1
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Gupta MN, Uversky VN. Protein structure-function continuum model: Emerging nexuses between specificity, evolution, and structure. Protein Sci 2024; 33:e4968. [PMID: 38532700 DOI: 10.1002/pro.4968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Revised: 02/18/2024] [Accepted: 03/05/2024] [Indexed: 03/28/2024]
Abstract
The rationale for replacing the old binary of structure-function with the trinity of structure, disorder, and function has gained considerable ground in recent years. A continuum model based on the expanded form of the existing paradigm can now subsume importance of both conformational flexibility and intrinsic disorder in protein function. The disorder is actually critical for understanding the protein-protein interactions in many regulatory processes, formation of membrane-less organelles, and our revised notions of specificity as amply illustrated by moonlighting proteins. While its importance in formation of amyloids and function of prions is often discussed, the roles of intrinsic disorder in infectious diseases and protein function under extreme conditions are also becoming clear. This review is an attempt to discuss how our current understanding of protein function, specificity, and evolution fit better with the continuum model. This integration of structure and disorder under a single model may bring greater clarity in our continuing quest for understanding proteins and molecular mechanisms of their functionality.
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Affiliation(s)
- Munishwar Nath Gupta
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology, New Delhi, India
| | - Vladimir N Uversky
- Department of Molecular Medicine and USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
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2
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McCullagh M, Zeczycki TN, Kariyawasam CS, Durie CL, Halkidis K, Fitzkee NC, Holt JM, Fenton AW. What is allosteric regulation? Exploring the exceptions that prove the rule! J Biol Chem 2024; 300:105672. [PMID: 38272229 PMCID: PMC10897898 DOI: 10.1016/j.jbc.2024.105672] [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: 06/21/2023] [Revised: 01/09/2024] [Accepted: 01/12/2024] [Indexed: 01/27/2024] Open
Abstract
"Allosteric" was first introduced to mean the other site (i.e., a site distinct from the active or orthosteric site), an adjective for "regulation" to imply a regulatory outcome resulting from ligand binding at another site. That original idea outlines a system with two ligand-binding events at two distinct locations on a macromolecule (originally a protein system), which defines a four-state energy cycle. An allosteric energy cycle provides a quantifiable allosteric coupling constant and focuses our attention on the unique properties of the four equilibrated protein complexes that constitute the energy cycle. Because many observed phenomena have been referenced as "allosteric regulation" in the literature, the goal of this work is to use literature examples to explore which systems are and are not consistent with the two-ligand thermodynamic energy cycle-based definition of allosteric regulation. We emphasize the need for consistent language so comparisons can be made among the ever-increasing number of allosteric systems. Building on the mutually exclusive natures of an energy cycle definition of allosteric regulation versus classic two-state models, we conclude our discussion by outlining how the often-proposed Rube-Goldberg-like mechanisms are likely inconsistent with an energy cycle definition of allosteric regulation.
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Affiliation(s)
- Martin McCullagh
- Department of Chemistry, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Tonya N Zeczycki
- Department of Biochemistry and Molecular Biology, Brody School of Medicine at East Carolina University, Greenville, North Carolina, USA
| | - Chathuri S Kariyawasam
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi, USA
| | - Clarissa L Durie
- Department of Biochemistry, University of Missouri, Columbia, Missouri, USA
| | - Konstantine Halkidis
- Department of Hematologic Malignancies and Cellular Therapeutics, The University of Kansas Medical Center, Kansas City, Kansas, USA; Department of Biochemistry and Molecular Biology, The University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Nicholas C Fitzkee
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi, USA
| | - Jo M Holt
- Department of Biochemistry and Molecular Biology, The University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Aron W Fenton
- Department of Biochemistry and Molecular Biology, The University of Kansas Medical Center, Kansas City, Kansas, USA.
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3
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Ashton AW, Dhanjal HK, Rossner B, Mahmood H, Patel VI, Nadim M, Lota M, Shahid F, Li Z, Joyce D, Pajkos M, Dosztányi Z, Jiao X, Pestell RG. Acetylation of nuclear receptors in health and disease: an update. FEBS J 2024; 291:217-236. [PMID: 36471658 DOI: 10.1111/febs.16695] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 10/17/2022] [Accepted: 12/05/2022] [Indexed: 12/12/2022]
Abstract
Lysine acetylation is a common reversible post-translational modification of proteins that plays a key role in regulating gene expression. Nuclear receptors (NRs) include ligand-inducible transcription factors and orphan receptors for which the ligand is undetermined, which together regulate the expression of genes involved in development, metabolism, homeostasis, reproduction and human diseases including cancer. Since the original finding that the ERα, AR and HNF4 are acetylated, we now understand that the vast majority of NRs are acetylated and that this modification has profound effects on NR function. Acetylation sites are often conserved and involve both ordered and disordered regions of NRs. The acetylated residues function as part of an intramolecular signalling platform intersecting phosphorylation, methylation and other modifications. Acetylation of NR has been shown to impact recruitment into chromatin, co-repressor and coactivator complex formation, sensitivity and specificity of regulation by ligand and ligand antagonists, DNA binding, subcellular distribution and transcriptional activity. A growing body of evidence in mice indicates a vital role for NR acetylation in metabolism. Additionally, mutations of the NR acetylation site occur in human disease. This review focuses on the role of NR acetylation in coordinating signalling in normal physiology and disease.
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Affiliation(s)
- Anthony W Ashton
- Xavier University School of Medicine at Aruba, Oranjestad, Aruba
- Lankenau Institute for Medical Research, Wynnewood, PA, USA
| | | | - Benjamin Rossner
- Xavier University School of Medicine at Aruba, Oranjestad, Aruba
| | - Huma Mahmood
- Xavier University School of Medicine at Aruba, Oranjestad, Aruba
| | - Vivek I Patel
- Xavier University School of Medicine at Aruba, Oranjestad, Aruba
| | - Mohammad Nadim
- Xavier University School of Medicine at Aruba, Oranjestad, Aruba
| | - Manpreet Lota
- Xavier University School of Medicine at Aruba, Oranjestad, Aruba
| | - Farhan Shahid
- Xavier University School of Medicine at Aruba, Oranjestad, Aruba
| | - Zhiping Li
- Xavier University School of Medicine at Aruba, Oranjestad, Aruba
- Pennsylvania Cancer and Regenerative Medicine Research Center, Baruch S. Blumberg Institute, Wynnewood, PA, USA
| | - David Joyce
- Medical School, Faculty of Health and Medical Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Matyas Pajkos
- Department of Biochemistry, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Zsuzsanna Dosztányi
- Department of Biochemistry, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Xuanmao Jiao
- Xavier University School of Medicine at Aruba, Oranjestad, Aruba
- Pennsylvania Cancer and Regenerative Medicine Research Center, Baruch S. Blumberg Institute, Wynnewood, PA, USA
| | - Richard G Pestell
- Xavier University School of Medicine at Aruba, Oranjestad, Aruba
- Pennsylvania Cancer and Regenerative Medicine Research Center, Baruch S. Blumberg Institute, Wynnewood, PA, USA
- The Wistar Cancer Center, Philadelphia, PA, USA
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4
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Dreier JE, Prestel A, Martins JM, Brøndum SS, Nielsen O, Garbers AE, Suga H, Boomsma W, Rogers JM, Hartmann-Petersen R, Kragelund BB. A context-dependent and disordered ubiquitin-binding motif. Cell Mol Life Sci 2022; 79:484. [PMID: 35974206 PMCID: PMC9381478 DOI: 10.1007/s00018-022-04486-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 07/06/2022] [Accepted: 07/14/2022] [Indexed: 02/07/2023]
Abstract
Ubiquitin is a small, globular protein that is conjugated to other proteins as a posttranslational event. A palette of small, folded domains recognizes and binds ubiquitin to translate and effectuate this posttranslational signal. Recent computational studies have suggested that protein regions can recognize ubiquitin via a process of folding upon binding. Using peptide binding arrays, bioinformatics, and NMR spectroscopy, we have uncovered a disordered ubiquitin-binding motif that likely remains disordered when bound and thus expands the palette of ubiquitin-binding proteins. We term this motif Disordered Ubiquitin-Binding Motif (DisUBM) and find it to be present in many proteins with known or predicted functions in degradation and transcription. We decompose the determinants of the motif showing it to rely on features of aromatic and negatively charged residues, and less so on distinct sequence positions in line with its disordered nature. We show that the affinity of the motif is low and moldable by the surrounding disordered chain, allowing for an enhanced interaction surface with ubiquitin, whereby the affinity increases ~ tenfold. Further affinity optimization using peptide arrays pushed the affinity into the low micromolar range, but compromised context dependence. Finally, we find that DisUBMs can emerge from unbiased screening of randomized peptide libraries, featuring in de novo cyclic peptides selected to bind ubiquitin chains. We suggest that naturally occurring DisUBMs can recognize ubiquitin as a posttranslational signal to act as affinity enhancers in IDPs that bind to folded and ubiquitylated binding partners.
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Affiliation(s)
- Jesper E Dreier
- Structural Biology and NMR Laboratory, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark.,REPIN, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark
| | - Andreas Prestel
- Structural Biology and NMR Laboratory, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark
| | - João M Martins
- Department of Computer Science, University of Copenhagen, Universitetsparken 1, 2100, Copenhagen Ø, Denmark
| | - Sebastian S Brøndum
- Structural Biology and NMR Laboratory, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark
| | - Olaf Nielsen
- Functional Genomics, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark
| | - Anna E Garbers
- Structural Biology and NMR Laboratory, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark.,REPIN, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark
| | - Hiroaki Suga
- Department of Chemistry, Graduate School of Science, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Wouter Boomsma
- Department of Computer Science, University of Copenhagen, Universitetsparken 1, 2100, Copenhagen Ø, Denmark
| | - Joseph M Rogers
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 160, 2100, Copenhagen Ø, Denmark
| | - Rasmus Hartmann-Petersen
- REPIN, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark. .,The Linderstrøm Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark.
| | - Birthe B Kragelund
- Structural Biology and NMR Laboratory, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark. .,REPIN, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark. .,The Linderstrøm Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark.
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5
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Saldaño T, Escobedo N, Marchetti J, Zea DJ, Mac Donagh J, Velez Rueda AJ, Gonik E, García Melani A, Novomisky Nechcoff J, Salas MN, Peters T, Demitroff N, Fernandez Alberti S, Palopoli N, Fornasari MS, Parisi G. Impact of protein conformational diversity on AlphaFold predictions. Bioinformatics 2022; 38:2742-2748. [PMID: 35561203 DOI: 10.1093/bioinformatics/btac202] [Citation(s) in RCA: 48] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 02/10/2022] [Accepted: 03/31/2022] [Indexed: 11/12/2022] Open
Abstract
MOTIVATION After the outstanding breakthrough of AlphaFold in predicting protein 3D models, new questions appeared and remain unanswered. The ensemble nature of proteins, for example, challenges the structural prediction methods because the models should represent a set of conformers instead of single structures. The evolutionary and structural features captured by effective deep learning techniques may unveil the information to generate several diverse conformations from a single sequence. Here, we address the performance of AlphaFold2 predictions obtained through ColabFold under this ensemble paradigm. RESULTS Using a curated collection of apo-holo pairs of conformers, we found that AlphaFold2 predicts the holo form of a protein in ∼70% of the cases, being unable to reproduce the observed conformational diversity with the same error for both conformers. More importantly, we found that AlphaFold2's performance worsens with the increasing conformational diversity of the studied protein. This impairment is related to the heterogeneity in the degree of conformational diversity found between different members of the homologous family of the protein under study. Finally, we found that main-chain flexibility associated with apo-holo pairs of conformers negatively correlates with the predicted local model quality score plDDT, indicating that plDDT values in a single 3D model could be used to infer local conformational changes linked to ligand binding transitions. AVAILABILITY AND IMPLEMENTATION Data and code used in this manuscript are publicly available at https://gitlab.com/sbgunq/publications/af2confdiv-oct2021. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Tadeo Saldaño
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Bernal, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | - Nahuel Escobedo
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Bernal, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | - Julia Marchetti
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Bernal, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | | | - Juan Mac Donagh
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Bernal, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | - Ana Julia Velez Rueda
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Bernal, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | - Eduardo Gonik
- Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
- INIFTA (CONICET-UNLP) - Fotoquímica y Nanomateriales para el Ambiente y la Biología (nanoFOT), La Plata, Argentina
| | | | | | - Martín N Salas
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Bernal, Argentina
| | - Tomás Peters
- Fundación Instituto Leloir-Instituto de Investigaciones Bioquímicas de Buenos Aires, Buenos Aires, Argentina
| | - Nicolás Demitroff
- Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
- Fundación Instituto Leloir-Instituto de Investigaciones Bioquímicas de Buenos Aires, Buenos Aires, Argentina
| | - Sebastian Fernandez Alberti
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Bernal, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | - Nicolas Palopoli
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Bernal, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | - Maria Silvina Fornasari
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Bernal, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | - Gustavo Parisi
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Bernal, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
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6
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Kulkarni P, Leite VBP, Roy S, Bhattacharyya S, Mohanty A, Achuthan S, Singh D, Appadurai R, Rangarajan G, Weninger K, Orban J, Srivastava A, Jolly MK, Onuchic JN, Uversky VN, Salgia R. Intrinsically disordered proteins: Ensembles at the limits of Anfinsen's dogma. BIOPHYSICS REVIEWS 2022; 3:011306. [PMID: 38505224 PMCID: PMC10903413 DOI: 10.1063/5.0080512] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 02/17/2022] [Indexed: 03/21/2024]
Abstract
Intrinsically disordered proteins (IDPs) are proteins that lack rigid 3D structure. Hence, they are often misconceived to present a challenge to Anfinsen's dogma. However, IDPs exist as ensembles that sample a quasi-continuum of rapidly interconverting conformations and, as such, may represent proteins at the extreme limit of the Anfinsen postulate. IDPs play important biological roles and are key components of the cellular protein interaction network (PIN). Many IDPs can interconvert between disordered and ordered states as they bind to appropriate partners. Conformational dynamics of IDPs contribute to conformational noise in the cell. Thus, the dysregulation of IDPs contributes to increased noise and "promiscuous" interactions. This leads to PIN rewiring to output an appropriate response underscoring the critical role of IDPs in cellular decision making. Nonetheless, IDPs are not easily tractable experimentally. Furthermore, in the absence of a reference conformation, discerning the energy landscape representation of the weakly funneled IDPs in terms of reaction coordinates is challenging. To understand conformational dynamics in real time and decipher how IDPs recognize multiple binding partners with high specificity, several sophisticated knowledge-based and physics-based in silico sampling techniques have been developed. Here, using specific examples, we highlight recent advances in energy landscape visualization and molecular dynamics simulations to discern conformational dynamics and discuss how the conformational preferences of IDPs modulate their function, especially in phenotypic switching. Finally, we discuss recent progress in identifying small molecules targeting IDPs underscoring the potential therapeutic value of IDPs. Understanding structure and function of IDPs can not only provide new insight on cellular decision making but may also help to refine and extend Anfinsen's structure/function paradigm.
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Affiliation(s)
- Prakash Kulkarni
- Department of Medical Oncology and Therapeutics Research, City of Hope National Medical Center, Duarte, California 91010, USA
| | - Vitor B. P. Leite
- Departamento de Física, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista (UNESP), São José do Rio Preto, São Paulo 15054-000, Brazil
| | - Susmita Roy
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal 741246, India
| | - Supriyo Bhattacharyya
- Translational Bioinformatics, Center for Informatics, Department of Computational and Quantitative Medicine, City of Hope National Medical Center, Duarte, California 91010, USA
| | - Atish Mohanty
- Department of Medical Oncology and Therapeutics Research, City of Hope National Medical Center, Duarte, California 91010, USA
| | - Srisairam Achuthan
- Center for Informatics, Division of Research Informatics, City of Hope National Medical Center, Duarte, California 91010, USA
| | - Divyoj Singh
- Center for BioSystems Science and Engineering, Indian Institute of Science, Bangalore 560012, India
| | - Rajeswari Appadurai
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka, India
| | - Govindan Rangarajan
- Department of Mathematics, Indian Institute of Science, Bangalore 560012, India
| | - Keith Weninger
- Department of Physics, North Carolina State University, Raleigh, North Carolina 27695, USA
| | | | - Anand Srivastava
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka, India
| | - Mohit Kumar Jolly
- Center for BioSystems Science and Engineering, Indian Institute of Science, Bangalore 560012, India
| | - Jose N. Onuchic
- Center for Theoretical Biological Physics, Rice University, Houston, Texas 77005-1892, USA
| | | | - Ravi Salgia
- Department of Medical Oncology and Therapeutics Research, City of Hope National Medical Center, Duarte, California 91010, USA
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7
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Bondos SE, Dunker AK, Uversky VN. Intrinsically disordered proteins play diverse roles in cell signaling. Cell Commun Signal 2022; 20:20. [PMID: 35177069 PMCID: PMC8851865 DOI: 10.1186/s12964-022-00821-7] [Citation(s) in RCA: 56] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 12/11/2021] [Indexed: 11/29/2022] Open
Abstract
Abstract Signaling pathways allow cells to detect and respond to a wide variety of chemical (e.g. Ca2+ or chemokine proteins) and physical stimuli (e.g., sheer stress, light). Together, these pathways form an extensive communication network that regulates basic cell activities and coordinates the function of multiple cells or tissues. The process of cell signaling imposes many demands on the proteins that comprise these pathways, including the abilities to form active and inactive states, and to engage in multiple protein interactions. Furthermore, successful signaling often requires amplifying the signal, regulating or tuning the response to the signal, combining information sourced from multiple pathways, all while ensuring fidelity of the process. This sensitivity, adaptability, and tunability are possible, in part, due to the inclusion of intrinsically disordered regions in many proteins involved in cell signaling. The goal of this collection is to highlight the many roles of intrinsic disorder in cell signaling. Following an overview of resources that can be used to study intrinsically disordered proteins, this review highlights the critical role of intrinsically disordered proteins for signaling in widely diverse organisms (animals, plants, bacteria, fungi), in every category of cell signaling pathway (autocrine, juxtacrine, intracrine, paracrine, and endocrine) and at each stage (ligand, receptor, transducer, effector, terminator) in the cell signaling process. Thus, a cell signaling pathway cannot be fully described without understanding how intrinsically disordered protein regions contribute to its function. The ubiquitous presence of intrinsic disorder in different stages of diverse cell signaling pathways suggest that more mechanisms by which disorder modulates intra- and inter-cell signals remain to be discovered. Graphical abstract ![]()
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Affiliation(s)
- Sarah E Bondos
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, TX, 77843, USA.
| | - A Keith Dunker
- Center for Computational Biology and Bioinformatics, Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Vladimir N Uversky
- Department of Molecular Medicine and USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL, 33612, USA.,Institute for Biological Instrumentation of the Russian Academy of Sciences, Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Pushchino, Moscow Region, Russia, 142290
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8
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Multivalency enables unidirectional switch-like competition between intrinsically disordered proteins. Proc Natl Acad Sci U S A 2022; 119:2117338119. [PMID: 35012986 PMCID: PMC8784115 DOI: 10.1073/pnas.2117338119] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/22/2021] [Indexed: 12/31/2022] Open
Abstract
Intrinsically disordered proteins must compete for binding to common regulatory targets to carry out their biological functions. Previously, we showed that the activation domains of two disordered proteins, the transcription factor HIF-1α and its negative regulator CITED2, function as a unidirectional, allosteric molecular switch to control transcription of critical adaptive genes under conditions of oxygen deprivation. These proteins achieve transcriptional control by competing for binding to the TAZ1 domain of the transcriptional coactivators CREB-binding protein (CBP) and p300 (CREB: cyclic-AMP response element binding protein). To characterize the mechanistic details behind this molecular switch, we used solution NMR spectroscopy and complementary biophysical methods to determine the contributions of individual binding motifs in CITED2 to the overall competition process. An N-terminal region of the CITED2 activation domain, which forms a helix when bound to TAZ1, plays a critical role in initiating competition with HIF-1α by enabling formation of a ternary complex in a process that is highly dependent on the dynamics and disorder of the competing partners. Two other conserved binding motifs in CITED2, the LPEL motif and an aromatic/hydrophobic motif that we term ϕC, function synergistically to enhance binding of CITED2 and inhibit rebinding of HIF-1α. The apparent unidirectionality of competition between HIF-1α and CITED2 is lost when one or more of these binding regions is altered by truncation or mutation of the CITED2 peptide. Our findings illustrate the complexity of molecular interactions involving disordered proteins containing multivalent interaction motifs and provide insight into the unique mechanisms by which disordered proteins compete for occupancy of common molecular targets within the cell.
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9
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Iorio A, Roche J, Engilberge S, Coquelle N, Girard E, Sterpone F, Madern D. Biochemical, structural and dynamical studies reveal strong differences in the thermal-dependent allosteric behavior of two extremophilic lactate dehydrogenases. J Struct Biol 2021; 213:107769. [PMID: 34229075 DOI: 10.1016/j.jsb.2021.107769] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 06/29/2021] [Accepted: 06/29/2021] [Indexed: 11/28/2022]
Abstract
In this work, we combined biochemical and structural investigations with molecular dynamics (MD) simulations to analyze the very different thermal-dependent allosteric behavior of two lactate dehydrogenases (LDH) from thermophilic bacteria. We found that the enzyme from Petrotoga mobilis (P. mob) necessitates an absolute requirement of the allosteric effector (fructose 1, 6-bisphosphate) to ensure functionality. In contrast, even without allosteric effector, the LDH from Thermus thermophilus (T. the) is functional when the temperature is raised. We report the crystal structure of P. mob LDH in the Apo state solved at 1.9 Å resolution. We used this structure and the one from T. the, obtained previously, as a starting point for MD simulations at various temperatures. We found clear differences between the thermal dynamics, which accounts for the behavior of the two enzymes. Our work demonstrates that, within an allosteric enzyme, some areas act as local gatekeepers of signal transmission, allowing the enzyme to populate either the T-inactive or the R-active states with different degrees of stringency.
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Affiliation(s)
- Antonio Iorio
- CNRS, Université de Paris, UPR 9080, Laboratoire de Biochimie Théorique, Paris, France Institut de Biologie Physico-Chimique-Fondation Edmond de Rothschild, PSL Research University, Paris, France
| | - Jennifer Roche
- Univ. Grenoble Alpes, CEA, CNRS, IBS, 38000 Grenoble, France
| | - Sylvain Engilberge
- Univ. Grenoble Alpes, CEA, CNRS, IBS, 38000 Grenoble, France; Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institut, 5232 Villigen, Switzerland
| | - Nicolas Coquelle
- Large Scale Structures Group, Institut Laue-Langevin, 71 avenue des Martyrs, 38042 Cedex 9 Grenoble, France
| | - Eric Girard
- Univ. Grenoble Alpes, CEA, CNRS, IBS, 38000 Grenoble, France
| | - Fabio Sterpone
- CNRS, Université de Paris, UPR 9080, Laboratoire de Biochimie Théorique, Paris, France Institut de Biologie Physico-Chimique-Fondation Edmond de Rothschild, PSL Research University, Paris, France.
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10
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Jasuja R, Spencer D, Jayaraj A, Peng L, Krishna M, Lawney B, Patel P, Jayaram B, Thayer KM, Beveridge DL, Bhasin S. Estradiol induces allosteric coupling and partitioning of sex-hormone-binding globulin monomers among conformational states. iScience 2021; 24:102414. [PMID: 34041454 PMCID: PMC8144348 DOI: 10.1016/j.isci.2021.102414] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 02/13/2021] [Accepted: 04/07/2021] [Indexed: 11/24/2022] Open
Abstract
Sex-hormone-binding globulin (SHBG) regulates the transport and bioavailability of estradiol. The dynamics of estradiol's binding to SHBG are incompletely understood, although it is believed that estradiol binds to each monomer of SHBG dimer with identical affinity (Kd ∼2 nM). Contrary to the prevalent view, we show that estradiol's binding to SHBG is nonlinear, and the "apparent" Kd changes with varying estradiol and SHBG concentrations. Estradiol's binding to each SHBG monomer influences residues in the ligand-binding pocket of both monomers and differentially alters the conformational and energy landscapes of both monomers. Monomers are not energetically or conformationally equivalent even in fully bound state. Estradiol's binding to SHBG involves bidirectional, inter-monomeric allostery that changes the distribution of both monomers among various energy and conformational states. Inter-monomeric allostery offers a mechanism to extend the binding range of SHBG and regulate hormone bioavailability as estradiol concentrations vary widely during life.
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Affiliation(s)
- Ravi Jasuja
- Research Program in Men's Health: Aging and Metabolism, Boston Claude D. Pepper Older Americans Independence Center, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
- Function Promoting Therapies, Waltham, MA, USA
| | - Daniel Spencer
- Research Program in Men's Health: Aging and Metabolism, Boston Claude D. Pepper Older Americans Independence Center, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Abhilash Jayaraj
- Supercomputing Facility for Bioinformatics and Computational Biology, Indian Institute of Technology, New Delhi, 110 016 India
- Departments of Chemistry, Molecular Biology, and Biochemistry and Molecular Biophysics Program, Wesleyan University, Middletown, CT, USA
| | - Liming Peng
- Research Program in Men's Health: Aging and Metabolism, Boston Claude D. Pepper Older Americans Independence Center, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Meenakshi Krishna
- Research Program in Men's Health: Aging and Metabolism, Boston Claude D. Pepper Older Americans Independence Center, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Brian Lawney
- Center for Cancer Computational Biology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
- Function Promoting Therapies, Waltham, MA, USA
| | - Priyank Patel
- Research Program in Men's Health: Aging and Metabolism, Boston Claude D. Pepper Older Americans Independence Center, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Bhyravabhotla Jayaram
- Supercomputing Facility for Bioinformatics and Computational Biology, Indian Institute of Technology, New Delhi, 110 016 India
| | - Kelly M. Thayer
- Departments of Chemistry, Molecular Biology, and Biochemistry and Molecular Biophysics Program, Wesleyan University, Middletown, CT, USA
| | - David L. Beveridge
- Departments of Chemistry, Molecular Biology, and Biochemistry and Molecular Biophysics Program, Wesleyan University, Middletown, CT, USA
| | - Shalender Bhasin
- Research Program in Men's Health: Aging and Metabolism, Boston Claude D. Pepper Older Americans Independence Center, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
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11
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Biddle JW, Martinez-Corral R, Wong F, Gunawardena J. Allosteric conformational ensembles have unlimited capacity for integrating information. eLife 2021; 10:65498. [PMID: 34106049 PMCID: PMC8189718 DOI: 10.7554/elife.65498] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Accepted: 04/30/2021] [Indexed: 12/24/2022] Open
Abstract
Integration of binding information by macromolecular entities is fundamental to cellular functionality. Recent work has shown that such integration cannot be explained by pairwise cooperativities, in which binding is modulated by binding at another site. Higher-order cooperativities (HOCs), in which binding is collectively modulated by multiple other binding events, appear to be necessary but an appropriate mechanism has been lacking. We show here that HOCs arise through allostery, in which effective cooperativity emerges indirectly from an ensemble of dynamically interchanging conformations. Conformational ensembles play important roles in many cellular processes but their integrative capabilities remain poorly understood. We show that sufficiently complex ensembles can implement any form of information integration achievable without energy expenditure, including all patterns of HOCs. Our results provide a rigorous biophysical foundation for analysing the integration of binding information through allostery. We discuss the implications for eukaryotic gene regulation, where complex conformational dynamics accompanies widespread information integration.
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Affiliation(s)
- John W Biddle
- Department of Systems Biology, Harvard Medical School, Boston, United States
| | | | - Felix Wong
- Institute for Medical Engineering and Science, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, United States.,Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, United States
| | - Jeremy Gunawardena
- Department of Systems Biology, Harvard Medical School, Boston, United States
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12
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Gopi S, Lukose B, Naganathan AN. Diverse Native Ensembles Dictate the Differential Functional Responses of Nuclear Receptor Ligand-Binding Domains. J Phys Chem B 2021; 125:3546-3555. [PMID: 33818099 DOI: 10.1021/acs.jpcb.1c00972] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Native states of folded proteins are characterized by a large ensemble of conformations whose relative populations and interconversion dynamics determine the functional output. This is more apparent in transcription factors that have evolved to be inherently sensitive to small perturbations, thus fine-tuning gene expression. To explore the extent to which such functional features are imprinted on the folding landscape of transcription factor ligand-binding domains (LBDs), we characterize paralogous LBDs of the nuclear receptor (NR) family employing an energetically detailed and ensemble-based Ising-like statistical mechanical model. We find that the native ensembles of the LBDs from glucocorticoid receptor, PPAγ, and thyroid hormone receptor display a remarkable diversity in the width of the native wells, the number and nature of partially structured states, and hence the degree of conformational order. Monte Carlo simulations employing the full state representation of the ensemble highlight that many of the functional conformations coexist in equilibrium, whose relative populations are sensitive to both temperature and the strength of ligand binding. Allosteric modulation of the degree of structure at a coregulator binding site on ligand binding is shown to arise via a redistribution of populations in the native ensembles of glucocorticoid and PPAγ LBDs. Our results illustrate how functional requirements can drive the evolution of conformationally diverse native ensembles in paralogs.
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Affiliation(s)
- Soundhararajan Gopi
- Department of Biotechnology, Bhupat & Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600036, India
| | - Bincy Lukose
- Department of Biotechnology, Bhupat & Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600036, India
| | - Athi N Naganathan
- Department of Biotechnology, Bhupat & Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600036, India
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13
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NFAT5, which protects against hypertonicity, is activated by that stress via structuring of its intrinsically disordered domain. Proc Natl Acad Sci U S A 2020; 117:20292-20297. [PMID: 32747529 DOI: 10.1073/pnas.1911680117] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Nuclear Factor of Activated T cells 5 (NFAT5) is a transcription factor (TF) that mediates protection from adverse effects of hypertonicity by increasing transcription of genes, including those that lead to cellular accumulation of protective organic osmolytes. NFAT5 has three intrinsically ordered (ID) activation domains (ADs). Using the NFAT5 N-terminal domain (NTD), which contains AD1, as a model, we demonstrate by biophysical methods that the NTD senses osmolytes and hypertonicity, resulting in stabilization of its ID regions. In the presence of sufficient NaCl or osmolytes, trehalose and sorbitol, the NFAT5 NTD undergoes a disorder-to-order shift, adopting higher average secondary and tertiary structure. Thus, NFAT5 is activated by the stress that it protects against. In its salt and/or osmolyte-induced more ordered conformation, the NTD interacts with several proteins, including HMGI-C, which is known to protect against apoptosis. These findings raise the possibility that the increased intracellular ionic strength and elevated osmolytes caused by hypertonicity activate and stabilize NFAT5.
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14
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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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15
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A binding cooperativity switch driven by synergistic structural swelling of an osmo-regulatory protein pair. Nat Commun 2019; 10:1995. [PMID: 31040281 PMCID: PMC6491433 DOI: 10.1038/s41467-019-10002-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2018] [Accepted: 04/12/2019] [Indexed: 02/07/2023] Open
Abstract
Uropathogenic E. coli experience a wide range of osmolarity conditions before and after successful infection. Stress-responsive regulatory proteins in bacteria, particularly proteins of the Hha family and H-NS, a transcription repressor, sense such osmolarity changes and regulate transcription through unknown mechanisms. Here we use an array of experimental probes complemented by molecular simulations to show that Cnu, a member of the Hha protein family, acts as an exquisite molecular sensor of solvent ionic strength. The osmosensory behavior of Cnu involves a fine-tuned modulation of disorder in the fourth helix and the three-dimensional structure in a graded manner. Order-disorder transitions in H-NS act synergistically with molecular swelling of Cnu contributing to a salt-driven switch in binding cooperativity. Thus, sensitivity to ambient conditions can be imprinted at the molecular level by tuning not just the degree of order in the protein conformational ensemble but also through population redistributions of higher-order molecular complexes. The bacterial protein Cnu together with the transcription repressor H-NS regulate expression of virulence factors in an osmo-sensitive manner. Here authors show that the structure of Cnu swells with decreasing ionic strength driving the oligomerization of H-NS and regulating osmo-sensory response.
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16
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Recent Advances in Computational Protocols Addressing Intrinsically Disordered Proteins. Biomolecules 2019; 9:biom9040146. [PMID: 30979035 PMCID: PMC6523529 DOI: 10.3390/biom9040146] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 04/09/2019] [Accepted: 04/10/2019] [Indexed: 01/09/2023] Open
Abstract
Intrinsically disordered proteins (IDP) are abundant in the human genome and have recently emerged as major therapeutic targets for various diseases. Unlike traditional proteins that adopt a definitive structure, IDPs in free solution are disordered and exist as an ensemble of conformations. This enables the IDPs to signal through multiple signaling pathways and serve as scaffolds for multi-protein complexes. The challenge in studying IDPs experimentally stems from their disordered nature. Nuclear magnetic resonance (NMR), circular dichroism, small angle X-ray scattering, and single molecule Förster resonance energy transfer (FRET) can give the local structural information and overall dimension of IDPs, but seldom provide a unified picture of the whole protein. To understand the conformational dynamics of IDPs and how their structural ensembles recognize multiple binding partners and small molecule inhibitors, knowledge-based and physics-based sampling techniques are utilized in-silico, guided by experimental structural data. However, efficient sampling of the IDP conformational ensemble requires traversing the numerous degrees of freedom in the IDP energy landscape, as well as force-fields that accurately model the protein and solvent interactions. In this review, we have provided an overview of the current state of computational methods for studying IDP structure and dynamics and discussed the major challenges faced in this field.
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17
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Meijer FA, Leijten-van de Gevel IA, de Vries RMJM, Brunsveld L. Allosteric small molecule modulators of nuclear receptors. Mol Cell Endocrinol 2019; 485:20-34. [PMID: 30703487 DOI: 10.1016/j.mce.2019.01.022] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 01/23/2019] [Accepted: 01/25/2019] [Indexed: 02/08/2023]
Abstract
Nuclear Receptors (NRs) are multi-domain proteins, whose natural regulation occurs via ligands for a classical, orthosteric, binding pocket and via intra- and inter-domain allosteric mechanisms. Allosteric modulation of NRs via synthetic small molecules has recently emerged as an interesting entry to address the need for small molecules targeting NRs in pathology, via novel modes of action and with beneficial profiles. In this review the general concept of allosteric modulation in drug discovery is first discussed, serving as a background and inspiration for NRs. Subsequently, the review focuses on examples of small molecules that allosterically modulate NRs, with a strong focus on structural information and the ligand binding domain. Recently discovered nanomolar potent allosteric site NR modulators are catapulting allosteric targeting of NRs to the center of attention. The obtained insights serve as a basis for recommendations for the next steps to take in allosteric small molecular targeting of NRs.
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Affiliation(s)
- Femke A Meijer
- Laboratory of Chemical Biology, Department of Biomedical Engineering and Institute for Complex Molecular Systems, Technische Universiteit Eindhoven, Den Dolech 2, 5612AZ, Eindhoven, the Netherlands
| | - Iris A Leijten-van de Gevel
- Laboratory of Chemical Biology, Department of Biomedical Engineering and Institute for Complex Molecular Systems, Technische Universiteit Eindhoven, Den Dolech 2, 5612AZ, Eindhoven, the Netherlands
| | - Rens M J M de Vries
- Laboratory of Chemical Biology, Department of Biomedical Engineering and Institute for Complex Molecular Systems, Technische Universiteit Eindhoven, Den Dolech 2, 5612AZ, Eindhoven, the Netherlands
| | - Luc Brunsveld
- Laboratory of Chemical Biology, Department of Biomedical Engineering and Institute for Complex Molecular Systems, Technische Universiteit Eindhoven, Den Dolech 2, 5612AZ, Eindhoven, the Netherlands.
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18
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Lead Identification Through the Synergistic Action of Biomolecular NMR and In Silico Methodologies. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2019; 1824:299-316. [PMID: 30039415 DOI: 10.1007/978-1-4939-8630-9_18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
The combination of virtual screening with biomolecular NMR can be a powerful approach in the first steps toward drug discovery. Here, we describe how computational methodologies to screen large databases readily available for testing small molecules, in synergy with NMR techniques focused on protein-ligand interactions, can be used in the early lead compound identification process against a protein drug target.
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19
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Berlow RB, Martinez-Yamout MA, Dyson HJ, Wright PE. Role of Backbone Dynamics in Modulating the Interactions of Disordered Ligands with the TAZ1 Domain of the CREB-Binding Protein. Biochemistry 2019; 58:1354-1362. [PMID: 30775911 DOI: 10.1021/acs.biochem.8b01290] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The intrinsically disordered transactivation domains of HIF-1α and CITED2 compete for binding of the TAZ1 domain of the CREB-binding protein by a unidirectional allosteric mechanism involving direct competition for shared binding sites, ternary complex formation, and TAZ1 conformational changes. To gain insight into the mechanism by which CITED2 displaces HIF-1α from TAZ1, we used nuclear magnetic resonance spin relaxation methods to obtain an atomic-level description of the picosecond to nanosecond backbone dynamics that contribute to TAZ1 binding and competition. We show that HIF-1α and CITED2 adopt different dynamics in their complexes with TAZ1, with flexibility observed for HIF-1α in regions that would maintain accessibility for CITED2 to bind to TAZ1 and facilitate subsequent HIF-1α dissociation. In contrast, critical regions of CITED2 adopt a rigid structure in its complex with TAZ1, minimizing the ability of HIF-1α to compete for binding. We also find that TAZ1, previously thought to be a rigid scaffold for binding of disordered protein ligands, displays altered backbone dynamics in its various bound states. TAZ1 is more rigid in its CITED2-bound state than in its free state or in complex with HIF-1α, with increased rigidity observed not only in the CITED2 binding site but also in regions of TAZ1 that undergo conformational changes between the HIF-1α- and CITED2-bound structures. Taken together, these data suggest that backbone dynamics in TAZ1, as well as in the HIF-1α and CITED2 ligands, play a role in modulating the occupancy of TAZ1 and highlight the importance of characterizing both binding partners in molecular interactions.
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Affiliation(s)
- Rebecca B Berlow
- Department of Integrative Structural and Computational Biology and Skaggs Institute of Chemical Biology , The Scripps Research Institute , 10550 North Torrey Pines Road , La Jolla , California 92037 , United States
| | - Maria A Martinez-Yamout
- Department of Integrative Structural and Computational Biology and Skaggs Institute of Chemical Biology , The Scripps Research Institute , 10550 North Torrey Pines Road , La Jolla , California 92037 , United States
| | - H Jane Dyson
- Department of Integrative Structural and Computational Biology and Skaggs Institute of Chemical Biology , The Scripps Research Institute , 10550 North Torrey Pines Road , La Jolla , California 92037 , United States
| | - Peter E Wright
- Department of Integrative Structural and Computational Biology and Skaggs Institute of Chemical Biology , The Scripps Research Institute , 10550 North Torrey Pines Road , La Jolla , California 92037 , United States
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20
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A comprehensive ensemble model for comparing the allosteric effect of ordered and disordered proteins. PLoS Comput Biol 2018; 14:e1006393. [PMID: 30507941 PMCID: PMC6292653 DOI: 10.1371/journal.pcbi.1006393] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 12/13/2018] [Accepted: 11/02/2018] [Indexed: 12/26/2022] Open
Abstract
Intrinsically disordered proteins/regions (IDPs/IDRs) are prevalent in allosteric regulation. It was previously thought that intrinsic disorder is favorable for maximizing the allosteric coupling. Here, we propose a comprehensive ensemble model to compare the roles of both order-order transition and disorder-order transition in allosteric effect. It is revealed that the MWC pathway (order-order transition) has a higher probability than the EAM pathway (disorder-order transition) in allostery, suggesting a complicated role of IDPs/IDRs in regulatory proteins. In addition, an analytic formula for the maximal allosteric coupling response is obtained, which shows that too stable or too unstable state is unfavorable to endow allostery, and is thus helpful for rational design of allosteric drugs. Allosteric effect is an important regulation mechanism in biological processes, where the binding of a ligand at one site of a protein influences the function of a distant site. Conventionally, allostery was thought to originate from structural transition. However, in recent years, intrinsically disordered proteins (IDPs) were found to be widely involved in allosteric regulation in despite of their lack of ordered structure under physiological condition. It is still a mystery why IDPs are prevalent in allosteric proteins and how they differ from ordered proteins in allostery. Here, we propose a comprehensive ensemble model which includes both ordered and disordered states of a two-domain protein, and investigate the role of various state combinations in allosteric effect. By sampling the parameter space, we conclude that disordered proteins are less competitive than ordered proteins in performing allostery from a thermodynamic point of view. The prevalence of IDPs in allosteric regulation is likely determined by all their advantage, but not only by their capacity in endowing allostery.
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21
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Narayan A, Naganathan AN. Switching Protein Conformational Substates by Protonation and Mutation. J Phys Chem B 2018; 122:11039-11047. [PMID: 30048131 DOI: 10.1021/acs.jpcb.8b05108] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Protein modules that regulate the availability and conformational status of transcription factors determine the rapidity, duration, and magnitude of cellular response to changing conditions. One such system is the single-gene product Cnu, a four-helix bundle transcription co-repressor, which acts as a molecular thermosensor regulating the expression of virulence genes in enterobacteriaceae through modulation of its native conformational ensemble. Cnu and related genes have also been implicated in pH-dependent expression of virulence genes. We hypothesize that protonation of a conserved buried histidine (H45) in Cnu promotes large electrostatic frustration, thus disturbing the H-NS, a transcription factor, binding face. Spectroscopic and calorimetric methods reveal that H45 exhibits a suppressed p Ka of ∼5.1, the protonation of which switches the conformation to an alternate native ensemble in which the fourth helix is disordered. The population redistribution can also be achieved through a mutation H45V, which does not display any switching behavior at pH values greater than 4. The Wako-Saitô-Muñoz-Eaton (WSME) statistical mechanical model predicts specific differences in the conformations and fluctuations of the fourth and first helices of Cnu determining the observed pH response. We validate these predictions through fluorescence lifetime measurements of a sole tryptophan, highlighting the presence of both native and non-native interactions in the regions adjoining the binding face of Cnu. Our combined experimental-computational study thus shows that Cnu acts both as a thermo- and pH-sensor orchestrated via a subtle but quantifiable balance between the weak packing of a structural element and protonation of a buried histidine that promotes electrostatic frustration.
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Affiliation(s)
- Abhishek Narayan
- Department of Biotechnology, Bhupat & Jyoti Mehta School of Biosciences , Indian Institute of Technology Madras , Chennai 600036 , India
| | - Athi N Naganathan
- Department of Biotechnology, Bhupat & Jyoti Mehta School of Biosciences , Indian Institute of Technology Madras , Chennai 600036 , India
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22
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Anti-Correlation between the Dynamics of the Active Site Loop and C-Terminal Tail in Relation to the Homodimer Asymmetry of the Mouse Erythroid 5-Aminolevulinate Synthase. Int J Mol Sci 2018; 19:ijms19071899. [PMID: 29958424 PMCID: PMC6073955 DOI: 10.3390/ijms19071899] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 06/21/2018] [Accepted: 06/22/2018] [Indexed: 11/17/2022] Open
Abstract
Biosynthesis of heme represents a complex process that involves multiple stages controlled by different enzymes. The first of these proteins is a pyridoxal 5′-phosphate (PLP)-dependent homodimeric enzyme, 5-aminolevulinate synthase (ALAS), that catalyzes the rate-limiting step in heme biosynthesis, the condensation of glycine with succinyl-CoA. Genetic mutations in human erythroid-specific ALAS (ALAS2) are associated with two inherited blood disorders, X-linked sideroblastic anemia (XLSA) and X-linked protoporphyria (XLPP). XLSA is caused by diminished ALAS2 activity leading to decreased ALA and heme syntheses and ultimately ineffective erythropoiesis, whereas XLPP results from “gain-of-function” ALAS2 mutations and consequent overproduction of protoporphyrin IX and increase in Zn2+-protoporphyrin levels. All XLPP-linked mutations affect the intrinsically disordered C-terminal tail of ALAS2. Our earlier molecular dynamics (MD) simulation-based analysis showed that the activity of ALAS2 could be regulated by the conformational flexibility of the active site loop whose structural features and dynamics could be changed due to mutations. We also revealed that the dynamic behavior of the two protomers of the ALAS2 dimer differed. However, how the structural dynamics of ALAS2 active site loop and C-terminal tail dynamics are related to each other and contribute to the homodimer asymmetry remained unanswered questions. In this study, we used bioinformatics and computational biology tools to evaluate the role(s) of the C-terminal tail dynamics in the structure and conformational dynamics of the murine ALAS2 homodimer active site loop. To assess the structural correlation between these two regions, we analyzed their structural displacements and determined their degree of correlation. Here, we report that the dynamics of ALAS2 active site loop is anti-correlated with the dynamics of the C-terminal tail and that this anti-correlation can represent a molecular basis for the functional and dynamic asymmetry of the ALAS2 homodimer.
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23
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White JT, Li J, Grasso E, Wrabl JO, Hilser VJ. Ensemble allosteric model: energetic frustration within the intrinsically disordered glucocorticoid receptor. Philos Trans R Soc Lond B Biol Sci 2018; 373:20170175. [PMID: 29735729 PMCID: PMC5941170 DOI: 10.1098/rstb.2017.0175] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/22/2018] [Indexed: 01/21/2023] Open
Abstract
Allostery is an important regulatory phenomenon enabling precise control of biological function. Initial understanding of allostery was gained from seminal work on conformational changes exhibited by structured proteins. Within the last decade, protein allostery has also been demonstrated to occur within intrinsically disordered proteins. This emerging concept of disorder-mediated allostery can be usefully understood in the context of a thermodynamic ensemble. The advantage of this ensemble allosteric model is that it unifies the explanations of allostery occurring within both structured and disordered proteins. One central finding from this model is that energetic coupling, the transmission of a signal between separate regions (or domains) of a protein, is maximized when one or more domains are disordered. This is due to a disorder-order transition that contributes additional coupling energy to the allosteric system through formation of a molecular interaction surface or interface. A second key finding is that multiple interfaces may constructively or destructively interfere with each other, resulting in a new form of allosteric regulation called 'energetic frustration'. Articulating protein allostery in terms of the thermodynamic ensemble permits formulation of experimentally testable hypotheses which can increase fundamental understanding and direct drug-design efforts. These ideas are illustrated here with the specific case of human glucocorticoid receptor, a medically important multi-domain allosteric protein that contains both structured and disordered regions and exemplifies 'energetic frustration'.This article is part of a discussion meeting issue 'Allostery and molecular machines'.
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Affiliation(s)
- Jordan T White
- Department of Biology, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA
| | - Jing Li
- Department of Biology, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA
- Thomas C. Jenkins Department of Biophysics, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA
| | - Emily Grasso
- Department of Biology, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA
- Thomas C. Jenkins Department of Biophysics, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA
| | - James O Wrabl
- Department of Biology, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA
| | - Vincent J Hilser
- Department of Biology, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA
- Thomas C. Jenkins Department of Biophysics, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA
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24
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Berlow RB, Dyson HJ, Wright PE. Expanding the Paradigm: Intrinsically Disordered Proteins and Allosteric Regulation. J Mol Biol 2018; 430:2309-2320. [PMID: 29634920 DOI: 10.1016/j.jmb.2018.04.003] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 03/23/2018] [Accepted: 04/03/2018] [Indexed: 11/30/2022]
Abstract
Allosteric regulatory processes are implicated at all levels of biological function. Recent advances in our understanding of the diverse and functionally significant class of intrinsically disordered proteins have identified a multitude of ways in which disordered proteins function within the confines of the allosteric paradigm. Allostery within or mediated by intrinsically disordered proteins ensures robust and efficient signal integration through mechanisms that would be extremely unfavorable or even impossible for globular protein interaction partners. Here, we highlight recent examples that indicate the breadth of biological outcomes that can be achieved through allosteric regulation by intrinsically disordered proteins. Ongoing and future work in this rapidly evolving area of research will expand our appreciation of the central role of intrinsically disordered proteins in ensuring the fidelity and efficiency of cellular regulation.
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Affiliation(s)
- Rebecca B Berlow
- Department of Integrative Structural and Computational Biology and Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - H Jane Dyson
- Department of Integrative Structural and Computational Biology and Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Peter E Wright
- Department of Integrative Structural and Computational Biology and Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
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25
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Lisi GP, Currier AA, Loria JP. Glutamine Hydrolysis by Imidazole Glycerol Phosphate Synthase Displays Temperature Dependent Allosteric Activation. Front Mol Biosci 2018; 5:4. [PMID: 29468164 PMCID: PMC5808140 DOI: 10.3389/fmolb.2018.00004] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 01/09/2018] [Indexed: 11/13/2022] Open
Abstract
The enzyme imidazole glycerol phosphate synthase (IGPS) is a model for studies of long-range allosteric regulation in enzymes. Binding of the allosteric effector ligand N'-[5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamide-ribonucleotide (PRFAR) stimulates millisecond (ms) timescale motions in IGPS that enhance its catalytic function. We studied the effect of temperature on these critical conformational motions and the catalytic mechanism of IGPS from the hyperthermophile Thermatoga maritima in an effort to understand temperature-dependent allostery. Enzyme kinetic and NMR dynamics measurements show that apo and PRFAR-activated IGPS respond differently to changes in temperature. Multiple-quantum Carr-Purcell-Meiboom-Gill (CPMG) relaxation dispersion experiments performed at 303, 323, and 343 K (30, 50, and 70°C) reveal that millisecond flexibility is enhanced to a higher degree in apo IGPS than in the PRFAR-bound enzyme as the sample temperature is raised. We find that the flexibility of the apo enzyme is nearly identical to that of its PRFAR activated state at 343 K, whereas conformational motions are considerably different between these two forms of the enzyme at room temperature. Arrhenius analyses of these flexible sites show a varied range of activation energies that loosely correlate to allosteric communities identified by computational methods and reflect local changes in dynamics that may facilitate conformational sampling of the active conformation. In addition, kinetic assays indicate that allosteric activation by PRFAR decreases to 65-fold at 343 K, compared to 4,200-fold at 303 K, which mirrors the decreased effect of PRFAR on ms motions relative to the unactivated enzyme. These studies indicate that at the growth temperature of T. maritima, PFRAR is a weaker allosteric activator than it is at room temperature and illustrate that the allosteric mechanism of IGPS is temperature dependent.
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Affiliation(s)
- George P Lisi
- Department of Chemistry, Yale University, New Haven, CT, United States
| | - Allen A Currier
- Department of Chemistry, Yale University, New Haven, CT, United States
| | - J Patrick Loria
- Department of Chemistry, Yale University, New Haven, CT, United States.,Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, United States
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26
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Gardner NW, McGinness SM, Panchal J, Topp EM, Park C. A Cooperative Folding Unit as the Structural Link for Energetic Coupling within a Protein. Biochemistry 2017; 56:6555-6564. [PMID: 29166011 DOI: 10.1021/acs.biochem.7b00850] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Previously, we demonstrated that binding of a ligand to Escherichia coli cofactor-dependent phosphoglycerate mutase (dPGM), a homodimeric protein, is energetically coupled with dimerization. The equilibrium unfolding of dPGM occurs with a stable, monomeric intermediate. Binding of several nonsubstrate metabolites stabilizes the dimeric native form over the monomeric intermediate, reducing the population of the intermediate. Both the active site and the dimer interface appear to be unfolded in the intermediate. We hypothesized that a loop containing residues 118-152 was responsible for the energetic coupling between the dimer interface and the distal active site and was unfolded in the intermediate. Here, we investigated the structure of the dPGM intermediate by probing side-chain interactions and solvent accessibility of the peptide backbone. By comparing the effect of a mutation on the global stability and the stability of the intermediate, we determine an equilibrium φ value (φeq value), which provides information about whether side-chain interactions are retained or lost in the intermediate. Hydrogen/deuterium exchange coupled with mass spectrometry (HDX-MS) was used to investigate differences in the solvent accessibility of the peptide backbone in the intermediate and native forms of dPGM. The results of φeq value analysis and HDX-MS reveal the least stable folding unit of dPGM, which is unfolded in the intermediate and links the active site to the dimer interface. The structure of the intermediate reveals how the cooperative network of residues in dPGM gives rise to the observed energetic coupling between dimerization and ligand binding.
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Affiliation(s)
- Nathan W Gardner
- Department of Medicinal Chemistry and Molecular Pharmacology, ‡Interdisciplinary Life Science Graduate Program, §Department of Industrial and Physical Pharmacy, and ∥Bindley Bioscience Center, Purdue University , West Lafayette, Indiana 47907, United States
| | - Sarah M McGinness
- Department of Medicinal Chemistry and Molecular Pharmacology, ‡Interdisciplinary Life Science Graduate Program, §Department of Industrial and Physical Pharmacy, and ∥Bindley Bioscience Center, Purdue University , West Lafayette, Indiana 47907, United States
| | - Jainik Panchal
- Department of Medicinal Chemistry and Molecular Pharmacology, ‡Interdisciplinary Life Science Graduate Program, §Department of Industrial and Physical Pharmacy, and ∥Bindley Bioscience Center, Purdue University , West Lafayette, Indiana 47907, United States
| | - Elizabeth M Topp
- Department of Medicinal Chemistry and Molecular Pharmacology, ‡Interdisciplinary Life Science Graduate Program, §Department of Industrial and Physical Pharmacy, and ∥Bindley Bioscience Center, Purdue University , West Lafayette, Indiana 47907, United States
| | - Chiwook Park
- Department of Medicinal Chemistry and Molecular Pharmacology, ‡Interdisciplinary Life Science Graduate Program, §Department of Industrial and Physical Pharmacy, and ∥Bindley Bioscience Center, Purdue University , West Lafayette, Indiana 47907, United States
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27
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The contribution of intrinsically disordered regions to protein function, cellular complexity, and human disease. Biochem Soc Trans 2017; 44:1185-1200. [PMID: 27911701 PMCID: PMC5095923 DOI: 10.1042/bst20160172] [Citation(s) in RCA: 259] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 07/20/2016] [Accepted: 07/22/2016] [Indexed: 12/23/2022]
Abstract
In the 1960s, Christian Anfinsen postulated that the unique three-dimensional structure of a protein is determined by its amino acid sequence. This work laid the foundation for the sequence–structure–function paradigm, which states that the sequence of a protein determines its structure, and structure determines function. However, a class of polypeptide segments called intrinsically disordered regions does not conform to this postulate. In this review, I will first describe established and emerging ideas about how disordered regions contribute to protein function. I will then discuss molecular principles by which regulatory mechanisms, such as alternative splicing and asymmetric localization of transcripts that encode disordered regions, can increase the functional versatility of proteins. Finally, I will discuss how disordered regions contribute to human disease and the emergence of cellular complexity during organismal evolution.
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28
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Thayer KM, Lakhani B, Beveridge DL. Molecular Dynamics-Markov State Model of Protein Ligand Binding and Allostery in CRIB-PDZ: Conformational Selection and Induced Fit. J Phys Chem B 2017; 121:5509-5514. [PMID: 28489401 DOI: 10.1021/acs.jpcb.7b02083] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Conformational selection and induced fit are well-known contributors to ligand binding and allosteric effects in proteins. Molecular dynamics (MD) simulations now enable the theoretical study of protein-ligand binding in terms of ensembles of interconverting microstates and the population shifts characteristic of "dynamical allostery." Here we investigate protein-ligand binding and allostery based on a Markov state model (MSM) with states and rates obtained from all-atom MD simulations. As an exemplary case, we consider the single domain protein par-6 PDZ with and without ligand and allosteric effector. This is one of the smallest proteins in which allostery has been experimentally observed. In spite of the increased complexity intrinsic to a statistical ensemble perspective, we find that conformational selection and induced fit mechanisms can be readily identified in the analysis. In the nonallosteric pathway, MD-MSM shows that PDZ binds ligand via conformational selection. However, the allosteric pathway requires an activation step that involves a conformational change induced by the allosteric effector Cdc42. Once in the allosterically activated state, we find that ligand binding can proceed by conformational selection. Our MD-MSM model predicts that allostery in this and possibly other systems involves both induced fit and conformational selection, not just one or the other.
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Affiliation(s)
- Kelly M Thayer
- Departments of Chemistry, ‡Molecular Biology & Biochemistry, §Molecular Biophysics Program, and ∥Department of Computer Science, Wesleyan University , Middletown, Connecticut 06459, United States of America
| | - Bharat Lakhani
- Departments of Chemistry, ‡Molecular Biology & Biochemistry, §Molecular Biophysics Program, and ∥Department of Computer Science, Wesleyan University , Middletown, Connecticut 06459, United States of America
| | - David L Beveridge
- Departments of Chemistry, ‡Molecular Biology & Biochemistry, §Molecular Biophysics Program, and ∥Department of Computer Science, Wesleyan University , Middletown, Connecticut 06459, United States of America
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29
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Berlow RB, Dyson HJ, Wright PE. Hypersensitive termination of the hypoxic response by a disordered protein switch. Nature 2017; 543:447-451. [PMID: 28273070 PMCID: PMC5375031 DOI: 10.1038/nature21705] [Citation(s) in RCA: 117] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 02/14/2017] [Indexed: 12/18/2022]
Abstract
The cellular response to hypoxia is critical for cell survival and is fine-tuned to allow cells to recover from hypoxic stress and adapt to heterogeneous or fluctuating oxygen levels1,2. The hypoxic response is mediated by the α subunit of the transcription factor HIF-1 (HIF-1α)3, which interacts via its intrinsically disordered C-terminal transactivation domain with the TAZ1 (CH1) domain of the general transcriptional coactivators CBP and p300 to control transcription of critical adaptive genes4–6. One such gene is CITED2, a negative feedback regulator that attenuates HIF transcriptional activity by competing for TAZ1 binding through its own disordered transactivation domain7–9. Little is known about the molecular mechanism by which CITED2 displaces the tightly bound HIF-1α from their common cellular target. The HIF-1α and CITED2 transactivation domains bind to TAZ1 through helical motifs that flank a conserved LP(Q/E)L sequence that is essential for negative feedback regulation5,6,8,9. We show that CITED2 displaces HIF-1α by forming a transient ternary complex with TAZ1 and HIF-1α and competing for a shared binding site via its LPEL motif, thus promoting a conformational change in TAZ1 that increases the rate of HIF-1α dissociation. Through allosteric enhancement of HIF-1α release, CITED2 activates a highly responsive negative feedback circuit that rapidly and efficiently attenuates the hypoxic response, even at modest CITED2 concentrations. This hypersensitive regulatory switch is entirely dependent on the unique flexibility and binding properties of these intrinsically disordered proteins and exemplifies a likely common strategy used by the cell to respond rapidly to environmental signals.
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Affiliation(s)
- Rebecca B Berlow
- Department of Integrative Structural and Computational Biology and Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA
| | - H Jane Dyson
- Department of Integrative Structural and Computational Biology and Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA
| | - Peter E Wright
- Department of Integrative Structural and Computational Biology and Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA
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30
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Teilum K, Kunze MBA, Erlendsson S, Kragelund BB. (S)Pinning down protein interactions by NMR. Protein Sci 2017; 26:436-451. [PMID: 28019676 PMCID: PMC5326574 DOI: 10.1002/pro.3105] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2016] [Revised: 12/14/2016] [Accepted: 12/14/2016] [Indexed: 11/29/2022]
Abstract
Protein molecules are highly diverse communication platforms and their interaction repertoire stretches from atoms over small molecules such as sugars and lipids to macromolecules. An important route to understanding molecular communication is to quantitatively describe their interactions. These types of analyses determine the amounts and proportions of individual constituents that participate in a reaction as well as their rates of reactions and their thermodynamics. Although many different methods are available, there is currently no single method able to quantitatively capture and describe all types of protein reactions, which can span orders of magnitudes in affinities, reaction rates, and lifetimes of states. As the more versatile technique, solution NMR spectroscopy offers a remarkable catalogue of methods that can be successfully applied to the quantitative as well as qualitative descriptions of protein interactions. In this review we provide an easy-access approach to NMR for the non-NMR specialist and describe how and when solution state NMR spectroscopy is the method of choice for addressing protein ligand interaction. We describe very briefly the theoretical background and illustrate simple protein-ligand interactions as well as typical strategies for measuring binding constants using NMR spectroscopy. Finally, this review provides examples of caveats of the method as well as the options to improve the outcome of an NMR analysis of a protein interaction reaction.
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Affiliation(s)
- Kaare Teilum
- Structural Biology and NMR LaboratoryThe Linderstrøm‐Lang Centre for Protein Science, Department of Biology, University of CopenhagenOle Maaløes Vej 5, DK‐2200Copenhagen NDenmark
| | - Micha Ben Achim Kunze
- Structural Biology and NMR LaboratoryThe Linderstrøm‐Lang Centre for Protein Science, Department of Biology, University of CopenhagenOle Maaløes Vej 5, DK‐2200Copenhagen NDenmark
| | - Simon Erlendsson
- Structural Biology and NMR LaboratoryThe Linderstrøm‐Lang Centre for Protein Science, Department of Biology, University of CopenhagenOle Maaløes Vej 5, DK‐2200Copenhagen NDenmark
| | - Birthe B. Kragelund
- Structural Biology and NMR LaboratoryThe Linderstrøm‐Lang Centre for Protein Science, Department of Biology, University of CopenhagenOle Maaløes Vej 5, DK‐2200Copenhagen NDenmark
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31
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Schueler-Furman O, Wodak SJ. Computational approaches to investigating allostery. Curr Opin Struct Biol 2016; 41:159-171. [PMID: 27607077 DOI: 10.1016/j.sbi.2016.06.017] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 06/23/2016] [Indexed: 01/01/2023]
Abstract
Allosteric regulation plays a key role in many biological processes, such as signal transduction, transcriptional regulation, and many more. It is rooted in fundamental thermodynamic and dynamic properties of macromolecular systems that are still poorly understood and are moreover modulated by the cellular context. Here we review the computational approaches used in the investigation of allosteric processes in protein systems. We outline how the models of allostery have evolved from their initial formulation in the sixties to the current views, which more fully account for the roles of the thermodynamic and dynamic properties of the system. We then describe the major classes of computational approaches employed to elucidate the mechanisms of allostery, the insights they have provided, as well as their limitations. We complement this analysis by highlighting the role of computational approaches in promising practical applications, such as the engineering of regulatory modules and identifying allosteric binding sites.
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Affiliation(s)
- Ora Schueler-Furman
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada (IMRIC), Hebrew University, Hadassah Medical School, POB 12272, Jerusalem 91120, Israel
| | - Shoshana J Wodak
- VIB Structural Biology Research Center, VUB, Pleinlaan 2, 1050 Brussels, Belgium.
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32
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Lisi GP, Manley GA, Hendrickson H, Rivalta I, Batista VS, Loria JP. Dissecting Dynamic Allosteric Pathways Using Chemically Related Small-Molecule Activators. Structure 2016; 24:1155-66. [PMID: 27238967 PMCID: PMC4938718 DOI: 10.1016/j.str.2016.04.010] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 04/20/2016] [Accepted: 04/22/2016] [Indexed: 01/26/2023]
Abstract
The allosteric mechanism of the heterodimeric enzyme imidazole glycerol phosphate synthase was studied in detail with solution nuclear magnetic resonance spectroscopy and molecular dynamics simulations. We studied IGPS in complex with a series of allosteric activators corresponding to a large range of catalytic rate enhancements (26- to 4,900-fold), in which ligand binding is entropically driven. Conformational flexibility on the millisecond timescale plays a crucial role in intersubunit communication. Carr-Purcell-Meiboom-Gill relaxation dispersion experiments probing Ile, Leu, and Val methyl groups reveal that the apo- and glutamine-mimicked complexes are static on the millisecond timescale. Domain-wide motions are stimulated in the presence of the allosteric activators. These studies, in conjunction with ligand titrations, demonstrate that the allosteric network is widely dispersed and varies with the identity of the effector. Furthermore, we find that stronger allosteric ligands create more conformational flexibility on the millisecond timescale throughout HisF. This domain-wide loosening leads to maximum catalytic activity.
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Affiliation(s)
- George P Lisi
- Department of Chemistry, Yale University, New Haven, CT 06520, USA
| | - Gregory A Manley
- Department of Chemistry, Yale University, New Haven, CT 06520, USA
| | | | - Ivan Rivalta
- École Normale Supérieure de Lyon, CNRS, Université Lyon 1, Laboratoire de Chimie UMR 5182, 46, Allée d'Italie, 69364 Lyon Cedex 07, France
| | - Victor S Batista
- Department of Chemistry, Yale University, New Haven, CT 06520, USA.
| | - J Patrick Loria
- Department of Chemistry, Yale University, New Haven, CT 06520, USA; Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT 06520, USA.
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33
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Abstract
Allostery is a ubiquitous biological regulatory process in which distant binding sites within a protein or enzyme are functionally and thermodynamically coupled. Allosteric interactions play essential roles in many enzymological mechanisms, often facilitating formation of enzyme-substrate complexes and/or product release. Thus, elucidating the forces that drive allostery is critical to understanding the complex transformations of biomolecules. Currently, a number of models exist to describe allosteric behavior, taking into account energetics as well as conformational rearrangements and fluctuations. In the following Review, we discuss the use of solution NMR techniques designed to probe allosteric mechanisms in enzymes. NMR spectroscopy is unequaled in its ability to detect structural and dynamical changes in biomolecules, and the case studies presented herein demonstrate the range of insights to be gained from this valuable method. We also provide a detailed technical discussion of several specialized NMR experiments that are ideally suited for the study of enzymatic allostery.
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Affiliation(s)
- George P. Lisi
- Department of Chemistry, Yale University, New Haven, CT 06520
| | - J. Patrick Loria
- Department of Chemistry, Yale University, New Haven, CT 06520
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT 06520
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34
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Fenton AW. Are all regions of folded proteins that undergo ligand-dependent order-disorder transitions targets for allosteric peptide mimetics? Biopolymers 2016; 100:553-7. [PMID: 23520021 DOI: 10.1002/bip.22239] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Revised: 03/11/2013] [Accepted: 03/17/2013] [Indexed: 02/06/2023]
Abstract
Although the classical view of how proteins function relied on well folded structures, it is now recognized that the functions of many proteins are dependent on being intrinsically disordered. The primary consideration in this work is the intermediate group of proteins that are overall well folded, but which contain small regions that undergo order-disorder transitions. In particular, the current focus is on those order-disorder transitions that are energetically coupled to ligand binding. As exemplified by the case of human liver pyruvate kinase (hL-PYK), peptides that mimic the sequence of the order-disorder region can be used as allosteric regulators of the enzyme. On the basis of this example and others reported in the literature, we propose that a similar use of peptides that mimic protein regions that experience ligand-dependent order-disorder transitions can be a generalized initiation point for the development of allosteric drugs.
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Affiliation(s)
- Aron W Fenton
- Department of Biochemistry and Molecular Biology, The University of Kansas Medical Center, MS 3030, 3901 Rainbow Boulevard, Kansas City, KS, 66160
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35
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Csizmok V, Follis AV, Kriwacki RW, Forman-Kay JD. Dynamic Protein Interaction Networks and New Structural Paradigms in Signaling. Chem Rev 2016; 116:6424-62. [PMID: 26922996 DOI: 10.1021/acs.chemrev.5b00548] [Citation(s) in RCA: 130] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Understanding signaling and other complex biological processes requires elucidating the critical roles of intrinsically disordered proteins (IDPs) and regions (IDRs), which represent ∼30% of the proteome and enable unique regulatory mechanisms. In this review, we describe the structural heterogeneity of disordered proteins that underpins these mechanisms and the latest progress in obtaining structural descriptions of conformational ensembles of disordered proteins that are needed for linking structure and dynamics to function. We describe the diverse interactions of IDPs that can have unusual characteristics such as "ultrasensitivity" and "regulated folding and unfolding". We also summarize the mounting data showing that large-scale assembly and protein phase separation occurs within a variety of signaling complexes and cellular structures. In addition, we discuss efforts to therapeutically target disordered proteins with small molecules. Overall, we interpret the remodeling of disordered state ensembles due to binding and post-translational modifications within an expanded framework for allostery that provides significant insights into how disordered proteins transmit biological information.
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Affiliation(s)
- Veronika Csizmok
- Molecular Structure & Function, The Hospital for Sick Children , Toronto, ON M5G 0A4, Canada
| | - Ariele Viacava Follis
- Department of Structural Biology, St. Jude Children's Research Hospital , Memphis, Tennessee 38105, United States
| | - Richard W Kriwacki
- Department of Structural Biology, St. Jude Children's Research Hospital , Memphis, Tennessee 38105, United States.,Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Sciences Center , Memphis, Tennessee 38163, United States
| | - Julie D Forman-Kay
- Molecular Structure & Function, The Hospital for Sick Children , Toronto, ON M5G 0A4, Canada.,Department of Biochemistry, University of Toronto , Toronto, ON M5S 1A8, Canada
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36
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Morra G, Genoni A, Colombo G. Mechanisms of Differential Allosteric Modulation in Homologous Proteins: Insights from the Analysis of Internal Dynamics and Energetics of PDZ Domains. J Chem Theory Comput 2015; 10:5677-89. [PMID: 26583250 DOI: 10.1021/ct500326g] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Allostery is a general phenomenon in proteins whereby a perturbation at one site reverberates into a functional change at another one, through modulation of its conformational dynamics. Herein, we address the problem of how the molecular signal encoded by a ligand is differentially transmitted through the structures of two homologous PDZ proteins: PDZ2, which responds to binding with structural and dynamical changes in regions distal from the ligand site, and PDZ3, which is characterized by less-intense dynamical variations. We use novel methods of analysis of MD simulations in the unbound and bound states to investigate the determinants of the differential allosteric behavior of the two proteins. The analysis of the correlations between the redistribution of stabilization energy and local fluctuation patterns highlights the nucleus of residues responsible for the stabilization of the 3D fold, the stability core, as the substructure that defines the difference in the allosteric response: in PDZ2, it undergoes a consistent dynamic and energetic reorganization, whereas in PDZ3, it remains largely unperturbed. Specifically, we observe for PDZ2 a significant anticorrelation between the motions of distal loops and residues of the stability core and differences in the correlation patterns between the bound and unbound states. Such variation is not observed in PDZ3, indicating that its energetics and internal dynamics are less affected by the presence/absence of the ligand. Finally, we propose a model with a direct link between the modulation of the structural, energetic and dynamic properties of a protein, and its allosteric response to a perturbation.
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Affiliation(s)
- Giulia Morra
- Istituto di Chimica del Riconoscimento Molecolare, Consiglio Nazionale delle Ricerche Via Mario Bianco 9, 20131 Milano, Italy
| | - Alessandro Genoni
- Istituto di Chimica del Riconoscimento Molecolare, Consiglio Nazionale delle Ricerche Via Mario Bianco 9, 20131 Milano, Italy.,CNRS, Laboratoire SRSMC, UMR 7565, Vandoeuvre-lès-Nancy F-54506, France.,Université de Lorraine, Laboratoire SRSMC, UMR 7565, Vandoeuvre-lès-Nancy F-54506, France
| | - Giorgio Colombo
- Istituto di Chimica del Riconoscimento Molecolare, Consiglio Nazionale delle Ricerche Via Mario Bianco 9, 20131 Milano, Italy
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37
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Kornev AP, Taylor SS. Dynamics-Driven Allostery in Protein Kinases. Trends Biochem Sci 2015; 40:628-647. [PMID: 26481499 DOI: 10.1016/j.tibs.2015.09.002] [Citation(s) in RCA: 187] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 08/27/2015] [Accepted: 09/01/2015] [Indexed: 01/05/2023]
Abstract
Protein kinases have very dynamic structures and their functionality strongly depends on their dynamic state. Active kinases reveal a dynamic pattern with residues clustering into semirigid communities that move in μs-ms timescale. Previously detected hydrophobic spines serve as connectors between communities. Communities do not follow the traditional subdomain structure of the kinase core or its secondary structure elements. Instead they are organized around main functional units. Integration of the communities depends on the assembly of the hydrophobic spine and phosphorylation of the activation loop. Single mutations can significantly disrupt the dynamic infrastructure and thereby interfere with long-distance allosteric signaling that propagates throughout the whole molecule. Dynamics is proposed to be the underlying mechanism for allosteric regulation in protein kinases.
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Affiliation(s)
- Alexandr P Kornev
- Department of Pharmacology, University of California at San Diego, La Jolla, CA, 92093, USA.
| | - Susan S Taylor
- Department of Pharmacology, University of California at San Diego, La Jolla, CA, 92093, USA; Department of Chemistry and Biochemistry, University of California at San Diego, La Jolla, CA, 92093, USA.
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38
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Narayan V, Landré V, Ning J, Hernychova L, Muller P, Verma C, Walkinshaw MD, Blackburn EA, Ball KL. Protein-Protein Interactions Modulate the Docking-Dependent E3-Ubiquitin Ligase Activity of Carboxy-Terminus of Hsc70-Interacting Protein (CHIP). Mol Cell Proteomics 2015; 14:2973-87. [PMID: 26330542 PMCID: PMC4638040 DOI: 10.1074/mcp.m115.051169] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Indexed: 11/07/2022] Open
Abstract
CHIP is a tetratricopeptide repeat (TPR) domain protein that functions as an E3-ubiquitin ligase. As well as linking the molecular chaperones to the ubiquitin proteasome system, CHIP also has a docking-dependent mode where it ubiquitinates native substrates, thereby regulating their steady state levels and/or function. Here we explore the effect of Hsp70 on the docking-dependent E3-ligase activity of CHIP. The TPR-domain is revealed as a binding site for allosteric modulators involved in determining CHIP's dynamic conformation and activity. Biochemical, biophysical and modeling evidence demonstrate that Hsp70-binding to the TPR, or Hsp70-mimetic mutations, regulate CHIP-mediated ubiquitination of p53 and IRF-1 through effects on U-box activity and substrate binding. HDX-MS was used to establish that conformational-inhibition-signals extended from the TPR-domain to the U-box. This underscores inter-domain allosteric regulation of CHIP by the core molecular chaperones. Defining the chaperone-associated TPR-domain of CHIP as a manager of inter-domain communication highlights the potential for scaffolding modules to regulate, as well as assemble, complexes that are fundamental to protein homeostatic control.
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Affiliation(s)
- Vikram Narayan
- From the ‡IGMM, University of Edinburgh Cancer Research Centre, Cell Signalling Unit, Crewe Road South, Edinburgh EH4 2XR, UK
| | - Vivien Landré
- From the ‡IGMM, University of Edinburgh Cancer Research Centre, Cell Signalling Unit, Crewe Road South, Edinburgh EH4 2XR, UK
| | - Jia Ning
- From the ‡IGMM, University of Edinburgh Cancer Research Centre, Cell Signalling Unit, Crewe Road South, Edinburgh EH4 2XR, UK; §CTCB, Institute of Structural and Molecular Biology, University of Edinburgh, The King's Buildings, Mayfield Road, Edinburgh EH9 3JR, UK
| | - Lenka Hernychova
- ¶Regional Centre for Applied Molecular Oncology, Masaryk Memorial Cancer Institute, 656 53 Brno, Czech Republic
| | - Petr Muller
- ¶Regional Centre for Applied Molecular Oncology, Masaryk Memorial Cancer Institute, 656 53 Brno, Czech Republic
| | - Chandra Verma
- ‖Bioinformatics Institute (A*STAR), 30 Biopolis Street, 07-01 Matrix, Singapore 138671; Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543; School of Biological Sciences, Nanyang Technological University, 60 Nayang Drive, Singapore 637551
| | - Malcolm D Walkinshaw
- §CTCB, Institute of Structural and Molecular Biology, University of Edinburgh, The King's Buildings, Mayfield Road, Edinburgh EH9 3JR, UK
| | - Elizabeth A Blackburn
- §CTCB, Institute of Structural and Molecular Biology, University of Edinburgh, The King's Buildings, Mayfield Road, Edinburgh EH9 3JR, UK
| | - Kathryn L Ball
- From the ‡IGMM, University of Edinburgh Cancer Research Centre, Cell Signalling Unit, Crewe Road South, Edinburgh EH4 2XR, UK;
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39
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Berlow RB, Dyson HJ, Wright PE. Functional advantages of dynamic protein disorder. FEBS Lett 2015; 589:2433-40. [PMID: 26073260 DOI: 10.1016/j.febslet.2015.06.003] [Citation(s) in RCA: 138] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Revised: 05/29/2015] [Accepted: 06/01/2015] [Indexed: 11/19/2022]
Abstract
Intrinsically disordered proteins participate in many important cellular regulatory processes. The absence of a well-defined structure in the free state of a disordered domain, and even on occasion when it is bound to physiological partners, is fundamental to its function. Disordered domains are frequently the location of multiple sites for post-translational modification, the key element of metabolic control in the cell. When a disordered domain folds upon binding to a partner, the resulting complex buries a far greater surface area than in an interaction of comparably-sized folded proteins, thus maximizing specificity at modest protein size. Disorder also maintains accessibility of sites for post-translational modification. Because of their inherent plasticity, disordered domains frequently adopt entirely different structures when bound to different partners, increasing the repertoire of available interactions without the necessity for expression of many different proteins. This feature also adds to the faithfulness of cellular regulation, as the availability of a given disordered domain depends on competition between various partners relevant to different cellular processes.
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Affiliation(s)
- Rebecca B Berlow
- Department of Integrative Structural and Computational Biology and Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - H Jane Dyson
- Department of Integrative Structural and Computational Biology and Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Peter E Wright
- Department of Integrative Structural and Computational Biology and Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
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40
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Latysheva NS, Flock T, Weatheritt RJ, Chavali S, Babu MM. How do disordered regions achieve comparable functions to structured domains? Protein Sci 2015; 24:909-22. [PMID: 25752799 PMCID: PMC4456105 DOI: 10.1002/pro.2674] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Revised: 02/25/2015] [Accepted: 03/03/2015] [Indexed: 12/19/2022]
Abstract
The traditional structure to function paradigm conceives of a protein's function as emerging from its structure. In recent years, it has been established that unstructured, intrinsically disordered regions (IDRs) in proteins are equally crucial elements for protein function, regulation and homeostasis. In this review, we provide a brief overview of how IDRs can perform similar functions to structured proteins, focusing especially on the formation of protein complexes and assemblies and the mediation of regulated conformational changes. In addition to highlighting instances of such functional equivalence, we explain how differences in the biological and physicochemical properties of IDRs allow them to expand the functional and regulatory repertoire of proteins. We also discuss studies that provide insights into how mutations within functional regions of IDRs can lead to human diseases.
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Affiliation(s)
| | - Tilman Flock
- MRC Laboratory of Molecular BiologyCambridge, CB2 0QH, United Kingdom
| | | | - Sreenivas Chavali
- MRC Laboratory of Molecular BiologyCambridge, CB2 0QH, United Kingdom
| | - M Madan Babu
- MRC Laboratory of Molecular BiologyCambridge, CB2 0QH, United Kingdom
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41
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Papaleo E. Integrating atomistic molecular dynamics simulations, experiments, and network analysis to study protein dynamics: strength in unity. Front Mol Biosci 2015; 2:28. [PMID: 26075210 PMCID: PMC4445042 DOI: 10.3389/fmolb.2015.00028] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 05/08/2015] [Indexed: 12/11/2022] Open
Abstract
In the last years, we have been observing remarkable improvements in the field of protein dynamics. Indeed, we can now study protein dynamics in atomistic details over several timescales with a rich portfolio of experimental and computational techniques. On one side, this provides us with the possibility to validate simulation methods and physical models against a broad range of experimental observables. On the other side, it also allows a complementary and comprehensive view on protein structure and dynamics. What is needed now is a better understanding of the link between the dynamic properties that we observe and the functional properties of these important cellular machines. To make progresses in this direction, we need to improve the physical models used to describe proteins and solvent in molecular dynamics, as well as to strengthen the integration of experiments and simulations to overcome their own limitations. Moreover, now that we have the means to study protein dynamics in great details, we need new tools to understand the information embedded in the protein ensembles and in their dynamic signature. With this aim in mind, we should enrich the current tools for analysis of biomolecular simulations with attention to the effects that can be propagated over long distances and are often associated to important biological functions. In this context, approaches inspired by network analysis can make an important contribution to the analysis of molecular dynamics simulations.
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Affiliation(s)
- Elena Papaleo
- Structural Biology and Nuclear Magnetic Resonance Laboratory, Department of Biology, University of Copenhagen Copenhagen, Denmark
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42
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Abstract
The allosterically-induced outcome of nitric oxide (NO) binding to soluble guanylate cyclase (sGC) is well known but poorly understood. As described in this issue of Structure, Underbakke and coworkers apply a powerful hydrogen/deuterium exchange method to follow the key structural elements of the pathway between NO binding and sGC catalytic site activation.
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Affiliation(s)
- Andrew P Braun
- Department of Physiology and Pharmacology, Faculty of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, AB T2N 4N1, Canada
| | - David C Schriemer
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, AB T2N 4N1, Canada.
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43
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Affiliation(s)
- Irisbel Guzman
- Department
of Biochemistry, University of Illinois, Urbana, Illinois 61801, United States
| | - Martin Gruebele
- Department
of Chemistry, Department of Physics, Center for the Physics of Living
Cells, and Center for Biophysics and Quantitative Biology, University of Illinois, Urbana, Illinois 61801, United States
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44
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Gunawardena J. Time-scale separation--Michaelis and Menten's old idea, still bearing fruit. FEBS J 2014; 281:473-88. [PMID: 24103070 PMCID: PMC3991559 DOI: 10.1111/febs.12532] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 08/30/2013] [Accepted: 09/09/2013] [Indexed: 11/30/2022]
Abstract
Michaelis and Menten introduced to biochemistry the idea of time-scale separation, in which part of a system is assumed to be operating sufficiently fast compared to the rest so that it may be taken to have reached a steady state. This allows, in principle, the fast components to be eliminated, resulting in a simplified description of the system's behaviour. Similar ideas have been widely used in different areas of biology, including enzyme kinetics, protein allostery, receptor pharmacology, gene regulation and post-translational modification. However, the methods used have been independent and ad hoc. In the present study, we review the use of time-scale separation as a means to simplify the description of molecular complexity and discuss recent work setting out a single framework that unifies these separate calculations. The framework offers new capabilities for mathematical analysis and helps to do justice to Michaelis and Menten's insights about individual enzymes in the context of multi-enzyme biological systems.
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Affiliation(s)
- Jeremy Gunawardena
- Department of Systems Biology, Harvard Medical School 200 Longwood Avenue, Boston, MA 02115, USA. ; Tel: (617) 432 4839; Fax: (617) 432 5012
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45
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Tompa P. Multisteric Regulation by Structural Disorder in Modular Signaling Proteins: An Extension of the Concept of Allostery. Chem Rev 2013; 114:6715-32. [DOI: 10.1021/cr4005082] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Peter Tompa
- VIB Department of Structural
Biology, Vrije Universiteit Brussel, 1050 Brussels, Belgium
- Institute of Enzymology, Biological Research Center, Hungarian Academy
of Sciences, Budapest H-1113, Hungary
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46
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Xia Y, DiPrimio N, Keppel TR, Vo B, Fraser K, Battaile KP, Egan C, Bystroff C, Lovell S, Weis DD, Anderson JC, Karanicolas J. The designability of protein switches by chemical rescue of structure: mechanisms of inactivation and reactivation. J Am Chem Soc 2013; 135:18840-9. [PMID: 24313858 DOI: 10.1021/ja407644b] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The ability to selectively activate function of particular proteins via pharmacological agents is a longstanding goal in chemical biology. Recently, we reported an approach for designing a de novo allosteric effector site directly into the catalytic domain of an enzyme. This approach is distinct from traditional chemical rescue of enzymes in that it relies on disruption and restoration of structure, rather than active site chemistry, as a means to achieve modulate function. However, rationally identifying analogous de novo binding sites in other enzymes represents a key challenge for extending this approach to introduce allosteric control into other enzymes. Here we show that mutation sites leading to protein inactivation via tryptophan-to-glycine substitution and allowing (partial) reactivation by the subsequent addition of indole are remarkably frequent. Through a suite of methods including a cell-based reporter assay, computational structure prediction and energetic analysis, fluorescence studies, enzymology, pulse proteolysis, X-ray crystallography, and hydrogen-deuterium mass spectrometry, we find that these switchable proteins are most commonly modulated indirectly, through control of protein stability. Addition of indole in these cases rescues activity not by reverting a discrete conformational change, as we had observed in the sole previously reported example, but rather rescues activity by restoring protein stability. This important finding will dramatically impact the design of future switches and sensors built by this approach, since evaluating stability differences associated with cavity-forming mutations is a far more tractable task than predicting allosteric conformational changes. By analogy to natural signaling systems, the insights from this study further raise the exciting prospect of modulating stability to design optimal recognition properties into future de novo switches and sensors built through chemical rescue of structure.
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Affiliation(s)
- Yan Xia
- Department of Molecular Biosciences, ‡Department of Chemistry, §Protein Structure Laboratory, and ∥Center for Bioinformatics, University of Kansas , Lawrence, Kansas 66045, United States
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Abstract
IDPs (intrinsically disordered proteins) are common in eukaryotic genomes and have regulatory roles. In the cell, they are disordered, although not completely random. They bind weakly, but specifically, often remaining partially disordered even when bound. Whereas folded globular proteins have ‘executive’ roles in the cell, IDPs have an essential administrative function, making sure that the executive functions are properly co-ordinated. This makes them a good target for pharmaceutical intervention.
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