1
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Lyu F, Hakariya H, Hiraoka H, Li Z, Matsubara N, Soo Y, Hashiya F, Abe N, Shu Z, Nakamoto K, Kimura Y, Abe H. Intracellular Delivery of Antisense Oligonucleotides by Tri-Branched Cyclic Disulfide Units. ChemMedChem 2024; 19:e202400472. [PMID: 38957922 DOI: 10.1002/cmdc.202400472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2024] [Accepted: 06/26/2024] [Indexed: 07/04/2024]
Abstract
Therapeutic oligonucleotides, such as antisense DNA, show promise in treating previously untreatable diseases. However, their applications are still hindered by the poor membrane permeability of naked oligonucleotides. Therefore, it is necessary to develop efficient methods for intracellular oligonucleotide delivery. Previously, our group successfully developed disulfide-based Membrane Permeable Oligonucleotides (MPON), which achieved enhanced cellular uptake and gene silencing effects through an endocytosis-free uptake mechanism. Herein, we report a new molecular design for the next generation of MPON, called trimer MPON. The trimer MPON consists of a tri-branched backbone, three α-lipoic acid units, and a spacer linker between the oligonucleotides and tri-branched cyclic disulfide unit. We describe the design, synthesis, and functional evaluation of the trimer MPON, offering new insights into the molecular design for efficient oligonucleotide delivery.
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Affiliation(s)
- Fangjie Lyu
- Department of Chemistry, Graduate School of Science, Nagoya University, Nagoya, Aichi, 464-8602, Japan
| | - Hayase Hakariya
- Department of Chemistry, Graduate School of Science, Nagoya University, Nagoya, Aichi, 464-8602, Japan
| | - Haruka Hiraoka
- Department of Chemistry, Graduate School of Science, Nagoya University, Nagoya, Aichi, 464-8602, Japan
| | - Zhenmin Li
- Department of Chemistry, Graduate School of Science, Nagoya University, Nagoya, Aichi, 464-8602, Japan
| | - Noriaki Matsubara
- Department of Chemistry, Graduate School of Science, Nagoya University, Nagoya, Aichi, 464-8602, Japan
| | - Yonghao Soo
- Department of Chemistry, Graduate School of Science, Nagoya University, Nagoya, Aichi, 464-8602, Japan
| | - Fumitaka Hashiya
- Research Center for Materials Science, Nagoya University, Nagoya, Aichi, 464-8602, Japan
| | - Naoko Abe
- Department of Chemistry, Graduate School of Science, Nagoya University, Nagoya, Aichi, 464-8602, Japan
| | - Zhaoma Shu
- Department of Chemistry, Graduate School of Science, Nagoya University, Nagoya, Aichi, 464-8602, Japan
| | - Kosuke Nakamoto
- Department of Chemistry, Graduate School of Science, Nagoya University, Nagoya, Aichi, 464-8602, Japan
| | - Yasuaki Kimura
- Department of Chemistry, Graduate School of Science, Nagoya University, Nagoya, Aichi, 464-8602, Japan
| | - Hiroshi Abe
- Department of Chemistry, Graduate School of Science, Nagoya University, Nagoya, Aichi, 464-8602, Japan
- Research Center for Materials Science, Nagoya University, Nagoya, Aichi, 464-8602, Japan
- Institute for Glyco-core Research (iGCORE), Nagoya University, Nagoya, Aichi, 464-8601, Japan
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2
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Kuravsky M, Kelly C, Redfield C, Shammas SL. The transition state for coupled folding and binding of a disordered DNA binding domain resembles the unbound state. Nucleic Acids Res 2024:gkae794. [PMID: 39315703 DOI: 10.1093/nar/gkae794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Revised: 08/22/2024] [Accepted: 09/02/2024] [Indexed: 09/25/2024] Open
Abstract
The basic zippers (bZIPs) are one of two large eukaryotic families of transcription factors whose DNA binding domains are disordered in isolation but fold into stable α-helices upon target DNA binding. Here, we systematically disrupt pre-existing helical propensity within the DNA binding region of the homodimeric bZIP domain of cAMP-response element binding protein (CREB) using Ala-Gly scanning and examine the impact on target binding kinetics. We find that the secondary structure of the transition state strongly resembles that of the unbound state. The residue closest to the dimerization domain is largely folded within both unbound and transition states; dimerization apparently propagates additional helical propensity into the basic region. The results are consistent with electrostatically-enhanced DNA binding, followed by rapid folding from the folded zipper outwards. Fly-casting theory suggests that protein disorder can accelerate binding. Interestingly however, we did not observe higher association rate constants for mutants with lower levels of residual structure in the unbound state.
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Affiliation(s)
- Mikhail Kuravsky
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Conor Kelly
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | | | - Sarah L Shammas
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
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3
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Li T, Motta S, He Y. Deciphering the Mystery in p300 Taz2-p53 TAD2 Recognition. J Chem Theory Comput 2024. [PMID: 39141804 DOI: 10.1021/acs.jctc.4c00541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/16/2024]
Abstract
Intrinsically disordered proteins (IDPs) engage in various fundamental biological activities, and their behavior is of particular importance for a better understanding of the verbose but well-organized signal transduction in cells. IDPs exhibit uniquely paradoxical features with low affinity but simultaneously high specificity in recognizing their binding targets. The transcription factor p53 plays a crucial role in cancer suppression, carrying out some of its biological functions using its disordered regions, such as N-terminal transactivation domain 2 (TAD2). Exploration of the binding and unbinding processes between proteins is challenging, and the inherently disordered properties of these regions further complicate the issue. Computer simulations are a powerful tool to complement the experiments to fill gaps to explore the binding/unbinding processes between proteins. Here, we investigated the binding mechanism between p300 Taz2 and p53 TAD2 through extensive molecular dynamics (MD) simulations using the physics-based UNited RESidue (UNRES) force field with additional Go̅-like potentials. Distance restraints extracted from the NMR-resolved structures were imposed on intermolecular residue pairs to accelerate binding simulations, in which Taz2 was immobilized in a native-like conformation and disordered TAD2 was fully free. Starting from six structures with TAD2 placed at different positions around Taz2, we observed a metastable intermediate state in which the middle helical segment of TAD2 is anchored in the binding pocket, highlighting the significance of the TAD2 helix in directing protein recognition. Physics-based binding simulations show that successful binding is achieved after a series of stages, including (1) protein collisions to initiate the formation of encounter complexes, (2) partial attachment of TAD2, and finally (3) full attachment of TAD2 to the correct binding pocket of Taz2. Furthermore, machine-learning-based PathDetect-SOM was used to identify two binding pathways, the encounter complexes, and the intermediate states.
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Affiliation(s)
- Tongtong Li
- Department of Chemistry & Chemical Biology, The University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Stefano Motta
- Department of Earth and Environmental Sciences, University of Milano-Bicocca, Milan 20126, Italy
| | - Yi He
- Department of Chemistry & Chemical Biology, The University of New Mexico, Albuquerque, New Mexico 87131, United States
- Translational Informatics Division, Department of Internal Medicine, The University of New Mexico, Albuquerque, New Mexico 87131, United States
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4
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McIvor JAP, Larsen DS, Mercadante D. Charge Relaying within a Phospho-Motif Rescue Binding Competency of a Disordered Transcription Factor. J Chem Inf Model 2024; 64:6041-6052. [PMID: 39074869 DOI: 10.1021/acs.jcim.4c00286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/31/2024]
Abstract
Structural disorder in proteins is central to cellular signaling, where conformational plasticity equips molecules to promiscuously interact with different partners. By engaging with multiple binding partners via the rearrangement of its three helices, the nuclear coactivator binding domain (NCBD) of the CBP/p300 transcription factor is a paradigmatic example of promiscuity. Recently, molecular simulations and experiments revealed that, through the establishment of long-range electrostatic interactions, intended as salt-bridges formed between the post-translationally inserted phosphate and positively charged residues in helix H3 of NCBD, phosphorylation triggers NCBD compaction, lowering its affinity for binding partners. By means of extensive molecular simulations, we here investigated the effect of short-range electrostatics on the conformational ensemble of NCBD, by monitoring the interactions between a phosphorylated serine and conserved positively charged residues within the NCBD phospho-motif. We found that empowering proximal electrostatic interactions, as opposed to long-range electrostatics, can reshape the NCBD ensemble rescuing the binding competency of phosphorylated NCBD. Given the conservation of positive charges in phospho-motifs, proximal electrostatic interactions might dampen the effects of phosphorylation and act as a relay to regulate phosphorylated intrinsically disordered proteins, ultimately tuning the binding affinity for different cellular partners.
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Affiliation(s)
- Jordan A P McIvor
- School of Chemical Sciences, The University of Auckland, 23 Symonds Street, Auckland 1010, New Zealand
| | - Danaé S Larsen
- School of Chemical Sciences, The University of Auckland, 23 Symonds Street, Auckland 1010, New Zealand
| | - Davide Mercadante
- School of Chemical Sciences, The University of Auckland, 23 Symonds Street, Auckland 1010, New Zealand
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5
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Arai M, Suetaka S, Ooka K. Dynamics and interactions of intrinsically disordered proteins. Curr Opin Struct Biol 2024; 84:102734. [PMID: 38039868 DOI: 10.1016/j.sbi.2023.102734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 10/27/2023] [Accepted: 10/30/2023] [Indexed: 12/03/2023]
Abstract
Intrinsically disordered proteins (IDPs) are widespread in eukaryotes and participate in a variety of important cellular processes. Numerous studies using state-of-the-art experimental and theoretical methods have advanced our understanding of IDPs and revealed that disordered regions engage in a large repertoire of intra- and intermolecular interactions through their conformational dynamics, thereby regulating many intracellular functions in concert with folded domains. The mechanisms by which IDPs interact with their partners are diverse, depending on their conformational propensities, and include induced fit, conformational selection, and their mixtures. In addition, IDPs are implicated in many diseases, and progress has been made in designing inhibitors of IDP-mediated interactions. Here we review these recent advances with a focus on the dynamics and interactions of IDPs.
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Affiliation(s)
- Munehito Arai
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan; Komaba Organization for Educational Excellence, College of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan; Department of Physics, Graduate School of Science, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan.
| | - Shunji Suetaka
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan
| | - Koji Ooka
- Komaba Organization for Educational Excellence, College of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan
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6
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Hossain M, Huda N, Bhuyan AK. A three-state mechanism for trifluoroethanol denaturation of an intrinsically disordered protein (IDP). J Biochem 2023; 174:519-531. [PMID: 37709541 DOI: 10.1093/jb/mvad067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 09/05/2023] [Accepted: 09/13/2023] [Indexed: 09/16/2023] Open
Abstract
Relating the amino acid composition and sequence to chain folding and binding preferences of intrinsically disordered proteins (IDPs) has emerged as a huge challenge. While globular proteins have respective 3D structures that are unique to their individual functions, IDPs violate this structure-function paradigm because rather than having a well-defined structure an ensemble of rapidly interconverting disordered structures characterize an IDP. This work measures 2,2,2-trifluoroethanol (TFE)-induced equilibrium transitions of an IDP called AtPP16-1 (Arabidopsis thaliana phloem protein type 16-1) by using fluorescence, circular dichroism, infrared and nuclear magnetic resonance (NMR) methods at pH 4, 298 K. Low TFE reversibly removes the tertiary structure to produce an ensemble of obligate intermediate ($\mathrm{I}$) retaining the native-state ($\mathrm{N}$) secondary structure. The intermediate $\mathrm{I}$ is preceded by a non-obligate tryptophan-specific intermediate ${\mathrm{I}}_{\mathrm{w}}$ whose population is detectable for AtPP16-1 specifically. Accumulation of such non-obligate intermediates is discriminated according to the sequence composition of the protein. In all cases, however, a tertiary structure-unfolded general obligate intermediate $\mathrm{I}$ is indispensable. The $\mathrm{I}$ ensemble has higher helical propensity conducive to the acquisition of an exceedingly large level of α-helices by a reversible denaturation transition of $\mathrm{I}$ to the denatured state $\mathrm{D}$ as the TFE level is increased. Strikingly, it is the same $\mathrm{N}\rightleftharpoons \mathrm{I}\rightleftharpoons \mathrm{D}$ scheme typifying the TFE transitions of globular proteins. The high-energy state $\mathrm{I}$ characterized by increased helical propensity is called a universal intermediate encountered in both genera of globular and disordered proteins. Neither $\mathrm{I}$ nor $\mathrm{D}$ strictly show molten globule (MG)-like properties, dismissing the belief that TFE promotes MGs.
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Affiliation(s)
- Mujahid Hossain
- School of Chemistry, University of Hyderabad, Hyderabad 500046, India
| | - Noorul Huda
- School of Chemistry, University of Hyderabad, Hyderabad 500046, India
| | - Abani K Bhuyan
- School of Chemistry, University of Hyderabad, Hyderabad 500046, India
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7
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Su X, Pang YT, Li W, Gumbart JC, Kelley J, Torres M. N-terminal intrinsic disorder is an ancestral feature of Gγ subunits that influences the balance between different Gβγ signaling axes in yeast. J Biol Chem 2023; 299:104947. [PMID: 37354971 PMCID: PMC10393545 DOI: 10.1016/j.jbc.2023.104947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 06/02/2023] [Accepted: 06/16/2023] [Indexed: 06/26/2023] Open
Abstract
Activated G protein-coupled receptors promote the dissociation of heterotrimeric G proteins into Gα and Gβγ subunits that bind to effector proteins to drive intracellular signaling responses. In yeast, Gβγ subunits coordinate the simultaneous activation of multiple signaling axes in response to mating pheromones, including MAP kinase (MAPK)-dependent transcription, cell polarization, and cell cycle arrest responses. The Gγ subunit in this complex contains an N-terminal intrinsically disordered region that governs Gβγ-dependent signal transduction in yeast and mammals. Here, we demonstrate that N-terminal intrinsic disorder is likely an ancestral feature that has been conserved across different Gγ subtypes and organisms. To understand the functional contribution of structural disorder in this region, we introduced precise point mutations that produce a stepwise disorder-to-order transition in the N-terminal tail of the canonical yeast Gγ subunit, Ste18. Mutant tail structures were confirmed using circular dichroism and molecular dynamics and then substituted for the wildtype gene in yeast. We find that increasing the number of helix-stabilizing mutations, but not isometric mutation controls, has a negative and proteasome-independent effect on Ste18 protein levels as well as a differential effect on pheromone-induced levels of active MAPK/Fus3, but not MAPK/Kss1. When expressed at wildtype levels, we further show that mutants with an alpha-helical N terminus exhibit a counterintuitive shift in Gβγ signaling that reduces active MAPK/Fus3 levels whilst increasing cell polarization and cell cycle arrest. These data reveal a role for Gγ subunit intrinsically disordered regions in governing the balance between multiple Gβγ signaling axes.
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Affiliation(s)
- Xinya Su
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Yui Tik Pang
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Wei Li
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA; Southeast Center for Mathematics and Biology, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - J C Gumbart
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Joshua Kelley
- Department of Molecular and Biomedical Sciences, University of Maine, Orono, Maine, USA
| | - Matthew Torres
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA; Southeast Center for Mathematics and Biology, Georgia Institute of Technology, Atlanta, Georgia, USA.
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8
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Lasorsa A, Bera K, Malki I, Dupré E, Cantrelle FX, Merzougui H, Sinnaeve D, Hanoulle X, Hritz J, Landrieu I. Conformation and Affinity Modulations by Multiple Phosphorylation Occurring in the BIN1 SH3 Domain Binding Site of the Tau Protein Proline-Rich Region. Biochemistry 2023. [PMID: 37167199 DOI: 10.1021/acs.biochem.2c00717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
An increase in phosphorylation of the Tau protein is associated with Alzheimer's disease (AD) progression through unclear molecular mechanisms. In general, phosphorylation modifies the interaction of intrinsically disordered proteins, such as Tau, with other proteins; however, elucidating the structural basis of this regulation mechanism remains challenging. The bridging integrator-1 gene is an AD genetic determinant whose gene product, BIN1, directly interacts with Tau. The proline-rich motif recognized within a Tau(210-240) peptide by the SH3 domain of BIN1 (BIN1 SH3) is defined as 216PTPP219, and this interaction is modulated by phosphorylation. Phosphorylation of T217 within the Tau(210-240) peptide led to a 6-fold reduction in the affinity, while single phosphorylation at either T212, T231, or S235 had no effect on the interaction. Nonetheless, combined phosphorylation of T231 and S235 led to a 3-fold reduction in the affinity, although these phosphorylations are not within the BIN1 SH3-bound region of the Tau peptide. Using nuclear magnetic resonance (NMR) spectroscopy, these phosphorylations were shown to affect the local secondary structure and dynamics of the Tau(210-240) peptide. Models of the (un)phosphorylated peptides were obtained from molecular dynamics (MD) simulation validated by experimental data and showed compaction of the phosphorylated peptide due to increased salt bridge formation. This dynamic folding might indirectly impact the BIN1 SH3 binding by a decreased accessibility of the binding site. Regulation of the binding might thus not only be due to local electrostatic or steric effects from phosphorylation but also to the modification of the conformational properties of Tau.
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Affiliation(s)
- Alessia Lasorsa
- CNRS EMR9002 Integrative Structural Biology, Lille F-59000, France
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1167 - RID-AGE - Risk Factors and Molecular Determinants of Aging-Related Diseases, Lille F-59000, France
| | - Krishnendu Bera
- CEITEC MU, Masaryk University, Kamenice 753/5, Brno 625 00, Czech Republic
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, Brno 625 00, Czech Republic
- Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5, Brno 625 00, Czech Republic
| | - Idir Malki
- CNRS EMR9002 Integrative Structural Biology, Lille F-59000, France
| | - Elian Dupré
- CNRS EMR9002 Integrative Structural Biology, Lille F-59000, France
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1167 - RID-AGE - Risk Factors and Molecular Determinants of Aging-Related Diseases, Lille F-59000, France
| | - François-Xavier Cantrelle
- CNRS EMR9002 Integrative Structural Biology, Lille F-59000, France
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1167 - RID-AGE - Risk Factors and Molecular Determinants of Aging-Related Diseases, Lille F-59000, France
| | - Hamida Merzougui
- CNRS EMR9002 Integrative Structural Biology, Lille F-59000, France
| | - Davy Sinnaeve
- CNRS EMR9002 Integrative Structural Biology, Lille F-59000, France
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1167 - RID-AGE - Risk Factors and Molecular Determinants of Aging-Related Diseases, Lille F-59000, France
| | - Xavier Hanoulle
- CNRS EMR9002 Integrative Structural Biology, Lille F-59000, France
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1167 - RID-AGE - Risk Factors and Molecular Determinants of Aging-Related Diseases, Lille F-59000, France
| | - Jozef Hritz
- CEITEC MU, Masaryk University, Kamenice 753/5, Brno 625 00, Czech Republic
- Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5, Brno 625 00, Czech Republic
| | - Isabelle Landrieu
- CNRS EMR9002 Integrative Structural Biology, Lille F-59000, France
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1167 - RID-AGE - Risk Factors and Molecular Determinants of Aging-Related Diseases, Lille F-59000, France
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9
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Evolutionary fine-tuning of residual helix structure in disordered proteins manifests in complex structure and lifetime. Commun Biol 2023; 6:63. [PMID: 36653471 PMCID: PMC9849366 DOI: 10.1038/s42003-023-04445-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 01/09/2023] [Indexed: 01/19/2023] Open
Abstract
Transcription depends on complex networks, where folded hub proteins interact with intrinsically disordered transcription factors undergoing coupled folding and binding. For this, local residual structure, a prototypical feature of intrinsic disorder, is key. Here, we dissect the unexplored functional potential of residual structure by comparing structure, kinetics, and thermodynamics within the model system constituted of the DREB2A transcription factor interacting with the αα-hub RCD1-RST. To maintain biological relevance, we developed an orthogonal evolutionary approach for the design of variants with varying amounts of structure. Biophysical analysis revealed a correlation between the amount of residual helical structure and binding affinity, manifested in altered complex lifetime due to changed dissociation rate constants. It also showed a correlation between helical structure in free and bound DREB2A variants. Overall, this study demonstrated how evolution can balance and fine-tune residual structure to regulate complexes in coupled folding and binding, potentially affecting transcription factor competition.
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10
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Buholzer KJ, McIvor J, Zosel F, Teppich C, Nettels D, Mercadante D, Schuler B. Multilayered allosteric modulation of coupled folding and binding by phosphorylation, peptidyl-prolyl cis/trans isomerization, and diversity of interaction partners. J Chem Phys 2022; 157:235102. [PMID: 36550025 DOI: 10.1063/5.0128273] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Intrinsically disordered proteins (IDPs) play key roles in cellular regulation, including signal transduction, transcription, and cell-cycle control. Accordingly, IDPs can commonly interact with numerous different target proteins, and their interaction networks are expected to be highly regulated. However, many of the underlying regulatory mechanisms have remained unclear. Here, we examine the representative case of the nuclear coactivator binding domain (NCBD) of the large multidomain protein CBP, a hub in transcriptional regulation, and the interaction with several of its binding partners. Single-molecule Förster resonance energy transfer measurements show that phosphorylation of NCBD reduces its binding affinity, with effects that vary depending on the binding partner and the site and number of modifications. The complexity of the interaction is further increased by the dependence of the affinities on peptidyl-prolyl cis/trans isomerization in NCBD. Overall, our results reveal the potential for allosteric regulation on at least three levels: the different affinities of NCBD for its different binding partners, the differential modulation of these affinities by phosphorylation, and the effect of peptidyl-prolyl cis/trans isomerization on binding.
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Affiliation(s)
- Karin J Buholzer
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Jordan McIvor
- School of Chemical Sciences, The University of Auckland, Auckland, New Zealand
| | - Franziska Zosel
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Christian Teppich
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Daniel Nettels
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Davide Mercadante
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Benjamin Schuler
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
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11
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Roesgaard MA, Lundsgaard JE, Newcombe EA, Jacobsen NL, Pesce F, Tranchant EE, Lindemose S, Prestel A, Hartmann-Petersen R, Lindorff-Larsen K, Kragelund BB. Deciphering the Alphabet of Disorder-Glu and Asp Act Differently on Local but Not Global Properties. Biomolecules 2022; 12:biom12101426. [PMID: 36291634 PMCID: PMC9599281 DOI: 10.3390/biom12101426] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 09/21/2022] [Accepted: 09/28/2022] [Indexed: 12/29/2022] Open
Abstract
Compared to folded proteins, the sequences of intrinsically disordered proteins (IDPs) are enriched in polar and charged amino acids. Glutamate is one of the most enriched amino acids in IDPs, while the chemically similar amino acid aspartate is less enriched. So far, the underlying functional differences between glutamates and aspartates in IDPs remain poorly understood. In this study, we examine the differential effects of aspartate and glutamates in IDPs by comparing the function and conformational ensemble of glutamate and aspartate variants of the disordered protein Dss1, using a range of assays, including interaction studies, nuclear magnetic resonance spectroscopy, small-angle X-ray scattering and molecular dynamics simulation. First, we analyze the sequences of the rapidly growing database of experimentally verified IDPs (DisProt) and show that glutamate enrichment is not caused by a taxonomy bias in IDPs. From analyses of local and global structural properties as well as cell growth and protein-protein interactions using a model acidic IDP from yeast and three Glu/Asp variants, we find that while the Glu/Asp variants support similar function and global dimensions, the variants differ in their binding affinities and population of local transient structural elements. We speculate that these local structural differences may play roles in functional diversity, where glutamates can support increased helicity, important for folding and binding, while aspartates support extended structures and form helical caps, as well as playing more relevant roles in, e.g., transactivation domains and ion-binding.
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12
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Hadži S, Lah J. The free energy folding penalty accompanying binding of intrinsically disordered α-helical motifs. Protein Sci 2022; 31:e4370. [PMID: 35762718 PMCID: PMC9202546 DOI: 10.1002/pro.4370] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 05/30/2022] [Accepted: 05/31/2022] [Indexed: 12/29/2022]
Abstract
Intrinsically disordered proteins (IDPs) are abundant in eukaryotic proteomes and preform critical roles in many cellular processes, most often through the association with globular proteins. Despite lacking a stable three-dimensional structure by themselves, they may acquire a defined conformation upon binding globular targets. The most common type of secondary structure acquired by these binding motifs entails formation of an α-helix. It has been hypothesized that such disorder-to-order transitions are associated with a significant free energy penalty due to IDP folding, which reduces the overall IDP-target affinity. However, the exact magnitude of IDP folding penalty in α-helical binding motifs has not been systematically estimated. Here, we report the folding penalty contributions for 30 IDPs undergoing folding-upon-binding and find that the average IDP folding penalty is +2.0 kcal/mol and ranges from 0.7 to 3.5 kcal/mol. We observe that the folding penalty scales approximately linearly with the change in IDP helicity upon binding, which provides a simple empirical way to estimate folding penalty. We analyze to what extent do pre-structuring and target-bound IDP dynamics (fuzziness) reduce the folding penalty and find that these effects combined, on average, reduce the folding cost by around half. Taken together, the presented analysis provides a quantitative basis for understanding the role of folding penalty in IDP-target interactions and introduces a method estimate this quantity. Estimation and reduction of IDP folding penalty may prove useful in the rational design of helix-stabilized inhibitors of IDP-target interactions. STATEMENT: The α-helical binding motifs are ubiquitous among the intrinsically disordered proteins (IDPs). Upon binding their targets, they undergo a disorder-to-order transition, which is accompanied by a significant folding penalty whose magnitude is generally not known. Here, we use recently developed statistical-thermodynamic model to estimate the folding penalties for 30 IDPs and clarify the roles of IDP pre-folding and bound-state dynamics in reducing the folding penalty.
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Affiliation(s)
- San Hadži
- Department of Physical Chemistry, Faculty of Chemistry and Chemical TechnologyUniversity of LjubljanaLjubljana
| | - Jurij Lah
- Department of Physical Chemistry, Faculty of Chemistry and Chemical TechnologyUniversity of LjubljanaLjubljana
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13
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Disordered regions flanking the binding interface modulate affinity between CBP and NCOA. J Mol Biol 2022; 434:167643. [DOI: 10.1016/j.jmb.2022.167643] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 05/13/2022] [Accepted: 05/16/2022] [Indexed: 01/01/2023]
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14
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Camacho-Zarco AR, Schnapka V, Guseva S, Abyzov A, Adamski W, Milles S, Jensen MR, Zidek L, Salvi N, Blackledge M. NMR Provides Unique Insight into the Functional Dynamics and Interactions of Intrinsically Disordered Proteins. Chem Rev 2022; 122:9331-9356. [PMID: 35446534 PMCID: PMC9136928 DOI: 10.1021/acs.chemrev.1c01023] [Citation(s) in RCA: 45] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
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Intrinsically disordered
proteins are ubiquitous throughout all
known proteomes, playing essential roles in all aspects of cellular
and extracellular biochemistry. To understand their function, it is
necessary to determine their structural and dynamic behavior and to
describe the physical chemistry of their interaction trajectories.
Nuclear magnetic resonance is perfectly adapted to this task, providing
ensemble averaged structural and dynamic parameters that report on
each assigned resonance in the molecule, unveiling otherwise inaccessible
insight into the reaction kinetics and thermodynamics that are essential
for function. In this review, we describe recent applications of NMR-based
approaches to understanding the conformational energy landscape, the
nature and time scales of local and long-range dynamics and how they
depend on the environment, even in the cell. Finally, we illustrate
the ability of NMR to uncover the mechanistic basis of functional
disordered molecular assemblies that are important for human health.
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Affiliation(s)
| | - Vincent Schnapka
- Université Grenoble Alpes, CEA, CNRS, IBS, 38000 Grenoble, France
| | - Serafima Guseva
- Université Grenoble Alpes, CEA, CNRS, IBS, 38000 Grenoble, France
| | - Anton Abyzov
- Université Grenoble Alpes, CEA, CNRS, IBS, 38000 Grenoble, France
| | - Wiktor Adamski
- Université Grenoble Alpes, CEA, CNRS, IBS, 38000 Grenoble, France
| | - Sigrid Milles
- Université Grenoble Alpes, CEA, CNRS, IBS, 38000 Grenoble, France
| | | | - Lukas Zidek
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 82500 Brno, Czech Republic.,Central European Institute of Technology, Masaryk University, Kamenice 5, 82500 Brno, Czech Republic
| | - Nicola Salvi
- Université Grenoble Alpes, CEA, CNRS, IBS, 38000 Grenoble, France
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15
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Bril’kov MS, Dobrovolska O, Ødegård-Fougner Ø, Turcu DC, Strømland Ø, Underhaug J, Aasland R, Halskau Ø. Binding Specificity of ASHH2 CW Domain Toward H3K4me1 Ligand Is Coupled to Its Structural Stability Through Its α1-Helix. Front Mol Biosci 2022; 9:763750. [PMID: 35495628 PMCID: PMC9043364 DOI: 10.3389/fmolb.2022.763750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 02/25/2022] [Indexed: 11/14/2022] Open
Abstract
The CW domain binds to histone tail modifications found in different protein families involved in epigenetic regulation and chromatin remodeling. CW domains recognize the methylation state of the fourth lysine on histone 3 and could, therefore, be viewed as a reader of epigenetic information. The specificity toward different methylation states such as me1, me2, or me3 depends on the particular CW subtype. For example, the CW domain of ASHH2 methyltransferase binds preferentially to H3K4me1, and MORC3 binds to both H3K4me2 and me3 modifications, while ZCWPW1 is more specific to H3K4me3. The structural basis for these preferential bindings is not well understood, and recent research suggests that a more complete picture will emerge if dynamical and energetic assessments are included in the analysis of interactions. This study uses fold assessment by NMR in combination with mutagenesis, ITC affinity measurements, and thermal denaturation studies to investigate possible couplings between ASHH2 CW selectivity toward H3K4me1 and the stabilization of the domain and loops implicated in binding. The key elements of the binding site—the two tryptophans and the α1-helix form and maintain the binding pocket— were perturbed by mutagenesis and investigated. Results show that the α1-helix maintains the overall stability of the fold via the I915 and L919 residues and that the correct binding consolidates the loops designated as η1 and η3, as well as the C-terminal. This consolidation is incomplete for H3K4me3 binding to CW, which experiences a decrease in overall thermal stability on binding. Loop mutations not directly involved in the binding site, nonetheless, affect the equilibrium positions of the key residues.
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Affiliation(s)
- Maxim S. Bril’kov
- Department of Biological Sciences, University of Bergen, Bergen, Norway
- Department of Pharmacy, University of Tromsø, Tromsø, Norway
| | - Olena Dobrovolska
- Department of Biological Sciences, University of Bergen, Bergen, Norway
| | - Øyvind Ødegård-Fougner
- Department of Biological Sciences, University of Bergen, Bergen, Norway
- Department of Molecular Cell Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo, Norway
| | - Diana C. Turcu
- Department of Biological Sciences, University of Bergen, Bergen, Norway
| | | | - Jarl Underhaug
- Department of Chemistry, University of Bergen, Bergen, Norway
| | - Rein Aasland
- Department of Biosciences, University of Oslo, Oslo, Norway
- *Correspondence: Rein Aasland, ; Øyvind Halskau,
| | - Øyvind Halskau
- Department of Biological Sciences, University of Bergen, Bergen, Norway
- *Correspondence: Rein Aasland, ; Øyvind Halskau,
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16
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Human Vitamin K Epoxide Reductase as a Target of Its Redox Protein. Int J Mol Sci 2022; 23:ijms23073899. [PMID: 35409257 PMCID: PMC8998853 DOI: 10.3390/ijms23073899] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 03/29/2022] [Accepted: 03/30/2022] [Indexed: 02/05/2023] Open
Abstract
Human vitamin K epoxide reductase (hVKORC1) enzymatic activity requires an initial activation by a specific redox protein, a less studied step in the hVKORC1 vital cycle. Significant steric conditions must be met by enzymes, being that to adapt their configurations is mandatory for hVKORC1 activation. We studied, by molecular dynamics (MD) simulations, the folding and conformational plasticity of hVKORC1 in its inactive (fully oxidised) state using available structures, crystallographic and from de novo modelling. According to the obtained results, hVKORC1 is a modular protein composed of the stable transmembrane domain (TMD) and intrinsically disordered luminal (L) loop, possessing the great plasticity/adaptability required to perform various steps of the activation process. The docking (HADDOCK) of Protein Disulfide Isomerase (PDI) onto different hVKORC1 conformations clearly indicated that the most interpretable solutions were found on the target closed L-loop form, a prevalent conformation of hVKORC1’s oxidised state. We also suggest that the cleaved L-loop is an appropriate entity to study hVKORC1 recognition/activation by its redox protein. Additionally, the application of hVKORC1 (membrane protein) in aqueous solution is likely to prove to be very useful in practice in either in silico studies or in vitro experiments.
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17
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Rational design of a helical peptide inhibitor targeting c-Myb–KIX interaction. Sci Rep 2022; 12:816. [PMID: 35058484 PMCID: PMC8776815 DOI: 10.1038/s41598-021-04497-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 12/22/2021] [Indexed: 01/05/2023] Open
Abstract
The transcription factor c-Myb promotes the proliferation of hematopoietic cells by interacting with the KIX domain of CREB-binding protein; however, its aberrant expression causes leukemia. Therefore, inhibitors of the c-Myb–KIX interaction are potentially useful as antitumor drugs. Since the intrinsically disordered transactivation domain (TAD) of c-Myb binds KIX via a conformational selection mechanism where helix formation precedes binding, stabilizing the helical structure of c-Myb TAD is expected to increase the KIX-binding affinity. Here, to develop an inhibitor of the c-Myb–KIX interaction, we designed mutants of the c-Myb TAD peptide fragment where the helical structure is stabilized, based on theoretical predictions using AGADIR. Three of the four initially designed peptides each had a different Lys-to-Arg substitution on the helix surface opposite the KIX-binding interface. Furthermore, the triple mutant with three Lys-to-Arg substitutions, named RRR, showed a high helical propensity and achieved three-fold higher affinity to KIX than the wild-type TAD with a dissociation constant of 80 nM. Moreover, the RRR inhibitor efficiently competed out the c-Myb–KIX interaction. These results suggest that stabilizing the helical structure based on theoretical predictions, especially by conservative Lys-to-Arg substitutions, is a simple and useful strategy for designing helical peptide inhibitors of protein–protein interactions.
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18
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Sharma N, Gadhave K, Kumar P, Giri R. Transactivation domain of Adenovirus Early Region 1A (E1A): Investigating folding dynamics and aggregation. Curr Res Struct Biol 2022; 4:29-40. [PMID: 35146445 PMCID: PMC8801969 DOI: 10.1016/j.crstbi.2022.01.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 12/05/2021] [Accepted: 01/04/2022] [Indexed: 02/06/2023] Open
Abstract
Transactivation domain of Adenovirus Early region 1A (E1A) oncoprotein is an intrinsically disordered molecular hub protein. It is involved in binding to different domains of human cell transcriptional co-activators such as retinoblastoma (pRb), CREB-binding protein (CBP), and its paralogue p300. The conserved region 1 (TAD) of E1A is known to undergo structural transitions and folds upon interaction with transcriptional adaptor zinc finger 2 (TAZ2). Previous reports on Taz2-E1A studies have suggested the formation of helical conformations of E1A-TAD. However, the folding behavior of the TAD region in isolation has not been studied in detail. Here, we have elucidated the folding behavior of E1A peptide at varied temperatures and solution conditions. Further, we have studied the effects of macromolecular crowding on E1A-TAD peptide. Additionally, we have also predicted the molecular recognition features of E1A using MoRF predictors. The predicted MoRFs are consistent with its structural transitions observed during TAZ2 interactions for transcriptional regulation in literature. Also, as a general rule of MoRFs, E1A undergoes helical transitions in alcohol and osmolyte solution. Finally, we studied the aggregation behavior of E1A, where we observed that the E1A could form amyloid-like aggregates that are cytotoxic to mammalian cells.
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Affiliation(s)
- Nitin Sharma
- School of Basic Sciences, Indian Institute of Technology Mandi, Kamand, Himachal Pradesh, 175005, India
| | - Kundlik Gadhave
- School of Basic Sciences, Indian Institute of Technology Mandi, Kamand, Himachal Pradesh, 175005, India
| | - Prateek Kumar
- School of Basic Sciences, Indian Institute of Technology Mandi, Kamand, Himachal Pradesh, 175005, India
| | - Rajanish Giri
- School of Basic Sciences, Indian Institute of Technology Mandi, Kamand, Himachal Pradesh, 175005, India
- BioX Center, Indian Institute of Technology Mandi, Kamand, Himachal Pradesh, 175005, India
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19
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Molecular Simulations of Intrinsically Disordered Proteins and Their Binding Mechanisms. Methods Mol Biol 2022; 2376:343-362. [PMID: 34845619 DOI: 10.1007/978-1-0716-1716-8_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Intrinsically disordered proteins (IDPs) lack well-defined secondary or tertiary structures in solution but are found to be involved in a wide range of critical cellular processes that highlight their functional importance. IDPs usually undergo folding upon binding to their targets. Such binding coupled to folding behavior has widened our perspective on the protein structure-dynamics-function paradigm in molecular biology. However, characterizing the folding upon binding mechanism of IDPs experimentally remains quite challenging. Molecular simulations emerge as a potentially powerful tool that offers information complementary to experiments. Here we present a general computational framework for the molecular simulations of IDP folding upon binding processes that combines all-atom molecular dynamics (MD) and coarse-grained simulations. The classical all-atom molecular dynamics approach using GPU acceleration allows the researcher to explore the properties of the IDP conformational ensemble, whereas coarse-grained structure-based models implemented with parameters carefully calibrated to available experimental measurements can be used to simulate the entire folding upon binding process. We also discuss a set of tools for the analysis of MD trajectories and describe the details of the computational protocol to follow so that it can be adapted by the user to study any IDP in isolation and in complex with partners.
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20
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Malagrinò F, Diop A, Pagano L, Nardella C, Toto A, Gianni S. Unveiling induced folding of intrinsically disordered proteins - Protein engineering, frustration and emerging themes. Curr Opin Struct Biol 2021; 72:153-160. [PMID: 34902817 DOI: 10.1016/j.sbi.2021.11.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 10/26/2021] [Accepted: 11/01/2021] [Indexed: 01/01/2023]
Abstract
Intrinsically disordered proteins (IDPs) can be generally described as a class of proteins that lack a well-defined ordered structure in isolation at physiological conditions. Upon binding to their physiological ligands, IDPs typically undergo a disorder-to-order transition, which may or may not lead to the complete folding of the IDP. In this short review, we focus on some of the key findings pertaining to the mechanisms of such induced folding. In particular, first we describe the general features of the reaction; then, we discuss some of the most remarkable findings obtained from applying protein engineering in synergy with kinetic studies to induced folding; and finally, we offer a critical view on some of the emerging themes when considering the structural heterogeneity of IDPs vis-à-vis to their inherent frustration.
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Affiliation(s)
- Francesca Malagrinò
- Istituto Pasteur, Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche "A. Rossi Fanelli" and Istituto di Biologia e Patologia Molecolari Del CNR, Sapienza Università, di Roma, 00185, Rome, Italy
| | - Awa Diop
- Istituto Pasteur, Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche "A. Rossi Fanelli" and Istituto di Biologia e Patologia Molecolari Del CNR, Sapienza Università, di Roma, 00185, Rome, Italy
| | - Livia Pagano
- Istituto Pasteur, Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche "A. Rossi Fanelli" and Istituto di Biologia e Patologia Molecolari Del CNR, Sapienza Università, di Roma, 00185, Rome, Italy
| | - Caterina Nardella
- Istituto Pasteur, Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche "A. Rossi Fanelli" and Istituto di Biologia e Patologia Molecolari Del CNR, Sapienza Università, di Roma, 00185, Rome, Italy
| | - Angelo Toto
- Istituto Pasteur, Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche "A. Rossi Fanelli" and Istituto di Biologia e Patologia Molecolari Del CNR, Sapienza Università, di Roma, 00185, Rome, Italy.
| | - Stefano Gianni
- Istituto Pasteur, Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche "A. Rossi Fanelli" and Istituto di Biologia e Patologia Molecolari Del CNR, Sapienza Università, di Roma, 00185, Rome, Italy.
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21
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Emperador A. Accurate Description of Protein-Protein Recognition and Protein Aggregation with the Implicit-Solvent-Based PACSAB Protein Model. Polymers (Basel) 2021; 13:polym13234172. [PMID: 34883675 PMCID: PMC8659885 DOI: 10.3390/polym13234172] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 11/12/2021] [Accepted: 11/18/2021] [Indexed: 02/01/2023] Open
Abstract
We used the PACSAB protein model, based on the implicit solvation approach, to simulate protein–protein recognition and study the effect of helical structure on the association of aggregating peptides. After optimization, the PACSAB force field was able to reproduce correctly both the correct binding interface in ubiquitin dimerization and the conformational ensemble of the disordered protein activator for hormone and retinoid receptor (ACTR). The PACSAB model allowed us to predict the native binding of ACTR with its binding partner, reproducing the refolding upon binding mechanism of the disordered protein.
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Affiliation(s)
- Agustí Emperador
- Department of Physics, Universitat Politècnica de Catalunya, B4-B5 Campus Nord, Jordi Girona 1-3, 08034 Barcelona, Spain
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22
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Prieto VA, Namitz KEW, Showalter SA. Transient Electrostatic Interactions between Fcp1 and Rap74 Bias the Conformational Ensemble of the Complex with Minimal Impact on Binding Affinity. J Phys Chem B 2021; 125:10917-10927. [PMID: 34550709 DOI: 10.1021/acs.jpcb.1c05131] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Intrinsically disordered protein (IDP) sequences often contain a high proportion of charged residues in conjunction with their high degree of hydrophilicity and solvation. For high net charge IDPs, long-range electrostatic interactions are thought to play a role in modulating the strength or kinetics of protein-protein interactions. In this work, we examined intramolecular interactions mediated by charged regions of a model IDP, the C-terminal tail of the phosphatase Fcp1. Specifically, this work focuses on intermolecular interactions between acidic and basic patches in the primary structure of Fcp1 and their contributions to binding its predominantly basic partner, the winged helix domain of Rap74. We observe both intramolecular and intermolecular interactions through paramagnetic relaxation enhancement (PRE) consistent with oppositely charged regions associating with one another, both in unbound Fcp1 and in the Fcp1-Rap74 complex. Formation of this complex is strongly driven by hydrophobic interactions in the minimal binding motif. Here, we test the hypothesis that charged residues in Fcp1 that flank the binding helix also contribute to the strength of binding. Charge inversion mutations in Fcp1 generally support this hypothesis, while PRE data suggest substitution of observed transient interactions in the unbound ensemble for similarly transient interactions with Rap74 in the complex.
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Affiliation(s)
- Victor A Prieto
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Kevin E W Namitz
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Scott A Showalter
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.,Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
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23
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The sequence-ensemble relationship in fuzzy protein complexes. Proc Natl Acad Sci U S A 2021; 118:2020562118. [PMID: 34504009 DOI: 10.1073/pnas.2020562118] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/11/2021] [Indexed: 11/18/2022] Open
Abstract
Intrinsically disordered proteins (IDPs) interact with globular proteins through a variety of mechanisms, resulting in the structurally heterogeneous ensembles known as fuzzy complexes. While there exists a reasonable comprehension on how IDP sequence determines the unbound IDP ensemble, little is known about what shapes the structural characteristics of IDPs bound to their targets. Using a statistical thermodynamic model, we show that the target-bound ensembles are determined by a simple code that combines the IDP sequence and the distribution of IDP-target interaction hotspots. These two parameters define the conformational space of target-bound IDPs and rationalize the observed structural heterogeneity of fuzzy complexes. The presented model successfully reproduces the dynamical signatures of target-bound IDPs from the NMR relaxation experiments as well as the changes of interaction affinity and the IDP helicity induced by mutations. The model explains how the target-bound IDP ensemble adapts to mutations in order to achieve an optimal balance between conformational freedom and interaction energy. Taken together, the presented sequence-ensemble relationship of fuzzy complexes explains the different manifestations of IDP disorder in folding-upon-binding processes.
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24
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Lindorff-Larsen K, Kragelund BB. On the potential of machine learning to examine the relationship between sequence, structure, dynamics and function of intrinsically disordered proteins. J Mol Biol 2021; 433:167196. [PMID: 34390736 DOI: 10.1016/j.jmb.2021.167196] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 08/03/2021] [Accepted: 08/04/2021] [Indexed: 11/29/2022]
Abstract
Intrinsically disordered proteins (IDPs) constitute a broad set of proteins with few uniting and many diverging properties. IDPs-and intrinsically disordered regions (IDRs) interspersed between folded domains-are generally characterized as having no persistent tertiary structure; instead they interconvert between a large number of different and often expanded structures. IDPs and IDRs are involved in an enormously wide range of biological functions and reveal novel mechanisms of interactions, and while they defy the common structure-function paradigm of folded proteins, their structural preferences and dynamics are important for their function. We here discuss open questions in the field of IDPs and IDRs, focusing on areas where machine learning and other computational methods play a role. We discuss computational methods aimed to predict transiently formed local and long-range structure, including methods for integrative structural biology. We discuss the many different ways in which IDPs and IDRs can bind to other molecules, both via short linear motifs, as well as in the formation of larger dynamic complexes such as biomolecular condensates. We discuss how experiments are providing insight into such complexes and may enable more accurate predictions. Finally, we discuss the role of IDPs in disease and how new methods are needed to interpret the mechanistic effects of genomic variants in IDPs.
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Affiliation(s)
- Kresten Lindorff-Larsen
- Structural Biology and NMR Laboratory & Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen. Ole Maaløes Vej 5, DK-2200 Copenhagen N, Denmark.
| | - Birthe B Kragelund
- Structural Biology and NMR Laboratory & Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen. Ole Maaløes Vej 5, DK-2200 Copenhagen N, Denmark.
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25
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Jensen TMT, Bartling CRO, Karlsson OA, Åberg E, Haugaard-Kedström LM, Strømgaard K, Jemth P. Molecular Details of a Coupled Binding and Folding Reaction between the Amyloid Precursor Protein and a Folded Domain. ACS Chem Biol 2021; 16:1191-1200. [PMID: 34161732 PMCID: PMC8291497 DOI: 10.1021/acschembio.1c00176] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
![]()
Intrinsically disordered
regions in proteins often function as
binding motifs in protein–protein interactions. The mechanistic
aspects and molecular details of such coupled binding and folding
reactions, which involve formation of multiple noncovalent bonds,
have been broadly studied theoretically, but experimental data are
scarce. Here, using a combination of protein semisynthesis to incorporate
phosphorylated amino acids, backbone amide-to-ester modifications,
side chain substitutions, and binding kinetics, we examined the interaction
between the intrinsically disordered motif of amyloid precursor protein
(APP) and the phosphotyrosine binding (PTB) domain of Mint2. We show
that the interaction is regulated by a self-inhibitory segment of
the PTB domain previously termed ARM. The helical ARM linker decreases
the association rate constant 30-fold through a fast pre-equilibrium
between an open and a closed state. Extensive side chain substitutions
combined with kinetic experiments demonstrate that the rate-limiting
transition state for the binding reaction is governed by native and
non-native hydrophobic interactions and hydrogen bonds. Hydrophobic
interactions were found to be particularly important during crossing
of the transition state barrier. Furthermore, linear free energy relationships
show that the overall coupled binding and folding reaction involves
cooperative formation of interactions with roughly 30% native contacts
formed at the transition state. Our data support an emerging picture
of coupled binding and folding reactions following overall chemical
principles similar to those of folding of globular protein domains
but with greater malleability of ground and transition states.
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Affiliation(s)
- Thomas M. T. Jensen
- Center for Biopharmaceuticals, Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 162, 2100 Copenhagen, Denmark
- Department of Medical Biochemistry and Microbiology, Uppsala University, BMC, Box 582, SE-75123 Uppsala, Sweden
| | - Christian R. O. Bartling
- Center for Biopharmaceuticals, Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 162, 2100 Copenhagen, Denmark
| | - O. Andreas Karlsson
- Department of Medical Biochemistry and Microbiology, Uppsala University, BMC, Box 582, SE-75123 Uppsala, Sweden
| | - Emma Åberg
- Department of Medical Biochemistry and Microbiology, Uppsala University, BMC, Box 582, SE-75123 Uppsala, Sweden
| | - Linda M. Haugaard-Kedström
- Center for Biopharmaceuticals, Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 162, 2100 Copenhagen, Denmark
| | - Kristian Strømgaard
- Center for Biopharmaceuticals, Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 162, 2100 Copenhagen, Denmark
| | - Per Jemth
- Department of Medical Biochemistry and Microbiology, Uppsala University, BMC, Box 582, SE-75123 Uppsala, Sweden
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26
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Gao M, Han Y, Zeng Y, Su Z, Huang Y. Introducing intrinsic disorder reduces electrostatic steering in protein-protein interactions. Biophys J 2021; 120:2998-3007. [PMID: 34214536 DOI: 10.1016/j.bpj.2021.06.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 04/03/2021] [Accepted: 06/17/2021] [Indexed: 02/05/2023] Open
Abstract
Protein-protein interactions underlie many critical biology functions, such as cellular signaling and gene expression, in which electrostatic interactions can play a critical role in mediating the specificity and stability of protein complexes. A substantial portion of proteins are intrinsically disordered, and the influences of structural disorder on binding kinetics and thermodynamics have been widely investigated. However, whether the effect of electrostatic steering depends on structural disorder remains unexplored. In this work, we addressed the consequence of introducing intrinsic disorder in the electrostatic steering of the E3/Im3 complex using molecular dynamics simulation. Our results recapitulated the experimental observations that the responses of stability and kinetics to salt concentration for the ordered E3/Im3 complex were larger than those for the disordered E3/Im3 complex. Mechanistic analysis revealed that the native contact interactions involved in the encounter state and the transition state were essentially identical for both ordered and disordered E3. Therefore, the observed difference in electrostatic steering between ordered E3 and disordered E3 may result from their difference in conformation rather than their difference in binding mechanism. Because charged residues are frequently involved in protein-protein interactions, our results suggest that increasing structural disorder is expected to generally modulate the effect of electrostatic steering.
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Affiliation(s)
- Meng Gao
- Key Laboratory of Industrial Fermentation, Ministry of Education, Wuhan, China; Hubei Key Laboratory of Industrial Microbiology, Department of Biological Engineering, Wuhan, China; National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, China
| | - Yue Han
- Key Laboratory of Industrial Fermentation, Ministry of Education, Wuhan, China; Hubei Key Laboratory of Industrial Microbiology, Department of Biological Engineering, Wuhan, China; National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, China
| | - Yifan Zeng
- Key Laboratory of Industrial Fermentation, Ministry of Education, Wuhan, China; Hubei Key Laboratory of Industrial Microbiology, Department of Biological Engineering, Wuhan, China; National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, China
| | - Zhengding Su
- Key Laboratory of Industrial Fermentation, Ministry of Education, Wuhan, China; Hubei Key Laboratory of Industrial Microbiology, Department of Biological Engineering, Wuhan, China; National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, China
| | - Yongqi Huang
- Key Laboratory of Industrial Fermentation, Ministry of Education, Wuhan, China; Hubei Key Laboratory of Industrial Microbiology, Department of Biological Engineering, Wuhan, China; National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, China.
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27
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On the specificity of protein-protein interactions in the context of disorder. Biochem J 2021; 478:2035-2050. [PMID: 34101805 PMCID: PMC8203207 DOI: 10.1042/bcj20200828] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 05/14/2021] [Accepted: 05/17/2021] [Indexed: 02/07/2023]
Abstract
With the increased focus on intrinsically disordered proteins (IDPs) and their large interactomes, the question about their specificity — or more so on their multispecificity — arise. Here we recapitulate how specificity and multispecificity are quantified and address through examples if IDPs in this respect differ from globular proteins. The conclusion is that quantitatively, globular proteins and IDPs are similar when it comes to specificity. However, compared with globular proteins, IDPs have larger interactome sizes, a phenomenon that is further enabled by their flexibility, repetitive binding motifs and propensity to adapt to different binding partners. For IDPs, this adaptability, interactome size and a higher degree of multivalency opens for new interaction mechanisms such as facilitated exchange through trimer formation and ultra-sensitivity via threshold effects and ensemble redistribution. IDPs and their interactions, thus, do not compromise the definition of specificity. Instead, it is the sheer size of their interactomes that complicates its calculation. More importantly, it is this size that challenges how we conceptually envision, interpret and speak about their specificity.
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28
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Glaser M, Bruce NJ, Han SB, Wade RC. Simulation of the Positive Inotropic Peptide S100A1ct in Aqueous Environment by Gaussian Accelerated Molecular Dynamics. J Phys Chem B 2021; 125:4654-4666. [PMID: 33944558 DOI: 10.1021/acs.jpcb.1c00902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The S100A1ct peptide, consisting of the C-terminal 20 residues of the S100A1 protein fused to an N-terminal 6-residue hydrophilic tag, has been found to exert a positive inotropic effect, resulting in improved contractile performance of failing cardiac and skeletal muscle without arrhythmic side-effects. The S100A1ct peptide thus has high potential for the treatment of acute heart failure. As a step toward understanding its molecular mechanism of action, and to provide a basis for peptidomimetic design to optimize its properties, we here describe de novo structure predictions and molecular dynamics simulations to characterize the conformational landscape of S100A1ct in aqueous environment. In S100A1, the C-terminal 20 residues form an α-helix, but de novo peptide structure predictions indicate that other conformations are also possible. Conventional molecular dynamics simulations in implicit and explicit solvent corroborated this finding. To ensure adequate sampling, we performed simulations of a tagged 10-residue segment of S100A1ct, and we carried out Gaussian accelerated molecular dynamics simulations of the peptides. These simulations showed that although the helical conformation of S100A1ct was the most energetically stable, the peptide can adopt a range of kinked conformations, suggesting that its activity may be related to its ability to act as a conformational switch.
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Affiliation(s)
- Manuel Glaser
- Heidelberg Institute for Theoretical Studies (HITS), Schloss-Wolfsbrunnenweg 35, 69118 Heidelberg, Germany.,Informatics for Life, Heidelberg, Germany
| | - Neil J Bruce
- Heidelberg Institute for Theoretical Studies (HITS), Schloss-Wolfsbrunnenweg 35, 69118 Heidelberg, Germany.,Informatics for Life, Heidelberg, Germany
| | - Sungho Bosco Han
- Heidelberg Institute for Theoretical Studies (HITS), Schloss-Wolfsbrunnenweg 35, 69118 Heidelberg, Germany.,Faculty of Biosciences, Heidelberg University, 69120 Heidelberg, Germany
| | - Rebecca C Wade
- Heidelberg Institute for Theoretical Studies (HITS), Schloss-Wolfsbrunnenweg 35, 69118 Heidelberg, Germany.,Informatics for Life, Heidelberg, Germany.,Faculty of Biosciences, Heidelberg University, 69120 Heidelberg, Germany.,Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ-ZMBH Alliance and Interdisciplinary Center for Scientific Computing (IWR), 69120 Heidelberg, Germany
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29
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Karlsson E, Paissoni C, Erkelens AM, Tehranizadeh ZA, Sorgenfrei FA, Andersson E, Ye W, Camilloni C, Jemth P. Mapping the transition state for a binding reaction between ancient intrinsically disordered proteins. J Biol Chem 2021; 295:17698-17712. [PMID: 33454008 PMCID: PMC7762952 DOI: 10.1074/jbc.ra120.015645] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 10/15/2020] [Indexed: 12/24/2022] Open
Abstract
Intrinsically disordered protein domains often have multiple binding partners. It is plausible that the strength of pairing with specific partners evolves from an initial low affinity to a higher affinity. However, little is known about the molecular changes in the binding mechanism that would facilitate such a transition. We previously showed that the interaction between two intrinsically disordered domains, NCBD and CID, likely emerged in an ancestral deuterostome organism as a low-affinity interaction that subsequently evolved into a higher-affinity interaction before the radiation of modern vertebrate groups. Here we map native contacts in the transition states of the low-affinity ancestral and high-affinity human NCBD/CID interactions. We show that the coupled binding and folding mechanism is overall similar but with a higher degree of native hydrophobic contact formation in the transition state of the ancestral complex and more heterogeneous transient interactions, including electrostatic pairings, and an increased disorder for the human complex. Adaptation to new binding partners may be facilitated by this ability to exploit multiple alternative transient interactions while retaining the overall binding and folding pathway.
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Affiliation(s)
- Elin Karlsson
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Cristina Paissoni
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milano, Italy
| | - Amanda M Erkelens
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Zeinab A Tehranizadeh
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden; Department of Medicinal Chemistry, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Frieda A Sorgenfrei
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Eva Andersson
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Weihua Ye
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Carlo Camilloni
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milano, Italy.
| | - Per Jemth
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden.
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30
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Staby L, Bugge K, Falbe-Hansen RG, Salladini E, Skriver K, Kragelund BB. Connecting the αα-hubs: same fold, disordered ligands, new functions. Cell Commun Signal 2021; 19:2. [PMID: 33407551 PMCID: PMC7788954 DOI: 10.1186/s12964-020-00686-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 11/18/2020] [Indexed: 11/25/2022] Open
Abstract
Background Signal fidelity depends on protein–protein interaction–‘hubs’ integrating cues from large interactomes. Recently, and based on a common secondary structure motif, the αα-hubs were defined, which are small α-helical domains of large, modular proteins binding intrinsically disordered transcriptional regulators.
Methods Comparative structural biology. Results We assign the harmonin-homology-domain (HHD, also named the harmonin N-terminal domain, NTD) present in large proteins such as harmonin, whirlin, cerebral cavernous malformation 2, and regulator of telomere elongation 1 to the αα-hubs. The new member of the αα-hubs expands functionality to include scaffolding of supra-modular complexes mediating sensory perception, neurovascular integrity and telomere regulation, and reveal novel features of the αα-hubs. As a common trait, the αα-hubs bind intrinsically disordered ligands of similar properties integrating similar cellular cues, but without cross-talk. Conclusion The inclusion of the HHD in the αα-hubs has uncovered new features, exemplifying the utility of identifying groups of hub domains, whereby discoveries in one member may cross-fertilize discoveries in others. These features make the αα-hubs unique models for decomposing signal specificity and fidelity. Using these as models, together with other suitable hub domain, we may advance the functional understanding of hub proteins and their role in cellular communication and signaling, as well as the role of intrinsically disordered proteins in signaling networks. Video Abstract
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Affiliation(s)
- Lasse Staby
- REPIN, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Katrine Bugge
- REPIN, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | | | - Edoardo Salladini
- REPIN, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Karen Skriver
- REPIN, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
| | - Birthe B Kragelund
- REPIN, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
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31
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Bugge K, Staby L, Salladini E, Falbe-Hansen RG, Kragelund BB, Skriver K. αα-Hub domains and intrinsically disordered proteins: A decisive combo. J Biol Chem 2021; 296:100226. [PMID: 33361159 PMCID: PMC7948954 DOI: 10.1074/jbc.rev120.012928] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 12/22/2020] [Accepted: 12/22/2020] [Indexed: 01/02/2023] Open
Abstract
Hub proteins are central nodes in protein-protein interaction networks with critical importance to all living organisms. Recently, a new group of folded hub domains, the αα-hubs, was defined based on a shared αα-hairpin supersecondary structural foundation. The members PAH, RST, TAFH, NCBD, and HHD are found in large proteins such as Sin3, RCD1, TAF4, CBP, and harmonin, which organize disordered transcriptional regulators and membrane scaffolds in interactomes of importance to human diseases and plant quality. In this review, studies of structures, functions, and complexes across the αα-hubs are described and compared to provide a unified description of the group. This analysis expands the associated molecular concepts of "one domain-one binding site", motif-based ligand binding, and coupled folding and binding of intrinsically disordered ligands to additional concepts of importance to signal fidelity. These include context, motif reversibility, multivalency, complex heterogeneity, synergistic αα-hub:ligand folding, accessory binding sites, and supramodules. We propose that these multifaceted protein-protein interaction properties are made possible by the characteristics of the αα-hub fold, including supersite properties, dynamics, variable topologies, accessory helices, and malleability and abetted by adaptability of the disordered ligands. Critically, these features provide additional filters for specificity. With the presentations of new concepts, this review opens for new research questions addressing properties across the group, which are driven from concepts discovered in studies of the individual members. Combined, the members of the αα-hubs are ideal models for deconvoluting signal fidelity maintained by folded hubs and their interactions with intrinsically disordered ligands.
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Affiliation(s)
- Katrine Bugge
- REPIN and The Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark; Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Lasse Staby
- REPIN and The Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark; Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Edoardo Salladini
- REPIN and The Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Rasmus G Falbe-Hansen
- REPIN and The Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Birthe B Kragelund
- REPIN and The Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark; Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
| | - Karen Skriver
- REPIN and The Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
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32
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Kakeshpour T, Ramanujam V, Barnes CA, Shen Y, Ying J, Bax A. A lowly populated, transient β-sheet structure in monomeric Aβ 1-42 identified by multinuclear NMR of chemical denaturation. Biophys Chem 2020; 270:106531. [PMID: 33453683 DOI: 10.1016/j.bpc.2020.106531] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 12/08/2020] [Accepted: 12/13/2020] [Indexed: 02/07/2023]
Abstract
Chemical denaturation is a well-established approach for probing the equilibrium between folded and unfolded states of proteins. We demonstrate applicability of this method to the detection of a small population of a transiently folded structural element in a system that is often considered to be intrinsically fully disordered. The 1HN, 15N, 13Cα, and 13C' chemical shifts of Aβ1-40 and Aβ1-42 peptides and their M35-oxidized variants were monitored as a function of urea concentration and compared to analogous urea titrations of synthetic pentapeptides of homologous sequence. Fitting of the chemical shift titrations yields a 10 ± 1% population for a structured element at the C-terminus of Aβ1-42 that folds with a cooperativity of m = 0.06 kcal/mol·M. The fit also yields the chemical shifts of the folded state and, using a database search, for Aβ1-42 these shifts identified an antiparallel intramolecular β-sheet for residues I32-A42, linked by a type I' β-turn at G37 and G38. The structure is destabilized by oxidation of M35. Paramagnetic relaxation rates and two previously reported weak, medium-range NOE interactions are consistent with this transient β-sheet. Introduction of the requisite A42C mutation and tagging with MTSL resulted in a small stabilization of this β-sheet. Chemical shift analysis suggests a C-terminal β-sheet may be present in Aβ1-40 too, but the turn type at G37 is not type I'. The approach to derive Transient Structure from chemical Denaturation by NMR (TSD-NMR), demonstrated here for Aβ peptides, provides a sensitive tool for identifying the presence of lowly populated, transiently ordered elements in proteins that are considered to be intrinsically disordered, and permits extraction of structural data for such elements.
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Affiliation(s)
- Tayeb Kakeshpour
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA
| | - Venkat Ramanujam
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA
| | - C Ashley Barnes
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA
| | - Yang Shen
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA
| | - Jinfa Ying
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA
| | - Ad Bax
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA.
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33
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Dixit K, Karanth NM, Nair S, Kumari K, Chakrabarti KS, Savithri HS, Sarma SP. Aromatic Interactions Drive the Coupled Folding and Binding of the Intrinsically Disordered Sesbania mosaic Virus VPg Protein. Biochemistry 2020; 59:4663-4680. [PMID: 33269926 DOI: 10.1021/acs.biochem.0c00721] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The plant Sesbania mosaic virus [a (+)-ssRNA sobemovirus] VPg protein is intrinsically disordered in solution. For the virus life cycle, the VPg protein is essential for replication and for polyprotein processing that is carried out by a virus-encoded protease. The nuclear magnetic resonance (NMR)-derived tertiary structure of the protease-bound VPg shows it to have a novel tertiary structure with an α-β-β-β topology. The quaternary structure of the high-affinity protease-VPg complex (≈27 kDa) has been determined using HADDOCK protocols with NMR (residual dipolar coupling, dihedral angle, and nuclear Overhauser enhancement) restraints and mutagenesis data as inputs. The geometry of the complex is in excellent agreement with long-range orientational restraints such as residual dipolar couplings and ring-current shifts. A "vein" of aromatic residues on the protease surface is pivotal for the folding of VPg via intermolecular edge-to-face π···π stacking between Trp271 and Trp368 of the protease and VPg, respectively, and for the CH···π interactions between Leu361 of VPg and Trp271 of the protease. The structure of the protease-VPg complex provides a molecular framework for predicting sites of important posttranslational modifications such as RNA linkage and phosphorylation and a better understanding of the coupled folding upon binding of intrinsically disordered proteins. The structural data presented here augment the limited structural data available on viral proteins, given their propensity for structural disorder.
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Affiliation(s)
- Karuna Dixit
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka 560012, India
| | - N Megha Karanth
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka 560012, India
| | - Smita Nair
- Department of Biochemistry, Indian Institute of Science, Bangalore, Karnataka 560012, India
| | - Khushboo Kumari
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka 560012, India
| | | | - Handanahal S Savithri
- Department of Biochemistry, Indian Institute of Science, Bangalore, Karnataka 560012, India
| | - Siddhartha P Sarma
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka 560012, India
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34
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Miyazono KI, Ito T, Fukatsu Y, Wada H, Kurisaki A, Tanokura M. Structural basis for transcriptional coactivator recognition by SMAD2 in TGF-β signaling. Sci Signal 2020; 13:13/662/eabb9043. [PMID: 33323411 DOI: 10.1126/scisignal.abb9043] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Transforming growth factor-β (TGF-β) proteins regulate multiple cellular functions, including cell proliferation, apoptosis, and extracellular matrix formation. The dysregulation of TGF-β signaling causes diseases such as cancer and fibrosis, and therefore, understanding the biochemical basis of TGF-β signal transduction is important for elucidating pathogenic mechanisms in these diseases. SMAD proteins are transcription factors that mediate TGF-β signaling-dependent gene expression. The transcriptional coactivator CBP directly interacts with the MH2 domains of SMAD2 to activate SMAD complex-dependent gene expression. Here, we report the structural basis for CBP recognition by SMAD2. The crystal structures of the SMAD2 MH2 domain in complex with the SMAD2-binding region of CBP showed that CBP forms an amphiphilic helix on the hydrophobic surface of SMAD2. The expression of a mutated CBP peptide that showed increased SMAD2 binding repressed SMAD2-dependent gene expression in response to TGF-β signaling in cultured cells. Disrupting the interaction between SMAD2 and CBP may therefore be a promising strategy for suppressing SMAD-dependent gene expression.
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Affiliation(s)
- Ken-Ichi Miyazono
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | - Tomoko Ito
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | - Yui Fukatsu
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Nara 630-0192, Japan
| | - Hikaru Wada
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | - Akira Kurisaki
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Nara 630-0192, Japan
| | - Masaru Tanokura
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan.
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35
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Bauer V, Schmidtgall B, Gógl G, Dolenc J, Osz J, Nominé Y, Kostmann C, Cousido-Siah A, Mitschler A, Rochel N, Travé G, Kieffer B, Torbeev V. Conformational editing of intrinsically disordered protein by α-methylation. Chem Sci 2020; 12:1080-1089. [PMID: 34163874 PMCID: PMC8178997 DOI: 10.1039/d0sc04482b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Intrinsically disordered proteins (IDPs) constitute a large portion of “Dark Proteome” – difficult to characterize or yet to be discovered protein structures. Here we used conformationally constrained α-methylated amino acids to bias the conformational ensemble in the free unstructured activation domain of transcriptional coactivator ACTR. Different sites and patterns of substitutions were enabled by chemical protein synthesis and led to distinct populations of α-helices. A specific substitution pattern resulted in a substantially higher binding affinity to nuclear coactivator binding domain (NCBD) of CREB-binding protein, a natural binding partner of ACTR. The first X-ray structure of the modified ACTR domain - NCBD complex visualized a unique conformation of ACTR and confirmed that the key α-methylated amino acids are localized within α-helices in the bound state. This study demonstrates a strategy for characterization of individual conformational states of IDPs. Control of protein conformation was achieved for intrinsically disordered protein by incorporation of α-methylated amino acids.![]()
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Affiliation(s)
- Valentin Bauer
- Institut de Science et d'Ingénierie Supramoléculaires (ISIS), International Center for Frontier Research in Chemistry (icFRC), University of Strasbourg, CNRS, UMR 7006 Strasbourg France
| | - Boris Schmidtgall
- Institut de Science et d'Ingénierie Supramoléculaires (ISIS), International Center for Frontier Research in Chemistry (icFRC), University of Strasbourg, CNRS, UMR 7006 Strasbourg France
| | - Gergő Gógl
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM (U1258), University of Strasbourg, CNRS, UMR 7104 Illkirch France.,Équipe Labellisée Ligue contre le cancer France
| | - Jozica Dolenc
- Chemistry
- Biology
- Pharmacy Information Center, ETH Zurich Zurich Switzerland
| | - Judit Osz
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM (U1258), University of Strasbourg, CNRS, UMR 7104 Illkirch France
| | - Yves Nominé
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM (U1258), University of Strasbourg, CNRS, UMR 7104 Illkirch France.,Équipe Labellisée Ligue contre le cancer France
| | - Camille Kostmann
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM (U1258), University of Strasbourg, CNRS, UMR 7104 Illkirch France.,Équipe Labellisée Ligue contre le cancer France
| | - Alexandra Cousido-Siah
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM (U1258), University of Strasbourg, CNRS, UMR 7104 Illkirch France.,Équipe Labellisée Ligue contre le cancer France
| | - André Mitschler
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM (U1258), University of Strasbourg, CNRS, UMR 7104 Illkirch France.,Équipe Labellisée Ligue contre le cancer France
| | - Natacha Rochel
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM (U1258), University of Strasbourg, CNRS, UMR 7104 Illkirch France
| | - Gilles Travé
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM (U1258), University of Strasbourg, CNRS, UMR 7104 Illkirch France.,Équipe Labellisée Ligue contre le cancer France
| | - Bruno Kieffer
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM (U1258), University of Strasbourg, CNRS, UMR 7104 Illkirch France
| | - Vladimir Torbeev
- Institut de Science et d'Ingénierie Supramoléculaires (ISIS), International Center for Frontier Research in Chemistry (icFRC), University of Strasbourg, CNRS, UMR 7006 Strasbourg France
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36
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Gianni S, Jemth P. Affinity versus specificity in coupled binding and folding reactions. Protein Eng Des Sel 2020; 32:355-357. [PMID: 31397874 DOI: 10.1093/protein/gzz020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 06/17/2019] [Accepted: 07/04/2019] [Indexed: 01/08/2023] Open
Abstract
Intrinsically disordered protein regions may fold upon binding to an interaction partner. It is often argued that such coupled binding and folding enables the combination of high specificity with low affinity. The basic tenet is that an unfavorable folding equilibrium will make the overall binding weaker while maintaining the interaction interface. While theoretically solid, we argue that this concept may be misleading for intrinsically disordered proteins. In fact, experimental evidence suggests that interactions of disordered regions usually involve extended conformations. In such cases, the disordered region is exceptionally unlikely to fold into a bound conformation in the absence of its binding partner. Instead, these disordered regions can bind to their partners in multiple different conformations and then fold into the native bound complex, thus, if anything, increasing the affinity through folding. We concede that (de)stabilization of native structural elements such as helices will modulate affinity, but this could work both ways, decreasing or increasing the stability of the complex. Moreover, experimental data show that intrinsically disordered binding regions display a range of affinities and specificities dictated by the particular side chains and length of the disordered region and not necessarily by the fact that they are disordered. We find it more likely that intrinsically disordered regions are common in protein-protein interactions because they increase the repertoire of binding partners, providing an accessible route to evolve interactions rather than providing a stability-affinity trade-off.
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Affiliation(s)
- Stefano Gianni
- Dipartimento di Scienze Biochimiche "A. Rossi Fanelli", Istituto Pasteur-Fondazione Cenci Bolognetti and Istituto di Biologia e Patologia Molecolari del CNR, Sapienza Università di Roma, Rome 00185, Italy
| | - Per Jemth
- Department of Medical Biochemistry and Microbiology, Uppsala University, BMC, Box 582, SE-75123 Uppsala, Sweden
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37
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Rogers JM. Peptide Folding and Binding Probed by Systematic Non-canonical Mutagenesis. Front Mol Biosci 2020; 7:100. [PMID: 32671094 PMCID: PMC7326784 DOI: 10.3389/fmolb.2020.00100] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 05/04/2020] [Indexed: 12/20/2022] Open
Abstract
Many proteins and peptides fold upon binding another protein. Mutagenesis has proved an essential tool in the study of these multi-step molecular recognition processes. By comparing the biophysical behavior of carefully selected mutants, the concert of interactions and conformational changes that occur during folding and binding can be separated and assessed. Recently, this mutagenesis approach has been radically expanded by deep mutational scanning methods, which allow for many thousands of mutations to be examined in parallel. Furthermore, these high-throughput mutagenesis methods have been expanded to include mutations to non-canonical amino acids, returning peptide structure-activity relationships with unprecedented depth and detail. These developments are timely, as the insights they provide can guide the optimization of de novo cyclic peptides, a promising new modality for chemical probes and therapeutic agents.
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Affiliation(s)
- Joseph M Rogers
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
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38
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Bugge K, Brakti I, Fernandes CB, Dreier JE, Lundsgaard JE, Olsen JG, Skriver K, Kragelund BB. Interactions by Disorder - A Matter of Context. Front Mol Biosci 2020; 7:110. [PMID: 32613009 PMCID: PMC7308724 DOI: 10.3389/fmolb.2020.00110] [Citation(s) in RCA: 101] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 05/11/2020] [Indexed: 12/15/2022] Open
Abstract
Living organisms depend on timely and organized interactions between proteins linked in interactomes of high complexity. The recent increased precision by which protein interactions can be studied, and the enclosure of intrinsic structural disorder, suggest that it is time to zoom out and embrace protein interactions beyond the most central points of physical encounter. The present paper discusses protein-protein interactions in the view of structural disorder with an emphasis on flanking regions and contexts of disorder-based interactions. Context constitutes an overarching concept being of physicochemical, biomolecular, and physiological nature, but it also includes the immediate molecular context of the interaction. For intrinsically disordered proteins, which often function by exploiting short linear motifs, context contributes in highly regulatory and decisive manners and constitute a yet largely unrecognized source of interaction potential in a multitude of biological processes. Through selected examples, this review emphasizes how multivalency, charges and charge clusters, hydrophobic patches, dynamics, energetic frustration, and ensemble redistribution of flanking regions or disordered contexts are emerging as important contributors to allosteric regulation, positive and negative cooperativity, feedback regulation and negative selection in binding. The review emphasizes that understanding context, and in particular the role the molecular disordered context and flanking regions take on in protein interactions, constitute an untapped well of energetic modulation potential, also of relevance to drug discovery and development.
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Affiliation(s)
- Katrine Bugge
- REPIN, Department of Biology, University of Copenhagen, Copenhagen, Denmark
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Inna Brakti
- REPIN, Department of Biology, University of Copenhagen, Copenhagen, Denmark
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Catarina B. Fernandes
- REPIN, Department of Biology, University of Copenhagen, Copenhagen, Denmark
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Jesper E. Dreier
- REPIN, Department of Biology, University of Copenhagen, Copenhagen, Denmark
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Jeppe E. Lundsgaard
- REPIN, Department of Biology, University of Copenhagen, Copenhagen, Denmark
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Johan G. Olsen
- REPIN, Department of Biology, University of Copenhagen, Copenhagen, Denmark
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Karen Skriver
- REPIN, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Birthe B. Kragelund
- REPIN, Department of Biology, University of Copenhagen, Copenhagen, Denmark
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Copenhagen, Denmark
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Malagrinò F, Visconti L, Pagano L, Toto A, Troilo F, Gianni S. Understanding the Binding Induced Folding of Intrinsically Disordered Proteins by Protein Engineering: Caveats and Pitfalls. Int J Mol Sci 2020; 21:ijms21103484. [PMID: 32429036 PMCID: PMC7279032 DOI: 10.3390/ijms21103484] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 05/11/2020] [Accepted: 05/12/2020] [Indexed: 12/20/2022] Open
Abstract
Many proteins lack a well-defined three-dimensional structure in isolation. These proteins, typically denoted as intrinsically disordered proteins (IDPs), may display a characteristic disorder-to-order transition when binding their physiological partner(s). From an experimental perspective, it is of great importance to establish the general grounds to understand how such folding processes may be explored. Here we discuss the caveats and the pitfalls arising when applying to IDPs one of the key techniques to characterize the folding of globular proteins, the Φ value analysis. This method is based on measurements of the free energy changes of transition and native states upon conservative, non-disrupting, mutations. On the basis of available data, we reinforce the validity of Φ value analysis in the study of IDPs and suggest future experiments to further validate this powerful experimental method.
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Chou CH, Lim JC, Lai YH, Chen YT, Lo YH, Huang JJ. Characterizations of protein-ligand reaction kinetics by transistor-microfluidic integrated sensors. Anal Chim Acta 2020; 1110:1-10. [DOI: 10.1016/j.aca.2020.03.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 02/11/2020] [Accepted: 03/07/2020] [Indexed: 11/28/2022]
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Toto A, Malagrinò F, Visconti L, Troilo F, Pagano L, Brunori M, Jemth P, Gianni S. Templated folding of intrinsically disordered proteins. J Biol Chem 2020; 295:6586-6593. [PMID: 32253236 DOI: 10.1074/jbc.rev120.012413] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Much of our current knowledge of biological chemistry is founded in the structure-function relationship, whereby sequence determines structure that determines function. Thus, the discovery that a large fraction of the proteome is intrinsically disordered, while being functional, has revolutionized our understanding of proteins and raised new and interesting questions. Many intrinsically disordered proteins (IDPs) have been determined to undergo a disorder-to-order transition when recognizing their physiological partners, suggesting that their mechanisms of folding are intrinsically different from those observed in globular proteins. However, IDPs also follow some of the classic paradigms established for globular proteins, pointing to important similarities in their behavior. In this review, we compare and contrast the folding mechanisms of globular proteins with the emerging features of binding-induced folding of intrinsically disordered proteins. Specifically, whereas disorder-to-order transitions of intrinsically disordered proteins appear to follow rules of globular protein folding, such as the cooperative nature of the reaction, their folding pathways are remarkably more malleable, due to the heterogeneous nature of their folding nuclei, as probed by analysis of linear free-energy relationship plots. These insights have led to a new model for the disorder-to-order transition in IDPs termed "templated folding," whereby the binding partner dictates distinct structural transitions en route to product, while ensuring a cooperative folding.
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Affiliation(s)
- Angelo Toto
- Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche "A. Rossi Fanelli" and Istituto di Biologia e Patologia Molecolari del CNR, Sapienza Università di Roma, 00185 Rome, Italy
| | - Francesca Malagrinò
- Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche "A. Rossi Fanelli" and Istituto di Biologia e Patologia Molecolari del CNR, Sapienza Università di Roma, 00185 Rome, Italy
| | - Lorenzo Visconti
- Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche "A. Rossi Fanelli" and Istituto di Biologia e Patologia Molecolari del CNR, Sapienza Università di Roma, 00185 Rome, Italy
| | - Francesca Troilo
- Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche "A. Rossi Fanelli" and Istituto di Biologia e Patologia Molecolari del CNR, Sapienza Università di Roma, 00185 Rome, Italy
| | - Livia Pagano
- Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche "A. Rossi Fanelli" and Istituto di Biologia e Patologia Molecolari del CNR, Sapienza Università di Roma, 00185 Rome, Italy
| | - Maurizio Brunori
- Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche "A. Rossi Fanelli" and Istituto di Biologia e Patologia Molecolari del CNR, Sapienza Università di Roma, 00185 Rome, Italy
| | - Per Jemth
- Department of Medical Biochemistry and Microbiology, Uppsala University, BMC Box 582, SE-75123 Uppsala, Sweden
| | - Stefano Gianni
- Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche "A. Rossi Fanelli" and Istituto di Biologia e Patologia Molecolari del CNR, Sapienza Università di Roma, 00185 Rome, Italy
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42
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Ezerski JC, Zhang P, Jennings NC, Waxham MN, Cheung MS. Molecular Dynamics Ensemble Refinement of Intrinsically Disordered Peptides According to Deconvoluted Spectra from Circular Dichroism. Biophys J 2020; 118:1665-1678. [PMID: 32145192 PMCID: PMC7136346 DOI: 10.1016/j.bpj.2020.02.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 02/07/2020] [Accepted: 02/18/2020] [Indexed: 02/08/2023] Open
Abstract
We have developed a computational method of atomistically refining the structural ensemble of intrinsically disordered peptides (IDPs) facilitated by experimental measurements using circular dichroism spectroscopy (CD). A major challenge surrounding this approach stems from the deconvolution of experimental CD spectra into secondary structure features of the IDP ensemble. Currently available algorithms for CD deconvolution were designed to analyze the spectra of proteins with stable secondary structures. Herein, our work aims to minimize any bias from the peptide deconvolution analysis by implementing a non-negative linear least-squares fitting algorithm in conjunction with a CD reference data set that contains soluble and denatured proteins (SDP48). The non-negative linear least-squares method yields the best results for deconvolution of proteins with higher disordered content than currently available methods, according to a validation analysis of a set of protein spectra with Protein Data Bank entries. We subsequently used this analysis to deconvolute our experimental CD data to refine our computational model of the peptide secondary structure ensemble produced by all-atom molecular dynamics simulations with implicit solvent. We applied this approach to determine the ensemble structures of a set of short IDPs, that mimic the calmodulin binding domain of calcium/calmodulin-dependent protein kinase II and its 1-amino-acid and 3-amino-acid mutants. Our study offers a, to our knowledge, novel way to solve the ensemble secondary structures of IDPs in solution, which is important to advance the understanding of their roles in regulating signaling pathways through the formation of complexes with multiple partners.
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Affiliation(s)
- Jacob C Ezerski
- Department of Physics, University of Houston, Houston, Texas
| | - Pengzhi Zhang
- Department of Physics, University of Houston, Houston, Texas
| | | | - M Neal Waxham
- Department of Neurobiology and Anatomy, University of Texas, Health Science Center at Houston, Houston, Texas
| | - Margaret S Cheung
- Department of Physics, University of Houston, Houston, Texas; Center for Theoretical Biological Physics, Rice University, Houston, Texas.
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Zhou J, Shao Z, Liu J, Duan Q, Wang X, Li J, Yang H. From Endocytosis to Nonendocytosis: The Emerging Era of Gene Delivery. ACS APPLIED BIO MATERIALS 2020; 3:2686-2701. [DOI: 10.1021/acsabm.9b01131] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Jie Zhou
- MOE Key Laboratory for Analytical Science of Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou 350116, People’s Republic of China
- Institute of Molecular Medicine, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Jiao Tong University, Shanghai 200240, People’s Republic of China
| | - Zhentao Shao
- Institute of Molecular Medicine, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Jiao Tong University, Shanghai 200240, People’s Republic of China
| | - Jia Liu
- Institute of Molecular Medicine, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Jiao Tong University, Shanghai 200240, People’s Republic of China
| | - Qiao Duan
- Institute of Molecular Medicine, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Jiao Tong University, Shanghai 200240, People’s Republic of China
| | - Xiang Wang
- Institute of Molecular Medicine, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Jiao Tong University, Shanghai 200240, People’s Republic of China
| | - Juan Li
- MOE Key Laboratory for Analytical Science of Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou 350116, People’s Republic of China
- Institute of Molecular Medicine, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Jiao Tong University, Shanghai 200240, People’s Republic of China
| | - Huanghao Yang
- MOE Key Laboratory for Analytical Science of Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou 350116, People’s Republic of China
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44
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Holehouse AS, Sukenik S. Controlling Structural Bias in Intrinsically Disordered Proteins Using Solution Space Scanning. J Chem Theory Comput 2020; 16:1794-1805. [DOI: 10.1021/acs.jctc.9b00604] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Alex S. Holehouse
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110, United States
- Center for Science and Engineering of Living Systems, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Shahar Sukenik
- Department of Chemistry and Chemical Biology, UC Merced, Merced, California 95340, United States
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45
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Guillien M, le Maire A, Mouhand A, Bernadó P, Bourguet W, Banères JL, Sibille N. IDPs and their complexes in GPCR and nuclear receptor signaling. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2020; 174:105-155. [DOI: 10.1016/bs.pmbts.2020.05.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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46
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Yang J, Gao M, Xiong J, Su Z, Huang Y. Features of molecular recognition of intrinsically disordered proteins via coupled folding and binding. Protein Sci 2019; 28:1952-1965. [PMID: 31441158 PMCID: PMC6798136 DOI: 10.1002/pro.3718] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 08/16/2019] [Accepted: 08/20/2019] [Indexed: 12/12/2022]
Abstract
The sequence-structure-function paradigm of proteins has been revolutionized by the discovery of intrinsically disordered proteins (IDPs) or intrinsically disordered regions (IDRs). In contrast to traditional ordered proteins, IDPs/IDRs are unstructured under physiological conditions. The absence of well-defined three-dimensional structures in the free state of IDPs/IDRs is fundamental to their function. Folding upon binding is an important mode of molecular recognition for IDPs/IDRs. While great efforts have been devoted to investigating the complex structures and binding kinetics and affinities, our knowledge on the binding mechanisms of IDPs/IDRs remains very limited. Here, we review recent advances on the binding mechanisms of IDPs/IDRs. The structures and kinetic parameters of IDPs/IDRs can vary greatly, and the binding mechanisms can be highly dependent on the structural properties of IDPs/IDRs. IDPs/IDRs can employ various combinations of conformational selection and induced fit in a binding process, which can be templated by the target and/or encoded by the IDP/IDR. Further studies should provide deeper insights into the molecular recognition of IDPs/IDRs and enable the rational design of IDP/IDR binding mechanisms in the future.
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Affiliation(s)
- Jing Yang
- Department of Biological Engineering and Key Laboratory of Industrial Fermentation (Ministry of Education)Hubei University of TechnologyWuhanHubeiChina
- Institute of Biomedical and Pharmaceutical SciencesHubei University of TechnologyWuhanHubeiChina
| | - Meng Gao
- Department of Biological Engineering and Key Laboratory of Industrial Fermentation (Ministry of Education)Hubei University of TechnologyWuhanHubeiChina
- Institute of Biomedical and Pharmaceutical SciencesHubei University of TechnologyWuhanHubeiChina
| | - Junwen Xiong
- Department of Biological Engineering and Key Laboratory of Industrial Fermentation (Ministry of Education)Hubei University of TechnologyWuhanHubeiChina
- Institute of Biomedical and Pharmaceutical SciencesHubei University of TechnologyWuhanHubeiChina
| | - Zhengding Su
- Department of Biological Engineering and Key Laboratory of Industrial Fermentation (Ministry of Education)Hubei University of TechnologyWuhanHubeiChina
- Institute of Biomedical and Pharmaceutical SciencesHubei University of TechnologyWuhanHubeiChina
| | - Yongqi Huang
- Department of Biological Engineering and Key Laboratory of Industrial Fermentation (Ministry of Education)Hubei University of TechnologyWuhanHubeiChina
- Institute of Biomedical and Pharmaceutical SciencesHubei University of TechnologyWuhanHubeiChina
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47
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Davey NE, Babu MM, Blackledge M, Bridge A, Capella-Gutierrez S, Dosztanyi Z, Drysdale R, Edwards RJ, Elofsson A, Felli IC, Gibson TJ, Gutmanas A, Hancock JM, Harrow J, Higgins D, Jeffries CM, Le Mercier P, Mészáros B, Necci M, Notredame C, Orchard S, Ouzounis CA, Pancsa R, Papaleo E, Pierattelli R, Piovesan D, Promponas VJ, Ruch P, Rustici G, Romero P, Sarntivijai S, Saunders G, Schuler B, Sharan M, Shields DC, Sussman JL, Tedds JA, Tompa P, Turewicz M, Vondrasek J, Vranken WF, Wallace BA, Wichapong K, Tosatto SCE. An intrinsically disordered proteins community for ELIXIR. F1000Res 2019; 8. [PMID: 31824649 PMCID: PMC6880265 DOI: 10.12688/f1000research.20136.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/18/2019] [Indexed: 01/20/2023] Open
Abstract
Intrinsically disordered proteins (IDPs) and intrinsically disordered regions (IDRs) are now recognised as major determinants in cellular regulation. This white paper presents a roadmap for future e-infrastructure developments in the field of IDP research within the ELIXIR framework. The goal of these developments is to drive the creation of high-quality tools and resources to support the identification, analysis and functional characterisation of IDPs. The roadmap is the result of a workshop titled “An intrinsically disordered protein user community proposal for ELIXIR” held at the University of Padua. The workshop, and further consultation with the members of the wider IDP community, identified the key priority areas for the roadmap including the development of standards for data annotation, storage and dissemination; integration of IDP data into the ELIXIR Core Data Resources; and the creation of benchmarking criteria for IDP-related software. Here, we discuss these areas of priority, how they can be implemented in cooperation with the ELIXIR platforms, and their connections to existing ELIXIR Communities and international consortia. The article provides a preliminary blueprint for an IDP Community in ELIXIR and is an appeal to identify and involve new stakeholders.
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Affiliation(s)
- Norman E Davey
- Division of Cancer Biology, Institute of Cancer Research, UK, London, SW3 6JB, UK
| | - M Madan Babu
- MRC Laboratory of Molecular Biology,, Cambridge, CB2 0QH, UK
| | - Martin Blackledge
- Institut de Biologie Structurale, Université Grenoble Alpes, Grenoble, 38000, France
| | - Alan Bridge
- Swiss-Prot Group, SIB Swiss Institute of Bioinformatics, Geneva, Switzerland
| | | | - Zsuzsanna Dosztanyi
- Department of Biochemistry, Eötvös Loránd University, Budapest, H-1117, Hungary
| | | | - Richard J Edwards
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Arne Elofsson
- Department of Biochemistry and Biophysics and Science for Life Laboratory, Stockholm University, Stockholm, Sweden
| | - Isabella C Felli
- Department of Chemistry and CERM "Ugo Schiff", University of Florence, Florence, Italy
| | - Toby J Gibson
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Aleksandras Gutmanas
- Protein Data Bank in Europe, European Bioinformatics Institute (EMBL-EBI), European Molecular Biology Laboratory, Cambridge, CB10 1SD, UK
| | - John M Hancock
- ELIXIR Hub, Wellcome Genome Campus, Cambridge, CB10 1SD, UK
| | - Jen Harrow
- ELIXIR Hub, Wellcome Genome Campus, Cambridge, CB10 1SD, UK
| | - Desmond Higgins
- Conway Institute of Biomolecular & Biomedical Research, University College Dublin, Belfield, Dublin, D4, Ireland
| | - Cy M Jeffries
- European Molecular Biology Laboratory, Hamburg, Germany
| | - Philippe Le Mercier
- Swiss-Prot Group, SIB Swiss Institute of Bioinformatics, Geneva, Switzerland
| | - Balint Mészáros
- Department of Biochemistry, Eötvös Loránd University, Budapest, H-1117, Hungary
| | - Marco Necci
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Cedric Notredame
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, 08003, Spain.,Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Sandra Orchard
- European Bioinformatics Institute (EMBL-EBI), European Molecular Biology Laboratory, Cambridge, CB10 1SD, UK
| | - Christos A Ouzounis
- BCPL-CPERI, Centre for Research & Technology Hellas (CERTH), Thessalonica, 57001, Greece
| | - Rita Pancsa
- Institute of Enzymology, Research Centre for Natural Sciences of the Hungarian Academy of Sciences, Budapest, H-1117, Hungary
| | - Elena Papaleo
- Computational Biology Laboratory, Danish Cancer Society Research Center, Copenhagen, 2100, Denmark
| | - Roberta Pierattelli
- Department of Chemistry and CERM "Ugo Schiff", University of Florence, Florence, Italy
| | - Damiano Piovesan
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Vasilis J Promponas
- Bioinformatics Research Laboratory, Department of Biological Sciences, University of Cyprus, Nicosia, CY-1678, Cyprus
| | - Patrick Ruch
- HES-SO/HEG and SIB Text Mining, Swiss Institute of Bioinformatics, Geneva, Switzerland
| | - Gabriella Rustici
- Department of Genetics, University of Cambridge, Cambridge, CB2 3EH, UK
| | - Pedro Romero
- University of Wisconsin-Madison, Madison, WI, 53706-1544, USA
| | | | - Gary Saunders
- ELIXIR Hub, Wellcome Genome Campus, Cambridge, CB10 1SD, UK
| | - Benjamin Schuler
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Malvika Sharan
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Denis C Shields
- Conway Institute of Biomolecular & Biomedical Research, University College Dublin, Belfield, Dublin, D4, Ireland
| | - Joel L Sussman
- Department of Structural Biology and the Israel Structural Proteomics, Center (ISPC), Weizmann Institute of Science, Reḥovot, 7610001, Israel
| | | | - Peter Tompa
- VIB Center for Structural Biology (CSB), VIB Flemish Institute for Biotechnology, Brussels, 1050, Belgium
| | - Michael Turewicz
- Faculty of Medicine, Medizinisches Proteom-Center, Ruhr University Bochum, GesundheitsCampus 4, Bochum, 44801, Germany
| | - Jiri Vondrasek
- Institute of Organic Chemistry and Biochemistry, CAS, Prague, Czech Republic
| | - Wim F Vranken
- VUB/ULB Interuniversity Institute of Bioinformatics in Brussels and Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, B-1050, Belgium
| | - Bonnie Ann Wallace
- Institute of Structural and Molecular Biology, Birkbeck College, University of London, London, WC1H 0HA, UK
| | - Kanin Wichapong
- Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
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48
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Bukowski GS, Horness RE, Thielges MC. Involvement of Local, Rapid Conformational Dynamics in Binding of Flexible Recognition Motifs. J Phys Chem B 2019; 123:8387-8396. [PMID: 31535866 DOI: 10.1021/acs.jpcb.9b07036] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Flexible protein sequences populate ensembles of rapidly interconverting states differentiated by small-scale fluctuations; however, elucidating whether and how the ensembles determine function experimentally is challenged by the combined high spatial and temporal resolution needed to capture the states. We used carbon-deuterium (C-D) bond vibrations incorporated as infrared probes to characterize with residue-specific detail the heterogeneity of states adopted by proline-rich (PR) sequences and assess their involvement in recognition of Src homology 3 domains. The C-D absorption envelopes provided evidence for two or three sub-populations at all proline residues. The changes in the subpopulations induced by binding generally reflected recognition by conformational selection but depended on the residue and the state of the ligand to illuminate distinct mechanisms among the PR ligands. Notably, the spectral data indicate that greater adaptability among the states is associated with reduced recognition specificity and that perturbation to the ensemble populations contributes to differences in binding entropy. Broadly, the study quantifies rapidly interconverting ensembles with residue-specific detail and implicates them in function.
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Affiliation(s)
- Gregory S Bukowski
- Department of Chemistry , Indiana University, Bloomington , Bloomington , Indiana 47405 , United States
| | - Rachel E Horness
- Department of Chemistry , Indiana University, Bloomington , Bloomington , Indiana 47405 , United States
| | - Megan C Thielges
- Department of Chemistry , Indiana University, Bloomington , Bloomington , Indiana 47405 , United States
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49
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Abstract
Structural disorder is widespread in regulatory protein networks. Weak and transient interactions render disordered proteins particularly sensitive to fluctuations in solution conditions such as ion and crowder concentrations. How this sensitivity alters folding coupled binding reactions, however, has not been fully understood. Here, we demonstrate that salt jointly modulates polymer properties and binding affinities of 5 disordered proteins from a transcription factor network. A combination of single-molecule Förster resonance energy transfer experiments, polymer theory, and molecular simulations shows that all 5 proteins expand with increasing ionic strengths due to Debye-Hückel charge screening. Simultaneously, pairwise affinities between the proteins increase by an order of magnitude within physiological salt limits. A quantitative analysis shows that 50% of the affinity increase can be explained by changes in the disordered state. Disordered state properties therefore have a functional relevance even if these states are not directly involved in biological functions. Numerical solutions of coupled binding equilibria with our results show that networks of homologous disordered proteins can function surprisingly robustly in fluctuating cellular environments, despite the sensitivity of its individual proteins.
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50
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Karlsson E, Andersson E, Jones NC, Hoffmann SV, Jemth P, Kjaergaard M. Coupled Binding and Helix Formation Monitored by Synchrotron-Radiation Circular Dichroism. Biophys J 2019; 117:729-742. [PMID: 31378314 PMCID: PMC6712486 DOI: 10.1016/j.bpj.2019.07.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 06/29/2019] [Accepted: 07/10/2019] [Indexed: 01/27/2023] Open
Abstract
Intrinsically disordered proteins organize interaction networks in the cell in many regulation and signaling processes. These proteins often gain structure upon binding to their target proteins in multistep reactions involving the formation of both secondary and tertiary structure. To understand the interactions of disordered proteins, we need to understand the mechanisms of these coupled folding and binding reactions. We studied helix formation in the binding of the molten globule-like nuclear coactivator binding domain and the disordered interaction domain from activator of thyroid hormone and retinoid receptors. We demonstrate that helix formation in a rapid binding reaction can be followed by stopped-flow synchrotron-radiation circular dichroism (CD) spectroscopy and describe the design of such a beamline. Fluorescence-monitored binding experiments of activator of thyroid hormone and retinoid receptors and nuclear coactivator binding domain display several kinetic phases, including one concentration-independent phase, which is consistent with an intermediate stabilized at high ionic strength. Time-resolved CD experiments show that almost all helicity is formed upon initial association of the proteins or separated from the encounter complex by only a small energy barrier. Through simulation of mechanistic models, we show that the intermediate observed at high ionic strength likely involves a structural rearrangement with minor overall changes in helicity. Our experiments provide a benchmark for simulations of coupled binding reactions and demonstrate the feasibility of using synchrotron-radiation CD for mechanistic studies of protein-protein interactions.
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Affiliation(s)
- Elin Karlsson
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Eva Andersson
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Nykola C Jones
- ISA, Department of Physics and Astronomy, Aarhus, Denmark
| | | | - Per Jemth
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden.
| | - Magnus Kjaergaard
- Department of Molecular Biology and Genetics, Aarhus, Denmark; Aarhus Institute of Advanced Studies, Aarhus University, Aarhus, Denmark.
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