceland
| | - Erik D Holmstrom
- Department of Molecular Biosciences, University of Kansas, 1200 Sunnyside, Lawrence, KS 66045, USA; Department of Chemistry, University of Kansas, 1200 Sunnyside, Lawrence, KS 66045, USA
| | - Daniel Nettels
- Department of Biochemistry, University of Zurich, Switzerland
| | - Andrea Sottini
- Department of Biochemistry, University of Zurich, Switzerland
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53
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Spassov DS, Ruiz-Saenz A, Piple A, Moasser MM. A Dimerization Function in the Intrinsically Disordered N-Terminal Region of Src. Cell Rep 2019; 25:449-463.e4. [PMID: 30304684 PMCID: PMC6226010 DOI: 10.1016/j.celrep.2018.09.035] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 07/09/2018] [Accepted: 09/12/2018] [Indexed: 01/30/2023] Open
Abstract
The mode of regulation of Src kinases has been elucidated by crystallographic studies identifying conserved structured protein modules involved in an orderly set of intramolecular associations and ligand interactions. Despite these detailed insights, much of the complex behavior and diversity in the Src family remains unexplained. A key missing piece is the function of the unstructured N-terminal region. We report here the function of the N-terminal region in binding within a hydrophobic pocket in the kinase domain of a dimerization partner. Dimerization substantially enhances autophosphorylation and phosphorylation of selected substrates, and interfering with dimerization is disruptive to these functions. Dimerization and Y419 phosphorylation are codependent events creating a bistable switch. Given the versatility inherent in this intrinsically disordered region, its multisite phosphorylations, and its divergence within the family, the unique domain likely functions as a central signaling hub overseeing much of the activities and unique functions of Src family kinases. Spassov et al. report that Src exists in cells and functions as a dimer and that dimerization and autophosphorylation are codependent events. Through a comprehensive structure-function analysis, they show that the dimer is an asymmetric dimer held through the interaction of the myristoylated N-terminal unique domain of one partner with a hydrophobic pocket in the kinase domain of another.
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Affiliation(s)
- Danislav S Spassov
- Department of Medicine, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Ana Ruiz-Saenz
- Department of Medicine, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Amit Piple
- Department of Medicine, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Mark M Moasser
- Department of Medicine, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94143, USA.
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54
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Arbesú M, Pons M. Integrating disorder in globular multidomain proteins: Fuzzy sensors and the role of SH3 domains. Arch Biochem Biophys 2019; 677:108161. [PMID: 31678340 DOI: 10.1016/j.abb.2019.108161] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 10/20/2019] [Accepted: 10/24/2019] [Indexed: 12/25/2022]
Abstract
Intrinsically disordered proteins represent about one third of eukaryotic proteins. An additional third correspond to proteins containing folded domains as well as large intrinsically disordered regions (IDR). While IDRs may represent functionally autonomous domains, in some instances it has become clear that they provide a new layer of regulation for the activity displayed by the folded domains. The sensitivity of the conformational ensembles defining the properties of IDR to small changes in the cellular environment and the capacity to modulate this response through post-translational modifications makes IDR ideal sensors enabling continuous, integrative responses to complex cellular inputs. Folded domains (FD), on the other hand, are ideal effectors, e.g. by catalyzing enzymatic reactions or participating in binary on/off switches. In this perspective review we discuss the possible role of intramolecular fuzzy complexes to integrate the very different dynamic scales of IDR and FD, inspired on the recent observations of such dynamic complexes in Src family kinases, and we explore the possible general role of the SH3 domains connecting IDRs and FD.
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Affiliation(s)
- Miguel Arbesú
- Biomolecular NMR laboratory. Department of Inorganic and Organic Chemistry. University of Barcelona, Baldiri Reixac, 10-12, 08028, Barcelona, Spain
| | - Miquel Pons
- Biomolecular NMR laboratory. Department of Inorganic and Organic Chemistry. University of Barcelona, Baldiri Reixac, 10-12, 08028, Barcelona, Spain.
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55
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Is the cell really a machine? J Theor Biol 2019; 477:108-126. [PMID: 31173758 DOI: 10.1016/j.jtbi.2019.06.002] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2018] [Revised: 05/06/2019] [Accepted: 06/03/2019] [Indexed: 01/03/2023]
Abstract
It has become customary to conceptualize the living cell as an intricate piece of machinery, different to a man-made machine only in terms of its superior complexity. This familiar understanding grounds the conviction that a cell's organization can be explained reductionistically, as well as the idea that its molecular pathways can be construed as deterministic circuits. The machine conception of the cell owes a great deal of its success to the methods traditionally used in molecular biology. However, the recent introduction of novel experimental techniques capable of tracking individual molecules within cells in real time is leading to the rapid accumulation of data that are inconsistent with an engineering view of the cell. This paper examines four major domains of current research in which the challenges to the machine conception of the cell are particularly pronounced: cellular architecture, protein complexes, intracellular transport, and cellular behaviour. It argues that a new theoretical understanding of the cell is emerging from the study of these phenomena which emphasizes the dynamic, self-organizing nature of its constitution, the fluidity and plasticity of its components, and the stochasticity and non-linearity of its underlying processes.
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56
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Baul U, Chakraborty D, Mugnai ML, Straub JE, Thirumalai D. Sequence Effects on Size, Shape, and Structural Heterogeneity in Intrinsically Disordered Proteins. J Phys Chem B 2019; 123:3462-3474. [PMID: 30913885 PMCID: PMC6920032 DOI: 10.1021/acs.jpcb.9b02575] [Citation(s) in RCA: 103] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Intrinsically disordered proteins (IDPs) lack well-defined three-dimensional structures, thus challenging the archetypal notion of structure-function relationships. Determining the ensemble of conformations that IDPs explore under physiological conditions is the first step toward understanding their diverse cellular functions. Here, we quantitatively characterize the structural features of IDPs as a function of sequence and length using coarse-grained simulations. For diverse IDP sequences, with the number of residues ( NT) ranging from 20 to 441, our simulations not only reproduce the radii of gyration ( Rg) obtained from experiments, but also predict the full scattering intensity profiles in excellent agreement with small-angle X-ray scattering experiments. The Rg values are well-described by the standard Flory scaling law, Rg = Rg0 NTν, with ν ≈ 0.588, making it tempting to assert that IDPs behave as polymers in a good solvent. However, clustering analysis reveals that the menagerie of structures explored by IDPs is diverse, with the extent of heterogeneity being highly sequence-dependent, even though ensemble-averaged properties, such as the dependence of Rg on chain length, may suggest synthetic polymer-like behavior in a good solvent. For example, we show that for the highly charged Prothymosin-α, a substantial fraction of conformations is highly compact. Even if the sequence compositions are similar, as is the case for α-Synuclein and a truncated construct from the Tau protein, there are substantial differences in the conformational heterogeneity. Taken together, these observations imply that metrics based on net charge or related quantities alone cannot be used to anticipate the phases of IDPs, either in isolation or in complex with partner IDPs or RNA. Our work sets the stage for probing the interactions of IDPs with each other, with folded protein domains, or with partner RNAs, which are critical for describing the structures of stress granules and biomolecular condensates with important cellular functions.
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Affiliation(s)
- Upayan Baul
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Debayan Chakraborty
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Mauro L. Mugnai
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - John E. Straub
- Department of Chemistry, Boston University, Boston, Massachusetts 02215, United States
| | - D. Thirumalai
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
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57
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Estaña A, Sibille N, Delaforge E, Vaisset M, Cortés J, Bernadó P. Realistic Ensemble Models of Intrinsically Disordered Proteins Using a Structure-Encoding Coil Database. Structure 2019; 27:381-391.e2. [DOI: 10.1016/j.str.2018.10.016] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 07/13/2018] [Accepted: 10/19/2018] [Indexed: 11/27/2022]
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58
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Milles S, Salvi N, Blackledge M, Jensen MR. Characterization of intrinsically disordered proteins and their dynamic complexes: From in vitro to cell-like environments. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2018; 109:79-100. [PMID: 30527137 DOI: 10.1016/j.pnmrs.2018.07.001] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Revised: 07/16/2018] [Accepted: 07/16/2018] [Indexed: 05/08/2023]
Abstract
Over the last two decades, it has become increasingly clear that a large fraction of the human proteome is intrinsically disordered or contains disordered segments of significant length. These intrinsically disordered proteins (IDPs) play important regulatory roles throughout biology, underlining the importance of understanding their conformational behavior and interaction mechanisms at the molecular level. Here we review recent progress in the NMR characterization of the structure and dynamics of IDPs in various functional states and environments. We describe the complementarity of different NMR parameters for quantifying the conformational propensities of IDPs in their isolated and phosphorylated states, and we discuss the challenges associated with obtaining structural models of dynamic protein-protein complexes involving IDPs. In addition, we review recent progress in understanding the conformational behavior of IDPs in cell-like environments such as in the presence of crowding agents, in membrane-less organelles and in the complex environment of the human cell.
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Affiliation(s)
- Sigrid Milles
- Univ. Grenoble Alpes, CNRS, CEA, IBS, F-38000 Grenoble, France
| | - Nicola Salvi
- Univ. Grenoble Alpes, CNRS, CEA, IBS, F-38000 Grenoble, France
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59
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Firman T, Ghosh K. Sequence charge decoration dictates coil-globule transition in intrinsically disordered proteins. J Chem Phys 2018; 148:123305. [PMID: 29604827 DOI: 10.1063/1.5005821] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
We present an analytical theory to compute conformations of heteropolymers-applicable to describe disordered proteins-as a function of temperature and charge sequence. The theory describes coil-globule transition for a given protein sequence when temperature is varied and has been benchmarked against the all-atom Monte Carlo simulation (using CAMPARI) of intrinsically disordered proteins (IDPs). In addition, the model quantitatively shows how subtle alterations of charge placement in the primary sequence-while maintaining the same charge composition-can lead to significant changes in conformation, even as drastic as a coil (swelled above a purely random coil) to globule (collapsed below a random coil) and vice versa. The theory provides insights on how to control (enhance or suppress) these changes by tuning the temperature (or solution condition) and charge decoration. As an application, we predict the distribution of conformations (at room temperature) of all naturally occurring IDPs in the DisProt database and notice significant size variation even among IDPs with a similar composition of positive and negative charges. Based on this, we provide a new diagram-of-states delineating the sequence-conformation relation for proteins in the DisProt database. Next, we study the effect of post-translational modification, e.g., phosphorylation, on IDP conformations. Modifications as little as two-site phosphorylation can significantly alter the size of an IDP with everything else being constant (temperature, salt concentration, etc.). However, not all possible modification sites have the same effect on protein conformations; there are certain "hot spots" that can cause maximal change in conformation. The location of these "hot spots" in the parent sequence can readily be identified by using a sequence charge decoration metric originally introduced by Sawle and Ghosh. The ability of our model to predict conformations (both expanded and collapsed states) of IDPs at a high-throughput level can provide valuable insights into the different mechanisms by which phosphorylation/charge mutation controls IDP function.
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Affiliation(s)
- Taylor Firman
- Molecular and Cellular Biophysics, University of Denver, Denver, Colorado 80208, USA and Department of Physics and Astronomy, University of Denver, Denver, Colorado 80208, USA
| | - Kingshuk Ghosh
- Molecular and Cellular Biophysics, University of Denver, Denver, Colorado 80208, USA and Department of Physics and Astronomy, University of Denver, Denver, Colorado 80208, USA
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60
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Cukier RI. Generating Intrinsically Disordered Protein Conformational Ensembles from a Database of Ramachandran Space Pair Residue Probabilities Using a Markov Chain. J Phys Chem B 2018; 122:9087-9101. [DOI: 10.1021/acs.jpcb.8b05797] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Robert I. Cukier
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824-1322, United States
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61
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Cukier RI. Conformational Ensembles Exhibit Extensive Molecular Recognition Features. ACS OMEGA 2018; 3:9907-9920. [PMID: 31459119 PMCID: PMC6644992 DOI: 10.1021/acsomega.8b00898] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 08/14/2018] [Indexed: 06/10/2023]
Abstract
Intrinsically disordered proteins (IDPs) are important for signaling and regulatory pathways. In contrast to folded proteins, they sample a diverse conformational space. IDPs have residue ranges within a sequence that have been referred to as molecular recognition features (MoRFs). A MoRF can be viewed as contiguous residues exhibiting a conformational disorder that become ordered upon binding to another protein or ligand. In this work, we introduce a structural characterization of MoRFs based on entropy and mutual information (MI). In this view, a MoRF is a set of contiguous residues that exhibit a large entropy (from rotameric residue sampling) and large MI, the latter indicating a dependence among the residues' rotameric sampling comprising the MoRF. The methodology is first applied to a number of ubiquitin ensembles that were obtained based on nuclear magnetic resonance experiments. One is a denatured Ub ensemble that has a large entropy for various unitSizes (number of contiguous residues) but essentially zero MI, indicting no dependence among the residue rotamer sampling. Another ensemble does exhibit extensive regions along the sequence where there are MoRFs centered on nonsecondary structure regions. The MoRFs are present for unitSizes 2-10. That a substantial number of MoRFs are present in Ub strongly suggests a conformational selection mechanism for this protein. Two additional ensembles for the cyclin-dependent kinase inhibitor Sic1 and for the amyloid protein α-synuclein, which have been shown to be IDPs, are also analyzed. Both exhibit MoRF-like character.
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62
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Cragnell C, Rieloff E, Skepö M. Utilizing Coarse-Grained Modeling and Monte Carlo Simulations to Evaluate the Conformational Ensemble of Intrinsically Disordered Proteins and Regions. J Mol Biol 2018; 430:2478-2492. [DOI: 10.1016/j.jmb.2018.03.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 03/03/2018] [Accepted: 03/12/2018] [Indexed: 11/16/2022]
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63
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Calcium-Binding Proteins with Disordered Structure and Their Role in Secretion, Storage, and Cellular Signaling. Biomolecules 2018; 8:biom8020042. [PMID: 29921816 PMCID: PMC6022996 DOI: 10.3390/biom8020042] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 06/12/2018] [Accepted: 06/14/2018] [Indexed: 12/19/2022] Open
Abstract
Calcium is one of the most important second messengers and its intracellular signaling regulates many aspects of cell physiology. Calcium ions, like phosphate ions, are highly charged and thus are able to alter protein conformation upon binding; thereby they constitute key factors in signal transduction. One of the most common calcium-binding structural motifs is the EF-hand, a well-defined helix-loop-helix structural domain, present in many calcium-binding proteins (CBPs). Nonetheless, some CBPs contain non-canonical, disordered motifs, which usually bind calcium with high capacity and low affinity, and which represent a subset of proteins with specific functions, but these functions rarely involve signaling. When compared with phosphorylation-mediated signal transduction, the role of intrinsic disorder in calcium signaling is significantly less prominent and not direct. The list of known examples of intrinsically disordered CBPs is relatively short and the disorder in these examples seems to be linked to secretion and storage. Calcium-sensitive phosphatase calcineurin is an exception, but it represents an example of transient disorder, which is, nevertheless, vital to the functioning of this protein. The underlying reason for the different role of disordered proteins in the two main cellular signaling systems appears to be linked to the gradient of calcium concentration, present in all living cells.
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64
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Developing a molecular dynamics force field for both folded and disordered protein states. Proc Natl Acad Sci U S A 2018; 115:E4758-E4766. [PMID: 29735687 PMCID: PMC6003505 DOI: 10.1073/pnas.1800690115] [Citation(s) in RCA: 589] [Impact Index Per Article: 98.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Many proteins that perform important biological functions are completely or partially disordered under physiological conditions. Molecular dynamics simulations could be a powerful tool for the structural characterization of such proteins, but it has been unclear whether the physical models (force fields) used in simulations are sufficiently accurate. Here, we systematically compare the accuracy of a number of different force fields in simulations of both ordered and disordered proteins, finding that each force field has strengths and limitations. We then describe a force field that substantially improves on the state-of-the-art accuracy for simulations of disordered proteins without sacrificing accuracy for folded proteins, thus broadening the range of biological systems amenable to molecular dynamics simulations. Molecular dynamics (MD) simulation is a valuable tool for characterizing the structural dynamics of folded proteins and should be similarly applicable to disordered proteins and proteins with both folded and disordered regions. It has been unclear, however, whether any physical model (force field) used in MD simulations accurately describes both folded and disordered proteins. Here, we select a benchmark set of 21 systems, including folded and disordered proteins, simulate these systems with six state-of-the-art force fields, and compare the results to over 9,000 available experimental data points. We find that none of the tested force fields simultaneously provided accurate descriptions of folded proteins, of the dimensions of disordered proteins, and of the secondary structure propensities of disordered proteins. Guided by simulation results on a subset of our benchmark, however, we modified parameters of one force field, achieving excellent agreement with experiment for disordered proteins, while maintaining state-of-the-art accuracy for folded proteins. The resulting force field, a99SB-disp, should thus greatly expand the range of biological systems amenable to MD simulation. A similar approach could be taken to improve other force fields.
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65
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Beier A, Schwarz TC, Kurzbach D, Platzer G, Tribuzio F, Konrat R. Modulation of Correlated Segment Fluctuations in IDPs upon Complex Formation as an Allosteric Regulatory Mechanism. J Mol Biol 2018; 430:2439-2452. [PMID: 29733855 DOI: 10.1016/j.jmb.2018.04.035] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 04/13/2018] [Accepted: 04/26/2018] [Indexed: 12/29/2022]
Abstract
Molecular recognition of and by intrinsically disordered proteins (IDPs) is an intriguing and still largely elusive phenomenon. Typically, protein recognition involving IDPs requires either folding upon binding or, alternatively, the formation of "fuzzy complexes." Here we show via correlation analyses of paramagnetic relaxation enhancement data unprecedented and striking alterations of the concerted fluctuations within the conformational ensemble of IDPs upon ligand binding. We study the binding of α-synuclein to calmodulin, a ubiquitous calcium-binding protein, and the binding of the extracellular matrix IDP osteopontin to heparin, a mimic of the extracellular matrix ligand hyaluronic acid. In both cases, binding leads to reduction of correlated long-range motions in these two IDPs and thus indicates a loosening of structural compaction upon binding. Most importantly, however, the simultaneous presence of correlated and anti-correlated fluctuations in IDPs suggests the prevalence of "energetic frustration" and provides an explanation for the puzzling observation of disordered allostery in IDPs.
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Affiliation(s)
- Andreas Beier
- Christian Doppler Laboratory for High-Content Structural Biology and Biotechnology, Department of Computational and Structural Biology, Max F. Perutz Laboratories, University of Vienna, Dr-Bohr-Gasse 9, A-1030 Vienna, Austria
| | - Thomas C Schwarz
- Department of Computational and Structural Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Dennis Kurzbach
- Laboratoire des biomolécules, LBM, Département de chimie, École normale supérieure, PSL University, Sorbonne Université, CNRS, 75005 Paris, France
| | - Gerald Platzer
- Christian Doppler Laboratory for High-Content Structural Biology and Biotechnology, Department of Computational and Structural Biology, Max F. Perutz Laboratories, University of Vienna, Dr-Bohr-Gasse 9, A-1030 Vienna, Austria
| | - Francesca Tribuzio
- Department of Computational and Structural Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Robert Konrat
- Christian Doppler Laboratory for High-Content Structural Biology and Biotechnology, Department of Computational and Structural Biology, Max F. Perutz Laboratories, University of Vienna, Dr-Bohr-Gasse 9, A-1030 Vienna, Austria; Department of Computational and Structural Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria.
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66
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Arbesú M, Iruela G, Fuentes H, Teixeira JMC, Pons M. Intramolecular Fuzzy Interactions Involving Intrinsically Disordered Domains. Front Mol Biosci 2018; 5:39. [PMID: 29761107 PMCID: PMC5936776 DOI: 10.3389/fmolb.2018.00039] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 04/03/2018] [Indexed: 01/16/2023] Open
Abstract
Structural disorder is an essential ingredient for function in many proteins and protein complexes. Fuzzy complexes describe the many instances where disorder is maintained as a critical element of protein interactions. In this minireview we discuss how intramolecular fuzzy interactions function in signaling complexes. Focussing on the Src family of kinases, we argue that the intrinsically disordered domains that are unique for each of the family members and display a clear fingerprint of long range interactions in Src, might have critical roles as functional sensor or effectors and mediate allosteric communication via fuzzy interactions.
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Affiliation(s)
- Miguel Arbesú
- BioNMR Laboratory, Inorganic and Organic Chemistry Department, University of Barcelona, Barcelona, Spain
| | - Guillermo Iruela
- BioNMR Laboratory, Inorganic and Organic Chemistry Department, University of Barcelona, Barcelona, Spain
| | - Héctor Fuentes
- BioNMR Laboratory, Inorganic and Organic Chemistry Department, University of Barcelona, Barcelona, Spain
| | - João M C Teixeira
- BioNMR Laboratory, Inorganic and Organic Chemistry Department, University of Barcelona, Barcelona, Spain
| | - Miquel Pons
- BioNMR Laboratory, Inorganic and Organic Chemistry Department, University of Barcelona, Barcelona, Spain
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67
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Berlow RB, Dyson HJ, Wright PE. Expanding the Paradigm: Intrinsically Disordered Proteins and Allosteric Regulation. J Mol Biol 2018; 430:2309-2320. [PMID: 29634920 DOI: 10.1016/j.jmb.2018.04.003] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 03/23/2018] [Accepted: 04/03/2018] [Indexed: 11/30/2022]
Abstract
Allosteric regulatory processes are implicated at all levels of biological function. Recent advances in our understanding of the diverse and functionally significant class of intrinsically disordered proteins have identified a multitude of ways in which disordered proteins function within the confines of the allosteric paradigm. Allostery within or mediated by intrinsically disordered proteins ensures robust and efficient signal integration through mechanisms that would be extremely unfavorable or even impossible for globular protein interaction partners. Here, we highlight recent examples that indicate the breadth of biological outcomes that can be achieved through allosteric regulation by intrinsically disordered proteins. Ongoing and future work in this rapidly evolving area of research will expand our appreciation of the central role of intrinsically disordered proteins in ensuring the fidelity and efficiency of cellular regulation.
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Affiliation(s)
- Rebecca B Berlow
- Department of Integrative Structural and Computational Biology and Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - H Jane Dyson
- Department of Integrative Structural and Computational Biology and Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - 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, CA 92037, USA.
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68
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Cukier RI. Generating intrinsically disordered protein conformational ensembles from a Markov chain. J Chem Phys 2018; 148:105102. [DOI: 10.1063/1.5010428] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Robert I. Cukier
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824-1322, USA
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69
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Bokor M, Tantos Á, Mészáros A, Jenei B, Haminda R, Tompa P, Tompa K. Molecular Motions and Interactions in Aqueous Solutions of Thymosin-β 4 , Stabilin C-Terminal Domain (CTD) and Their 1:1 Complex Studied by 1 H NMR Spectroscopy. Chemphyschem 2018; 19:848-856. [PMID: 29274195 DOI: 10.1002/cphc.201701187] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Indexed: 01/08/2023]
Abstract
Wide-line 1 H NMR measurements were extended and all results were reinterpreted in a new thermodynamics-based approach to study aqueous solutions of thymosin-β4 (Tβ4 ), stabilin C-terminal domain (CTD) and their 1:1 complex. The energy distributions of the potential barriers, which control motion of protein-bound water molecules, were determined. Heterogeneous and homogeneous regions were found at the protein-water interface. The measure of heterogeneity gives a quantitative value for the portion of disordered parts in the protein. Ordered structural elements were found extending up to 20 % of the whole proteins. About 40 % of the binding sites of free Tβ4 become involved in bonds holding the complex together. The complex has the most heterogeneous solvent accessible surface (SAS) in terms of protein-water interactions. The complex is more disordered than Tβ4 or stabilin CTD. The greater SAS area of the complex is interpreted as a clear sign of its open structure.
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Affiliation(s)
- Mónika Bokor
- Experimental Solid State Research, Wigner Research Centre for Physics of the Hungarian Academy of Sciences, Konkoly-Thege út 29-33. 1121, Budapest, Hungary
| | - Ágnes Tantos
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, 1117, Budapest, Hungary
| | - Attila Mészáros
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, 1117, Budapest, Hungary
| | - Bence Jenei
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, 1117, Budapest, Hungary
| | - Réka Haminda
- Chemical Institute, Eötvös Lóránd University, Pázmány P. sétány 1A, 1117, Budapest, Hungary
| | - Péter Tompa
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, 1117, Budapest, Hungary.,VIB Structural Biology Research Center (SBRC), Pleinlaan 2, 1050, Brussels, Belgium
| | - Kálmán Tompa
- Experimental Solid State Research, Wigner Research Centre for Physics of the Hungarian Academy of Sciences, Konkoly-Thege út 29-33. 1121, Budapest, Hungary
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70
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Bhattacharya S, Xu L, Thompson D. Revisiting the earliest signatures of amyloidogenesis: Roadmaps emerging from computational modeling and experiment. WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE 2018. [DOI: 10.1002/wcms.1359] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Shayon Bhattacharya
- Department of Physics, Bernal InstituteUniversity of LimerickLimerickIreland
| | - Liang Xu
- Department of Physics, Bernal InstituteUniversity of LimerickLimerickIreland
| | - Damien Thompson
- Department of Physics, Bernal InstituteUniversity of LimerickLimerickIreland
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71
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Sashi P, Singarapu KK, Bhuyan AK. Solution NMR Structure and Backbone Dynamics of Partially Disordered Arabidopsis thaliana Phloem Protein 16-1, a Putative mRNA Transporter. Biochemistry 2018; 57:912-924. [DOI: 10.1021/acs.biochem.7b01071] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Pulikallu Sashi
- School
of Chemistry, University of Hyderabad, Hyderabad 500046, India
| | - Kiran K. Singarapu
- Innovation
Plaza, Integrated Product Development Organization, Dr. Reddy’s Laboratory, Hyderabad 500090, India
| | - Abani K. Bhuyan
- School
of Chemistry, University of Hyderabad, Hyderabad 500046, India
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72
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Abstract
Experimental methods for the characterization of protein complexes have been instrumental in achieving our current understanding of the protein universe and continue to progress with each year that passes. In this chapter, we review some of the most important tools and techniques in the field, covering the important points in X-ray crystallography, cryo-electron microscopy, NMR spectroscopy, and mass spectrometry. Novel developments are making it possible to study large protein complexes at near-atomic resolutions, and we also now have the ability to study the dynamics and assembly pathways of protein complexes across a range of sizes.
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Affiliation(s)
- Jonathan N Wells
- MRC Human Genetics Unit, Institute of Genetics & Molecular Medicine, University of Edinburgh, Edinburgh, UK.
| | - Joseph A Marsh
- MRC Human Genetics Unit, Institute of Genetics & Molecular Medicine, University of Edinburgh, Edinburgh, UK
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73
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Uversky VN. The roles of intrinsic disorder-based liquid-liquid phase transitions in the "Dr. Jekyll-Mr. Hyde" behavior of proteins involved in amyotrophic lateral sclerosis and frontotemporal lobar degeneration. Autophagy 2017; 13:2115-2162. [PMID: 28980860 DOI: 10.1080/15548627.2017.1384889] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Pathological developments leading to amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD) are associated with misbehavior of several key proteins, such as SOD1 (superoxide dismutase 1), TARDBP/TDP-43, FUS, C9orf72, and dipeptide repeat proteins generated as a result of the translation of the intronic hexanucleotide expansions in the C9orf72 gene, PFN1 (profilin 1), GLE1 (GLE1, RNA export mediator), PURA (purine rich element binding protein A), FLCN (folliculin), RBM45 (RNA binding motif protein 45), SS18L1/CREST, HNRNPA1 (heterogeneous nuclear ribonucleoprotein A1), HNRNPA2B1 (heterogeneous nuclear ribonucleoprotein A2/B1), ATXN2 (ataxin 2), MAPT (microtubule associated protein tau), and TIA1 (TIA1 cytotoxic granule associated RNA binding protein). Although these proteins are structurally and functionally different and have rather different pathological functions, they all possess some levels of intrinsic disorder and are either directly engaged in or are at least related to the physiological liquid-liquid phase transitions (LLPTs) leading to the formation of various proteinaceous membrane-less organelles (PMLOs), both normal and pathological. This review describes the normal and pathological functions of these ALS- and FTLD-related proteins, describes their major structural properties, glances at their intrinsic disorder status, and analyzes the involvement of these proteins in the formation of normal and pathological PMLOs, with the ultimate goal of better understanding the roles of LLPTs and intrinsic disorder in the "Dr. Jekyll-Mr. Hyde" behavior of those proteins.
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Affiliation(s)
- Vladimir N Uversky
- a Department of Molecular Medicine and USF Health Byrd Alzheimer's Research Institute , Morsani College of Medicine , University of South Florida , Tampa , FL , USA.,b Institute for Biological Instrumentation of the Russian Academy of Sciences , Pushchino, Moscow region , Russia
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74
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Song J, Gomes GN, Shi T, Gradinaru CC, Chan HS. Conformational Heterogeneity and FRET Data Interpretation for Dimensions of Unfolded Proteins. Biophys J 2017; 113:1012-1024. [PMID: 28877485 DOI: 10.1016/j.bpj.2017.07.023] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 07/26/2017] [Accepted: 07/31/2017] [Indexed: 12/28/2022] Open
Abstract
A mathematico-physically valid formulation is required to infer properties of disordered protein conformations from single-molecule Förster resonance energy transfer (smFRET). Conformational dimensions inferred by conventional approaches that presume a homogeneous conformational ensemble can be unphysical. When all possible-heterogeneous as well as homogeneous-conformational distributions are taken into account without prejudgment, a single value of average transfer efficiency 〈E〉 between dyes at two chain ends is generally consistent with highly diverse, multiple values of the average radius of gyration 〈Rg〉. Here we utilize unbiased conformational statistics from a coarse-grained explicit-chain model to establish a general logical framework to quantify this fundamental ambiguity in smFRET inference. As an application, we address the long-standing controversy regarding the denaturant dependence of 〈Rg〉 of unfolded proteins, focusing on Protein L as an example. Conventional smFRET inference concluded that 〈Rg〉 of unfolded Protein L is highly sensitive to [GuHCl], but data from SAXS suggested a near-constant 〈Rg〉 irrespective of [GuHCl]. Strikingly, our analysis indicates that although the reported 〈E〉 values for Protein L at [GuHCl] = 1 and 7 M are very different at 0.75 and 0.45, respectively, the Bayesian Rg2 distributions consistent with these two 〈E〉 values overlap by as much as 75%. Our findings suggest, in general, that the smFRET-SAXS discrepancy regarding unfolded protein dimensions likely arise from highly heterogeneous conformational ensembles at low or zero denaturant, and that additional experimental probes are needed to ascertain the nature of this heterogeneity.
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Affiliation(s)
- Jianhui Song
- School of Polymer Science and Engineering, Qingdao University of Science and Technology, Qingdao, Shandong, China; Departments of Biochemistry and Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Gregory-Neal Gomes
- Department of Chemical and Physical Sciences, University of Toronto Mississauga, Mississauga, Ontario, Canada; Department of Physics, University of Toronto, Toronto, Ontario, Canada
| | - Tongfei Shi
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, China
| | - Claudiu C Gradinaru
- Department of Chemical and Physical Sciences, University of Toronto Mississauga, Mississauga, Ontario, Canada; Department of Physics, University of Toronto, Toronto, Ontario, Canada
| | - Hue Sun Chan
- Departments of Biochemistry and Molecular Genetics, University of Toronto, Toronto, Ontario, Canada.
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75
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Charlier C, Bouvignies G, Pelupessy P, Walrant A, Marquant R, Kozlov M, De Ioannes P, Bolik-Coulon N, Sagan S, Cortes P, Aggarwal AK, Carlier L, Ferrage F. Structure and Dynamics of an Intrinsically Disordered Protein Region That Partially Folds upon Binding by Chemical-Exchange NMR. J Am Chem Soc 2017; 139:12219-12227. [PMID: 28780862 DOI: 10.1021/jacs.7b05823] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Many intrinsically disordered proteins (IDPs) and protein regions (IDRs) engage in transient, yet specific, interactions with a variety of protein partners. Often, if not always, interactions with a protein partner lead to partial folding of the IDR. Characterizing the conformational space of such complexes is challenging: in solution-state NMR, signals of the IDR in the interacting region become broad, weak, and often invisible, while X-ray crystallography only provides information on fully ordered regions. There is thus a need for a simple method to characterize both fully and partially ordered regions in the bound state of IDPs. Here, we introduce an approach based on monitoring chemical exchange by NMR to investigate the state of an IDR that folds upon binding through the observation of the free state of the protein. Structural constraints for the bound state are obtained from chemical shifts, and site-specific dynamics of the bound state are characterized by relaxation rates. The conformation of the interacting part of the IDR was determined and subsequently docked onto the structure of the folded partner. We apply the method to investigate the interaction between the disordered C-terminal region of Artemis and the DNA binding domain of Ligase IV. We show that we can accurately reproduce the structure of the core of the complex determined by X-ray crystallography and identify a broader interface. The method is widely applicable to the biophysical investigation of complexes of disordered proteins and folded proteins.
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Affiliation(s)
- Cyril Charlier
- Laboratoire des Biomolécules, Département de chimie, École normale supérieure, UPMC Université Paris 06, CNRS, PSL Research University , 24 rue Lhomond, Paris 75005, France.,Sorbonne Universités, UPMC Université Paris 06, École normale supérieure, CNRS, Laboratoire des Biomolécules (LBM) , Paris 75005, France
| | - Guillaume Bouvignies
- Laboratoire des Biomolécules, Département de chimie, École normale supérieure, UPMC Université Paris 06, CNRS, PSL Research University , 24 rue Lhomond, Paris 75005, France.,Sorbonne Universités, UPMC Université Paris 06, École normale supérieure, CNRS, Laboratoire des Biomolécules (LBM) , Paris 75005, France
| | - Philippe Pelupessy
- Laboratoire des Biomolécules, Département de chimie, École normale supérieure, UPMC Université Paris 06, CNRS, PSL Research University , 24 rue Lhomond, Paris 75005, France.,Sorbonne Universités, UPMC Université Paris 06, École normale supérieure, CNRS, Laboratoire des Biomolécules (LBM) , Paris 75005, France
| | - Astrid Walrant
- Laboratoire des Biomolécules, Département de chimie, École normale supérieure, UPMC Université Paris 06, CNRS, PSL Research University , 24 rue Lhomond, Paris 75005, France.,Sorbonne Universités, UPMC Université Paris 06, École normale supérieure, CNRS, Laboratoire des Biomolécules (LBM) , Paris 75005, France
| | - Rodrigue Marquant
- Laboratoire des Biomolécules, Département de chimie, École normale supérieure, UPMC Université Paris 06, CNRS, PSL Research University , 24 rue Lhomond, Paris 75005, France.,Sorbonne Universités, UPMC Université Paris 06, École normale supérieure, CNRS, Laboratoire des Biomolécules (LBM) , Paris 75005, France
| | - Mikhail Kozlov
- Department of Medicine, Immunology Institute, Icahn School of Medicine at Mount Sinai , 1425 Madison Avenue, New York, New York 10029, United States
| | - Pablo De Ioannes
- Department of Structural and Chemical Biology, Icahn School of Medicine at Mount Sinai , 1425 Madison Avenue, New York, New York 10029, United States
| | - Nicolas Bolik-Coulon
- Laboratoire des Biomolécules, Département de chimie, École normale supérieure, UPMC Université Paris 06, CNRS, PSL Research University , 24 rue Lhomond, Paris 75005, France.,Sorbonne Universités, UPMC Université Paris 06, École normale supérieure, CNRS, Laboratoire des Biomolécules (LBM) , Paris 75005, France
| | - Sandrine Sagan
- Laboratoire des Biomolécules, Département de chimie, École normale supérieure, UPMC Université Paris 06, CNRS, PSL Research University , 24 rue Lhomond, Paris 75005, France.,Sorbonne Universités, UPMC Université Paris 06, École normale supérieure, CNRS, Laboratoire des Biomolécules (LBM) , Paris 75005, France
| | - Patricia Cortes
- Department of Medicine, Immunology Institute, Icahn School of Medicine at Mount Sinai , 1425 Madison Avenue, New York, New York 10029, United States.,Department of Molecular, Cellular and Biomedical Science, CUNY School of Medicine, City College of New York , 160 Convent Avenue, New York, New York 10031, United States
| | - Aneel K Aggarwal
- Department of Structural and Chemical Biology, Icahn School of Medicine at Mount Sinai , 1425 Madison Avenue, New York, New York 10029, United States
| | - Ludovic Carlier
- Laboratoire des Biomolécules, Département de chimie, École normale supérieure, UPMC Université Paris 06, CNRS, PSL Research University , 24 rue Lhomond, Paris 75005, France.,Sorbonne Universités, UPMC Université Paris 06, École normale supérieure, CNRS, Laboratoire des Biomolécules (LBM) , Paris 75005, France
| | - Fabien Ferrage
- Laboratoire des Biomolécules, Département de chimie, École normale supérieure, UPMC Université Paris 06, CNRS, PSL Research University , 24 rue Lhomond, Paris 75005, France.,Sorbonne Universités, UPMC Université Paris 06, École normale supérieure, CNRS, Laboratoire des Biomolécules (LBM) , Paris 75005, France
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76
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Uversky VN. Intrinsic Disorder, Protein-Protein Interactions, and Disease. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2017; 110:85-121. [PMID: 29413001 DOI: 10.1016/bs.apcsb.2017.06.005] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
It is recognized now that biologically active proteins without stable tertiary structure (known as intrinsically disordered proteins, IDPs) and hybrid proteins containing ordered domains and intrinsically disordered protein regions (IDPRs) are important players found in any given proteome. These IDPs/IDPRs possess functions that complement functional repertoire of their ordered counterparts, being commonly related to recognition, as well as control and regulation of various signaling pathways. They are interaction masters, being able to utilize a wide spectrum of interaction mechanisms, ranging from induced folding to formation of fuzzy complexes where significant levels of disorder are preserved, to polyvalent stochastic interactions playing crucial roles in the liquid-liquid phase transitions leading to the formation of proteinaceous membrane-less organelles. IDPs/IDPRs are tightly controlled themselves via various means, including alternative splicing, precisely controlled expression and degradation, binding to specific partners, and posttranslational modifications. Distortions in the regulation and control of IDPs/IDPRs, as well as their aberrant interactivity are commonly associated with various human diseases. This review presents some aspects of the intrinsic disorder-based functionality and dysfunctionality, paying special attention to the normal and pathological protein-protein interactions.
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Affiliation(s)
- Vladimir N Uversky
- USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL, United States; Institute for Biological Instrumentation, Russian Academy of Sciences, Pushchino, Moscow Region, Russia.
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77
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Complementary uses of small angle X-ray scattering and X-ray crystallography. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2017; 1865:1623-1630. [PMID: 28743534 DOI: 10.1016/j.bbapap.2017.07.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 07/10/2017] [Accepted: 07/20/2017] [Indexed: 12/11/2022]
Abstract
Most proteins function within networks and, therefore, protein interactions are central to protein function. Although stable macromolecular machines have been extensively studied, dynamic protein interactions remain poorly understood. Small-angle X-ray scattering probes the size, shape and dynamics of proteins in solution at low resolution and can be used to study samples in a large range of molecular weights. Therefore, it has emerged as a powerful technique to study the structure and dynamics of biomolecular systems and bridge fragmented information obtained using high-resolution techniques. Here we review how small-angle X-ray scattering can be combined with other structural biology techniques to study protein dynamics. This article is part of a Special Issue entitled: Biophysics in Canada, edited by Lewis Kay, John Baenziger, Albert Berghuis and Peter Tieleman.
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78
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Unraveling the meaning of chemical shifts in protein NMR. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2017; 1865:1564-1576. [PMID: 28716441 DOI: 10.1016/j.bbapap.2017.07.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 06/29/2017] [Accepted: 07/07/2017] [Indexed: 12/14/2022]
Abstract
Chemical shifts are among the most informative parameters in protein NMR. They provide wealth of information about protein secondary and tertiary structure, protein flexibility, and protein-ligand binding. In this report, we review the progress in interpreting and utilizing protein chemical shifts that has occurred over the past 25years, with a particular focus on the large body of work arising from our group and other Canadian NMR laboratories. More specifically, this review focuses on describing, assessing, and providing some historical context for various chemical shift-based methods to: (1) determine protein secondary and super-secondary structure; (2) derive protein torsion angles; (3) assess protein flexibility; (4) predict residue accessible surface area; (5) refine 3D protein structures; (6) determine 3D protein structures and (7) characterize intrinsically disordered proteins. This review also briefly covers some of the methods that we previously developed to predict chemical shifts from 3D protein structures and/or protein sequence data. It is hoped that this review will help to increase awareness of the considerable utility of NMR chemical shifts in structural biology and facilitate more widespread adoption of chemical-shift based methods by the NMR spectroscopists, structural biologists, protein biophysicists, and biochemists worldwide. This article is part of a Special Issue entitled: Biophysics in Canada, edited by Lewis Kay, John Baenziger, Albert Berghuis and Peter Tieleman.
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79
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Atkinson J, Clarke MW, Warnica JM, Boddington KF, Graether SP. Structure of an Intrinsically Disordered Stress Protein Alone and Bound to a Membrane Surface. Biophys J 2017; 111:480-491. [PMID: 27508433 DOI: 10.1016/j.bpj.2016.07.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 06/25/2016] [Accepted: 07/01/2016] [Indexed: 12/19/2022] Open
Abstract
Dehydrins are a group of intrinsically disordered proteins that protect plants from damage caused by drought, cold, and high salinity. Like other intrinsically disordered proteins, dehydrins can gain structure when bound to a ligand. Previous studies have shown that dehydrins are able to protect liposomes from cold damage, but the interactions that drive membrane binding and the detailed structure of the bound and unbound forms are not known. We use an ensemble-structure approach to generate models of a dehydrin known as K2 in the presence and absence of sodium dodecyl sulfate micelles, and we docked the bound structure to the micelle. The collection of residual dipolar coupling data, amide protection factors, and paramagnetic relaxation enhancement distances, in combination with chemical shifts and relaxation measurements, allows for determining plausible structures that are not otherwise visible in time-averaged structural data. The results show that in the bound structure, the conserved lysines are important for membrane binding, whereas the flanking hydrophobic residues play a lesser role. The unbound structure shows a high level of disorder and an extended structure. We propose that the structural differences between bound and unbound forms allow dehydrins to act as molecular shields in their unbound state and as membrane protectants in their bound state. Unlike α-synuclein, the significant gain of α-helicity in K2 at low concentrations of sodium dodecyl sulfate is not due to a decrease in the critical micelle concentration. The study provides structural insight into how a disordered protein can interact with a membrane surface.
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Affiliation(s)
- John Atkinson
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Matthew W Clarke
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Josephine M Warnica
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Kelly F Boddington
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Steffen P Graether
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada.
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80
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Gomes GN, Gradinaru CC. Insights into the conformations and dynamics of intrinsically disordered proteins using single-molecule fluorescence. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2017. [PMID: 28625737 DOI: 10.1016/j.bbapap.2017.06.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Most proteins are not static structures, but many of them are found in a dynamic state, exchanging conformations on various time scales as a key aspect of their biological function. An entire spectrum of structural disorder exists in proteins and obtaining a satisfactory quantitative description of these states remains a challenge. Single-molecule fluorescence spectroscopy techniques are uniquely suited for this task, by measuring conformations without ensemble averaging and kinetics without interference from asynchronous processes. In this paper we review some of the recent successes in applying single-molecule fluorescence to different disordered protein systems, including interactions with their cellular targets and self-aggregation processes. We also discuss the implementation of computational methods and polymer physics models that are essential for inferring global dimension parameters for these proteins from smFRET data. Regarding future directions; 3- or 4-color FRET methods can provide multiple distances within a disordered ensemble simultaneously. In addition, integrating complementary experimental data from smFRET, NMR and SAXS will provide meaningful constraints for molecular simulations and will lead to more accurate structural representations of disordered proteins. This article is part of a Special Issue entitled: Biophysics in Canada, edited by Lewis Kay, John Baenziger, Albert Berghuis and Peter Tieleman.
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Affiliation(s)
- Gregory-Neal Gomes
- Department of Chemical and Physical Sciences, University of Toronto Mississauga, Mississauga, Ontario L5L 1C6, Canada; Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
| | - Claudiu C Gradinaru
- Department of Chemical and Physical Sciences, University of Toronto Mississauga, Mississauga, Ontario L5L 1C6, Canada; Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada.
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81
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Zabik NL, Imhof MM, Martic-Milne S. Structural evaluations of tau protein conformation: methodologies and approaches. Biochem Cell Biol 2017; 95:338-349. [PMID: 28278386 DOI: 10.1139/bcb-2016-0227] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Protein-misfolding diseases are based on a common principle of aggregation initiated by intra- and inter-molecular contacts. The structural and conformational changes induced by biochemical transformations such as post-translational modifications (PTMs), often lead to protein unfolding and misfolding. Thus, these order-to-disorder or disorder-to-order transitions may regulate cellular function. Tau, a neuronal protein, regulates microtubule (MT) structure and overall cellular integrity. However, misfolded tau modified by PTMs results in MT destabilization, toxic tau aggregate formation, and ultimately cell death, leading to neurodegeneration. Currently, the lack of structural information surrounding tau severely limits understanding of neurodegeneration. This minireview focuses on the current methodologies and approaches aimed at probing tau conformation and the role of conformation in various aspects of tau biochemistry. The recent applications of nuclear magnetic resonance, mass spectrometry, Förster resonance electron transfer, and molecular dynamics simulations toward structural analysis of conformational landscapes of tau will be described. The strategies developed for structural evaluation of tau may significantly improve our understanding of misfolding diseases.
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Affiliation(s)
- Nicole L Zabik
- Department of Chemistry, Oakland University, Rochester, MI 48309, USA.,Department of Chemistry, Oakland University, Rochester, MI 48309, USA
| | - Matthew M Imhof
- Department of Chemistry, Oakland University, Rochester, MI 48309, USA.,Department of Chemistry, Oakland University, Rochester, MI 48309, USA
| | - Sanela Martic-Milne
- Department of Chemistry, Oakland University, Rochester, MI 48309, USA.,Department of Chemistry, Oakland University, Rochester, MI 48309, USA
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82
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Lun CM, Bishop BM, Smith LC. Multitasking Immune Sp185/333 Protein, rSpTransformer-E1, and Its Recombinant Fragments Undergo Secondary Structural Transformation upon Binding Targets. THE JOURNAL OF IMMUNOLOGY 2017; 198:2957-2966. [PMID: 28242650 DOI: 10.4049/jimmunol.1601795] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 01/26/2017] [Indexed: 12/31/2022]
Abstract
The purple sea urchin, Strongylocentrotus purpuratus, expresses a diverse immune response protein family called Sp185/333. A recombinant Sp185/333 protein, previously called rSp0032, shows multitasking antipathogen binding ability, suggesting that the protein family mediates a flexible and effective immune response to multiple foreign cells. Bioinformatic analysis predicts that rSp0032 is intrinsically disordered, and its multiple binding characteristic suggests structural flexibility to adopt different conformations depending on the characteristics of the target. To address the flexibility and structural shifting hypothesis, circular dichroism analysis of rSp0032 suggests that it transforms from disordered (random coil) to α helical structure. This structural transformation may be the basis for the strong affinity between rSp0032 and several pathogen-associated molecular patterns. The N-terminal Gly-rich fragment of rSp0032 and the C-terminal His-rich fragment show unique transformations by either intensifying the α helical structure or changing from α helical to β strand depending on the solvents and molecules added to the buffer. Based on these results, we propose a name change from rSp0032 to rSpTransformer-E1 to represent its flexible structural conformations and its E1 element pattern. Given that rSpTransformer-E1 shifts its conformation in the presence of solvents and binding targets and that all Sp185/333 proteins are predicted to be disordered, many or all of these proteins may undergo structural transformation to enable multitasking binding activity toward a wide range of targets. Consequently, we also propose an overarching name change for the entire family from Sp185/333 proteins to SpTransformer proteins.
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Affiliation(s)
- Cheng Man Lun
- Department of Biological Sciences, George Washington University, Washington, DC 20052; and
| | - Barney M Bishop
- Department of Chemistry and Biochemistry, George Mason University, Manassas, VA 20110
| | - L Courtney Smith
- Department of Biological Sciences, George Washington University, Washington, DC 20052; and
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83
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Lin YH, Song J, Forman-Kay JD, Chan HS. Random-phase-approximation theory for sequence-dependent, biologically functional liquid-liquid phase separation of intrinsically disordered proteins. J Mol Liq 2017. [DOI: 10.1016/j.molliq.2016.09.090] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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84
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An allosteric conduit facilitates dynamic multisite substrate recognition by the SCF Cdc4 ubiquitin ligase. Nat Commun 2017; 8:13943. [PMID: 28045046 PMCID: PMC5216119 DOI: 10.1038/ncomms13943] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 11/15/2016] [Indexed: 02/07/2023] Open
Abstract
The ubiquitin ligase SCFCdc4 mediates phosphorylation-dependent elimination of numerous substrates by binding one or more Cdc4 phosphodegrons (CPDs). Methyl-based NMR analysis of the Cdc4 WD40 domain demonstrates that Cyclin E, Sic1 and Ash1 degrons have variable effects on the primary Cdc4WD40 binding pocket. Unexpectedly, a Sic1-derived multi-CPD substrate (pSic1) perturbs methyls around a previously documented allosteric binding site for the chemical inhibitor SCF-I2. NMR cross-saturation experiments confirm direct contact between pSic1 and the allosteric pocket. Phosphopeptide affinity measurements reveal negative allosteric communication between the primary CPD and allosteric pockets. Mathematical modelling indicates that the allosteric pocket may enhance ultrasensitivity by tethering pSic1 to Cdc4. These results suggest negative allosteric interaction between two distinct binding pockets on the Cdc4WD40 domain may facilitate dynamic exchange of multiple CPD sites to confer ultrasensitive dependence on substrate phosphorylation.
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85
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Hybrid Applications of Solution Scattering to Aid Structural Biology. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1009:215-227. [PMID: 29218562 DOI: 10.1007/978-981-10-6038-0_13] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Biomolecular applications of solution X-ray and neutron scattering (SAXS and SANS, respectively) started in late 1960s - early 1970s but were relatively limited in their ability to provide a detailed structural picture and lagged behind what became the two primary methods of experimental structural biology - X-ray crystallography and NMR. However, improvements in both data analysis and instrumentation led to an explosive growth in the number of studies that used small-angle scattering (SAS) for investigation of macromolecular structure, often in combination with other biophysical techniques. Such hybrid applications are nowadays quickly becoming a norm whenever scattering data are used for two reasons. First, it is generally accepted that SAS data on their own cannot lead to a uniquely defined high-resolution structural model, creating a need for supplementing them with information from complementary techniques. Second, solution scattering data are frequently applied in situations when a method such NMR or X-ray crystallography cannot provide a satisfactory structural picture, which makes these additional restraints highly desirable. Maturation of the hybrid bio-SAS approaches brings to light new questions including completeness of the conformational space sampling, model validation, and data compatibility.
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86
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Cordeiro TN, Herranz-Trillo F, Urbanek A, Estaña A, Cortés J, Sibille N, Bernadó P. Structural Characterization of Highly Flexible Proteins by Small-Angle Scattering. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1009:107-129. [DOI: 10.1007/978-981-10-6038-0_7] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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87
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Quilis I, Igual JC. A comparative study of the degradation of yeast cyclins Cln1 and Cln2. FEBS Open Bio 2016; 7:74-87. [PMID: 28097090 PMCID: PMC5221467 DOI: 10.1002/2211-5463.12157] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 10/06/2016] [Accepted: 11/03/2016] [Indexed: 11/09/2022] Open
Abstract
The yeast cyclins Cln1 and Cln2 are very similar in both sequence and function, but some differences in their functionality and localization have been recently described. The control of Cln1 and Cln2 cellular levels is crucial for proper cell cycle initiation. In this work, we analyzed the degradation patterns of Cln1 and Cln2 in order to further investigate the possible differences between them. Both cyclins show the same half-life but, while Cln2 degradation depends on ubiquitin ligases SCFGrr1 and SCFCdc4, Cln1 is affected only by SCFGrr1. Degradation analysis of chimeric cyclins, constructed by combining fragments from Cln1 and Cln2, identifies the N-terminal sequence of the proteins as responsible of the cyclin degradation pattern. In particular, the N-terminal region of Cln2 is required to mediate degradation by SCFCdc4. This region is involved in nuclear import of Cln1 and Cln2, which suggests that differences in degradation may be due to differences in localization. Moreover, a comparison of the cyclins that differ only in the presence of the Cln2 nuclear export signal indicates a greater instability of exported cyclins, thus reinforcing the idea that cyclin stability is influenced by their localization.
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Affiliation(s)
- Inma Quilis
- Departament de Bioquímica i Biologia Molecular and ERI BiotecMed Universitat de València Burjassot Spain
| | - J Carlos Igual
- Departament de Bioquímica i Biologia Molecular and ERI BiotecMed Universitat de València Burjassot Spain
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88
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Martin EW, Holehouse AS, Grace CR, Hughes A, Pappu RV, Mittag T. Sequence Determinants of the Conformational Properties of an Intrinsically Disordered Protein Prior to and upon Multisite Phosphorylation. J Am Chem Soc 2016; 138:15323-15335. [PMID: 27807972 PMCID: PMC5675102 DOI: 10.1021/jacs.6b10272] [Citation(s) in RCA: 177] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Many cell signaling events are coordinated by intrinsically disordered protein regions (IDRs) that undergo multisite Serine/Threonine phosphorylation. The conformational properties of these IDRs prior to and following multisite phosphorylation are directly relevant to understanding their functions. Here, we present results from biophysical studies and molecular simulations that quantify the conformational properties of an 81-residue IDR from the S. cerevisiae transcription factor Ash1. We show that the unphosphorylated Ash1 IDR adopts coil-like conformations that are expanded and well-solvated. This result contradicts inferences regarding global compaction that are derived from heuristics based on amino acid compositions for IDRs with low proline contents. Upon phosphorylation at ten distinct sites, the global conformational properties of pAsh1 are indistinguishable from those of unphosphorylated Ash1. This insensitivity derives from compensatory changes to the pattern of local and long-range intrachain contacts. We show that the conformational properties of Ash1 and pAsh1 can be explained in terms of the linear sequence patterning of proline and charged residues vis-à-vis all other residues. The sequence features of the Ash1 IDR are shared by many other IDRs that undergo multisite phosphorylation. Accordingly, we propose that our findings might be generalizable to other IDRs involved in cell signaling.
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Affiliation(s)
- Erik W. Martin
- Department of Structural Biology, St. Jude Children’s Research Hospital, 263 Danny Thomas Place, Memphis, TN 38105, USA
| | - Alex S. Holehouse
- Department of Biomedical Engineering and Center for Biological Systems Engineering, Washington University in St. Louis, One Brookings Drive, Campus Box 1097, St. Louis, MO 63130, USA
| | - Christy R. Grace
- Department of Structural Biology, St. Jude Children’s Research Hospital, 263 Danny Thomas Place, Memphis, TN 38105, USA
| | - Alex Hughes
- Department of Structural Biology, St. Jude Children’s Research Hospital, 263 Danny Thomas Place, Memphis, TN 38105, USA
| | - Rohit V. Pappu
- Department of Biomedical Engineering and Center for Biological Systems Engineering, Washington University in St. Louis, One Brookings Drive, Campus Box 1097, St. Louis, MO 63130, USA
| | - Tanja Mittag
- Department of Structural Biology, St. Jude Children’s Research Hospital, 263 Danny Thomas Place, Memphis, TN 38105, USA
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89
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Bhowmick A, Brookes DH, Yost SR, Dyson HJ, Forman-Kay JD, Gunter D, Head-Gordon M, Hura GL, Pande VS, Wemmer DE, Wright PE, Head-Gordon T. Finding Our Way in the Dark Proteome. J Am Chem Soc 2016; 138:9730-42. [PMID: 27387657 PMCID: PMC5051545 DOI: 10.1021/jacs.6b06543] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The traditional structure-function paradigm has provided significant insights for well-folded proteins in which structures can be easily and rapidly revealed by X-ray crystallography beamlines. However, approximately one-third of the human proteome is comprised of intrinsically disordered proteins and regions (IDPs/IDRs) that do not adopt a dominant well-folded structure, and therefore remain "unseen" by traditional structural biology methods. This Perspective considers the challenges raised by the "Dark Proteome", in which determining the diverse conformational substates of IDPs in their free states, in encounter complexes of bound states, and in complexes retaining significant disorder requires an unprecedented level of integration of multiple and complementary solution-based experiments that are analyzed with state-of-the art molecular simulation, Bayesian probabilistic models, and high-throughput computation. We envision how these diverse experimental and computational tools can work together through formation of a "computational beamline" that will allow key functional features to be identified in IDP structural ensembles.
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Affiliation(s)
- Asmit Bhowmick
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA 94720
| | - David H. Brookes
- Department of Chemistry, University of California, Berkeley, CA 94720
| | - Shane R. Yost
- Department of Chemistry, University of California, Berkeley, CA 94720
| | - H. Jane Dyson
- Department of Integrative Structural and Computational Biology, Scripps Research Institute, La Jolla, California 92037
| | - Julie D. Forman-Kay
- Molecular Structure and Function Program, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Daniel Gunter
- Computational Research Division, Lawrence Berkeley National Laboratory, Berkeley CA, 94720
| | | | - Gregory L. Hura
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley CA, 94720
| | - Vijay S. Pande
- Department of Chemistry, Stanford University, Stanford, CA 94305
| | - David E. Wemmer
- Department of Chemistry, University of California, Berkeley, CA 94720
| | - Peter E. Wright
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Teresa Head-Gordon
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA 94720
- Department of Chemistry, University of California, Berkeley, CA 94720
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley CA, 94720
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90
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Wei G, Xi W, Nussinov R, Ma B. Protein Ensembles: How Does Nature Harness Thermodynamic Fluctuations for Life? The Diverse Functional Roles of Conformational Ensembles in the Cell. Chem Rev 2016; 116:6516-51. [PMID: 26807783 PMCID: PMC6407618 DOI: 10.1021/acs.chemrev.5b00562] [Citation(s) in RCA: 253] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
All soluble proteins populate conformational ensembles that together constitute the native state. Their fluctuations in water are intrinsic thermodynamic phenomena, and the distributions of the states on the energy landscape are determined by statistical thermodynamics; however, they are optimized to perform their biological functions. In this review we briefly describe advances in free energy landscape studies of protein conformational ensembles. Experimental (nuclear magnetic resonance, small-angle X-ray scattering, single-molecule spectroscopy, and cryo-electron microscopy) and computational (replica-exchange molecular dynamics, metadynamics, and Markov state models) approaches have made great progress in recent years. These address the challenging characterization of the highly flexible and heterogeneous protein ensembles. We focus on structural aspects of protein conformational distributions, from collective motions of single- and multi-domain proteins, intrinsically disordered proteins, to multiprotein complexes. Importantly, we highlight recent studies that illustrate functional adjustment of protein conformational ensembles in the crowded cellular environment. We center on the role of the ensemble in recognition of small- and macro-molecules (protein and RNA/DNA) and emphasize emerging concepts of protein dynamics in enzyme catalysis. Overall, protein ensembles link fundamental physicochemical principles and protein behavior and the cellular network and its regulation.
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Affiliation(s)
- Guanghong Wei
- State Key Laboratory of Surface Physics, Key Laboratory for Computational Physical Sciences (MOE), and Department of Physics, Fudan University, Shanghai, P. R. China
| | - Wenhui Xi
- State Key Laboratory of Surface Physics, Key Laboratory for Computational Physical Sciences (MOE), and Department of Physics, Fudan University, Shanghai, P. R. China
| | - Ruth Nussinov
- Basic Science Program, Leidos Biomedical Research, Inc. Cancer and Inflammation Program, National Cancer Institute, Frederick, Maryland 21702, USA
- Sackler Inst. of Molecular Medicine Department of Human Genetics and Molecular Medicine Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Buyong Ma
- Basic Science Program, Leidos Biomedical Research, Inc. Cancer and Inflammation Program, National Cancer Institute, Frederick, Maryland 21702, USA
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91
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Dynamics of the BH3-Only Protein Binding Interface of Bcl-xL. Biophys J 2016; 109:1049-57. [PMID: 26331262 DOI: 10.1016/j.bpj.2015.07.043] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 07/24/2015] [Accepted: 07/30/2015] [Indexed: 02/07/2023] Open
Abstract
The balance and interplay between pro-death and pro-survival members of the B-cell lymphoma-2 (Bcl-2) family proteins play key roles in regulation of the mitochondrial pathway of programmed cell death. Recent NMR and biochemical studies have revealed that binding of the proapoptotic BH3-only protein PUMA induces significant unfolding of antiapoptotic Bcl-xL at the interface, which in turn disrupts the Bcl-xL/p53 interaction to activate apoptosis. However, the molecular mechanism of such regulated unfolding of Bcl-xL is not fully understood. Analysis of the existing Protein Data Bank structures of Bcl-xL in both bound and unbound states reveal substantial intrinsic heterogeneity at its BH3-only protein binding interface. Large-scale atomistic simulations were performed in explicit solvent for six representative structures to further investigate the intrinsic conformational dynamics of Bcl-xL. The results support that the BH3-only protein binding interface of Bcl-xL is much more dynamic compared to the rest of the protein, both unbound and when bound to various BH3-only proteins. Such intrinsic interfacial conformational dynamics likely provides a physical basis that allows Bcl-xL to respond sensitively to detailed biophysical properties of the ligand. The ability of Bcl-xL to retain or even enhance dynamics at the interface in bound states could further facilitate the regulation of its interactions with various BH3-only proteins such as through posttranslational modifications.
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92
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Hendus-Altenburger R, Pedraz-Cuesta E, Olesen CW, Papaleo E, Schnell JA, Hopper JTS, Robinson CV, Pedersen SF, Kragelund BB. The human Na(+)/H(+) exchanger 1 is a membrane scaffold protein for extracellular signal-regulated kinase 2. BMC Biol 2016; 14:31. [PMID: 27083547 PMCID: PMC4833948 DOI: 10.1186/s12915-016-0252-7] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 03/29/2016] [Indexed: 11/22/2022] Open
Abstract
Background Extracellular signal-regulated kinase 2 (ERK2) is an S/T kinase with more than 200 known substrates, and with critical roles in regulation of cell growth and differentiation and currently no membrane proteins have been linked to ERK2 scaffolding. Methods and results Here, we identify the human Na+/H+ exchanger 1 (hNHE1) as a membrane scaffold protein for ERK2 and show direct hNHE1-ERK1/2 interaction in cellular contexts. Using nuclear magnetic resonance (NMR) spectroscopy and immunofluorescence analysis we demonstrate that ERK2 scaffolding by hNHE1 occurs by one of three D-domains and by two non-canonical F-sites located in the disordered intracellular tail of hNHE1, mutation of which reduced cellular hNHE1-ERK1/2 co-localization, as well as reduced cellular ERK1/2 activation. Time-resolved NMR spectroscopy revealed that ERK2 phosphorylated the disordered tail of hNHE1 at six sites in vitro, in a distinct temporal order, with the phosphorylation rates at the individual sites being modulated by the docking sites in a distant dependent manner. Conclusions This work characterizes a new type of scaffolding complex, which we term a “shuffle complex”, between the disordered hNHE1-tail and ERK2, and provides a molecular mechanism for the important ERK2 scaffolding function of the membrane protein hNHE1, which regulates the phosphorylation of both hNHE1 and ERK2. Electronic supplementary material The online version of this article (doi:10.1186/s12915-016-0252-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ruth Hendus-Altenburger
- Cell and Developmental Biology, Department of Biology, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen Ø, Denmark.,Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200, Copenhagen N, Denmark
| | - Elena Pedraz-Cuesta
- Cell and Developmental Biology, Department of Biology, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen Ø, Denmark
| | - Christina W Olesen
- Cell and Developmental Biology, Department of Biology, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen Ø, Denmark
| | - Elena Papaleo
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200, Copenhagen N, Denmark
| | - Jeff A Schnell
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200, Copenhagen N, Denmark
| | - Jonathan T S Hopper
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford, OX1 3QZ, UK
| | - Carol V Robinson
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford, OX1 3QZ, UK
| | - Stine F Pedersen
- Cell and Developmental Biology, Department of Biology, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen Ø, Denmark.
| | - Birthe B Kragelund
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200, Copenhagen N, Denmark.
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93
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Burger VM, Nolasco DO, Stultz CM. Expanding the Range of Protein Function at the Far End of the Order-Structure Continuum. J Biol Chem 2016; 291:6706-13. [PMID: 26851282 PMCID: PMC4807258 DOI: 10.1074/jbc.r115.692590] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The traditional view of the structure-function paradigm is that a protein's function is inextricably linked to a well defined, three-dimensional structure, which is determined by the protein's primary amino acid sequence. However, it is now accepted that a number of proteins do not adopt a unique tertiary structure in solution and that some degree of disorder is required for many proteins to perform their prescribed functions. In this review, we highlight how a number of protein functions are facilitated by intrinsic disorder and introduce a new protein structure taxonomy that is based on quantifiable metrics of a protein's disorder.
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Affiliation(s)
- Virginia M Burger
- From the Research Laboratory for Electronics, Department of Electrical Engineering & Computer Science, and
| | - Diego O Nolasco
- From the Research Laboratory for Electronics, Department of Electrical Engineering & Computer Science, and
| | - Collin M Stultz
- From the Research Laboratory for Electronics, Department of Electrical Engineering & Computer Science, and the Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02138
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94
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Csizmok V, Follis AV, Kriwacki RW, Forman-Kay JD. Dynamic Protein Interaction Networks and New Structural Paradigms in Signaling. Chem Rev 2016; 116:6424-62. [PMID: 26922996 DOI: 10.1021/acs.chemrev.5b00548] [Citation(s) in RCA: 130] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Understanding signaling and other complex biological processes requires elucidating the critical roles of intrinsically disordered proteins (IDPs) and regions (IDRs), which represent ∼30% of the proteome and enable unique regulatory mechanisms. In this review, we describe the structural heterogeneity of disordered proteins that underpins these mechanisms and the latest progress in obtaining structural descriptions of conformational ensembles of disordered proteins that are needed for linking structure and dynamics to function. We describe the diverse interactions of IDPs that can have unusual characteristics such as "ultrasensitivity" and "regulated folding and unfolding". We also summarize the mounting data showing that large-scale assembly and protein phase separation occurs within a variety of signaling complexes and cellular structures. In addition, we discuss efforts to therapeutically target disordered proteins with small molecules. Overall, we interpret the remodeling of disordered state ensembles due to binding and post-translational modifications within an expanded framework for allostery that provides significant insights into how disordered proteins transmit biological information.
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Affiliation(s)
- Veronika Csizmok
- Molecular Structure & Function, The Hospital for Sick Children , Toronto, ON M5G 0A4, Canada
| | - Ariele Viacava Follis
- Department of Structural Biology, St. Jude Children's Research Hospital , Memphis, Tennessee 38105, United States
| | - Richard W Kriwacki
- Department of Structural Biology, St. Jude Children's Research Hospital , Memphis, Tennessee 38105, United States.,Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Sciences Center , Memphis, Tennessee 38163, United States
| | - Julie D Forman-Kay
- Molecular Structure & Function, The Hospital for Sick Children , Toronto, ON M5G 0A4, Canada.,Department of Biochemistry, University of Toronto , Toronto, ON M5S 1A8, Canada
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95
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Qi H, Prabakaran S, Cantrelle FX, Chambraud B, Gunawardena J, Lippens G, Landrieu I. Characterization of Neuronal Tau Protein as a Target of Extracellular Signal-regulated Kinase. J Biol Chem 2016; 291:7742-53. [PMID: 26858248 DOI: 10.1074/jbc.m115.700914] [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: 10/28/2015] [Indexed: 01/16/2023] Open
Abstract
Tau neuronal protein has a central role in neurodegeneration and is implicated in Alzheimer disease development. Abnormal phosphorylation of Tau impairs its interaction with other proteins and is associated with its dysregulation in pathological conditions. Molecular mechanisms leading to hyperphosphorylation of Tau in pathological conditions are unknown. Here, we characterize phosphorylation of Tau by extracellular-regulated kinase (ERK2), a mitogen-activated kinase (MAPK) that responds to extracellular signals. Analysis ofin vitrophosphorylated Tau by activated recombinant ERK2 with nuclear magnetic resonance spectroscopy (NMR) reveals phosphorylation of 15 Ser/Thr sites.In vitrophosphorylation of Tau using rat brain extract and subsequent NMR analysis identifies the same sites. Phosphorylation with rat brain extract is known to transform Tau into an Alzheimer disease-like state. Our results indicate that phosphorylation of Tau by ERK2 alone is sufficient to produce the same characteristics. We further investigate the mechanism of ERK2 phosphorylation of Tau. Kinases are known to recognize their protein substrates not only by their specificity for a targeted Ser or Thr phosphorylation site but also by binding to linear-peptide motifs called docking sites. We identify two main ERK2 docking sites in Tau sequence using NMR. Our results suggest that ERK2 dysregulation in Alzheimer disease could lead to abnormal phosphorylation of Tau resulting in the pathology of the disease.
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Affiliation(s)
- Haoling Qi
- From Lille University, CNRS UMR8576, F-59000 Lille, France
| | - Sudhakaran Prabakaran
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, and
| | | | | | - Jeremy Gunawardena
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, and
| | - Guy Lippens
- From Lille University, CNRS UMR8576, F-59000 Lille, France
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96
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Gurry T, Fisher CK, Schmidt M, Stultz CM. Analyzing Ensembles of Amyloid Proteins Using Bayesian Statistics. Methods Mol Biol 2016; 1345:269-280. [PMID: 26453218 DOI: 10.1007/978-1-4939-2978-8_17] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Intrinsically disordered proteins (IDPs) are notoriously difficult to study experimentally because they rapidly interconvert between many dissimilar conformations during their biological lifetime, and therefore cannot be described by a single structure. The importance of studying these systems, however, is underscored by the fact that they form toxic aggregates that play a role in the pathogenesis of many disorders. The first step towards a comprehensive understanding of the aggregation mechanism of these proteins involves a description of their thermally accessible states under physiologic conditions. The resulting conformational ensembles correspond to coarse-grained descriptions of their energy landscapes, where the number of structures in the ensemble is related to the resolution in which one views the free energy surface. Here, we provide step-by-step instructions on how to use experimental data to construct a conformational ensemble for an IDP using a Variational Bayesian Weighting (VBW) algorithm. We further discuss how to leverage this Bayesian approach to identify statistically significant ensemble-wide observations that can form the basis of further experimental studies.
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Affiliation(s)
- Thomas Gurry
- Computational and Systems Biology Initiative, Massachusetts Institute of Technology, Cambridge, MA, 02139-4307, USA
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, 02139-4307, USA
| | | | - Molly Schmidt
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, 02139-4307, USA
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, 02139-4307, USA
| | - Collin M Stultz
- Computational and Systems Biology Initiative, Massachusetts Institute of Technology, Cambridge, MA, 02139-4307, USA.
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, 02139-4307, USA.
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, 02139-4307, USA.
- The Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, 02139-4307, USA.
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97
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Song J, Gomes GN, Gradinaru CC, Chan HS. An Adequate Account of Excluded Volume Is Necessary To Infer Compactness and Asphericity of Disordered Proteins by Förster Resonance Energy Transfer. J Phys Chem B 2015; 119:15191-202. [DOI: 10.1021/acs.jpcb.5b09133] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
| | - Gregory-Neal Gomes
- Department
of Chemical and Physical Sciences, University of Toronto Mississauga, Mississauga, Ontario L5L 1C6, Canada
| | - Claudiu C. Gradinaru
- Department
of Chemical and Physical Sciences, University of Toronto Mississauga, Mississauga, Ontario L5L 1C6, Canada
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98
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Dennis JW. Many Light Touches Convey the Message. Trends Biochem Sci 2015; 40:673-686. [DOI: 10.1016/j.tibs.2015.08.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 08/14/2015] [Accepted: 08/21/2015] [Indexed: 11/28/2022]
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99
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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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Biophysical Methods to Investigate Intrinsically Disordered Proteins: Avoiding an “Elephant and Blind Men” Situation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 870:215-60. [DOI: 10.1007/978-3-319-20164-1_7] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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