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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Holehouse AS, Kragelund BB. The molecular basis for cellular function of intrinsically disordered protein regions. Nat Rev Mol Cell Biol 2024; 25:187-211. [PMID: 37957331 DOI: 10.1038/s41580-023-00673-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/26/2023] [Indexed: 11/15/2023]
Abstract
Intrinsically disordered protein regions exist in a collection of dynamic interconverting conformations that lack a stable 3D structure. These regions are structurally heterogeneous, ubiquitous and found across all kingdoms of life. Despite the absence of a defined 3D structure, disordered regions are essential for cellular processes ranging from transcriptional control and cell signalling to subcellular organization. Through their conformational malleability and adaptability, disordered regions extend the repertoire of macromolecular interactions and are readily tunable by their structural and chemical context, making them ideal responders to regulatory cues. Recent work has led to major advances in understanding the link between protein sequence and conformational behaviour in disordered regions, yet the link between sequence and molecular function is less well defined. Here we consider the biochemical and biophysical foundations that underlie how and why disordered regions can engage in productive cellular functions, provide examples of emerging concepts and discuss how protein disorder contributes to intracellular information processing and regulation of cellular function.
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Affiliation(s)
- Alex S Holehouse
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St Louis, MO, USA.
- Center for Biomolecular Condensates, Washington University in St Louis, St Louis, MO, USA.
| | - Birthe B Kragelund
- REPIN, Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
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3
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Zavrtanik U, Medved T, Purič S, Vranken W, Lah J, Hadži S. Leucine Motifs Stabilize Residual Helical Structure in Disordered Proteins. J Mol Biol 2024; 436:168444. [PMID: 38218366 DOI: 10.1016/j.jmb.2024.168444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Revised: 12/31/2023] [Accepted: 01/09/2024] [Indexed: 01/15/2024]
Abstract
Many examples are known of regions of intrinsically disordered proteins that fold into α-helices upon binding to their targets. These helical binding motifs (HBMs) can be partially helical also in the unbound state, and this so-called residual structure can affect binding affinity and kinetics. To investigate the underlying mechanisms governing the formation of residual helical structure, we assembled a dataset of experimental helix contents of 65 peptides containing HBM that fold-upon-binding. The average residual helicity is 17% and increases to 60% upon target binding. The helix contents of residual and target-bound structures do not correlate, however the relative location of helix elements in both states shows a strong overlap. Compared to the general disordered regions, HBMs are enriched in amino acids with high helix preference and these residues are typically involved in target binding, explaining the overlap in helix positions. In particular, we find that leucine residues and leucine motifs in HBMs are the major contributors to helix stabilization and target-binding. For the two model peptides, we show that substitution of leucine motifs to other hydrophobic residues (valine or isoleucine) leads to reduction of residual helicity, supporting the role of leucine as helix stabilizer. From the three hydrophobic residues only leucine can efficiently stabilize residual helical structure. We suggest that the high occurrence of leucine motifs and a general preference for leucine at binding interfaces in HBMs can be explained by its unique ability to stabilize helical elements.
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Affiliation(s)
- Uroš Zavrtanik
- Department of Physical Chemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Tadej Medved
- Department of Physical Chemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Samo Purič
- Graduate Study Program, Faculty of Chemistry and Chemical Technology, University of Ljubljana, SI-1000 Ljubljana, Slovenia
| | - Wim Vranken
- Artificial Intelligence Laboratory, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium; Interuniversity Institute of Bioinformatics in Brussels, ULB/VUB, Triomflaan, 1050 Brussels, Belgium; Structural Biology Brussels, Vrije Universiteit Brussel, Brussels 1050, Belgium; VIB Structural Biology Research Centre, Brussels 1050, Belgium
| | - Jurij Lah
- Department of Physical Chemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - San Hadži
- Department of Physical Chemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, 1000 Ljubljana, Slovenia.
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4
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Mantonico MV, De Leo F, Quilici G, Colley LS, De Marchis F, Crippa M, Mezzapelle R, Schulte T, Zucchelli C, Pastorello C, Carmeno C, Caprioglio F, Ricagno S, Giachin G, Ghitti M, Bianchi ME, Musco G. The acidic intrinsically disordered region of the inflammatory mediator HMGB1 mediates fuzzy interactions with CXCL12. Nat Commun 2024; 15:1201. [PMID: 38331917 PMCID: PMC10853541 DOI: 10.1038/s41467-024-45505-7] [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: 05/17/2023] [Accepted: 01/26/2024] [Indexed: 02/10/2024] Open
Abstract
Chemokine heterodimers activate or dampen their cognate receptors during inflammation. The CXCL12 chemokine forms with the fully reduced (fr) alarmin HMGB1 a physiologically relevant heterocomplex (frHMGB1•CXCL12) that synergically promotes the inflammatory response elicited by the G-protein coupled receptor CXCR4. The molecular details of complex formation were still elusive. Here we show by an integrated structural approach that frHMGB1•CXCL12 is a fuzzy heterocomplex. Unlike previous assumptions, frHMGB1 and CXCL12 form a dynamic equimolar assembly, with structured and unstructured frHMGB1 regions recognizing the CXCL12 dimerization surface. We uncover an unexpected role of the acidic intrinsically disordered region (IDR) of HMGB1 in heterocomplex formation and its binding to CXCR4 on the cell surface. Our work shows that the interaction of frHMGB1 with CXCL12 diverges from the classical rigid heterophilic chemokines dimerization. Simultaneous interference with multiple interactions within frHMGB1•CXCL12 might offer pharmacological strategies against inflammatory conditions.
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Affiliation(s)
- Malisa Vittoria Mantonico
- Biomolecular NMR Laboratory, Division of Genetics and Cell Biology, IRCCS Ospedale San Raffaele, Milan, Italy
- School of Medicine, Università Vita e Salute-San Raffaele, Milan, Italy
| | - Federica De Leo
- Biomolecular NMR Laboratory, Division of Genetics and Cell Biology, IRCCS Ospedale San Raffaele, Milan, Italy
- Experimental Therapeutics Program, IFOM ETS - The AIRC Institute of Molecular Oncology and AIRC, Fondazione AIRC per la Ricerca sul Cancro ETS, Milan, Italy
| | - Giacomo Quilici
- Biomolecular NMR Laboratory, Division of Genetics and Cell Biology, IRCCS Ospedale San Raffaele, Milan, Italy
| | - Liam Sean Colley
- HMGBiotech S.r.l., 20133, Milan, Italy
- School of Medicine and Surgery, Università Milano-Bicocca, 20126, Milan, Italy
| | - Francesco De Marchis
- School of Medicine, Università Vita e Salute-San Raffaele, Milan, Italy
- Chromatin Dynamics Unit, Division of Genetics and Cell Biology, IRCCS Ospedale San Raffaele, Milan, Italy
| | - Massimo Crippa
- Chromatin Dynamics Unit, Division of Genetics and Cell Biology, IRCCS Ospedale San Raffaele, Milan, Italy
| | - Rosanna Mezzapelle
- School of Medicine, Università Vita e Salute-San Raffaele, Milan, Italy
- Chromatin Dynamics Unit, Division of Genetics and Cell Biology, IRCCS Ospedale San Raffaele, Milan, Italy
| | - Tim Schulte
- Institute of Molecular and Translational Cardiology, IRCCS Policlinico San Donato, Milan, Italy
| | - Chiara Zucchelli
- Biomolecular NMR Laboratory, Division of Genetics and Cell Biology, IRCCS Ospedale San Raffaele, Milan, Italy
| | - Chiara Pastorello
- Biomolecular NMR Laboratory, Division of Genetics and Cell Biology, IRCCS Ospedale San Raffaele, Milan, Italy
| | - Camilla Carmeno
- Biomolecular NMR Laboratory, Division of Genetics and Cell Biology, IRCCS Ospedale San Raffaele, Milan, Italy
| | - Francesca Caprioglio
- School of Medicine, Università Vita e Salute-San Raffaele, Milan, Italy
- Chromatin Dynamics Unit, Division of Genetics and Cell Biology, IRCCS Ospedale San Raffaele, Milan, Italy
| | - Stefano Ricagno
- Institute of Molecular and Translational Cardiology, IRCCS Policlinico San Donato, Milan, Italy
- Department of Biosciences, Università degli Studi di Milano, Milan, Italy
| | - Gabriele Giachin
- Department of Chemical Sciences (DiSC), University of Padua, 35131, Padova, Italy
| | - Michela Ghitti
- Biomolecular NMR Laboratory, Division of Genetics and Cell Biology, IRCCS Ospedale San Raffaele, Milan, Italy.
| | - Marco Emilio Bianchi
- School of Medicine, Università Vita e Salute-San Raffaele, Milan, Italy
- Chromatin Dynamics Unit, Division of Genetics and Cell Biology, IRCCS Ospedale San Raffaele, Milan, Italy
| | - Giovanna Musco
- Biomolecular NMR Laboratory, Division of Genetics and Cell Biology, IRCCS Ospedale San Raffaele, Milan, Italy.
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5
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Sisk TR, Robustelli P. Folding-upon-binding pathways of an intrinsically disordered protein from a deep Markov state model. Proc Natl Acad Sci U S A 2024; 121:e2313360121. [PMID: 38294935 PMCID: PMC10861926 DOI: 10.1073/pnas.2313360121] [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: 08/10/2023] [Accepted: 11/22/2023] [Indexed: 02/02/2024] Open
Abstract
A central challenge in the study of intrinsically disordered proteins is the characterization of the mechanisms by which they bind their physiological interaction partners. Here, we utilize a deep learning-based Markov state modeling approach to characterize the folding-upon-binding pathways observed in a long timescale molecular dynamics simulation of a disordered region of the measles virus nucleoprotein NTAIL reversibly binding the X domain of the measles virus phosphoprotein complex. We find that folding-upon-binding predominantly occurs via two distinct encounter complexes that are differentiated by the binding orientation, helical content, and conformational heterogeneity of NTAIL. We observe that folding-upon-binding predominantly proceeds through a multi-step induced fit mechanism with several intermediates and do not find evidence for the existence of canonical conformational selection pathways. We observe four kinetically separated native-like bound states that interconvert on timescales of eighty to five hundred nanoseconds. These bound states share a core set of native intermolecular contacts and stable NTAIL helices and are differentiated by a sequential formation of native and non-native contacts and additional helical turns. Our analyses provide an atomic resolution structural description of intermediate states in a folding-upon-binding pathway and elucidate the nature of the kinetic barriers between metastable states in a dynamic and heterogenous, or "fuzzy", protein complex.
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Affiliation(s)
- Thomas R. Sisk
- Department of Chemistry, Dartmouth College, Hanover, NH03755
| | - Paul Robustelli
- Department of Chemistry, Dartmouth College, Hanover, NH03755
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6
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Lobel JH, Ingolia NT. Defining the mechanisms and properties of post-transcriptional regulatory disordered regions by high-throughput functional profiling. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.01.578453. [PMID: 38370681 PMCID: PMC10871298 DOI: 10.1101/2024.02.01.578453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Disordered regions within RNA binding proteins are required to control mRNA decay and protein synthesis. To understand how these disordered regions modulate gene expression, we surveyed regulatory activity across the entire disordered proteome using a high-throughput functional assay. We identified hundreds of regulatory sequences within intrinsically disordered regions and demonstrate how these elements cooperate with core mRNA decay machinery to promote transcript turnover. Coupling high-throughput functional profiling with mutational scanning revealed diverse molecular features, ranging from defined motifs to overall sequence composition, underlying the regulatory effects of disordered peptides. Machine learning analysis implicated aromatic residues in particular contexts as critical determinants of repressor activity, consistent with their roles in forming protein-protein interactions with downstream effectors. Our results define the molecular principles and biochemical mechanisms that govern post-transcriptional gene regulation by disordered regions and exemplify the encoding of diverse yet specific functions in the absence of well-defined structure.
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Affiliation(s)
- Joseph H Lobel
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Nicholas T Ingolia
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
- Lead contact
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7
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James EI, Baggett DW, Chang E, Schachter J, Nixey T, Choi K, Guttman M, Nath A. Tryptanthrin Analogs Substoichiometrically Inhibit Seeded and Unseeded Tau4RD Aggregation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.02.578649. [PMID: 38352474 PMCID: PMC10862865 DOI: 10.1101/2024.02.02.578649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
Microtubule-associated protein tau is an intrinsically disordered protein (IDP) that forms characteristic fibrillar aggregates in several diseases, the most well-known of which is Alzheimer's disease (AD). Despite keen interest in disrupting or inhibiting tau aggregation to treat AD and related dementias, there are currently no FDA-approved tau-targeting drugs. This is due, in part, to the fact that tau and other IDPs do not exhibit a single well-defined conformation but instead populate a fluctuating conformational ensemble that precludes finding a stable "druggable" pocket. Despite this challenge, we previously reported the discovery of two novel families of tau ligands, including a class of aggregation inhibitors, identified through a protocol that combines molecular dynamics, structural analysis, and machine learning. Here we extend our exploration of tau druggability with the identification of tryptanthrin and its analogs as potent, substoichiometric aggregation inhibitors, with the best compounds showing potencies in the low nanomolar range even at a ~100-fold molar excess of tau4RD. Moreover, conservative changes in small molecule structure can have large impacts on inhibitory potency, demonstrating that similar structure-activity relationship (SAR) principles as used for traditional drug development also apply to tau and potentially to other IDPs.
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Affiliation(s)
- Ellie I. James
- Department of Medicinal Chemistry, University of Washington, Seattle, WA
- Molecular Engineering & Sciences Institute, University of Washington, Seattle, WA
| | - David W. Baggett
- Department of Medicinal Chemistry, University of Washington, Seattle, WA
- Current address: Department of Structural Biology, St. Jude Children’s Research Hospital, Memphis, TN
| | - Edcon Chang
- Takeda Development Center Americas, San Diego, CA
| | | | - Thomas Nixey
- Takeda Development Center Americas, San Diego, CA
| | | | - Miklos Guttman
- Department of Medicinal Chemistry, University of Washington, Seattle, WA
- Molecular Engineering & Sciences Institute, University of Washington, Seattle, WA
| | - Abhinav Nath
- Department of Medicinal Chemistry, University of Washington, Seattle, WA
- Molecular Engineering & Sciences Institute, University of Washington, Seattle, WA
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8
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Jiao X, Di Sante G, Casimiro MC, Tantos A, Ashton AW, Li Z, Quach Y, Bhargava D, Di Rocco A, Pupo C, Crosariol M, Lazar T, Tompa P, Wang C, Yu Z, Zhang Z, Aldaaysi K, Vadlamudi R, Mann M, Skordalakes E, Kossenkov A, Du Y, Pestell RG. A cyclin D1 intrinsically disordered domain accesses modified histone motifs to govern gene transcription. Oncogenesis 2024; 13:4. [PMID: 38191593 PMCID: PMC10774418 DOI: 10.1038/s41389-023-00502-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 11/09/2023] [Accepted: 12/05/2023] [Indexed: 01/10/2024] Open
Abstract
The essential G1-cyclin, CCND1, is frequently overexpressed in cancer, contributing to tumorigenesis by driving cell-cycle progression. D-type cyclins are rate-limiting regulators of G1-S progression in mammalian cells via their ability to bind and activate CDK4 and CDK6. In addition, cyclin D1 conveys kinase-independent transcriptional functions of cyclin D1. Here we report that cyclin D1 associates with H2BS14 via an intrinsically disordered domain (IDD). The same region of cyclin D1 was necessary for the induction of aneuploidy, induction of the DNA damage response, cyclin D1-mediated recruitment into chromatin, and CIN gene transcription. In response to DNA damage H2BS14 phosphorylation occurs, resulting in co-localization with γH2AX in DNA damage foci. Cyclin D1 ChIP seq and γH2AX ChIP seq revealed ~14% overlap. As the cyclin D1 IDD functioned independently of the CDK activity to drive CIN, the IDD domain may provide a rationale new target to complement CDK-extinction strategies.
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Affiliation(s)
- Xuanmao Jiao
- Baruch S. Blumberg Institute, Doylestown, PA, 18902, USA
- Xavier University School of Medicine at Aruba, Oranjestad, Aruba
| | | | - Mathew C Casimiro
- Baruch S. Blumberg Institute, Doylestown, PA, 18902, USA
- Department of Science and Mathematics, Abraham Baldwin Agricultural College, Tifton, GA, 31794, USA
| | - Agnes Tantos
- Institute of Enzymology, Hun-Ren Research Centre for Natural Sciences, Budapest, Hungary
| | - Anthony W Ashton
- Baruch S. Blumberg Institute, Doylestown, PA, 18902, USA
- Xavier University School of Medicine at Aruba, Oranjestad, Aruba
- Division of Cardiovascular Medicine, Lankenau Institute for Medical Research, Wynnewood, PA, 19003, USA
| | - Zhiping Li
- Baruch S. Blumberg Institute, Doylestown, PA, 18902, USA
- Xavier University School of Medicine at Aruba, Oranjestad, Aruba
| | - Yen Quach
- Xavier University School of Medicine at Aruba, Oranjestad, Aruba
| | | | | | - Claudia Pupo
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Marco Crosariol
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Tamas Lazar
- VIB-VUB Center for Structural Biology, Vrije Universiteit Brussel, Brussels, 1050, Belgium
| | - Peter Tompa
- Institute of Enzymology, Hun-Ren Research Centre for Natural Sciences, Budapest, Hungary
- VIB-VUB Center for Structural Biology, Vrije Universiteit Brussel, Brussels, 1050, Belgium
| | - Chenguang Wang
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Zuoren Yu
- Research Center for Translational Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, 200120, China
| | - Zhao Zhang
- Baruch S. Blumberg Institute, Doylestown, PA, 18902, USA
| | - Kawthar Aldaaysi
- Xavier University School of Medicine at Aruba, Oranjestad, Aruba
| | - Ratna Vadlamudi
- Department of Obstetrics and Gynecology, University of Texas Health Sciences Center, San Antonio, TX, 78229, USA
| | - Monica Mann
- Department of Obstetrics and Gynecology, University of Texas Health Sciences Center, San Antonio, TX, 78229, USA
| | | | | | - Yanming Du
- Baruch S. Blumberg Institute, Doylestown, PA, 18902, USA
| | - Richard G Pestell
- Baruch S. Blumberg Institute, Doylestown, PA, 18902, USA.
- Xavier University School of Medicine at Aruba, Oranjestad, Aruba.
- The Wistar Institute, Philadelphia, PA, 19107, USA.
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9
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Raveh B, Eliasian R, Rashkovits S, Russel D, Hayama R, Sparks SE, Singh D, Lim R, Villa E, Rout MP, Cowburn D, Sali A. Integrative spatiotemporal map of nucleocytoplasmic transport. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.12.31.573409. [PMID: 38260487 PMCID: PMC10802240 DOI: 10.1101/2023.12.31.573409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
The Nuclear Pore Complex (NPC) facilitates rapid and selective nucleocytoplasmic transport of molecules as large as ribosomal subunits and viral capsids. It is not clear how key emergent properties of this transport arise from the system components and their interactions. To address this question, we constructed an integrative coarse-grained Brownian dynamics model of transport through a single NPC, followed by coupling it with a kinetic model of Ran-dependent transport in an entire cell. The microscopic model parameters were fitted to reflect experimental data and theoretical information regarding the transport, without making any assumptions about its emergent properties. The resulting reductionist model is validated by reproducing several features of transport not used for its construction, such as the morphology of the central transporter, rates of passive and facilitated diffusion as a function of size and valency, in situ radial distributions of pre-ribosomal subunits, and active transport rates for viral capsids. The model suggests that the NPC functions essentially as a virtual gate whose flexible phenylalanine-glycine (FG) repeat proteins raise an entropy barrier to diffusion through the pore. Importantly, this core functionality is greatly enhanced by several key design features, including 'fuzzy' and transient interactions, multivalency, redundancy in the copy number of FG nucleoporins, exponential coupling of transport kinetics and thermodynamics in accordance with the transition state theory, and coupling to the energy-reliant RanGTP concentration gradient. These design features result in the robust and resilient rate and selectivity of transport for a wide array of cargo ranging from a few kilodaltons to megadaltons in size. By dissecting these features, our model provides a quantitative starting point for rationally modulating the transport system and its artificial mimics.
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10
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Torres Robles J, Lou HJ, Shi G, Pan PL, Turk BE. Linear motif specificity in signaling through p38α and ERK2 mitogen-activated protein kinases. Proc Natl Acad Sci U S A 2023; 120:e2316599120. [PMID: 37988460 PMCID: PMC10691213 DOI: 10.1073/pnas.2316599120] [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: 09/29/2023] [Accepted: 10/26/2023] [Indexed: 11/23/2023] Open
Abstract
Mitogen-activated protein kinase (MAPK) cascades are essential for eukaryotic cells to integrate and respond to diverse stimuli. Maintaining specificity in signaling through MAPK networks is key to coupling distinct inputs to appropriate cellular responses. Docking sites-short linear motifs found in MAPK substrates, regulators, and scaffolds-can promote signaling specificity through selective interactions, but how they do so remains unresolved. Here, we screened a proteomic library for sequences interacting with the MAPKs extracellular signal-regulated kinase 2 (ERK2) and p38α, identifying selective and promiscuous docking motifs. Sequences specific for p38α had high net charge and lysine content, and selective binding depended on a pair of acidic residues unique to the p38α docking interface. Finally, we validated a set of full-length proteins harboring docking sites selected in our screens to be authentic MAPK interactors and substrates. This study identifies features that help define MAPK signaling networks and explains how specific docking motifs promote signaling integrity.
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Affiliation(s)
- Jaylissa Torres Robles
- Department of Chemistry, Yale University, New Haven, CT06520
- Department of Pharmacology, Yale School of Medicine, New Haven, CT06520
| | - Hua Jane Lou
- Department of Pharmacology, Yale School of Medicine, New Haven, CT06520
| | - Guangda Shi
- Department of Pharmacology, Yale School of Medicine, New Haven, CT06520
| | | | - Benjamin E. Turk
- Department of Pharmacology, Yale School of Medicine, New Haven, CT06520
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11
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McCarthy DR, Remington JM, Ferrell JB, Schneebeli ST, Li J. Nano-Bio Interactions between DNA Nanocages and Human Serum Albumin. J Chem Theory Comput 2023; 19:7873-7881. [PMID: 37877553 PMCID: PMC11070245 DOI: 10.1021/acs.jctc.3c00720] [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] [Indexed: 10/26/2023]
Abstract
DNA nanostructures have emerged as promising nanomedical tools due to their biocompatibility and tunable behavior. Recent work has shown that DNA nanocages decorated with organic dendrimers strongly bind human serum albumin (HSA), yet the dynamic structures of these complexes remain uncharacterized. This theoretical and computational investigation elucidates the fuzzy interactions between dendritically functionalized cubic DNA nanocages and HSA. The dendrimer-HSA interactions occur via nonspecific binding with the protein thermodynamically and kinetically free to cross the open faces of the cubic scaffold. However, the rigidity of the DNA scaffold prevents the binding energetics from scaling with the number of dendrimers. These discoveries not only provide a useful framework by which to model general interactions of DNA nanostructures complexed with serum proteins but also give valuable molecular insight into the design of next-generation DNA nanomedicines.
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Affiliation(s)
| | | | | | - Severin T. Schneebeli
- Department of Chemistry, University of Vermont, Burlington, VT 05405
- Department of Industrial and Physical Pharmacy and Department of Chemistry, Purdue University, West Lafayette, IN 47907
| | - Jianing Li
- Department of Chemistry, University of Vermont, Burlington, VT 05405
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN 47907
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12
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Brown AD, Lynch K, Langelaan DN. The C-terminal transactivation domain of MITF interacts promiscuously with co-activator CBP/p300. Sci Rep 2023; 13:16094. [PMID: 37752231 PMCID: PMC10522771 DOI: 10.1038/s41598-023-43207-6] [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: 07/18/2023] [Accepted: 09/21/2023] [Indexed: 09/28/2023] Open
Abstract
The microphthalmia-associated transcription factor (MITF) is one of four closely related members of the MiT/TFE family (TFEB, TFE3, TFEC) that regulate a wide range of cellular processes. MITF is a key regulator of melanocyte-associated genes, and essential to proper development of the melanocyte cell lineage. Abnormal MITF activity can contribute to the onset of several diseases including melanoma, where MITF is an amplified oncogene. To enhance transcription, MITF recruits the co-activator CREB-binding protein (CBP) and its homolog p300 to gene promoters, however the molecular determinants of their interaction are not yet fully understood. Here, we characterize the interactions between the C-terminal MITF transactivation domain and CBP/p300. Using NMR spectroscopy, protein pulldown assays, and isothermal titration calorimetry we determine the C-terminal region of MITF is intrinsically disordered and binds with high-affinity to both TAZ1 and TAZ2 of CBP/p300. Mutagenesis studies revealed two conserved motifs within MITF that are necessary for TAZ2 binding and critical for MITF-dependent transcription of a reporter gene. Finally, we observe the transactivation potential of the MITF C-terminal region is reliant on the N-terminal transactivation domain for function. Taken together, our study helps elucidate the molecular details of how MITF interacts with CBP/p300 through multiple redundant interactions that lend insight into MITF function in melanocytes and melanoma.
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Affiliation(s)
- Alexandra D Brown
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, B3H 4R2, Canada
| | - Kyle Lynch
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, B3H 4R2, Canada
| | - David N Langelaan
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, B3H 4R2, Canada.
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13
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Sisk T, Robustelli P. Folding-upon-binding pathways of an intrinsically disordered protein from a deep Markov state model. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.21.550103. [PMID: 37546728 PMCID: PMC10401938 DOI: 10.1101/2023.07.21.550103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
A central challenge in the study of intrinsically disordered proteins is the characterization of the mechanisms by which they bind their physiological interaction partners. Here, we utilize a deep learning based Markov state modeling approach to characterize the folding-upon-binding pathways observed in a long-time scale molecular dynamics simulation of a disordered region of the measles virus nucleoprotein NTAIL reversibly binding the X domain of the measles virus phosphoprotein complex. We find that folding-upon-binding predominantly occurs via two distinct encounter complexes that are differentiated by the binding orientation, helical content, and conformational heterogeneity of NTAIL. We do not, however, find evidence for the existence of canonical conformational selection or induced fit binding pathways. We observe four kinetically separated native-like bound states that interconvert on time scales of eighty to five hundred nanoseconds. These bound states share a core set of native intermolecular contacts and stable NTAIL helices and are differentiated by a sequential formation of native and non-native contacts and additional helical turns. Our analyses provide an atomic resolution structural description of intermediate states in a folding-upon-binding pathway and elucidate the nature of the kinetic barriers between metastable states in a dynamic and heterogenous, or "fuzzy", protein complex.
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Affiliation(s)
- Thomas Sisk
- Dartmouth College, Department of Chemistry, Hanover, NH, 03755
| | - Paul Robustelli
- Dartmouth College, Department of Chemistry, Hanover, NH, 03755
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14
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Norris V, Oláh J, Krylov SN, Uversky VN, Ovádi J. The Sherpa hypothesis: Phenotype-Preserving Disordered Proteins stabilize the phenotypes of neurons and oligodendrocytes. NPJ Syst Biol Appl 2023; 9:31. [PMID: 37433867 DOI: 10.1038/s41540-023-00291-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Accepted: 06/19/2023] [Indexed: 07/13/2023] Open
Abstract
Intrinsically disordered proteins (IDPs), which can interact with many partner proteins, are central to many physiological functions and to various pathologies that include neurodegeneration. Here, we introduce the Sherpa hypothesis, according to which a subset of stable IDPs that we term Phenotype-Preserving Disordered Proteins (PPDP) play a central role in protecting cell phenotypes from perturbations. To illustrate and test this hypothesis, we computer-simulate some salient features of how cells evolve and differentiate in the presence of either a single PPDP or two incompatible PPDPs. We relate this virtual experiment to the pathological interactions between two PPDPs, α-synuclein and Tubulin Polymerization Promoting Protein/p25, in neurodegenerative disorders. Finally, we discuss the implications of the Sherpa hypothesis for aptamer-based therapies of such disorders.
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Affiliation(s)
- Vic Norris
- Laboratory of Microbiology Signals and Microenvironment, University of Rouen, 76821, Mont Saint Aignan, France.
| | - Judit Oláh
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, H-1117, Hungary
| | - Sergey N Krylov
- Centre for Research on Biomolecular Interactions, York University, Toronto, ON M3J1P3, Canada
| | - Vladimir N Uversky
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, 33612, USA
| | - Judit Ovádi
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, H-1117, Hungary
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15
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Cermakova K, Hodges HC. Interaction modules that impart specificity to disordered protein. Trends Biochem Sci 2023; 48:477-490. [PMID: 36754681 PMCID: PMC10106370 DOI: 10.1016/j.tibs.2023.01.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 01/09/2023] [Accepted: 01/12/2023] [Indexed: 02/09/2023]
Abstract
Intrinsically disordered regions (IDRs) are especially enriched among proteins that regulate chromatin and transcription. As a result, mechanisms that influence specificity of IDR-driven interactions have emerged as exciting unresolved issues for understanding gene regulation. We review the molecular elements frequently found within IDRs that confer regulatory specificity. In particular, we summarize the differing roles of disordered low-complexity regions (LCRs) and short linear motifs (SLiMs) towards selective nuclear regulation. Examination of IDR-driven interactions highlights SLiMs as organizers of selectivity, with widespread roles in gene regulation and integration of cellular signals. Analysis of recurrent interactions between SLiMs and folded domains suggests diverse avenues for SLiMs to influence phase-separated condensates and highlights opportunities to manipulate these interactions for control of biological activity.
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Affiliation(s)
- Katerina Cermakova
- Department of Molecular and Cellular Biology, Center for Precision Environmental Health, Baylor College of Medicine, Houston, TX, USA
| | - H Courtney Hodges
- Department of Molecular and Cellular Biology, Center for Precision Environmental Health, Baylor College of Medicine, Houston, TX, USA; Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, USA; Department of Bioengineering, Rice University, Houston, TX, USA; Center for Cancer Epigenetics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
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16
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Investigation of the Fuzzy Complex between RSV Nucleoprotein and Phosphoprotein to Optimize an Inhibition Assay by Fluorescence Polarization. Int J Mol Sci 2022; 24:ijms24010569. [PMID: 36614009 PMCID: PMC9820559 DOI: 10.3390/ijms24010569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 12/21/2022] [Accepted: 12/23/2022] [Indexed: 12/30/2022] Open
Abstract
The interaction between Respiratory Syncytial Virus phosphoprotein P and nucleoprotein N is essential for the formation of the holo RSV polymerase that carries out replication. In vitro screening of antivirals targeting the N-P protein interaction requires a molecular interaction model, ideally consisting of a complex between N protein and a short peptide corresponding to the C-terminal tail of the P protein. However, the flexibility of C-terminal P peptides as well as their phosphorylation status play a role in binding and may bias the outcome of an inhibition assay. We therefore investigated binding affinities and dynamics of this interaction by testing two N protein constructs and P peptides of different lengths and composition, using nuclear magnetic resonance and fluorescence polarization (FP). We show that, although the last C-terminal Phe241 residue is the main determinant for anchoring P to N, only longer peptides afford sub-micromolar affinity, despite increasing mobility towards the N-terminus. We investigated competitive binding by peptides and small compounds, including molecules used as fluorescent labels in FP. Based on these results, we draw optimized parameters for a robust RSV N-P inhibition assay and validated this assay with the M76 molecule, which displays antiviral properties, for further screening of chemical libraries.
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17
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Structure-Based Function and Regulation of NCX Variants: Updates and Challenges. Int J Mol Sci 2022; 24:ijms24010061. [PMID: 36613523 PMCID: PMC9820601 DOI: 10.3390/ijms24010061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Revised: 12/14/2022] [Accepted: 12/15/2022] [Indexed: 12/24/2022] Open
Abstract
The plasma-membrane homeostasis Na+/Ca2+ exchangers (NCXs) mediate Ca2+ extrusion/entry to dynamically shape Ca2+ signaling/in biological systems ranging from bacteria to humans. The NCX gene orthologs, isoforms, and their splice variants are expressed in a tissue-specific manner and exhibit nearly 104-fold differences in the transport rates and regulatory specificities to match the cell-specific requirements. Selective pharmacological targeting of NCX variants could benefit many clinical applications, although this intervention remains challenging, mainly because a full-size structure of eukaryotic NCX is unavailable. The crystal structure of the archaeal NCX_Mj, in conjunction with biophysical, computational, and functional analyses, provided a breakthrough in resolving the ion transport mechanisms. However, NCX_Mj (whose size is nearly three times smaller than that of mammalian NCXs) cannot serve as a structure-dynamic model for imitating high transport rates and regulatory modules possessed by eukaryotic NCXs. The crystal structures of isolated regulatory domains (obtained from eukaryotic NCXs) and their biophysical analyses by SAXS, NMR, FRET, and HDX-MS approaches revealed structure-based variances of regulatory modules. Despite these achievements, it remains unclear how multi-domain interactions can decode and integrate diverse allosteric signals, thereby yielding distinct regulatory outcomes in a given ortholog/isoform/splice variant. This article summarizes the relevant issues from the perspective of future developments.
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18
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Fenton M, Borcherds W, Chen L, Anbanandam A, Levy R, Chen J, Daughdrill G. The MDMX Acidic Domain Uses Allovalency to Bind Both p53 and MDMX. J Mol Biol 2022; 434:167844. [PMID: 36181774 PMCID: PMC9644833 DOI: 10.1016/j.jmb.2022.167844] [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: 05/11/2022] [Revised: 09/05/2022] [Accepted: 09/22/2022] [Indexed: 01/10/2023]
Abstract
Autoinhibition of p53 binding to MDMX requires two short-linear motifs (SLiMs) containing adjacent tryptophan (WW) and tryptophan-phenylalanine (WF) residues. NMR spectroscopy was used to show the WW and WF motifs directly compete for the p53 binding site on MDMX and circular dichroism spectroscopy was used to show the WW motif becomes helical when it is bound to the p53 binding domain (p53BD) of MDMX. Binding studies using isothermal titration calorimetry showed the WW motif is a stronger inhibitor of p53 binding than the WF motif when they are both tethered to p53BD by the natural disordered linker. We also investigated how the WW and WF motifs interact with the DNA binding domain (DBD) of p53. Both motifs bind independently to similar sites on DBD that overlap the DNA binding site. Taken together our work defines a model for complex formation between MDMX and p53 where a pair of disordered SLiMs bind overlapping sites on both proteins.
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Affiliation(s)
- Malissa Fenton
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, FL 33620, United States
| | - Wade Borcherds
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, FL 33620, United States
| | - Lihong Chen
- Molecular Oncology Department, Moffitt Cancer Center, Tampa, FL 33612, United States
| | - Asokan Anbanandam
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, FL 33620, United States
| | - Robin Levy
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, FL 33620, United States
| | - Jiandong Chen
- Molecular Oncology Department, Moffitt Cancer Center, Tampa, FL 33612, United States
| | - Gary Daughdrill
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, FL 33620, United States.
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19
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Di Liegro CM, Schiera G, Schirò G, Di Liegro I. RNA-Binding Proteins as Epigenetic Regulators of Brain Functions and Their Involvement in Neurodegeneration. Int J Mol Sci 2022; 23:ijms232314622. [PMID: 36498959 PMCID: PMC9739182 DOI: 10.3390/ijms232314622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 11/18/2022] [Accepted: 11/22/2022] [Indexed: 11/25/2022] Open
Abstract
A central aspect of nervous system development and function is the post-transcriptional regulation of mRNA fate, which implies time- and site-dependent translation, in response to cues originating from cell-to-cell crosstalk. Such events are fundamental for the establishment of brain cell asymmetry, as well as of long-lasting modifications of synapses (long-term potentiation: LTP), responsible for learning, memory, and higher cognitive functions. Post-transcriptional regulation is in turn dependent on RNA-binding proteins that, by recognizing and binding brief RNA sequences, base modifications, or secondary/tertiary structures, are able to control maturation, localization, stability, and translation of the transcripts. Notably, most RBPs contain intrinsically disordered regions (IDRs) that are thought to be involved in the formation of membrane-less structures, probably due to liquid-liquid phase separation (LLPS). Such structures are evidenced as a variety of granules that contain proteins and different classes of RNAs. The other side of the peculiar properties of IDRs is, however, that, under altered cellular conditions, they are also prone to form aggregates, as observed in neurodegeneration. Interestingly, RBPs, as part of both normal and aggregated complexes, are also able to enter extracellular vesicles (EVs), and in doing so, they can also reach cells other than those that produced them.
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Affiliation(s)
- Carlo Maria Di Liegro
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche) (STEBICEF), University of Palermo, 90128 Palermo, Italy
| | - Gabriella Schiera
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche) (STEBICEF), University of Palermo, 90128 Palermo, Italy
| | - Giuseppe Schirò
- Department of Biomedicine, Neurosciences and Advanced Diagnostics (Dipartimento di Biomedicina, Neuroscienze e Diagnostica Avanzata) (Bi.N.D.), University of Palermo, 90127 Palermo, Italy
| | - Italia Di Liegro
- Department of Biomedicine, Neurosciences and Advanced Diagnostics (Dipartimento di Biomedicina, Neuroscienze e Diagnostica Avanzata) (Bi.N.D.), University of Palermo, 90127 Palermo, Italy
- Correspondence: ; Tel.: +39-091-238-97 (ext. 415/446)
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20
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Digging into the 3D Structure Predictions of AlphaFold2 with Low Confidence: Disorder and Beyond. Biomolecules 2022; 12:biom12101467. [PMID: 36291675 PMCID: PMC9599455 DOI: 10.3390/biom12101467] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 10/04/2022] [Accepted: 10/05/2022] [Indexed: 01/12/2023] Open
Abstract
AlphaFold2 (AF2) has created a breakthrough in biology by providing three-dimensional structure models for whole-proteome sequences, with unprecedented levels of accuracy. In addition, the AF2 pLDDT score, related to the model confidence, has been shown to provide a good measure of residue-wise disorder. Here, we combined AF2 predictions with pyHCA, a tool we previously developed to identify foldable segments and estimate their order/disorder ratio, from a single protein sequence. We focused our analysis on the AF2 predictions available for 21 reference proteomes (AFDB v1), in particular on their long foldable segments (>30 amino acids) that exhibit characteristics of soluble domains, as estimated by pyHCA. Among these segments, we provided a global analysis of those with very low pLDDT values along their entire length and compared their characteristics to those of segments with very high pLDDT values. We highlighted cases containing conditional order, as well as cases that could form well-folded structures but escape the AF2 prediction due to a shallow multiple sequence alignment and/or undocumented structure or fold. AF2 and pyHCA can therefore be advantageously combined to unravel cryptic structural features in whole proteomes and to refine predictions for different flavors of disorder.
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21
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Lenard AJ, Mulder FAA, Madl T. Solvent paramagnetic relaxation enhancement as a versatile method for studying structure and dynamics of biomolecular systems. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2022; 132-133:113-139. [PMID: 36496256 DOI: 10.1016/j.pnmrs.2022.09.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Revised: 09/14/2022] [Accepted: 09/15/2022] [Indexed: 06/17/2023]
Abstract
Solvent paramagnetic relaxation enhancement (sPRE) is a versatile nuclear magnetic resonance (NMR)-based method that allows characterization of the structure and dynamics of biomolecular systems through providing quantitative experimental information on solvent accessibility of NMR-active nuclei. Addition of soluble paramagnetic probes to the solution of a biomolecule leads to paramagnetic relaxation enhancement in a concentration-dependent manner. Here we review recent progress in the sPRE-based characterization of structural and dynamic properties of biomolecules and their complexes, and aim to deliver a comprehensive illustration of a growing number of applications of the method to various biological systems. We discuss the physical principles of sPRE measurements and provide an overview of available co-solute paramagnetic probes. We then explore how sPRE, in combination with complementary biophysical techniques, can further advance biomolecular structure determination, identification of interaction surfaces within protein complexes, and probing of conformational changes and low-population transient states, as well as deliver insights into weak, nonspecific, and transient interactions between proteins and co-solutes. In addition, we present examples of how the incorporation of solvent paramagnetic probes can improve the sensitivity of NMR experiments and discuss the prospects of applying sPRE to NMR metabolomics, drug discovery, and the study of intrinsically disordered proteins.
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Affiliation(s)
- Aneta J Lenard
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Ageing, Molecular Biology and Biochemistry, Research Unit Integrative Structural Biology, Medical University of Graz, 8010 Graz, Austria.
| | - Frans A A Mulder
- Interdisciplinary Nanoscience Center and Department of Chemistry, University of Aarhus, DK-8000 Aarhus, Denmark; Institute of Biochemistry, Johannes Kepler Universität Linz, 4040 Linz, Austria.
| | - Tobias Madl
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Ageing, Molecular Biology and Biochemistry, Research Unit Integrative Structural Biology, Medical University of Graz, 8010 Graz, Austria; BioTechMed-Graz, 8010 Graz, Austria.
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22
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Mitra S, Oikawa H, Rajendran D, Kowada T, Mizukami S, Naganathan AN, Takahashi S. Flexible Target Recognition of the Intrinsically Disordered DNA-Binding Domain of CytR Monitored by Single-Molecule Fluorescence Spectroscopy. J Phys Chem B 2022; 126:6136-6147. [PMID: 35969476 PMCID: PMC9422980 DOI: 10.1021/acs.jpcb.2c02791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 08/03/2022] [Indexed: 11/29/2022]
Abstract
The intrinsically disordered DNA-binding domain of cytidine repressor (CytR-DBD) folds in the presence of target DNA and regulates the expression of multiple genes in E. coli. To explore the conformational rearrangements in the unbound state and the target recognition mechanisms of CytR-DBD, we carried out single-molecule Förster resonance energy transfer (smFRET) measurements. The smFRET data of CytR-DBD in the absence of DNA show one major and one minor population assignable to an expanded unfolded state and a compact folded state, respectively. The population of the folded state increases and decreases upon titration with salt and denaturant, respectively, in an apparent two-state manner. The peak FRET efficiencies of both the unfolded and folded states change continuously with denaturant concentration, demonstrating the intrinsic flexibility of the DNA-binding domain and the deviation from a strict two-state transition. Remarkably, the CytR-DBD exhibits a compact structure when bound to both the specific and nonspecific DNA; however, the peak FRET efficiencies of the two structures are slightly but consistently different. The observed conformational heterogeneity highlights the potential structural changes required for CytR to bind variably spaced operator sequences.
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Affiliation(s)
- Shrutarshi Mitra
- Institute
of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan
- Department
of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
| | - Hiroyuki Oikawa
- Institute
of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan
- Department
of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
| | - Divya Rajendran
- Department
of Biotechnology, Bhupat & Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600036, India
| | - Toshiyuki Kowada
- Institute
of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan
| | - Shin Mizukami
- Institute
of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan
| | - Athi N. Naganathan
- Department
of Biotechnology, Bhupat & Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600036, India
| | - Satoshi Takahashi
- Institute
of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan
- Department
of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
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23
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Piersimoni L, Abd El Malek M, Bhatia T, Bender J, Brankatschk C, Calvo Sánchez J, Dayhoff GW, Di Ianni A, Figueroa Parra JO, Garcia-Martinez D, Hesselbarth J, Köppen J, Lauth LM, Lippik L, Machner L, Sachan S, Schmidt L, Selle R, Skalidis I, Sorokin O, Ubbiali D, Voigt B, Wedler A, Wei AAJ, Zorn P, Dunker AK, Köhn M, Sinz A, Uversky VN. Lighting up Nobel Prize-winning studies with protein intrinsic disorder. Cell Mol Life Sci 2022; 79:449. [PMID: 35882686 PMCID: PMC11072364 DOI: 10.1007/s00018-022-04468-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 06/18/2022] [Accepted: 07/04/2022] [Indexed: 11/03/2022]
Abstract
Intrinsically disordered proteins and regions (IDPs and IDRs) and their importance in biology are becoming increasingly recognized in biology, biochemistry, molecular biology and chemistry textbooks, as well as in current protein science and structural biology curricula. We argue that the sequence → dynamic conformational ensemble → function principle is of equal importance as the classical sequence → structure → function paradigm. To highlight this point, we describe the IDPs and/or IDRs behind the discoveries associated with 17 Nobel Prizes, 11 in Physiology or Medicine and 6 in Chemistry. The Nobel Laureates themselves did not always mention that the proteins underlying the phenomena investigated in their award-winning studies are in fact IDPs or contain IDRs. In several cases, IDP- or IDR-based molecular functions have been elucidated, while in other instances, it is recognized that the respective protein(s) contain IDRs, but the specific IDR-based molecular functions have yet to be determined. To highlight the importance of IDPs and IDRs as general principle in biology, we present here illustrative examples of IDPs/IDRs in Nobel Prize-winning mechanisms and processes.
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Affiliation(s)
- Lolita Piersimoni
- Research Training Group RTG2467, Martin Luther University Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Marina Abd El Malek
- Research Training Group RTG2467, Martin Luther University Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Twinkle Bhatia
- Research Training Group RTG2467, Martin Luther University Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Julian Bender
- Research Training Group RTG2467, Martin Luther University Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Christin Brankatschk
- Research Training Group RTG2467, Martin Luther University Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Jaime Calvo Sánchez
- Research Training Group RTG2467, Martin Luther University Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Guy W Dayhoff
- Department of Chemistry, College of Art and Sciences, University of South Florida, Tampa, FL, 33620, USA
| | - Alessio Di Ianni
- Research Training Group RTG2467, Martin Luther University Halle-Wittenberg, 06120, Halle (Saale), Germany
| | | | - Dailen Garcia-Martinez
- Research Training Group RTG2467, Martin Luther University Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Julia Hesselbarth
- Research Training Group RTG2467, Martin Luther University Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Janett Köppen
- Research Training Group RTG2467, Martin Luther University Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Luca M Lauth
- Research Training Group RTG2467, Martin Luther University Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Laurin Lippik
- Research Training Group RTG2467, Martin Luther University Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Lisa Machner
- Research Training Group RTG2467, Martin Luther University Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Shubhra Sachan
- Research Training Group RTG2467, Martin Luther University Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Lisa Schmidt
- Research Training Group RTG2467, Martin Luther University Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Robin Selle
- Research Training Group RTG2467, Martin Luther University Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Ioannis Skalidis
- Research Training Group RTG2467, Martin Luther University Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Oleksandr Sorokin
- Research Training Group RTG2467, Martin Luther University Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Daniele Ubbiali
- Research Training Group RTG2467, Martin Luther University Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Bruno Voigt
- Research Training Group RTG2467, Martin Luther University Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Alice Wedler
- Research Training Group RTG2467, Martin Luther University Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Alan An Jung Wei
- Research Training Group RTG2467, Martin Luther University Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Peter Zorn
- Research Training Group RTG2467, Martin Luther University Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Alan Keith Dunker
- Department of Biochemistry and Molecular Biology, Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Marcel Köhn
- Research Training Group RTG2467, Martin Luther University Halle-Wittenberg, 06120, Halle (Saale), Germany.
| | - Andrea Sinz
- Research Training Group RTG2467, Martin Luther University Halle-Wittenberg, 06120, Halle (Saale), Germany.
| | - Vladimir N Uversky
- Department of Molecular Medicine, USF Health Byrd Alzheimer's Institute, Morsani College of Medicine, University of South Florida, Tampa, FL, 33612, USA.
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24
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Hadži S, Lah J. The free energy folding penalty accompanying binding of intrinsically disordered α-helical motifs. Protein Sci 2022; 31:e4370. [PMID: 35762718 PMCID: PMC9202546 DOI: 10.1002/pro.4370] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 05/30/2022] [Accepted: 05/31/2022] [Indexed: 12/29/2022]
Abstract
Intrinsically disordered proteins (IDPs) are abundant in eukaryotic proteomes and preform critical roles in many cellular processes, most often through the association with globular proteins. Despite lacking a stable three-dimensional structure by themselves, they may acquire a defined conformation upon binding globular targets. The most common type of secondary structure acquired by these binding motifs entails formation of an α-helix. It has been hypothesized that such disorder-to-order transitions are associated with a significant free energy penalty due to IDP folding, which reduces the overall IDP-target affinity. However, the exact magnitude of IDP folding penalty in α-helical binding motifs has not been systematically estimated. Here, we report the folding penalty contributions for 30 IDPs undergoing folding-upon-binding and find that the average IDP folding penalty is +2.0 kcal/mol and ranges from 0.7 to 3.5 kcal/mol. We observe that the folding penalty scales approximately linearly with the change in IDP helicity upon binding, which provides a simple empirical way to estimate folding penalty. We analyze to what extent do pre-structuring and target-bound IDP dynamics (fuzziness) reduce the folding penalty and find that these effects combined, on average, reduce the folding cost by around half. Taken together, the presented analysis provides a quantitative basis for understanding the role of folding penalty in IDP-target interactions and introduces a method estimate this quantity. Estimation and reduction of IDP folding penalty may prove useful in the rational design of helix-stabilized inhibitors of IDP-target interactions. STATEMENT: The α-helical binding motifs are ubiquitous among the intrinsically disordered proteins (IDPs). Upon binding their targets, they undergo a disorder-to-order transition, which is accompanied by a significant folding penalty whose magnitude is generally not known. Here, we use recently developed statistical-thermodynamic model to estimate the folding penalties for 30 IDPs and clarify the roles of IDP pre-folding and bound-state dynamics in reducing the folding penalty.
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Affiliation(s)
- San Hadži
- Department of Physical Chemistry, Faculty of Chemistry and Chemical TechnologyUniversity of LjubljanaLjubljana
| | - Jurij Lah
- Department of Physical Chemistry, Faculty of Chemistry and Chemical TechnologyUniversity of LjubljanaLjubljana
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25
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Leeder WM, Geyer FK, Göringer HU. Fuzzy RNA recognition by the Trypanosoma brucei editosome. Nucleic Acids Res 2022; 50:5818-5833. [PMID: 35580050 PMCID: PMC9178004 DOI: 10.1093/nar/gkac357] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 04/20/2022] [Accepted: 04/26/2022] [Indexed: 11/30/2022] Open
Abstract
The assembly of high molecular mass ribonucleoprotein complexes typically relies on the binary interaction of defined RNA sequences or precisely folded RNA motifs with dedicated RNA-binding domains on the protein side. Here we describe a new molecular recognition principle of RNA molecules by a high molecular mass protein complex. By chemically probing the solvent accessibility of mitochondrial pre-mRNAs when bound to the Trypanosoma brucei editosome, we identified multiple similar but non-identical RNA motifs as editosome contact sites. However, by treating the different motifs as mathematical graph objects we demonstrate that they fit a consensus 2D-graph consisting of 4 vertices (V) and 3 edges (E) with a Laplacian eigenvalue of 0.5477 (λ2). We establish that synthetic 4V(3E)-RNAs are sufficient to compete for the editosomal pre-mRNA binding site and that they inhibit RNA editing in vitro. Furthermore, we demonstrate that only two topological indices are necessary to predict the binding of any RNA motif to the editosome with a high level of confidence. Our analysis corroborates that the editosome has adapted to the structural multiplicity of the mitochondrial mRNA folding space by recognizing a fuzzy continuum of RNA folds that fit a consensus graph descriptor.
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Affiliation(s)
| | - Felix Klaus Geyer
- Molecular Genetics, Technical University Darmstadt, 64287 Darmstadt, Germany
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26
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Elkhaligy H, Balbin CA, Siltberg-Liberles J. Comparative Analysis of Structural Features in SLiMs from Eukaryotes, Bacteria, and Viruses with Importance for Host-Pathogen Interactions. Pathogens 2022; 11:pathogens11050583. [PMID: 35631103 PMCID: PMC9147284 DOI: 10.3390/pathogens11050583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 05/06/2022] [Accepted: 05/11/2022] [Indexed: 11/19/2022] Open
Abstract
Protein-protein interactions drive functions in eukaryotes that can be described by short linear motifs (SLiMs). Conservation of SLiMs help illuminate functional SLiMs in eukaryotic protein families. However, the simplicity of eukaryotic SLiMs makes them appear by chance due to mutational processes not only in eukaryotes but also in pathogenic bacteria and viruses. Further, functional eukaryotic SLiMs are often found in disordered regions. Although proteomes from pathogenic bacteria and viruses have less disorder than eukaryotic proteomes, their proteins can successfully mimic eukaryotic SLiMs and disrupt host cellular function. Identifying important SLiMs in pathogens is difficult but essential for understanding potential host-pathogen interactions. We performed a comparative analysis of structural features for experimentally verified SLiMs from the Eukaryotic Linear Motif (ELM) database across viruses, bacteria, and eukaryotes. Our results revealed that many viral SLiMs and specific motifs found across viruses and eukaryotes, such as some glycosylation motifs, have less disorder. Analyzing the disorder and coil properties of equivalent SLiMs from pathogens and eukaryotes revealed that some motifs are more structured in pathogens than their eukaryotic counterparts and vice versa. These results support a varying mechanism of interaction between pathogens and their eukaryotic hosts for some of the same motifs.
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27
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Krishnan R, Ranganathan S, Maji SK, Padinhateeri R. Role of non-specific interactions in the phase-separation and maturation of macromolecules. PLoS Comput Biol 2022; 18:e1010067. [PMID: 35533203 PMCID: PMC9119624 DOI: 10.1371/journal.pcbi.1010067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 05/19/2022] [Accepted: 03/29/2022] [Indexed: 11/19/2022] Open
Abstract
Phase separation of biomolecules could be mediated by both specific and non-specific interactions. How the interplay between non-specific and specific interactions along with polymer entropy influences phase separation is an open question. We address this question by simulating self-associating molecules as polymer chains with a short core stretch that forms the specifically interacting functional interface and longer non-core regions that participate in non-specific/promiscuous interactions. Our results show that the interplay of specific (strength, ϵsp) and non-specific interactions (strength, ϵns) could result in phase separation of polymers and its transition to solid-like aggregates (mature state). In the absence of ϵns, the polymer chains do not dwell long enough in the vicinity of each other to undergo phase separation and transition into a mature state. On the other hand, in the limit of strong ϵns, the assemblies cannot transition into the mature state and form a non-specific assembly, suggesting an optimal range of interactions favoring mature multimers. In the scenario where only a fraction (Nfrac) of the non-core regions participate in attractive interactions, we find that slight modifications to either ϵns or Nfrac can result in dramatically altered self-assembled states. Using a combination of heterogeneous and homogeneous mix of polymers, we establish how this interplay between interaction energies dictates the propensity of biomolecules to find the correct binding partner at dilute concentrations in crowded environments.
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Affiliation(s)
- Rakesh Krishnan
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India
| | - Srivastav Ranganathan
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India
- * E-mail: (SR); (RP)
| | - Samir K. Maji
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India
| | - Ranjith Padinhateeri
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India
- * E-mail: (SR); (RP)
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28
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Insights into Membrane Curvature Sensing and Membrane Remodeling by Intrinsically Disordered Proteins and Protein Regions. J Membr Biol 2022; 255:237-259. [PMID: 35451616 PMCID: PMC9028910 DOI: 10.1007/s00232-022-00237-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 03/29/2022] [Indexed: 12/15/2022]
Abstract
Cellular membranes are highly dynamic in shape. They can rapidly and precisely regulate their shape to perform various cellular functions. The protein’s ability to sense membrane curvature is essential in various biological events such as cell signaling and membrane trafficking. As they are bound, these curvature-sensing proteins may also change the local membrane shape by one or more curvature driving mechanisms. Established curvature-sensing/driving mechanisms rely on proteins with specific structural features such as amphipathic helices and intrinsically curved shapes. However, the recent discovery and characterization of many proteins have shattered the protein structure–function paradigm, believing that the protein functions require a unique structural feature. Typically, such structure-independent functions are carried either entirely by intrinsically disordered proteins or hybrid proteins containing disordered regions and structured domains. It is becoming more apparent that disordered proteins and regions can be potent sensors/inducers of membrane curvatures. In this article, we outline the basic features of disordered proteins and regions, the motifs in such proteins that encode the function, membrane remodeling by disordered proteins and regions, and assays that may be employed to investigate curvature sensing and generation by ordered/disordered proteins.
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29
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AlphaFold2: A Role for Disordered Protein/Region Prediction? Int J Mol Sci 2022; 23:ijms23094591. [PMID: 35562983 PMCID: PMC9104326 DOI: 10.3390/ijms23094591] [Citation(s) in RCA: 53] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 04/18/2022] [Accepted: 04/19/2022] [Indexed: 01/27/2023] Open
Abstract
The development of AlphaFold2 marked a paradigm-shift in the structural biology community. Herein, we assess the ability of AlphaFold2 to predict disordered regions against traditional sequence-based disorder predictors. We find that AlphaFold2 performs well at discriminating disordered regions, but also note that the disorder predictor one constructs from an AlphaFold2 structure determines accuracy. In particular, a naïve, but non-trivial assumption that residues assigned to helices, strands, and H-bond stabilized turns are likely ordered and all other residues are disordered results in a dramatic overestimation in disorder; conversely, the predicted local distance difference test (pLDDT) provides an excellent measure of residue-wise disorder. Furthermore, by employing molecular dynamics (MD) simulations, we note an interesting relationship between the pLDDT and secondary structure, that may explain our observations and suggests a broader application of the pLDDT for characterizing the local dynamics of intrinsically disordered proteins and regions (IDPs/IDRs).
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30
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Antifeeva IA, Fonin AV, Fefilova AS, Stepanenko OV, Povarova OI, Silonov SA, Kuznetsova IM, Uversky VN, Turoverov KK. Liquid-liquid phase separation as an organizing principle of intracellular space: overview of the evolution of the cell compartmentalization concept. Cell Mol Life Sci 2022; 79:251. [PMID: 35445278 PMCID: PMC11073196 DOI: 10.1007/s00018-022-04276-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 03/24/2022] [Accepted: 03/27/2022] [Indexed: 12/14/2022]
Abstract
At the turn of the twenty-first century, fundamental changes took place in the understanding of the structure and function of proteins and then in the appreciation of the intracellular space organization. A rather mechanistic model of the organization of living matter, where the function of proteins is determined by their rigid globular structure, and the intracellular processes occur in rigidly determined compartments, was replaced by an idea that highly dynamic and multifunctional "soft matter" lies at the heart of all living things. According this "new view", the most important role in the spatio-temporal organization of the intracellular space is played by liquid-liquid phase transitions of biopolymers. These self-organizing cellular compartments are open dynamic systems existing at the edge of chaos. They are characterized by the exceptional structural and compositional dynamics, and their multicomponent nature and polyfunctionality provide means for the finely tuned regulation of various intracellular processes. Changes in the external conditions can cause a disruption of the biogenesis of these cellular bodies leading to the irreversible aggregation of their constituent proteins, followed by the transition to a gel-like state and the emergence of amyloid fibrils. This work represents a historical overview of changes in our understanding of the intracellular space compartmentalization. It also reflects methodological breakthroughs that led to a change in paradigms in this area of science and discusses modern ideas about the organization of the intracellular space. It is emphasized here that the membrane-less organelles have to combine a certain resistance to the changes in their environment and, at the same time, show high sensitivity to the external signals, which ensures the normal functioning of the cell.
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Affiliation(s)
- Iuliia A Antifeeva
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Av., 4, St. Petersburg, 194064, Russia
| | - Alexander V Fonin
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Av., 4, St. Petersburg, 194064, Russia
| | - Anna S Fefilova
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Av., 4, St. Petersburg, 194064, Russia
| | - Olesya V Stepanenko
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Av., 4, St. Petersburg, 194064, Russia
| | - Olga I Povarova
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Av., 4, St. Petersburg, 194064, Russia
| | - Sergey A Silonov
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Av., 4, St. Petersburg, 194064, Russia
| | - Irina M Kuznetsova
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Av., 4, St. Petersburg, 194064, Russia
| | - Vladimir N Uversky
- Department of Molecular Medicine and USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, 12901 Bruce B. Downs Blvd. MDC07, Tampa, FL, 33612, USA.
| | - Konstantin K Turoverov
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Av., 4, St. Petersburg, 194064, Russia.
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31
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Wang D, Wu S, Wang D, Song X, Yang M, Zhang W, Huang S, Weng J, Liu Z, Wang W. The importance of the compact disordered state in the fuzzy interactions between intrinsically disordered proteins. Chem Sci 2022; 13:2363-2377. [PMID: 35310482 PMCID: PMC8864705 DOI: 10.1039/d1sc06825c] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 01/21/2022] [Indexed: 11/23/2022] Open
Abstract
The intrinsically disordered C-terminal domain (CTD) of protein 4.1G is able to specifically bind a 26-residue intrinsically disordered region of NuMA, forming a dynamic fuzzy complex. As one of a few cases of extremely fuzzy interactions between two intrinsically disordered proteins/regions (IDPs/IDRs) without induced folding, the principle of the binding is unknown. Here, we combined experimental and computational methods to explore the detailed mechanism of the interaction between 4.1G-CTD and NuMA. MD simulations suggest that the kinetic hub states in the structure ensemble of 4.1G-CTD are favorable in the fuzzy complex. The feature of these hub states is that the binding 'hot spot' motifs βA and βB exhibit β strand propensities and are well packed to each other. The binding between 4.1G-CTD and NuMA is disrupted at low pH, which changes the intramolecular packing of 4.1G-CTD and weakens the packing between βA and βB motifs. Low pH conditions also lead to increased hydrodynamic radius and acceleration of backbone dynamics of 4.1G-CTD. All these results underscore the importance of tertiary structural arrangements and overall compactness of 4.1G-CTD in its binding to NuMA, i.e. the compact disordered state of 4.1G-CTD is crucial for binding. Different from the short linear motifs (SLiMs) that are often found to mediate IDP interactions, 4.1G-CTD functions as an intrinsically disordered domain (IDD), which is a functional and structural unit similar to conventional protein domains. This work sheds light on the molecular recognition mechanism of IDPs/IDRs and expands the conventional structure-function paradigm in protein biochemistry.
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Affiliation(s)
- Dan Wang
- Department of Chemistry, Multiscale Research Institute of Complex Systems and Institute of Biomedical Sciences, Fudan University Shanghai 200438 China
| | - Shaowen Wu
- Guangdong Key Laboratory for Crop Germplasm Resources Preservation and Utilization, Agro-biological Gene Research Center, Guangdong Academy of Agricultural Sciences Guangzhou 510640 Guangdong China
| | | | - Xingyu Song
- Department of Chemistry, Multiscale Research Institute of Complex Systems and Institute of Biomedical Sciences, Fudan University Shanghai 200438 China
| | - Maohua Yang
- Department of Chemistry, Multiscale Research Institute of Complex Systems and Institute of Biomedical Sciences, Fudan University Shanghai 200438 China
| | - Wolun Zhang
- LightEdge Technologies Limited Zhongshan 528403 China
| | - Shaohui Huang
- Institute of Biophysics, Chinese Academy of Sciences Beijing 100101 China
- University of Chinese Academy of Science Beijing 101408 China
| | - Jingwei Weng
- Department of Chemistry, Multiscale Research Institute of Complex Systems and Institute of Biomedical Sciences, Fudan University Shanghai 200438 China
| | - Zhijun Liu
- National Facility for Protein Science in Shanghai, Zhangjiang Lab, Shanghai Advanced Research Institute, Chinese Academy of Sciences Shanghai 201210 China
| | - Wenning Wang
- Department of Chemistry, Multiscale Research Institute of Complex Systems and Institute of Biomedical Sciences, Fudan University Shanghai 200438 China
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32
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Shukla S, Agarwal P, Kumar A. Disordered regions tune order in chromatin organization and function. Biophys Chem 2022; 281:106716. [PMID: 34844028 DOI: 10.1016/j.bpc.2021.106716] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 11/10/2021] [Accepted: 11/10/2021] [Indexed: 12/29/2022]
Abstract
Intrinsically disordered proteins or hybrid proteins with ordered domains and disordered regions (both collectively designated as IDP(R)s) defy the well-established structure-function paradigm due to their ability to perform multiple biological functions even in the absence of a well-defined 3D structure. IDP(R)s have a unique ability to exist as a functional heterogeneous ensemble, where they adopt multiple thermodynamically stable conformations with low energy barriers between states. The resultant structural plasticity or conformational adaptability provides them with a high functional diversity and ease of regulation. Hence, IDP(R)s are highly efficient biological machinery to mediate intricate cellular functions such as signaling, gene expression, and assembly of complex structures. One such structure is the nucleoprotein complex known as Chromatin. Interestingly, the proteins involved in shaping up the structure and function of chromatin are abundant in disordered regions, which serve more than just as mere flexible linkers. The disordered regions are involved in crucial processes such as gene expression regulation, chromatin architecture maintenance, and liquid-liquid phase separation initiation. This review is an attempt to explore the advantages and the functional and regulatory roles of intrinsic disorder in several Chromatin Associated Proteins from a mechanistic standpoint.
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Affiliation(s)
- Shivangi Shukla
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, India
| | - Prakhar Agarwal
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, India
| | - Ashutosh Kumar
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, India.
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33
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Abstract
This mini-review represents a brief, disorder-centric consideration of the interplay between order and disorder in proteins. The goal here is to show that inside the cell, folding, non-folding, and misfolding of proteins are interlinked on multiple levels. This is evidenced by the highly heterogeneous spatio-temporal structural organization of a protein molecule, where one can find differently (dis)ordered components that can undergo local or global order-to-disorder and disorder-to-order transitions needed for functionality. This is further illustrated by the fact that at particular moments of their life, most notably during their synthesis and degradation, all proteins are at least partially disordered. In addition to these intrinsic forms of disorder, proteins are constantly facing extrinsic disorder, which is intrinsic disorder in their functional partners. All this comprises the multileveled protein disorder cycle.
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Affiliation(s)
- Vladimir N Uversky
- Department of Molecular Medicine and Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL 33612 USA
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34
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Salem A, Wilson CJ, Rutledge BS, Dilliott A, Farhan S, Choy WY, Duennwald ML. Matrin3: Disorder and ALS Pathogenesis. Front Mol Biosci 2022; 8:794646. [PMID: 35083279 PMCID: PMC8784776 DOI: 10.3389/fmolb.2021.794646] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 11/30/2021] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder characterized by the degeneration of both upper and lower motor neurons in the brain and spinal cord. ALS is associated with protein misfolding and inclusion formation involving RNA-binding proteins, including TAR DNA-binding protein (TDP-43) and fused in sarcoma (FUS). The 125-kDa Matrin3 is a highly conserved nuclear DNA/RNA-binding protein that is implicated in many cellular processes, including binding and stabilizing mRNA, regulating mRNA nuclear export, modulating alternative splicing, and managing chromosomal distribution. Mutations in MATR3, the gene encoding Matrin3, have been identified as causal in familial ALS (fALS). Matrin3 lacks a prion-like domain that characterizes many other ALS-associated RNA-binding proteins, including TDP-43 and FUS, however, our bioinformatics analyses and preliminary studies document that Matrin3 contains long intrinsically disordered regions that may facilitate promiscuous interactions with many proteins and may contribute to its misfolding. In addition, these disordered regions in Matrin3 undergo numerous post-translational modifications, including phosphorylation, ubiquitination and acetylation that modulate the function and misfolding of the protein. Here we discuss the disordered nature of Matrin3 and review the factors that may promote its misfolding and aggregation, two elements that might explain its role in ALS pathogenesis.
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Affiliation(s)
- Ahmed Salem
- Department of Pathology and Laboratory Medicine, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - Carter J. Wilson
- Department of Applied Mathematics, Western University, London, ON, Canada
| | - Benjamin S. Rutledge
- Department of Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - Allison Dilliott
- Department of Neurology and Neurosurgery, McGill Universty, Montreal, QC, Canada
| | - Sali Farhan
- Department of Neurology and Neurosurgery, McGill Universty, Montreal, QC, Canada
- Department of Human Genetics, McGill Universty, Montreal, QC, Canada
| | - Wing-Yiu Choy
- Department of Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - Martin L. Duennwald
- Department of Pathology and Laboratory Medicine, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
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35
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Lin YH, Wu H, Jia B, Zhang M, Chan HS. Assembly of model postsynaptic densities involves interactions auxiliary to stoichiometric binding. Biophys J 2022; 121:157-171. [PMID: 34637756 PMCID: PMC8758407 DOI: 10.1016/j.bpj.2021.10.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Revised: 09/29/2021] [Accepted: 10/06/2021] [Indexed: 01/07/2023] Open
Abstract
The assembly of functional biomolecular condensates often involves liquid-liquid phase separation (LLPS) of proteins with multiple modular domains, which can be folded or conformationally disordered to various degrees. To understand the LLPS-driving domain-domain interactions, a fundamental question is how readily the interactions in the condensed phase can be inferred from interdomain interactions in dilute solutions. In particular, are the interactions leading to LLPS exclusively those underlying the formation of discrete interdomain complexes in homogeneous solutions? We address this question by developing a mean-field LLPS theory of two stoichiometrically constrained solute species. The theory is applied to the neuronal proteins SynGAP and PSD-95, whose complex coacervate serves as a rudimentary model for neuronal postsynaptic densities (PSDs). The predicted phase behaviors are compared with experiments. Previously, a three SynGAP/two PSD-95 ratio was determined for SynGAP/PSD-95 complexes in dilute solutions. However, when this 3:2 stoichiometry is uniformly imposed in our theory encompassing both dilute and condensed phases, the tie-line pattern of the predicted SynGAP/PSD-95 phase diagram differs drastically from that obtained experimentally. In contrast, theories embodying alternate scenarios postulating auxiliary SynGAP-PSD-95 as well as SynGAP-SynGAP and PSD-95-PSD-95 interactions, in addition to those responsible for stoichiometric SynGAP/PSD-95 complexes, produce tie-line patterns consistent with experiment. Hence, our combined theoretical-experimental analysis indicates that weaker interactions or higher-order complexes beyond the 3:2 stoichiometry, but not yet documented, are involved in the formation of SynGAP/PSD-95 condensates, imploring future efforts to ascertain the nature of these auxiliary interactions in PSD-like LLPS and underscoring a likely general synergy between stoichiometric, structurally specific binding and stochastic, multivalent "fuzzy" interactions in the assembly of functional biomolecular condensates.
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Affiliation(s)
- Yi-Hsuan Lin
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada,Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Haowei Wu
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Bowen Jia
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Mingjie Zhang
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China,School of Life Sciences, Southern University of Science and Technology, Shenzhen, China,Corresponding author
| | - Hue Sun Chan
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada,Corresponding author
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36
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Alghamdi M, Alamry SA, Bahlas SM, Uversky VN, Redwan EM. Circulating extracellular vesicles and rheumatoid arthritis: a proteomic analysis. Cell Mol Life Sci 2021; 79:25. [PMID: 34971426 PMCID: PMC11072894 DOI: 10.1007/s00018-021-04020-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 10/28/2021] [Accepted: 10/29/2021] [Indexed: 12/14/2022]
Abstract
Circulating extracellular vesicles (EVs) are membrane-bound nanoparticles secreted by most cells for intracellular communication and transportation of biomolecules. EVs carry proteins, lipids, nucleic acids, and receptors that are involved in human physiology and pathology. EV cargo is variable and highly related to the type and state of the cellular origin. Three subtypes of EVs have been identified: exosomes, microvesicles, and apoptotic bodies. Exosomes are the smallest and the most well-studied class of EVs that regulate different biological processes and participate in several diseases, such as cancers and autoimmune diseases. Proteomic analysis of exosomes succeeded in profiling numerous types of proteins involved in disease development and prognosis. In rheumatoid arthritis (RA), exosomes revealed a potential function in joint inflammation. These EVs possess a unique function, as they can transfer specific autoantigens and mediators between distant cells. Current proteomic data demonstrated that exosomes could provide beneficial effects against autoimmunity and exert an immunosuppressive action, particularly in RA. Based on these observations, effective therapeutic strategies have been developed for arthritis and other inflammatory disorders.
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Affiliation(s)
- Mohammed Alghamdi
- Biological Sciences Department, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah, 21589, Saudi Arabia
- Laboratory Department, University Medical Services Center, King Abdulaziz University, P.O. Box 80200, Jeddah, 21589, Saudi Arabia
| | - Sultan Abdulmughni Alamry
- Immunology Diagnostic Laboratory Department, King Abdulaziz University Hospital, P.O Box 80215, Jeddah, 21589, Saudi Arabia
| | - Sami M Bahlas
- Department of Internal Medicine, Faculty of Medicine, King Abdulaziz University, P.O. Box 80215, Jeddah, 21589, Saudi Arabia
| | - Vladimir N Uversky
- Biological Sciences Department, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah, 21589, Saudi Arabia
- Department of Molecular Medicine and USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Elrashdy M Redwan
- Biological Sciences Department, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah, 21589, Saudi Arabia.
- Therapeutic and Protective Proteins Laboratory, Protein Research Department, Genetic Engineering and Biotechnology Research Institute, City for Scientific Research and Technology Applications, New Borg EL-Arab, 21934, Alexandria, Egypt.
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Protein conformational dynamics and phenotypic switching. Biophys Rev 2021; 13:1127-1138. [PMID: 35059032 PMCID: PMC8724335 DOI: 10.1007/s12551-021-00858-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 10/18/2021] [Indexed: 12/14/2022] Open
Abstract
Intrinsically disordered proteins (IDPs) are proteins that lack rigid 3D structure but exist as conformational ensembles. Because of their structural plasticity, they can interact with multiple partners. The protein interactions between IDPs and their partners form scale-free protein interaction networks (PINs) that facilitate information flow in the cell. Because of their plasticity, IDPs typically occupy hub positions in cellular PINs. Furthermore, their conformational dynamics and propensity for post-translational modifications contribute to "conformational" noise which is distinct from the well-recognized transcriptional noise. Therefore, upregulation of IDPs in response to a specific input, such as stress, contributes to increased noise and, hence, an increase in stochastic, "promiscuous" interactions. These interactions lead to activation of latent pathways or can induce "rewiring" of the PIN to yield an optimal output underscoring the critical role of IDPs in regulating information flow. We have used PAGE4, a highly intrinsically disordered stress-response protein as a paradigm. Employing a variety of experimental and computational techniques, we have elucidated the role of PAGE4 in phenotypic switching of prostate cancer cells at a systems level. These cumulative studies over the past decade provide a conceptual framework to better understand how IDP conformational dynamics and conformational noise might facilitate cellular decision-making.
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38
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Ecsédi P, Gógl G, Nyitray L. Studying the Structures of Relaxed and Fuzzy Interactions: The Diverse World of S100 Complexes. Front Mol Biosci 2021; 8:749052. [PMID: 34708078 PMCID: PMC8542695 DOI: 10.3389/fmolb.2021.749052] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 09/06/2021] [Indexed: 01/04/2023] Open
Abstract
S100 proteins are small, dimeric, Ca2+-binding proteins of considerable interest due to their associations with cancer and rheumatic and neurodegenerative diseases. They control the functions of numerous proteins by forming protein–protein complexes with them. Several of these complexes were found to display “fuzzy” properties. Examining these highly flexible interactions, however, is a difficult task, especially from a structural biology point of view. Here, we summarize the available in vitro techniques that can be deployed to obtain structural information about these dynamic complexes. We also review the current state of knowledge about the structures of S100 complexes, focusing on their often-asymmetric nature.
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Affiliation(s)
- Péter Ecsédi
- Department of Biochemistry, Eötvös Loránd University, Budapest, Hungary
| | - Gergő Gógl
- Department of Integrative Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U1258/CNRS UMR 7104/Université de Strasbourg, Illkirch, France
| | - László Nyitray
- Department of Biochemistry, Eötvös Loránd University, Budapest, Hungary
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Morris OM, Torpey JH, Isaacson RL. Intrinsically disordered proteins: modes of binding with emphasis on disordered domains. Open Biol 2021; 11:210222. [PMID: 34610267 PMCID: PMC8492171 DOI: 10.1098/rsob.210222] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Our notions of protein function have long been determined by the protein structure-function paradigm. However, the idea that protein function is dictated by a prerequisite complementarity of shapes at the binding interface is becoming increasingly challenged. Interactions involving intrinsically disordered proteins (IDPs) have indicated a significant degree of disorder present in the bound state, ranging from static disorder to complete disorder, termed 'random fuzziness'. This review assesses the anatomy of an IDP and relates how its intrinsic properties permit promiscuity and allow for the various modes of interaction. Furthermore, a mechanistic overview of the types of disordered domains is detailed, while also relating to a recent example and the kinetic and thermodynamic principles governing its formation.
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Affiliation(s)
- Owen Michael Morris
- Department of Chemistry, Faculty of Natural, Mathematical and Engineering Sciences, King's College London, Britannia House, 7 Trinity Street, London SE1 1DB, UK
| | - James Hilary Torpey
- Department of Chemistry, Faculty of Natural, Mathematical and Engineering Sciences, King's College London, Britannia House, 7 Trinity Street, London SE1 1DB, UK
| | - Rivka Leah Isaacson
- Department of Chemistry, Faculty of Natural, Mathematical and Engineering Sciences, King's College London, Britannia House, 7 Trinity Street, London SE1 1DB, UK
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40
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The sequence-ensemble relationship in fuzzy protein complexes. Proc Natl Acad Sci U S A 2021; 118:2020562118. [PMID: 34504009 DOI: 10.1073/pnas.2020562118] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/11/2021] [Indexed: 11/18/2022] Open
Abstract
Intrinsically disordered proteins (IDPs) interact with globular proteins through a variety of mechanisms, resulting in the structurally heterogeneous ensembles known as fuzzy complexes. While there exists a reasonable comprehension on how IDP sequence determines the unbound IDP ensemble, little is known about what shapes the structural characteristics of IDPs bound to their targets. Using a statistical thermodynamic model, we show that the target-bound ensembles are determined by a simple code that combines the IDP sequence and the distribution of IDP-target interaction hotspots. These two parameters define the conformational space of target-bound IDPs and rationalize the observed structural heterogeneity of fuzzy complexes. The presented model successfully reproduces the dynamical signatures of target-bound IDPs from the NMR relaxation experiments as well as the changes of interaction affinity and the IDP helicity induced by mutations. The model explains how the target-bound IDP ensemble adapts to mutations in order to achieve an optimal balance between conformational freedom and interaction energy. Taken together, the presented sequence-ensemble relationship of fuzzy complexes explains the different manifestations of IDP disorder in folding-upon-binding processes.
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41
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Cardone C, Caseau CM, Bardiaux B, Thureaux A, Galloux M, Bajorek M, Eléouët JF, Litaudon M, Bontems F, Sizun C. A Structural and Dynamic Analysis of the Partially Disordered Polymerase-Binding Domain in RSV Phosphoprotein. Biomolecules 2021; 11:biom11081225. [PMID: 34439894 PMCID: PMC8392014 DOI: 10.3390/biom11081225] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 08/10/2021] [Accepted: 08/13/2021] [Indexed: 12/11/2022] Open
Abstract
The phosphoprotein P of Mononegavirales (MNV) is an essential co-factor of the viral RNA polymerase L. Its prime function is to recruit L to the ribonucleocapsid composed of the viral genome encapsidated by the nucleoprotein N. MNV phosphoproteins often contain a high degree of disorder. In Pneumoviridae phosphoproteins, the only domain with well-defined structure is a small oligomerization domain (POD). We previously characterized the differential disorder in respiratory syncytial virus (RSV) phosphoprotein by NMR. We showed that outside of RSV POD, the intrinsically disordered N-and C-terminal regions displayed a structural and dynamic diversity ranging from random coil to high helical propensity. Here we provide additional insight into the dynamic behavior of PCα, a domain that is C-terminal to POD and constitutes the RSV L-binding region together with POD. By using small phosphoprotein fragments centered on or adjacent to POD, we obtained a structural picture of the POD–PCα region in solution, at the single residue level by NMR and at lower resolution by complementary biophysical methods. We probed POD–PCα inter-domain contacts and showed that small molecules were able to modify the dynamics of PCα. These structural properties are fundamental to the peculiar binding mode of RSV phosphoprotein to L, where each of the four protomers binds to L in a different way.
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Affiliation(s)
- Christophe Cardone
- Institut de Chimie des Substances Naturelles, CNRS, Université Paris Saclay, 91190 Gif-sur-Yvette, France; (C.C.); (C.-M.C.); (M.L.); (F.B.)
| | - Claire-Marie Caseau
- Institut de Chimie des Substances Naturelles, CNRS, Université Paris Saclay, 91190 Gif-sur-Yvette, France; (C.C.); (C.-M.C.); (M.L.); (F.B.)
| | - Benjamin Bardiaux
- Structural Bioinformatics Unit, Department of Structural Biology and Chemistry, Institut Pasteur, CNRS UMR3528, 78015 Paris, France;
| | | | - Marie Galloux
- Unité de Virologie et Immunologie Moléculaires, INRAE, Université Paris Saclay, 78352 Jouy-en-Josas, France; (M.G.); (M.B.); (J.-F.E.)
| | - Monika Bajorek
- Unité de Virologie et Immunologie Moléculaires, INRAE, Université Paris Saclay, 78352 Jouy-en-Josas, France; (M.G.); (M.B.); (J.-F.E.)
| | - Jean-François Eléouët
- Unité de Virologie et Immunologie Moléculaires, INRAE, Université Paris Saclay, 78352 Jouy-en-Josas, France; (M.G.); (M.B.); (J.-F.E.)
| | - Marc Litaudon
- Institut de Chimie des Substances Naturelles, CNRS, Université Paris Saclay, 91190 Gif-sur-Yvette, France; (C.C.); (C.-M.C.); (M.L.); (F.B.)
| | - François Bontems
- Institut de Chimie des Substances Naturelles, CNRS, Université Paris Saclay, 91190 Gif-sur-Yvette, France; (C.C.); (C.-M.C.); (M.L.); (F.B.)
| | - Christina Sizun
- Institut de Chimie des Substances Naturelles, CNRS, Université Paris Saclay, 91190 Gif-sur-Yvette, France; (C.C.); (C.-M.C.); (M.L.); (F.B.)
- Correspondence:
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42
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Röder K. Is the H4 histone tail intrinsically disordered or intrinsically multifunctional? Phys Chem Chem Phys 2021; 23:5134-5142. [PMID: 33624669 DOI: 10.1039/d0cp05405d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The structural versatility of histone tails is one of the key elements in the organisation of chromatin, which allows for the compact storage of genomic information. However, this structural diversity also complicates experimental and computational studies. Here, the potential and free energy landscape for the isolated and bound H4 histone tail are explored. The landscapes exhibit a set of distinct structural ensembles separated by high energy barriers, with little difference between isolated and bound tails. This consistency is a desirable feature that facilitates the formation of transient interactions, which are required for the liquid-like chromatin organisation. The existence of multiple, distinct structures on a multifunnel energy landscape is likely to be associated with multifunctionality, i.e. a set of evolved, distinct functions. Contrasting it with previously reported results for other disordered peptides, this type of landscape may be associated with a conformational selection based binding mechanism. Given the similarity to other systems exhibiting similar multifunnel energy landscapes, the disorder in histone tails might be better described in context of multifunctionality.
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Affiliation(s)
- Konstantin Röder
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK.
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43
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Ozsvar J, Wang R, Tarakanova A, Buehler MJ, Weiss AS. Fuzzy binding model of molecular interactions between tropoelastin and integrin alphaVbeta3. Biophys J 2021; 120:3138-3151. [PMID: 34197806 DOI: 10.1016/j.bpj.2021.04.037] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 03/30/2021] [Accepted: 04/12/2021] [Indexed: 12/30/2022] Open
Abstract
Tropoelastin is the highly flexible monomer subunit of elastin, required for the resilience of the extracellular matrix in elastic tissues. To elicit biological signaling, multiple sites on tropoelastin bind to cell surface integrins in a poorly understood multifactorial process. We constructed a full atomistic molecular model of the interactions between tropoelastin and integrin αvβ3 using ensemble-based computational methodologies. Conformational changes of integrin αvβ3 associated with outside-in signaling were more frequently facilitated in an ensemble in which tropoelastin bound the integrin's α1 helix rather than the upstream canonical binding site. Our findings support a model of fuzzy binding, whereby many tropoelastin conformations and defined sites cooperatively interact with multiple αvβ3 regions. This model explains prior experimental binding to distinct tropoelastin regions, domains 17 and 36, and points to the cooperative participation of domain 20. Our study highlights the utility of ensemble-based approaches in helping to understand the interactive mechanisms of functionally significant flexible proteins.
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Affiliation(s)
- Jazmin Ozsvar
- Charles Perkins Centre, The University of Sydney, Sydney, Australia; School of Life and Environmental Sciences, The University of Sydney, Sydney, Australia
| | - Richard Wang
- Charles Perkins Centre, The University of Sydney, Sydney, Australia; School of Life and Environmental Sciences, The University of Sydney, Sydney, Australia
| | - Anna Tarakanova
- Department of Biomedical Engineering, University of Connecticut, Storrs, Connecticut; Department of Mechanical Engineering, University of Connecticut, Storrs, Connecticut
| | - Markus J Buehler
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Anthony S Weiss
- Charles Perkins Centre, The University of Sydney, Sydney, Australia; School of Life and Environmental Sciences, The University of Sydney, Sydney, Australia; Sydney Nano Institute, The University of Sydney, Sydney, Australia.
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44
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Papamokos GV, Tziatzos G, Papageorgiou DG, Georgatos S, Kaxiras E, Politou AS. Progressive Phosphorylation Modulates the Self-Association of a Variably Modified Histone H3 Peptide. Front Mol Biosci 2021; 8:698182. [PMID: 34179102 PMCID: PMC8226166 DOI: 10.3389/fmolb.2021.698182] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 05/31/2021] [Indexed: 11/19/2022] Open
Abstract
Protein phosphorylation is a key regulatory mechanism in eukaryotic cells. In the intrinsically disordered histone tails, phosphorylation is often a part of combinatorial post-translational modifications and an integral part of the “histone code” that regulates gene expression. Here, we study the association between two histone H3 tail peptides modified to different degrees, using fully atomistic molecular dynamics simulations. Assuming that the initial conformations are either α-helical or fully extended, we compare the propensity of the two peptides to associate with one another when both are unmodified, one modified and the other unmodified, or both modified. The simulations lead to the identification of distinct inter- and intramolecular interactions in the peptide dimer, highlighting a prominent role of a fine-tuned phosphorylation rheostat in peptide association. Progressive phosphorylation appears to modulate peptide charge, inducing strong and specific intermolecular interactions between the monomers, which do not result in the formation of amorphous or ordered aggregates, as documented by experimental evidence derived from Circular Dichroism and NMR spectroscopy. However, upon complete saturation of positive charges by phosphate groups, this effect is reversed: intramolecular interactions prevail and dimerization of zero-charge peptides is markedly reduced. These findings underscore the role of phosphorylation thresholds in the dynamics of intrinsically disordered proteins. Phosphorylation rheostats might account for the divergent effects of histone modifications on the modulation of chromatin structure.
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Affiliation(s)
- George V Papamokos
- Biomedical Division, The Institute of Molecular Biology and Biotechnology, FORTH-ITE, Ioannina, Greece.,Department of Physics and School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, United States.,Laboratory of Biological Chemistry, Medical School, University of Ioannina, Ioannina, Greece
| | - George Tziatzos
- Department of Materials Science and Engineering, University of Ioannina, Ioannina, Greece
| | | | - Spyros Georgatos
- Biomedical Division, The Institute of Molecular Biology and Biotechnology, FORTH-ITE, Ioannina, Greece.,Laboratory of Biology, School of Medicine, University of Ioannina, Ioannina, Greece
| | - Efthimios Kaxiras
- Department of Physics and School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, United States
| | - Anastasia S Politou
- Biomedical Division, The Institute of Molecular Biology and Biotechnology, FORTH-ITE, Ioannina, Greece.,Laboratory of Biological Chemistry, Medical School, University of Ioannina, Ioannina, Greece
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45
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How multisite phosphorylation impacts the conformations of intrinsically disordered proteins. PLoS Comput Biol 2021; 17:e1008939. [PMID: 33945530 PMCID: PMC8148376 DOI: 10.1371/journal.pcbi.1008939] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Revised: 05/25/2021] [Accepted: 04/06/2021] [Indexed: 12/15/2022] Open
Abstract
Phosphorylation of intrinsically disordered proteins (IDPs) can produce changes in structural and dynamical properties and thereby mediate critical biological functions. How phosphorylation effects intrinsically disordered proteins has been studied for an increasing number of IDPs, but a systematic understanding is still lacking. Here, we compare the collapse propensity of four disordered proteins, Ash1, the C-terminal domain of RNA polymerase (CTD2’), the cytosolic domain of E-Cadherin, and a fragment of the p130Cas, in unphosphorylated and phosphorylated forms using extensive all-atom molecular dynamics (MD) simulations. We find all proteins to show V-shape changes in their collapse propensity upon multi-site phosphorylation according to their initial net charge: phosphorylation expands neutral or overall negatively charged IDPs and shrinks positively charged IDPs. However, force fields including those tailored towards and commonly used for IDPs overestimate these changes. We find quantitative agreement of MD results with SAXS and NMR data for Ash1 and CTD2’ only when attenuating protein electrostatic interactions by using a higher salt concentration (e.g. 350 mM), highlighting the overstabilization of salt bridges in current force fields. We show that phosphorylation of IDPs also has a strong impact on the solvation of the protein, a factor that in addition to the actual collapse or expansion of the IDP should be considered when analyzing SAXS data. Compared to the overall mild change in global IDP dimension, the exposure of active sites can change significantly upon phosphorylation, underlining the large susceptibility of IDP ensembles to regulation through post-translational modifications. Intrinsically disordered proteins (IDPs) are a class of proteins that lack secondary and tertiary structures and instead explore a broad conformational ensemble. Their functions, from transcriptional regulation to signal transmission, are tightly regulated. IDPs are subject of extensive reversible post-translational modifications (PTMs), such as phosphorylation, methylation and glycosylation. Among these PTMs, phosphorylation is one of the most common and important PTMs. However, the mechanism of how phosphorylation affects the conformations and functions of IDPs remains unclear. To answer this question, we have performed extensive all-atom molecular dynamics simulations for four representative IDPs: Ash1, E-Cadherin, CTD2’ and p130Cas in their unphosphorylated and phosphorylated forms. Our results showed that all IDPs undergo a mild change upon multi-site phosphorylation, which is V-shaped: phosphorylation moderately expands neutral or overall negatively charged IDPs and shrinks positively charged IDPs. More importantly, in two of these IDPs, only two biologically relevant phosphorylation sites suffice to render the adjacent negatively charged active site significantly more exposed to the environment, which implies a higher probability to interact with other binding partners.
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46
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Sponga A, Arolas JL, Schwarz TC, Jeffries CM, Rodriguez Chamorro A, Kostan J, Ghisleni A, Drepper F, Polyansky A, De Almeida Ribeiro E, Pedron M, Zawadzka-Kazimierczuk A, Mlynek G, Peterbauer T, Doto P, Schreiner C, Hollerl E, Mateos B, Geist L, Faulkner G, Kozminski W, Svergun DI, Warscheid B, Zagrovic B, Gautel M, Konrat R, Djinović-Carugo K. Order from disorder in the sarcomere: FATZ forms a fuzzy but tight complex and phase-separated condensates with α-actinin. SCIENCE ADVANCES 2021; 7:eabg7653. [PMID: 34049882 PMCID: PMC8163081 DOI: 10.1126/sciadv.abg7653] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 04/13/2021] [Indexed: 05/03/2023]
Abstract
In sarcomeres, α-actinin cross-links actin filaments and anchors them to the Z-disk. FATZ (filamin-, α-actinin-, and telethonin-binding protein of the Z-disk) proteins interact with α-actinin and other core Z-disk proteins, contributing to myofibril assembly and maintenance. Here, we report the first structure and its cellular validation of α-actinin-2 in complex with a Z-disk partner, FATZ-1, which is best described as a conformational ensemble. We show that FATZ-1 forms a tight fuzzy complex with α-actinin-2 and propose an interaction mechanism via main molecular recognition elements and secondary binding sites. The obtained integrative model reveals a polar architecture of the complex which, in combination with FATZ-1 multivalent scaffold function, might organize interaction partners and stabilize α-actinin-2 preferential orientation in Z-disk. Last, we uncover FATZ-1 ability to phase-separate and form biomolecular condensates with α-actinin-2, raising the question whether FATZ proteins can create an interaction hub for Z-disk proteins through membraneless compartmentalization during myofibrillogenesis.
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Affiliation(s)
- Antonio Sponga
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Joan L Arolas
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Thomas C Schwarz
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Cy M Jeffries
- European Molecular Biology Laboratory (EMBL), Hamburg Unit, Hamburg, Germany
| | - Ariadna Rodriguez Chamorro
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Julius Kostan
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Andrea Ghisleni
- King's College London BHF Centre for Research Excellence, Randall Centre for Cell and Molecular Biophysics, London SE1 1UL, UK
| | - Friedel Drepper
- Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, 79104 Freiburg, Germany
| | - Anton Polyansky
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
- National Research University Higher School of Economics, Moscow 101000, Russia
| | - Euripedes De Almeida Ribeiro
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Miriam Pedron
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Anna Zawadzka-Kazimierczuk
- Biological and Chemical Research Centre, Faculty of Chemistry, University of Warsaw, Zwirki i Wigury 101, 02-089 Warsaw, Poland
| | - Georg Mlynek
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Thomas Peterbauer
- Department of Biochemistry and Cell Biology, Max Perutz Labs, University of Vienna, Dr. BohrGasse 9, A-1030 Vienna, Austria
| | - Pierantonio Doto
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Claudia Schreiner
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Eneda Hollerl
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Borja Mateos
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Leonhard Geist
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | | | - Wiktor Kozminski
- Biological and Chemical Research Centre, Faculty of Chemistry, University of Warsaw, Zwirki i Wigury 101, 02-089 Warsaw, Poland
| | - Dmitri I Svergun
- King's College London BHF Centre for Research Excellence, Randall Centre for Cell and Molecular Biophysics, London SE1 1UL, UK
| | - Bettina Warscheid
- Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, 79104 Freiburg, Germany
| | - Bojan Zagrovic
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Mathias Gautel
- King's College London BHF Centre for Research Excellence, Randall Centre for Cell and Molecular Biophysics, London SE1 1UL, UK
| | - Robert Konrat
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Kristina Djinović-Carugo
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria.
- Department of Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia
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47
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Del Amo-Maestro L, Sagar A, Pompach P, Goulas T, Scavenius C, Ferrero DS, Castrillo-Briceño M, Taulés M, Enghild JJ, Bernadó P, Gomis-Rüth FX. An Integrative Structural Biology Analysis of Von Willebrand Factor Binding and Processing by ADAMTS-13 in Solution. J Mol Biol 2021; 433:166954. [PMID: 33771572 DOI: 10.1016/j.jmb.2021.166954] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 03/16/2021] [Accepted: 03/16/2021] [Indexed: 10/21/2022]
Abstract
Von Willebrand Factor (vWF), a 300-kDa plasma protein key to homeostasis, is cleaved at a single site by multi-domain metallopeptidase ADAMTS-13. vWF is the only known substrate of this peptidase, which circulates in a latent form and becomes allosterically activated by substrate binding. Herein, we characterised the complex formed by a competent peptidase construct (AD13-MDTCS) comprising metallopeptidase (M), disintegrin-like (D), thrombospondin (T), cysteine-rich (C), and spacer (S) domains, with a 73-residue functionally relevant vWF-peptide, using nine complementary techniques. Pull-down assays, gel electrophoresis, and surface plasmon resonance revealed tight binding with sub-micromolar affinity. Cross-linking mass spectrometry with four reagents showed that, within the peptidase, domain D approaches M, C, and S. S is positioned close to M and C, and the peptide contacts all domains. Hydrogen/deuterium exchange mass spectrometry revealed strong and weak protection for C/D and M/S, respectively. Structural analysis by multi-angle laser light scattering and small-angle X-ray scattering in solution revealed that the enzyme adopted highly flexible unbound, latent structures and peptide-bound, active structures that differed from the AD13-MDTCS crystal structure. Moreover, the peptide behaved like a self-avoiding random chain. We integrated the results with computational approaches, derived an ensemble of structures that collectively satisfied all experimental restraints, and discussed the functional implications. The interaction conforms to a 'fuzzy complex' that follows a 'dynamic zipper' mechanism involving numerous reversible, weak but additive interactions that result in strong binding and cleavage. Our findings contribute to illuminating the biochemistry of the vWF:ADAMTS-13 axis.
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Affiliation(s)
- Laura Del Amo-Maestro
- Proteolysis Laboratory, Department of Structural Biology, Molecular Biology Institute of Barcelona (CSIC), Barcelona Science Park, c/Baldiri Reixac, 15-21, 08028 Barcelona, Catalonia, Spain
| | - Amin Sagar
- Centre de Biochimie Structurale, INSERM, CNRS and Université de Montpellier, 34090 Montpellier, France
| | - Petr Pompach
- Institute of Microbiology of the Czech Academy of Sciences, BIOCEV, Prumyslova 595, 252 50 Vestec, Czechia; Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Prumyslova 595, 252 50 Vestec, Czechia
| | - Theodoros Goulas
- Proteolysis Laboratory, Department of Structural Biology, Molecular Biology Institute of Barcelona (CSIC), Barcelona Science Park, c/Baldiri Reixac, 15-21, 08028 Barcelona, Catalonia, Spain
| | - Carsten Scavenius
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, 8000 Aarhus C, Denmark
| | - Diego S Ferrero
- Laboratory for Viruses and Large Biological Complexes, Department of Structural Biology, Molecular Biology Institute of Barcelona (CSIC), Barcelona Science Park, c/Baldiri Reixac, 15-21, 08028 Barcelona, Catalonia, Spain
| | - Mariana Castrillo-Briceño
- Proteolysis Laboratory, Department of Structural Biology, Molecular Biology Institute of Barcelona (CSIC), Barcelona Science Park, c/Baldiri Reixac, 15-21, 08028 Barcelona, Catalonia, Spain
| | - Marta Taulés
- Scientific and Technological Centers (CCiTUB), University of Barcelona, Lluís Solé i Sabaris, 1-3, 08028 Barcelona, Catalonia, Spain
| | - Jan J Enghild
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, 8000 Aarhus C, Denmark
| | - Pau Bernadó
- Centre de Biochimie Structurale, INSERM, CNRS and Université de Montpellier, 34090 Montpellier, France.
| | - F Xavier Gomis-Rüth
- Proteolysis Laboratory, Department of Structural Biology, Molecular Biology Institute of Barcelona (CSIC), Barcelona Science Park, c/Baldiri Reixac, 15-21, 08028 Barcelona, Catalonia, Spain.
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48
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Beveridge R, Calabrese AN. Structural Proteomics Methods to Interrogate the Conformations and Dynamics of Intrinsically Disordered Proteins. Front Chem 2021; 9:603639. [PMID: 33791275 PMCID: PMC8006314 DOI: 10.3389/fchem.2021.603639] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 01/19/2021] [Indexed: 12/21/2022] Open
Abstract
Intrinsically disordered proteins (IDPs) and regions of intrinsic disorder (IDRs) are abundant in proteomes and are essential for many biological processes. Thus, they are often implicated in disease mechanisms, including neurodegeneration and cancer. The flexible nature of IDPs and IDRs provides many advantages, including (but not limited to) overcoming steric restrictions in binding, facilitating posttranslational modifications, and achieving high binding specificity with low affinity. IDPs adopt a heterogeneous structural ensemble, in contrast to typical folded proteins, making it challenging to interrogate their structure using conventional tools. Structural mass spectrometry (MS) methods are playing an increasingly important role in characterizing the structure and function of IDPs and IDRs, enabled by advances in the design of instrumentation and the development of new workflows, including in native MS, ion mobility MS, top-down MS, hydrogen-deuterium exchange MS, crosslinking MS, and covalent labeling. Here, we describe the advantages of these methods that make them ideal to study IDPs and highlight recent applications where these tools have underpinned new insights into IDP structure and function that would be difficult to elucidate using other methods.
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Affiliation(s)
- Rebecca Beveridge
- Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, United Kingdom
| | - Antonio N. Calabrese
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
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49
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Price KL, Presler M, Uyehara CM, Shakes DC. The intrinsically disordered protein SPE-18 promotes localized assembly of MSP in Caenorhabditis elegans spermatocytes. Development 2021; 148:dev195875. [PMID: 33558389 PMCID: PMC7938801 DOI: 10.1242/dev.195875] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 02/02/2021] [Indexed: 01/26/2023]
Abstract
Many specialized cells use unconventional strategies of cytoskeletal control. Nematode spermatocytes discard their actin and tubulin following meiosis, and instead employ the regulated assembly/disassembly of the Major Sperm Protein (MSP) to drive sperm motility. However, prior to the meiotic divisions, MSP is sequestered through its assembly into paracrystalline structures called fibrous bodies (FBs). The accessory proteins that direct this sequestration process have remained mysterious. This study reveals SPE-18 as an intrinsically disordered protein that is essential for MSP assembly within FBs. In spe-18 mutant spermatocytes, MSP forms disorganized cortical fibers, and the cells arrest in meiosis without forming haploid sperm. In wild-type spermatocytes, SPE-18 localizes to pre-FB complexes and functions with the kinase SPE-6 to localize MSP assembly. Changing patterns of SPE-18 localization uncover previously unappreciated complexities in FB maturation. Later, within newly individualized spermatids, SPE-18 is rapidly lost, yet SPE-18 loss alone is insufficient for MSP disassembly. Our findings reveal an alternative strategy for sequestering cytoskeletal elements, not as monomers but in localized, bundled polymers. Additionally, these studies provide an important example of disordered proteins promoting ordered cellular structures.
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Affiliation(s)
- Kari L Price
- Department of Biology, William & Mary, Williamsburg, VA 23187, USA
| | - Marc Presler
- Department of Biology, William & Mary, Williamsburg, VA 23187, USA
| | | | - Diane C Shakes
- Department of Biology, William & Mary, Williamsburg, VA 23187, USA
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50
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Freiberger MI, Wolynes PG, Ferreiro DU, Fuxreiter M. Frustration in Fuzzy Protein Complexes Leads to Interaction Versatility. J Phys Chem B 2021; 125:2513-2520. [PMID: 33667107 PMCID: PMC8041309 DOI: 10.1021/acs.jpcb.0c11068] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
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Disordered
proteins frequently serve as interaction hubs involving
a constrained variety of partners. Complexes with different partners
frequently exhibit distinct binding modes, involving regions that
remain disordered in the bound state. While the conformational properties
of disordered proteins are well-characterized in their free states,
less is known about the molecular mechanisms by which specificity
can be achieved not with one but with multiple partners. Using the
energy landscape theory concept of protein frustration, we demonstrate
that complexes of disordered proteins exhibit a high degree of local
frustration, especically at the binding interface. These suboptimal
interactions lead to the possibility of multiple bound substates,
each displaying distinct frustration patterns, which are differently
populated in complexes with different partners. These results explain
how specificity of disordered proteins can be achieved without a single
common bound conformation and how the confliict between different
interactions can be used to control the binding to multiple partners.
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Affiliation(s)
- Maria I Freiberger
- Protein Physiology Lab, Departamento de Quimica Biologica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires-CONICET-IQUIBICEN, Buenos Aires, 1428, Argentina
| | - Peter G Wolynes
- Center for Theoretical Biological Physics, Rice University, Houston, Texas 77005, United States
| | - Diego U Ferreiro
- Protein Physiology Lab, Departamento de Quimica Biologica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires-CONICET-IQUIBICEN, Buenos Aires, 1428, Argentina
| | - Monika Fuxreiter
- Department of Biomedical Sciences, University of Padova, Padova, 35131, Italy.,Laboratory of Protein Dynamics, University of Debrecen, Debrecen, 4032, Hungary
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