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Muli CS, Tarasov SG, Walters KJ. High-throughput assay exploiting disorder-to-order conformational switches: application to the proteasomal Rpn10:E6AP complex. Chem Sci 2024; 15:4041-4053. [PMID: 38487241 PMCID: PMC10935766 DOI: 10.1039/d3sc06370d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 02/05/2024] [Indexed: 03/17/2024] Open
Abstract
Conformational switching is pervasively driven by protein interactions, particularly for intrinsically disordered binding partners. We developed a dually orthogonal fluorescence-based assay to monitor such events, exploiting environmentally sensitive fluorophores. This assay is applied to E3 ligase E6AP, as its AZUL domain induces a disorder-to-order switch in an intrinsically disordered region of the proteasome, the so-named Rpn10 AZUL-binding domain (RAZUL). By testing various fluorophores, we developed an assay appropriate for high-throughput screening of Rpn10:E6AP-disrupting ligands. We found distinct positions in RAZUL for fluorophore labeling with either acrylodan or Atto610, which had disparate spectral responses to E6AP binding. E6AP caused a hypsochromic shift with increased fluorescence of acrylodan-RAZUL while decreasing fluorescence intensity of Atto610-RAZUL. Combining RAZUL labeled with either acrylodan or Atto610 into a common sample achieved robust and orthogonal measurement of the E6AP-induced conformational switch. This approach is generally applicable to disorder-to-order (or vice versa) transitions mediated by molecular interactions.
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Affiliation(s)
- Christine S Muli
- Protein Processing Section, Center for Structural Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health Frederick MD 21702 USA
| | - Sergey G Tarasov
- Biophysics Resource, Center for Structural Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health Frederick MD 21702 USA
| | - Kylie J Walters
- Protein Processing Section, Center for Structural Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health Frederick MD 21702 USA
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2
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Muradyan N, Arakelov V, Sargsyan A, Paronyan A, Arakelov G, Nazaryan K. Impact of mutations on the stability of SARS-CoV-2 nucleocapsid protein structure. Sci Rep 2024; 14:5870. [PMID: 38467657 PMCID: PMC10928099 DOI: 10.1038/s41598-024-55157-8] [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: 10/30/2023] [Accepted: 02/21/2024] [Indexed: 03/13/2024] Open
Abstract
The nucleocapsid (N) protein of SARS-CoV-2 is known to participate in various host cellular processes, including interferon inhibition, RNA interference, apoptosis, and regulation of virus life cycles. Additionally, it has potential as a diagnostic antigen and/or immunogen. Our research focuses on examining structural changes caused by mutations in the N protein. We have modeled the complete tertiary structure of native and mutated forms of the N protein using Alphafold2. Notably, the N protein contains 3 disordered regions. The focus was on investigating the impact of mutations on the stability of the protein's dimeric structure based on binding free energy calculations (MM-PB/GB-SA) and RMSD fluctuations after MD simulations. The results demonstrated that 28 mutations out of 37 selected mutations analyzed, compared with wild-type N protein, resulted in a stable dimeric structure, while 9 mutations led to destabilization. Our results are important to understand the tertiary structure of the N protein dimer of SARS-CoV-2 and the effect of mutations on it, their behavior in the host cell, as well as for the research of other viruses belonging to the same genus additionally, to anticipate potential strategies for addressing this viral illness․.
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Affiliation(s)
- Nelli Muradyan
- Laboratory of Computational Modeling of Biological Processes, Institute of Molecular Biology of the National Academy of Sciences of the Republic of Armenia (NAS RA), 0014, Yerevan, Armenia
| | - Vahram Arakelov
- Laboratory of Computational Modeling of Biological Processes, Institute of Molecular Biology of the National Academy of Sciences of the Republic of Armenia (NAS RA), 0014, Yerevan, Armenia
| | - Arsen Sargsyan
- Laboratory of Computational Modeling of Biological Processes, Institute of Molecular Biology of the National Academy of Sciences of the Republic of Armenia (NAS RA), 0014, Yerevan, Armenia
- Russian-Armenian University, 0051, Yerevan, Armenia
| | - Adrine Paronyan
- Laboratory of Computational Modeling of Biological Processes, Institute of Molecular Biology of the National Academy of Sciences of the Republic of Armenia (NAS RA), 0014, Yerevan, Armenia
- Russian-Armenian University, 0051, Yerevan, Armenia
| | - Grigor Arakelov
- Laboratory of Computational Modeling of Biological Processes, Institute of Molecular Biology of the National Academy of Sciences of the Republic of Armenia (NAS RA), 0014, Yerevan, Armenia.
- Russian-Armenian University, 0051, Yerevan, Armenia.
| | - Karen Nazaryan
- Laboratory of Computational Modeling of Biological Processes, Institute of Molecular Biology of the National Academy of Sciences of the Republic of Armenia (NAS RA), 0014, Yerevan, Armenia
- Russian-Armenian University, 0051, Yerevan, Armenia
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3
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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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4
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Arai M, Suetaka S, Ooka K. Dynamics and interactions of intrinsically disordered proteins. Curr Opin Struct Biol 2024; 84:102734. [PMID: 38039868 DOI: 10.1016/j.sbi.2023.102734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 10/27/2023] [Accepted: 10/30/2023] [Indexed: 12/03/2023]
Abstract
Intrinsically disordered proteins (IDPs) are widespread in eukaryotes and participate in a variety of important cellular processes. Numerous studies using state-of-the-art experimental and theoretical methods have advanced our understanding of IDPs and revealed that disordered regions engage in a large repertoire of intra- and intermolecular interactions through their conformational dynamics, thereby regulating many intracellular functions in concert with folded domains. The mechanisms by which IDPs interact with their partners are diverse, depending on their conformational propensities, and include induced fit, conformational selection, and their mixtures. In addition, IDPs are implicated in many diseases, and progress has been made in designing inhibitors of IDP-mediated interactions. Here we review these recent advances with a focus on the dynamics and interactions of IDPs.
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Affiliation(s)
- Munehito Arai
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan; Komaba Organization for Educational Excellence, College of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan; Department of Physics, Graduate School of Science, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan.
| | - Shunji Suetaka
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan
| | - Koji Ooka
- Komaba Organization for Educational Excellence, College of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan
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5
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Silonov SA, Smirnov EY, Shmidt EA, Kuznetsova IM, Turoverov KK, Fonin AV. Insights into the Cellular Localization and Functional Properties of TSPYL5 Protein. Int J Mol Sci 2023; 25:39. [PMID: 38203210 PMCID: PMC10779080 DOI: 10.3390/ijms25010039] [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: 11/09/2023] [Revised: 12/11/2023] [Accepted: 12/16/2023] [Indexed: 01/12/2024] Open
Abstract
In recent years, the role of liquid-liquid phase separation (LLPS) and intrinsically disordered proteins (IDPs) in cellular molecular processes has received increasing attention from researchers. One such intrinsically disordered protein is TSPYL5, considered both as a marker and a potential therapeutic target for various oncological diseases. However, the role of TSPYL5 in intracellular processes remains unknown, and there is no clarity even in its intracellular localization. In this study, we characterized the intracellular localization and exchange dynamics with intracellular contents of TSPYL5 and its parts, utilizing TSPYL5 fusion proteins with EGFP. Our findings reveal that TSPYL5 can be localized in both the cytoplasm and nucleoplasm, including the nucleolus. The nuclear (nucleolar) localization of TSPYL5 is mediated by the nuclear/nucleolar localization sequences (NLS/NoLS) identified in the N-terminal intrinsically disordered region (4-27 aa), while its cytoplasmic localization is regulated by the ordered NAP-like domain (198-382 aa). Furthermore, our results underscore the significant role of the TSPYL5 N-terminal disordered region (1-198 aa) in the exchange dynamics with the nucleoplasm and its potential ability for phase separation. Bioinformatics analysis of the TSPYL5 interactome indicates its potential function as a histone and ribosomal protein chaperone. Taken together, these findings suggest a significant contribution of liquid-liquid phase separation to the processes involving TSPYL5, providing new insights into the role of this protein in the cell's molecular life.
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Affiliation(s)
- Sergey A. Silonov
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Russian Academy of Sciences, St. Petersburg 194064, Russia; (E.Y.S.); (E.A.S.); (I.M.K.); (K.K.T.)
| | | | | | | | | | - Alexander V. Fonin
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Russian Academy of Sciences, St. Petersburg 194064, Russia; (E.Y.S.); (E.A.S.); (I.M.K.); (K.K.T.)
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Varadi M, Tsenkov M, Velankar S. Challenges in bridging the gap between protein structure prediction and functional interpretation. Proteins 2023. [PMID: 37850517 DOI: 10.1002/prot.26614] [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: 06/28/2023] [Revised: 09/26/2023] [Accepted: 10/04/2023] [Indexed: 10/19/2023]
Abstract
The rapid evolution of protein structure prediction tools has significantly broadened access to protein structural data. Although predicted structure models have the potential to accelerate and impact fundamental and translational research significantly, it is essential to note that they are not validated and cannot be considered the ground truth. Thus, challenges persist, particularly in capturing protein dynamics, predicting multi-chain structures, interpreting protein function, and assessing model quality. Interdisciplinary collaborations are crucial to overcoming these obstacles. Databases like the AlphaFold Protein Structure Database, the ESM Metagenomic Atlas, and initiatives like the 3D-Beacons Network provide FAIR access to these data, enabling their interpretation and application across a broader scientific community. Whilst substantial advancements have been made in protein structure prediction, further progress is required to address the remaining challenges. Developing training materials, nurturing collaborations, and ensuring open data sharing will be paramount in this pursuit. The continued evolution of these tools and methodologies will deepen our understanding of protein function and accelerate disease pathogenesis and drug development discoveries.
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Affiliation(s)
- Mihaly Varadi
- Protein Data Bank in Europe, European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - Maxim Tsenkov
- Protein Data Bank in Europe, European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - Sameer Velankar
- Protein Data Bank in Europe, European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Hinxton, Cambridge, UK
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Murvai N, Gellen G, Micsonai A, Schlosser G, Kardos J. Cross-Linked α-Synuclein as Inhibitor of Amyloid Formation. Int J Mol Sci 2023; 24:13403. [PMID: 37686208 PMCID: PMC10487470 DOI: 10.3390/ijms241713403] [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: 07/11/2023] [Revised: 08/23/2023] [Accepted: 08/25/2023] [Indexed: 09/10/2023] Open
Abstract
The aggregation and amyloid formation of α-synuclein is associated with Parkinson's disease and other synucleinopathies. In its native, monomeric form α-synuclein is an intrinsically disordered protein represented by highly dynamic conformational ensembles. Inhibition of α-synuclein aggregation using small molecules, peptides, or proteins has been at the center of interest in recent years. Our aim was to explore the effects of cross-linking on the structure and aggregation/amyloid formation properties of α-synuclein. Comparative analysis of available high-resolution amyloid structures and representative structural models and MD trajectory of monomeric α-synuclein revealed that potential cross-links in the monomeric protein are mostly incompatible with the amyloid forms and thus might inhibit fibrillation. Monomeric α-synuclein has been intramolecularly chemically cross-linked under various conditions using different cross-linkers. We determined the location of cross-links and their frequency using mass spectrometry and found that most of them cannot be realized in the amyloid structures. The inhibitory potential of cross-linked proteins has been experimentally investigated using various methods, including thioflavin-T fluorescence and transmission electron microscopy. We found that conformational constraints applied by cross-linking fully blocked α-synuclein amyloid formation. Moreover, DTSSP-cross-linked molecules exhibited an inhibitory effect on the aggregation of unmodified α-synuclein as well.
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Affiliation(s)
- Nikoletta Murvai
- Department of Biochemistry, Institute of Biology, ELTE Eötvös Loránd University, H-1117 Budapest, Hungary
- ELTE—Functional Nucleic Acid Motifs Research Group, Department of Biochemistry, Institute of Biology, ELTE Eötvös Loránd University, H-1117 Budapest, Hungary
| | - Gabriella Gellen
- MTA-ELTE Lendület Ion Mobility Mass Spectrometry Research Group, Department of Analytical Chemistry, Institute of Chemistry, ELTE Eötvös Loránd University, H-1117 Budapest, Hungary
- Doctoral School of Molecular Cell and Immune Biology, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary
| | - András Micsonai
- Department of Biochemistry, Institute of Biology, ELTE Eötvös Loránd University, H-1117 Budapest, Hungary
- ELTE—Functional Nucleic Acid Motifs Research Group, Department of Biochemistry, Institute of Biology, ELTE Eötvös Loránd University, H-1117 Budapest, Hungary
- ELTE NAP Neuroimmunology Research Group, Department of Biochemistry, Institute of Biology, ELTE Eötvös Loránd University, H-1117 Budapest, Hungary
| | - Gitta Schlosser
- MTA-ELTE Lendület Ion Mobility Mass Spectrometry Research Group, Department of Analytical Chemistry, Institute of Chemistry, ELTE Eötvös Loránd University, H-1117 Budapest, Hungary
| | - József Kardos
- Department of Biochemistry, Institute of Biology, ELTE Eötvös Loránd University, H-1117 Budapest, Hungary
- ELTE NAP Neuroimmunology Research Group, Department of Biochemistry, Institute of Biology, ELTE Eötvös Loránd University, H-1117 Budapest, Hungary
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