1
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Pesce F, Bremer A, Tesei G, Hopkins JB, Grace CR, Mittag T, Lindorff-Larsen K. Design of intrinsically disordered protein variants with diverse structural properties. SCIENCE ADVANCES 2024; 10:eadm9926. [PMID: 39196930 DOI: 10.1126/sciadv.adm9926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 06/07/2024] [Indexed: 08/30/2024]
Abstract
Intrinsically disordered proteins (IDPs) perform a broad range of functions in biology, suggesting that the ability to design IDPs could help expand the repertoire of proteins with novel functions. Computational design of IDPs with specific conformational properties has, however, been difficult because of their substantial dynamics and structural complexity. We describe a general algorithm for designing IDPs with specific structural properties. We demonstrate the power of the algorithm by generating variants of naturally occurring IDPs that differ in compaction, long-range contacts, and propensity to phase separate. We experimentally tested and validated our designs and analyzed the sequence features that determine conformations. We show how our results are captured by a machine learning model, enabling us to speed up the algorithm. Our work expands the toolbox for computational protein design and will facilitate the design of proteins whose functions exploit the many properties afforded by protein disorder.
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Affiliation(s)
- Francesco Pesce
- Structural Biology and NMR Laboratory, The Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Anne Bremer
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Giulio Tesei
- Structural Biology and NMR Laboratory, The Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Jesse B Hopkins
- BioCAT, Department of Physics, Illinois Institute of Technology, Chicago, IL 60616, USA
| | - Christy R Grace
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Tanja Mittag
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Kresten Lindorff-Larsen
- Structural Biology and NMR Laboratory, The Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
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2
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Qin S, Zhou HX. Predicting the Sequence-Dependent Backbone Dynamics of Intrinsically Disordered Proteins. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.02.02.526886. [PMID: 36778236 PMCID: PMC9915584 DOI: 10.1101/2023.02.02.526886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
How the sequences of intrinsically disordered proteins (IDPs) code for functions is still an enigma. Dynamics, in particular residue-specific dynamics, holds crucial clues. Enormous efforts have been spent to characterize residue-specific dynamics of IDPs, mainly through NMR spin relaxation experiments. Here we present a sequence-based method, SeqDYN, for predicting residue-specific backbone dynamics of IDPs. SeqDYN employs a mathematical model with 21 parameters: one is a correlation length and 20 are the contributions of the amino acids to slow dynamics. Training on a set of 45 IDPs reveals aromatic, Arg, and long-branched aliphatic amino acids as the most active in slow dynamics whereas Gly and short polar amino acids as the least active. SeqDYN predictions not only provide an accurate and insightful characterization of sequence-dependent IDP dynamics but may also serve as indicators in a host of biophysical processes, including the propensities of IDP sequences to undergo phase separation.
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Affiliation(s)
- Sanbo Qin
- Department of Chemistry, University of Illinois Chicago, Chicago, IL 60607, USA
| | - Huan-Xiang Zhou
- Department of Chemistry, University of Illinois Chicago, Chicago, IL 60607, USA
- Department of Physics, University of Illinois Chicago, Chicago, IL 60607, USA
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3
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Cagliani R, Forni D, Mozzi A, Fuchs R, Tussia-Cohen D, Arrigoni F, Pozzoli U, De Gioia L, Hagai T, Sironi M. Evolution of Virus-like Features and Intrinsically Disordered Regions in Retrotransposon-derived Mammalian Genes. Mol Biol Evol 2024; 41:msae154. [PMID: 39101471 PMCID: PMC11299033 DOI: 10.1093/molbev/msae154] [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: 05/29/2024] [Revised: 07/16/2024] [Accepted: 07/19/2024] [Indexed: 08/06/2024] Open
Abstract
Several mammalian genes have originated from the domestication of retrotransposons, selfish mobile elements related to retroviruses. Some of the proteins encoded by these genes have maintained virus-like features; including self-processing, capsid structure formation, and the generation of different isoforms through -1 programmed ribosomal frameshifting. Using quantitative approaches in molecular evolution and biophysical analyses, we studied 28 retrotransposon-derived genes, with a focus on the evolution of virus-like features. By analyzing the rate of synonymous substitutions, we show that the -1 programmed ribosomal frameshifting mechanism in three of these genes (PEG10, PNMA3, and PNMA5) is conserved across mammals and originates alternative proteins. These genes were targets of positive selection in primates, and one of the positively selected sites affects a B-cell epitope on the spike domain of the PNMA5 capsid, a finding reminiscent of observations in infectious viruses. More generally, we found that retrotransposon-derived proteins vary in their intrinsically disordered region content and this is directly associated with their evolutionary rates. Most positively selected sites in these proteins are located in intrinsically disordered regions and some of them impact protein posttranslational modifications, such as autocleavage and phosphorylation. Detailed analyses of the biophysical properties of intrinsically disordered regions showed that positive selection preferentially targeted regions with lower conformational entropy. Furthermore, positive selection introduces variation in binary sequence patterns across orthologues, as well as in chain compaction. Our results shed light on the evolutionary trajectories of a unique class of mammalian genes and suggest a novel approach to study how intrinsically disordered region biophysical characteristics are affected by evolution.
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Affiliation(s)
- Rachele Cagliani
- Scientific Institute IRCCS E. MEDEA, Computational Biology Unit, Bosisio Parini 23842, Italy
| | - Diego Forni
- Scientific Institute IRCCS E. MEDEA, Computational Biology Unit, Bosisio Parini 23842, Italy
| | - Alessandra Mozzi
- Scientific Institute IRCCS E. MEDEA, Computational Biology Unit, Bosisio Parini 23842, Italy
| | - Rotem Fuchs
- Shmunis School of Biomedicine and Cancer Research, George S Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Dafna Tussia-Cohen
- Shmunis School of Biomedicine and Cancer Research, George S Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Federica Arrigoni
- Department of Biotechnology and Biosciences, University of Milan-Bicocca, Milan 20126, Italy
| | - Uberto Pozzoli
- Scientific Institute IRCCS E. MEDEA, Computational Biology Unit, Bosisio Parini 23842, Italy
| | - Luca De Gioia
- Department of Biotechnology and Biosciences, University of Milan-Bicocca, Milan 20126, Italy
| | - Tzachi Hagai
- Shmunis School of Biomedicine and Cancer Research, George S Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Manuela Sironi
- Scientific Institute IRCCS E. MEDEA, Computational Biology Unit, Bosisio Parini 23842, Italy
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4
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Juniku B, Mignon J, Carême R, Genco A, Obeid AM, Mottet D, Monari A, Michaux C. Intrinsic disorder and salt-dependent conformational changes of the N-terminal region of TFIP11 splicing factor. Int J Biol Macromol 2024; 277:134291. [PMID: 39089542 DOI: 10.1016/j.ijbiomac.2024.134291] [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: 05/30/2024] [Revised: 07/21/2024] [Accepted: 07/28/2024] [Indexed: 08/04/2024]
Abstract
Tuftelin Interacting Protein 11 (TFIP11) was identified as a critical human spliceosome assembly regulator, interacting with multiple proteins and localising in membrane-less organelles. However, a lack of structural information on TFIP11 limits the rationalisation of its biological role. TFIP11 is predicted as an intrinsically disordered protein (IDP), and more specifically concerning its N-terminal (N-TER) region. IDPs lack a defined tertiary structure, existing as a dynamic conformational ensemble, favouring protein-protein and protein-RNA interactions. IDPs are involved in liquid-liquid phase separation (LLPS), driving the formation of subnuclear compartments. Combining disorder prediction, molecular dynamics, and spectroscopy methods, this contribution shows the first evidence TFIP11 N-TER is a polyampholytic IDP, exhibiting a structural duality with the coexistence of ordered and disordered assemblies, depending on the ionic strength. Increasing the salt concentration enhances the protein conformational flexibility, presenting a more globule-like shape, and a fuzzier unstructured arrangement that could favour LLPS and protein-RNA interaction. The most charged and hydrophilic regions are the most impacted, including the G-Patch domain essential to TFIP11 function. This study gives a better understanding of the salt-dependent conformational behaviour of the N-TER TFIP11, supporting the hypothesis of the formation of different types of protein assembly, in line with its multiple biological roles.
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Affiliation(s)
- Blinera Juniku
- Laboratory of Physical Chemistry of Biomolecules, UCPTS, University of Namur, Rue de Bruxelles 61, B-5000 Namur, Belgium; Namur Research Institute for Life Sciences (NARILIS), University of Namur, Namur, Belgium; Namur Institute of Structured Matter (NISM), University of Namur, Namur, Belgium; GIGA-Molecular Biology of Diseases, Molecular Analysis of Gene Expression (MAGE) Laboratory, University of Liege, B34, Avenue de l'Hôpital, B-4000 Liège, Belgium
| | - Julien Mignon
- Laboratory of Physical Chemistry of Biomolecules, UCPTS, University of Namur, Rue de Bruxelles 61, B-5000 Namur, Belgium; Namur Research Institute for Life Sciences (NARILIS), University of Namur, Namur, Belgium; Namur Institute of Structured Matter (NISM), University of Namur, Namur, Belgium
| | - Rachel Carême
- Laboratory of Physical Chemistry of Biomolecules, UCPTS, University of Namur, Rue de Bruxelles 61, B-5000 Namur, Belgium
| | - Alexia Genco
- GIGA-Molecular Biology of Diseases, Molecular Analysis of Gene Expression (MAGE) Laboratory, University of Liege, B34, Avenue de l'Hôpital, B-4000 Liège, Belgium
| | - Anna Maria Obeid
- GIGA-Molecular Biology of Diseases, Molecular Analysis of Gene Expression (MAGE) Laboratory, University of Liege, B34, Avenue de l'Hôpital, B-4000 Liège, Belgium
| | - Denis Mottet
- GIGA-Molecular Biology of Diseases, Molecular Analysis of Gene Expression (MAGE) Laboratory, University of Liege, B34, Avenue de l'Hôpital, B-4000 Liège, Belgium.
| | - Antonio Monari
- Université Paris Cité and CNRS, ITODYS, F-75006, Paris, France
| | - Catherine Michaux
- Laboratory of Physical Chemistry of Biomolecules, UCPTS, University of Namur, Rue de Bruxelles 61, B-5000 Namur, Belgium; Namur Research Institute for Life Sciences (NARILIS), University of Namur, Namur, Belgium; Namur Institute of Structured Matter (NISM), University of Namur, Namur, Belgium.
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5
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Chen YR, Harel I, Singh PP, Ziv I, Moses E, Goshtchevsky U, Machado BE, Brunet A, Jarosz DF. Tissue-specific landscape of protein aggregation and quality control in an aging vertebrate. Dev Cell 2024; 59:1892-1911.e13. [PMID: 38810654 PMCID: PMC11265985 DOI: 10.1016/j.devcel.2024.04.014] [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: 08/30/2023] [Revised: 01/13/2024] [Accepted: 04/15/2024] [Indexed: 05/31/2024]
Abstract
Protein aggregation is a hallmark of age-related neurodegeneration. Yet, aggregation during normal aging and in tissues other than the brain is poorly understood. Here, we leverage the African turquoise killifish to systematically profile protein aggregates in seven tissues of an aging vertebrate. Age-dependent aggregation is strikingly tissue specific and not simply driven by protein expression differences. Experimental interrogation in killifish and yeast, combined with machine learning, indicates that this specificity is linked to protein-autonomous biophysical features and tissue-selective alterations in protein quality control. Co-aggregation of protein quality control machinery during aging may further reduce proteostasis capacity, exacerbating aggregate burden. A segmental progeria model with accelerated aging in specific tissues exhibits selectively increased aggregation in these same tissues. Intriguingly, many age-related protein aggregates arise in wild-type proteins that, when mutated, drive human diseases. Our data chart a comprehensive landscape of protein aggregation during vertebrate aging and identify strong, tissue-specific associations with dysfunction and disease.
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Affiliation(s)
- Yiwen R Chen
- Department of Chemical and Systems Biology, Stanford University, Stanford, CA 94305, USA
| | - Itamar Harel
- The Silberman Institute, the Hebrew University of Jerusalem, Givat Ram, Jerusalem 91904, Israel; Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Param Priya Singh
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Inbal Ziv
- Department of Chemical and Systems Biology, Stanford University, Stanford, CA 94305, USA
| | - Eitan Moses
- The Silberman Institute, the Hebrew University of Jerusalem, Givat Ram, Jerusalem 91904, Israel
| | - Uri Goshtchevsky
- The Silberman Institute, the Hebrew University of Jerusalem, Givat Ram, Jerusalem 91904, Israel
| | - Ben E Machado
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Anne Brunet
- Department of Genetics, Stanford University, Stanford, CA 94305, USA; Glenn Center for the Biology of Aging, Stanford University, Stanford, CA 94305, USA.
| | - Daniel F Jarosz
- Department of Chemical and Systems Biology, Stanford University, Stanford, CA 94305, USA; Department of Developmental Biology, Stanford University, Stanford, CA 94305, USA.
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6
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Ding X. Optimizing Force Fields with Experimental Data Using Ensemble Reweighting and Potential Contrasting. J Phys Chem B 2024; 128:6760-6769. [PMID: 38967278 DOI: 10.1021/acs.jpcb.4c02147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/06/2024]
Abstract
Despite force field improvements over the past decades, we still encounter situations where simulation results disagree with experiments due to force field inaccuracies. Such situations provide opportunities to improve force fields. In this study, we introduce a novel framework for optimizing force fields using experimental data. The unique feature of this framework is that it aims to optimize force fields to match experiments while minimizing the perturbation made to the original force field. To achieve this, we combine ensemble reweighting techniques with the potential contrasting method. Ensemble reweighting is used to reweight an ensemble of conformations generated using an existing force field to match experimental data while minimizing the perturbation to the original ensemble. Potential contrasting is then utilized to optimize force field parameters to reproduce the reweighted ensemble. We demonstrate the framework's effectiveness by optimizing a coarse-grained force field for intrinsically disordered proteins using experimental radius of gyration data.
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Affiliation(s)
- Xinqiang Ding
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, United States
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7
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Usher ET, Fossat MJ, Holehouse AS. Phosphorylation of disordered proteins tunes local and global intramolecular interactions. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.10.598315. [PMID: 38915510 PMCID: PMC11195077 DOI: 10.1101/2024.06.10.598315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
Protein post-translational modifications, such as phosphorylation, are important regulatory signals for diverse cellular functions. In particular, intrinsically disordered protein regions (IDRs) are subject to phosphorylation as a means to modulate their interactions and functions. Toward understanding the relationship between phosphorylation in IDRs and specific functional outcomes, we must consider how phosphorylation affects the IDR conformational ensemble. Various experimental techniques are suited to interrogate the features of IDR ensembles; molecular simulations can provide complementary insights and even illuminate ensemble features that may be experimentally inaccessible. Therefore, we sought to expand the tools available to study phosphorylated IDRs by all-atom Monte Carlo simulations. To this end, we implemented parameters for phosphoserine (pSer) and phosphothreonine (pThr) into the OPLS version of the continuum solvent model, ABSINTH, and assessed their performance in all-atom simulations compared to published findings. We simulated short (< 20 residues) and long (> 80 residues) phospho-IDRs that, collectively, survey both local and global phosphorylation-induced changes to the ensemble. Our simulations of four well-studied phospho-IDRs show near-quantitative agreement with published findings for these systems via metrics including changes to radius of gyration, transient helicity, and persistence length. We also leveraged the inherent advantage of sequence control in molecular simulations to explore the conformational effects of diverse combinations of phospho-sites in two multi-phosphorylated IDRs. Our results support and expand on prior observations that connect phosphorylation to changes in the IDR conformational ensemble. Herein, we describe phosphorylation as a means to alter sequence chemistry, net charge and charge patterning, and intramolecular interactions, which can collectively modulate the local and global IDR ensemble features.
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Affiliation(s)
- Emery T. Usher
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, USA
- Center for Biomolecular Condensates (CBC), Washington University in St. Louis, St. Louis, MO, USA
| | - Martin J. Fossat
- Department of Biological Physics, Max Planck Institute of Immunobiology and Epigenetics, Freiburg im Breisgau, Germany
| | - Alex S. Holehouse
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, USA
- Center for Biomolecular Condensates (CBC), Washington University in St. Louis, St. Louis, MO, USA
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8
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Alston JJ, Soranno A, Holehouse AS. Conserved molecular recognition by an intrinsically disordered region in the absence of sequence conservation. RESEARCH SQUARE 2024:rs.3.rs-4477977. [PMID: 38883712 PMCID: PMC11177979 DOI: 10.21203/rs.3.rs-4477977/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2024]
Abstract
Intrinsically disordered regions (IDRs) are critical for cellular function yet often appear to lack sequence conservation when assessed by multiple sequence alignments. This raises the question of if and how function can be encoded and preserved in these regions despite massive sequence variation. To address this question, we have applied coarse-grained molecular dynamics simulations to investigate non-specific RNA binding of coronavirus nucleocapsid proteins. Coronavirus nucleocapsid proteins consist of multiple interspersed disordered and folded domains that bind RNA. Here, we focus on the first two domains of coronavirus nucleocapsid proteins: the disordered N-terminal domain (NTD) and the folded RNA binding domain (RBD). While the NTD is highly variable across evolution, the RBD is structurally conserved. This combination makes the NTD-RBD a convenient model system for exploring the interplay between an IDR adjacent to a folded domain and how changes in IDR sequence can influence molecular recognition of a partner. Our results reveal a surprising degree of sequence-specificity encoded by both the composition and the precise order of the amino acids in the NTD. The presence of an NTD can - depending on the sequence - either suppress or enhance RNA binding. Despite this sensitivity, large-scale variation in NTD sequences is possible while certain sequence features are retained. Consequently, a conformationally-conserved dynamic and disordered RNA:protein complex is found across nucleocapsid protein orthologs despite large-scale changes in both NTD sequence and RBD surface chemistry. Taken together, these insights shed light on the ability of disordered regions to preserve functional characteristics despite their sequence variability.
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Affiliation(s)
- Jhullian J. Alston
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110, USA
- Center for Biomolecular Condensates, Washington University in St. Louis, St. Louis, MO, USA
- Present Address, Program In Cellular and Molecular Medicine (PCMM), Boston Children’s Hospital, Boston, MA, USA
| | - Andrea Soranno
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110, USA
- Center for Biomolecular Condensates, Washington University in St. Louis, St. Louis, MO, USA
| | - Alex S. Holehouse
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110, USA
- Center for Biomolecular Condensates, Washington University in St. Louis, St. Louis, MO, USA
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9
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He J, Huo X, Pei G, Jia Z, Yan Y, Yu J, Qu H, Xie Y, Yuan J, Zheng Y, Hu Y, Shi M, You K, Li T, Ma T, Zhang MQ, Ding S, Li P, Li Y. Dual-role transcription factors stabilize intermediate expression levels. Cell 2024; 187:2746-2766.e25. [PMID: 38631355 DOI: 10.1016/j.cell.2024.03.023] [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: 06/09/2023] [Revised: 12/08/2023] [Accepted: 03/18/2024] [Indexed: 04/19/2024]
Abstract
Precise control of gene expression levels is essential for normal cell functions, yet how they are defined and tightly maintained, particularly at intermediate levels, remains elusive. Here, using a series of newly developed sequencing, imaging, and functional assays, we uncover a class of transcription factors with dual roles as activators and repressors, referred to as condensate-forming level-regulating dual-action transcription factors (TFs). They reduce high expression but increase low expression to achieve stable intermediate levels. Dual-action TFs directly exert activating and repressing functions via condensate-forming domains that compartmentalize core transcriptional unit selectively. Clinically relevant mutations in these domains, which are linked to a range of developmental disorders, impair condensate selectivity and dual-action TF activity. These results collectively address a fundamental question in expression regulation and demonstrate the potential of level-regulating dual-action TFs as powerful effectors for engineering controlled expression levels.
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Affiliation(s)
- Jinnan He
- The IDG/McGovern Institute for Brain Research, MOE Key Laboratory of Bioinformatics, State Key Lab of Molecular Oncology, Center for Synthetic and Systems Biology, Tsinghua University, Beijing 100084, China; School of Pharmaceutical Sciences, Tsinghua University, Beijing 100084, China
| | - Xiangru Huo
- The IDG/McGovern Institute for Brain Research, MOE Key Laboratory of Bioinformatics, State Key Lab of Molecular Oncology, Center for Synthetic and Systems Biology, Tsinghua University, Beijing 100084, China; School of Pharmaceutical Sciences, Tsinghua University, Beijing 100084, China
| | - Gaofeng Pei
- State Key Laboratory of Membrane Biology, Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing 100084, China; Tsinghua University-Peking University Joint Center for Life Sciences, Beijing 100084, China
| | - Zeran Jia
- The IDG/McGovern Institute for Brain Research, MOE Key Laboratory of Bioinformatics, State Key Lab of Molecular Oncology, Center for Synthetic and Systems Biology, Tsinghua University, Beijing 100084, China; School of Pharmaceutical Sciences, Tsinghua University, Beijing 100084, China
| | - Yiming Yan
- The IDG/McGovern Institute for Brain Research, MOE Key Laboratory of Bioinformatics, State Key Lab of Molecular Oncology, Center for Synthetic and Systems Biology, Tsinghua University, Beijing 100084, China; School of Pharmaceutical Sciences, Tsinghua University, Beijing 100084, China
| | - Jiawei Yu
- The IDG/McGovern Institute for Brain Research, MOE Key Laboratory of Bioinformatics, State Key Lab of Molecular Oncology, Center for Synthetic and Systems Biology, Tsinghua University, Beijing 100084, China; School of Pharmaceutical Sciences, Tsinghua University, Beijing 100084, China
| | - Haozhi Qu
- The IDG/McGovern Institute for Brain Research, MOE Key Laboratory of Bioinformatics, State Key Lab of Molecular Oncology, Center for Synthetic and Systems Biology, Tsinghua University, Beijing 100084, China; School of Pharmaceutical Sciences, Tsinghua University, Beijing 100084, China
| | - Yunxin Xie
- The IDG/McGovern Institute for Brain Research, MOE Key Laboratory of Bioinformatics, State Key Lab of Molecular Oncology, Center for Synthetic and Systems Biology, Tsinghua University, Beijing 100084, China; School of Pharmaceutical Sciences, Tsinghua University, Beijing 100084, China
| | - Junsong Yuan
- The IDG/McGovern Institute for Brain Research, MOE Key Laboratory of Bioinformatics, State Key Lab of Molecular Oncology, Center for Synthetic and Systems Biology, Tsinghua University, Beijing 100084, China; School of Pharmaceutical Sciences, Tsinghua University, Beijing 100084, China
| | - Yuan Zheng
- The IDG/McGovern Institute for Brain Research, MOE Key Laboratory of Bioinformatics, State Key Lab of Molecular Oncology, Center for Synthetic and Systems Biology, Tsinghua University, Beijing 100084, China; School of Pharmaceutical Sciences, Tsinghua University, Beijing 100084, China
| | - Yanyan Hu
- School of Pharmaceutical Sciences, Tsinghua University, Beijing 100084, China; Tsinghua University-Peking University Joint Center for Life Sciences, Beijing 100084, China
| | - Minglei Shi
- Bioinformatics Division, National Research Center for Information Science and Technology, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Kaiqiang You
- Department of Biomedical Informatics, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Tingting Li
- Department of Biomedical Informatics, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Tianhua Ma
- School of Pharmaceutical Sciences, Tsinghua University, Beijing 100084, China; Tsinghua University-Peking University Joint Center for Life Sciences, Beijing 100084, China
| | - Michael Q Zhang
- Bioinformatics Division, National Research Center for Information Science and Technology, School of Medicine, Tsinghua University, Beijing 100084, China; Department of Biological Sciences, Center for Systems Biology, The University of Texas, Dallas, TX 75080-3021, USA
| | - Sheng Ding
- School of Pharmaceutical Sciences, Tsinghua University, Beijing 100084, China; Tsinghua University-Peking University Joint Center for Life Sciences, Beijing 100084, China
| | - Pilong Li
- State Key Laboratory of Membrane Biology, Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing 100084, China; Tsinghua University-Peking University Joint Center for Life Sciences, Beijing 100084, China.
| | - Yinqing Li
- The IDG/McGovern Institute for Brain Research, MOE Key Laboratory of Bioinformatics, State Key Lab of Molecular Oncology, Center for Synthetic and Systems Biology, Tsinghua University, Beijing 100084, China; School of Pharmaceutical Sciences, Tsinghua University, Beijing 100084, China.
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10
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Janson G, Feig M. Transferable deep generative modeling of intrinsically disordered protein conformations. PLoS Comput Biol 2024; 20:e1012144. [PMID: 38781245 PMCID: PMC11152266 DOI: 10.1371/journal.pcbi.1012144] [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: 02/08/2024] [Revised: 06/05/2024] [Accepted: 05/07/2024] [Indexed: 05/25/2024] Open
Abstract
Intrinsically disordered proteins have dynamic structures through which they play key biological roles. The elucidation of their conformational ensembles is a challenging problem requiring an integrated use of computational and experimental methods. Molecular simulations are a valuable computational strategy for constructing structural ensembles of disordered proteins but are highly resource-intensive. Recently, machine learning approaches based on deep generative models that learn from simulation data have emerged as an efficient alternative for generating structural ensembles. However, such methods currently suffer from limited transferability when modeling sequences and conformations absent in the training data. Here, we develop a novel generative model that achieves high levels of transferability for intrinsically disordered protein ensembles. The approach, named idpSAM, is a latent diffusion model based on transformer neural networks. It combines an autoencoder to learn a representation of protein geometry and a diffusion model to sample novel conformations in the encoded space. IdpSAM was trained on a large dataset of simulations of disordered protein regions performed with the ABSINTH implicit solvent model. Thanks to the expressiveness of its neural networks and its training stability, idpSAM faithfully captures 3D structural ensembles of test sequences with no similarity in the training set. Our study also demonstrates the potential for generating full conformational ensembles from datasets with limited sampling and underscores the importance of training set size for generalization. We believe that idpSAM represents a significant progress in transferable protein ensemble modeling through machine learning.
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Affiliation(s)
- Giacomo Janson
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, United States of America
| | - Michael Feig
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, United States of America
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11
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Liang Q, Peng N, Xie Y, Kumar N, Gao W, Miao Y. MolPhase, an advanced prediction algorithm for protein phase separation. EMBO J 2024; 43:1898-1918. [PMID: 38565952 PMCID: PMC11065880 DOI: 10.1038/s44318-024-00090-9] [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: 09/20/2023] [Revised: 02/27/2024] [Accepted: 03/14/2024] [Indexed: 04/04/2024] Open
Abstract
We introduce MolPhase, an advanced algorithm for predicting protein phase separation (PS) behavior that improves accuracy and reliability by utilizing diverse physicochemical features and extensive experimental datasets. MolPhase applies a user-friendly interface to compare distinct biophysical features side-by-side along protein sequences. By additional comparison with structural predictions, MolPhase enables efficient predictions of new phase-separating proteins and guides hypothesis generation and experimental design. Key contributing factors underlying MolPhase include electrostatic pi-interactions, disorder, and prion-like domains. As an example, MolPhase finds that phytobacterial type III effectors (T3Es) are highly prone to homotypic PS, which was experimentally validated in vitro biochemically and in vivo in plants, mimicking their injection and accumulation in the host during microbial infection. The physicochemical characteristics of T3Es dictate their patterns of association for multivalent interactions, influencing the material properties of phase-separating droplets based on the surrounding microenvironment in vivo or in vitro. Robust integration of MolPhase's effective prediction and experimental validation exhibit the potential to evaluate and explore how biomolecule PS functions in biological systems.
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Affiliation(s)
- Qiyu Liang
- School of Physical and Mathematical Sciences, Nanyang Technological University, 637371, Singapore, Singapore
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore, Singapore
| | - Nana Peng
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore, Singapore
| | - Yi Xie
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore, Singapore
| | - Nivedita Kumar
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore, Singapore
| | - Weibo Gao
- School of Physical and Mathematical Sciences, Nanyang Technological University, 637371, Singapore, Singapore
| | - Yansong Miao
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore, Singapore.
- Institute for Digital Molecular Analytics and Science, Nanyang Technological University, 636921, Singapore, Singapore.
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12
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Ibrahim KA, Naidu AS, Miljkovic H, Radenovic A, Yang W. Label-Free Techniques for Probing Biomolecular Condensates. ACS NANO 2024; 18:10738-10757. [PMID: 38609349 DOI: 10.1021/acsnano.4c01534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/14/2024]
Abstract
Biomolecular condensates play important roles in a wide array of fundamental biological processes, such as cellular compartmentalization, cellular regulation, and other biochemical reactions. Since their discovery and first observations, an extensive and expansive library of tools has been developed to investigate various aspects and properties, encompassing structural and compositional information, material properties, and their evolution throughout the life cycle from formation to eventual dissolution. This Review presents an overview of the expanded set of tools and methods that researchers use to probe the properties of biomolecular condensates across diverse scales of length, concentration, stiffness, and time. In particular, we review recent years' exciting development of label-free techniques and methodologies. We broadly organize the set of tools into 3 categories: (1) imaging-based techniques, such as transmitted-light microscopy (TLM) and Brillouin microscopy (BM), (2) force spectroscopy techniques, such as atomic force microscopy (AFM) and the optical tweezer (OT), and (3) microfluidic platforms and emerging technologies. We point out the tools' key opportunities, challenges, and future perspectives and analyze their correlative potential as well as compatibility with other techniques. Additionally, we review emerging techniques, namely, differential dynamic microscopy (DDM) and interferometric scattering microscopy (iSCAT), that have huge potential for future applications in studying biomolecular condensates. Finally, we highlight how some of these techniques can be translated for diagnostics and therapy purposes. We hope this Review serves as a useful guide for new researchers in this field and aids in advancing the development of new biophysical tools to study biomolecular condensates.
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13
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King MR, Ruff KM, Lin AZ, Pant A, Farag M, Lalmansingh JM, Wu T, Fossat MJ, Ouyang W, Lew MD, Lundberg E, Vahey MD, Pappu RV. Macromolecular condensation organizes nucleolar sub-phases to set up a pH gradient. Cell 2024; 187:1889-1906.e24. [PMID: 38503281 DOI: 10.1016/j.cell.2024.02.029] [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] [Revised: 01/02/2024] [Accepted: 02/22/2024] [Indexed: 03/21/2024]
Abstract
Nucleoli are multicomponent condensates defined by coexisting sub-phases. We identified distinct intrinsically disordered regions (IDRs), including acidic (D/E) tracts and K-blocks interspersed by E-rich regions, as defining features of nucleolar proteins. We show that the localization preferences of nucleolar proteins are determined by their IDRs and the types of RNA or DNA binding domains they encompass. In vitro reconstitutions and studies in cells showed how condensation, which combines binding and complex coacervation of nucleolar components, contributes to nucleolar organization. D/E tracts of nucleolar proteins contribute to lowering the pH of co-condensates formed with nucleolar RNAs in vitro. In cells, this sets up a pH gradient between nucleoli and the nucleoplasm. By contrast, juxta-nucleolar bodies, which have different macromolecular compositions, featuring protein IDRs with very different charge profiles, have pH values that are equivalent to or higher than the nucleoplasm. Our findings show that distinct compositional specificities generate distinct physicochemical properties for condensates.
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Affiliation(s)
- Matthew R King
- Department of Biomedical Engineering, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Kiersten M Ruff
- Department of Biomedical Engineering, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Andrew Z Lin
- Department of Biomedical Engineering, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Avnika Pant
- Department of Biomedical Engineering, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Mina Farag
- Department of Biomedical Engineering, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Jared M Lalmansingh
- Department of Biomedical Engineering, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Tingting Wu
- Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Department of Electrical and Systems Engineering, James F. McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Martin J Fossat
- Department of Biomedical Engineering, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Wei Ouyang
- Department of Bioengineering, Schools of Engineering and Medicine, Stanford University, Stanford, CA, USA; Department of Pathology, School of Medicine, Stanford University, Stanford, CA, USA; Science for Life Laboratory, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH-Royal Institute of Technology, Stockholm, Sweden
| | - Matthew D Lew
- Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Department of Electrical and Systems Engineering, James F. McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Emma Lundberg
- Department of Bioengineering, Schools of Engineering and Medicine, Stanford University, Stanford, CA, USA; Department of Pathology, School of Medicine, Stanford University, Stanford, CA, USA; Science for Life Laboratory, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH-Royal Institute of Technology, Stockholm, Sweden
| | - Michael D Vahey
- Department of Biomedical Engineering, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Rohit V Pappu
- Department of Biomedical Engineering, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA.
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14
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Sanchez‐Martinez S, Nguyen K, Biswas S, Nicholson V, Romanyuk AV, Ramirez J, Kc S, Akter A, Childs C, Meese EK, Usher ET, Ginell GM, Yu F, Gollub E, Malferrari M, Francia F, Venturoli G, Martin EW, Caporaletti F, Giubertoni G, Woutersen S, Sukenik S, Woolfson DN, Holehouse AS, Boothby TC. Labile assembly of a tardigrade protein induces biostasis. Protein Sci 2024; 33:e4941. [PMID: 38501490 PMCID: PMC10949331 DOI: 10.1002/pro.4941] [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: 11/01/2023] [Revised: 02/01/2024] [Accepted: 02/09/2024] [Indexed: 03/20/2024]
Abstract
Tardigrades are microscopic animals that survive desiccation by inducing biostasis. To survive drying tardigrades rely on intrinsically disordered CAHS proteins, which also function to prevent perturbations induced by drying in vitro and in heterologous systems. CAHS proteins have been shown to form gels both in vitro and in vivo, which has been speculated to be linked to their protective capacity. However, the sequence features and mechanisms underlying gel formation and the necessity of gelation for protection have not been demonstrated. Here we report a mechanism of fibrillization and gelation for CAHS D similar to that of intermediate filament assembly. We show that in vitro, gelation restricts molecular motion, immobilizing and protecting labile material from the harmful effects of drying. In vivo, we observe that CAHS D forms fibrillar networks during osmotic stress. Fibrillar networking of CAHS D improves survival of osmotically shocked cells. We observe two emergent properties associated with fibrillization; (i) prevention of cell volume change and (ii) reduction of metabolic activity during osmotic shock. We find that there is no significant correlation between maintenance of cell volume and survival, while there is a significant correlation between reduced metabolism and survival. Importantly, CAHS D's fibrillar network formation is reversible and metabolic rates return to control levels after CAHS fibers are resolved. This work provides insights into how tardigrades induce reversible biostasis through the self-assembly of labile CAHS gels.
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Affiliation(s)
| | - K. Nguyen
- Department of Molecular BiologyUniversity of WyomingLaramieWyomingUSA
| | - S. Biswas
- Department of Molecular BiologyUniversity of WyomingLaramieWyomingUSA
| | - V. Nicholson
- Department of Molecular BiologyUniversity of WyomingLaramieWyomingUSA
| | - A. V. Romanyuk
- School of ChemistryUniversity of BristolBristolUK
- Max Planck‐Bristol Centre for Minimal BiologyUniversity of BristolBristolUK
| | - J. Ramirez
- Department of Molecular BiologyUniversity of WyomingLaramieWyomingUSA
| | - S. Kc
- Department of Molecular BiologyUniversity of WyomingLaramieWyomingUSA
| | - A. Akter
- Department of Molecular BiologyUniversity of WyomingLaramieWyomingUSA
| | - C. Childs
- Department of Molecular BiologyUniversity of WyomingLaramieWyomingUSA
| | - E. K. Meese
- Department of Molecular BiologyUniversity of WyomingLaramieWyomingUSA
| | - E. T. Usher
- Department of Biochemistry and Molecular BiophysicsWashington University School of MedicineSt. LouisMissouriUSA
- Center for Biomolecular CondensatesWashington University in St. LouisSt. LouisMissouriUSA
| | - G. M. Ginell
- Department of Biochemistry and Molecular BiophysicsWashington University School of MedicineSt. LouisMissouriUSA
- Center for Biomolecular CondensatesWashington University in St. LouisSt. LouisMissouriUSA
| | - F. Yu
- Quantitative Systems Biology ProgramUniversity of California MercedMercedCaliforniaUSA
| | - E. Gollub
- Department of Chemistry and BiochemistryUniversity of California MercedMercedCaliforniaUSA
| | - M. Malferrari
- Dipartimento di Chimica “Giacomo Ciamician”Università di BolognaBolognaItaly
| | - F. Francia
- Laboratorio di Biochimica e Biofisica Molecolare, Dipartimento di Farmacia e Biotecnologie, FaBiTUniversità di BolognaBolognaItaly
| | - G. Venturoli
- Laboratorio di Biochimica e Biofisica Molecolare, Dipartimento di Farmacia e Biotecnologie, FaBiTUniversità di BolognaBolognaItaly
- Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia (CNISM), c/o Dipartimento di Fisica e Astronomia (DIFA)Università di BolognaBolognaItaly
| | - E. W. Martin
- Department of Structural BiologySt. Jude Children's Research HospitalMemphisTennesseeUSA
| | - F. Caporaletti
- Van't Hoff Institute for Molecular SciencesUniversity of AmsterdamAmsterdamThe Netherlands
| | - G. Giubertoni
- Van't Hoff Institute for Molecular SciencesUniversity of AmsterdamAmsterdamThe Netherlands
| | - S. Woutersen
- Van't Hoff Institute for Molecular SciencesUniversity of AmsterdamAmsterdamThe Netherlands
| | - S. Sukenik
- Quantitative Systems Biology ProgramUniversity of California MercedMercedCaliforniaUSA
- Department of Chemistry and BiochemistryUniversity of California MercedMercedCaliforniaUSA
| | - D. N. Woolfson
- School of ChemistryUniversity of BristolBristolUK
- Max Planck‐Bristol Centre for Minimal BiologyUniversity of BristolBristolUK
- School of BiochemistryUniversity of Bristol, Biomedical Sciences BuildingBristolUK
| | - A. S. Holehouse
- Department of Biochemistry and Molecular BiophysicsWashington University School of MedicineSt. LouisMissouriUSA
- Center for Biomolecular CondensatesWashington University in St. LouisSt. LouisMissouriUSA
| | - T. C. Boothby
- Department of Molecular BiologyUniversity of WyomingLaramieWyomingUSA
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15
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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: 48] [Impact Index Per Article: 48.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [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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16
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Moses D, Guadalupe K, Yu F, Flores E, Perez AR, McAnelly R, Shamoon NM, Kaur G, Cuevas-Zepeda E, Merg AD, Martin EW, Holehouse AS, Sukenik S. Structural biases in disordered proteins are prevalent in the cell. Nat Struct Mol Biol 2024; 31:283-292. [PMID: 38177684 PMCID: PMC10873198 DOI: 10.1038/s41594-023-01148-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 10/04/2023] [Indexed: 01/06/2024]
Abstract
Intrinsically disordered proteins and protein regions (IDPs) are prevalent in all proteomes and are essential to cellular function. Unlike folded proteins, IDPs exist in an ensemble of dissimilar conformations. Despite this structural plasticity, intramolecular interactions create sequence-specific structural biases that determine an IDP ensemble's three-dimensional shape. Such structural biases can be key to IDP function and are often measured in vitro, but whether those biases are preserved inside the cell is unclear. Here we show that structural biases in IDP ensembles found in vitro are recapitulated inside human-derived cells. We further reveal that structural biases can change in a sequence-dependent manner due to changes in the intracellular milieu, subcellular localization, and intramolecular interactions with tethered well-folded domains. We propose that the structural sensitivity of IDP ensembles can be leveraged for biological function, can be the underlying cause of IDP-driven pathology or can be used to design disorder-based biosensors and actuators.
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Affiliation(s)
- David Moses
- Department of Chemistry and Biochemistry, University of California, Merced, Merced, CA, USA
- Center for Cellular and Biomolecular Machines, University of California, Merced, Merced, CA, USA
| | - Karina Guadalupe
- Department of Chemistry and Biochemistry, University of California, Merced, Merced, CA, USA
- Center for Cellular and Biomolecular Machines, University of California, Merced, Merced, CA, USA
| | - Feng Yu
- Center for Cellular and Biomolecular Machines, University of California, Merced, Merced, CA, USA
- Quantitative and Systems Biology Program, University of California, Merced, Merced, CA, USA
| | - Eduardo Flores
- Department of Chemistry and Biochemistry, University of California, Merced, Merced, CA, USA
- Center for Cellular and Biomolecular Machines, University of California, Merced, Merced, CA, USA
| | - Anthony R Perez
- Department of Chemistry and Biochemistry, University of California, Merced, Merced, CA, USA
- Center for Cellular and Biomolecular Machines, University of California, Merced, Merced, CA, USA
| | - Ralph McAnelly
- Department of Chemistry and Biochemistry, University of California, Merced, Merced, CA, USA
| | - Nora M Shamoon
- Center for Cellular and Biomolecular Machines, University of California, Merced, Merced, CA, USA
- California State University, Stanislaus, Turlock, CA, USA
| | - Gagandeep Kaur
- Department of Chemistry and Biochemistry, University of California, Merced, Merced, CA, USA
| | | | - Andrea D Merg
- Department of Chemistry and Biochemistry, University of California, Merced, Merced, CA, USA
- Center for Cellular and Biomolecular Machines, University of California, Merced, Merced, CA, USA
| | - Erik W Martin
- Department of Structural Biology, St Jude Children's Research Hospital, Memphis, TN, USA
- Dewpoint Therapeutics, Boston, MA, USA
| | - Alex S Holehouse
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, USA
- Center for Science and Engineering of Living Systems, Washington University in St. Louis, St. Louis, MO, USA
| | - Shahar Sukenik
- Department of Chemistry and Biochemistry, University of California, Merced, Merced, CA, USA.
- Center for Cellular and Biomolecular Machines, University of California, Merced, Merced, CA, USA.
- Quantitative and Systems Biology Program, University of California, Merced, Merced, CA, USA.
- Health Sciences Research Institute, University of California, Merced, Merced, CA, USA.
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17
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Saikia B, Baruah A. Recent advances in de novo computational design and redesign of intrinsically disordered proteins and intrinsically disordered protein regions. Arch Biochem Biophys 2024; 752:109857. [PMID: 38097100 DOI: 10.1016/j.abb.2023.109857] [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: 10/06/2023] [Revised: 12/10/2023] [Accepted: 12/10/2023] [Indexed: 12/17/2023]
Abstract
In the early 2000s, the concept of "unstructured biology" has emerged to be an important field in protein science by generating various new research directions. Many novel strategies and methods have been developed that are focused on effectively identifying/predicting intrinsically disordered proteins (IDPs) and intrinsically disordered protein regions (IDPRs), identifying their potential functions, disorder based drug design etc. Due to the range of functions of IDPs/IDPRs and their involvement in various debilitating diseases they are of contemporary interest to the scientific community. Recent researches are focused on designing/redesigning specific IDPs/IDPRs de novo. These de novo design/redesigns of IDPs/IDPRs are carried out by altering compositional biases and specific sequence patterning parameters. The main focus of these researches is to influence specific molecular functions, phase behavior, cellular phenotypes etc. In this review, we first provide the differences of natively folded and natively unfolded or IDPs with respect to their potential energy landscapes. Here, we provide current understandings on the different computational design strategies and methods that have been utilized in de novo design and redesigns of IDPs and IDPRs. Finally, we conclude the review by discussing the challenges that have been faced during the computational design/design attempts of IDPs/IDPRs.
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Affiliation(s)
- Bondeepa Saikia
- Department of Chemistry, Dibrugarh University, Dibrugarh, 786004, Assam, India
| | - Anupaul Baruah
- Department of Chemistry, Dibrugarh University, Dibrugarh, 786004, Assam, India.
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18
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Garg A, González-Foutel NS, Gielnik MB, Kjaergaard M. Design of functional intrinsically disordered proteins. Protein Eng Des Sel 2024; 37:gzae004. [PMID: 38431892 DOI: 10.1093/protein/gzae004] [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: 10/02/2023] [Revised: 12/22/2023] [Indexed: 03/05/2024] Open
Abstract
Many proteins do not fold into a fixed three-dimensional structure, but rather function in a highly disordered state. These intrinsically disordered proteins pose a unique challenge to protein engineering and design: How can proteins be designed de novo if not by tailoring their structure? Here, we will review the nascent field of design of intrinsically disordered proteins with focus on applications in biotechnology and medicine. The design goals should not necessarily be the same as for de novo design of folded proteins as disordered proteins have unique functional strengths and limitations. We focus on functions where intrinsically disordered proteins are uniquely suited including disordered linkers, desiccation chaperones, sensors of the chemical environment, delivery of pharmaceuticals, and constituents of biomolecular condensates. Design of functional intrinsically disordered proteins relies on a combination of computational tools and heuristics gleaned from sequence-function studies. There are few cases where intrinsically disordered proteins have made it into industrial applications. However, we argue that disordered proteins can perform many roles currently performed by organic polymers, and that these proteins might be more designable due to their modularity.
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Affiliation(s)
- Ankush Garg
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark
| | | | - Maciej B Gielnik
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark
| | - Magnus Kjaergaard
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, 8000 Aarhus, Denmark
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19
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Liu Q, Liu W, Niu Y, Wang T, Dong J. Liquid-liquid phase separation in plants: Advances and perspectives from model species to crops. PLANT COMMUNICATIONS 2024; 5:100663. [PMID: 37496271 PMCID: PMC10811348 DOI: 10.1016/j.xplc.2023.100663] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 06/23/2023] [Accepted: 07/20/2023] [Indexed: 07/28/2023]
Abstract
Membraneless biomolecular condensates play important roles in both normal biological activities and responses to environmental stimuli in living organisms. Liquid‒liquid phase separation (LLPS) is an organizational mechanism that has emerged in recent years to explain the formation of biomolecular condensates. In the past decade, advances in LLPS research have contributed to breakthroughs in disease fields. By contrast, although LLPS research in plants has progressed over the past 5 years, it has been concentrated on the model plant Arabidopsis, which has limited relevance to agricultural production. In this review, we provide an overview of recently reported advances in LLPS in plants, with a particular focus on photomorphogenesis, flowering, and abiotic and biotic stress responses. We propose that many potential LLPS proteins also exist in crops and may affect crop growth, development, and stress resistance. This possibility presents a great challenge as well as an opportunity for rigorous scientific research on the biological functions and applications of LLPS in crops.
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Affiliation(s)
- Qianwen Liu
- College of Biological Sciences, China Agricultural University, Beijing 100193, China; College of Life Sciences, Henan Agricultural University, Zhengzhou 450002, China
| | - Wenxuan Liu
- College of Life Sciences, Henan Agricultural University, Zhengzhou 450002, China
| | - Yiding Niu
- Key Laboratory of Forage and Endemic Crop Biology, Ministry of Education, School of Life Sciences, Inner Mongolia University, Hohhot 010021, China
| | - Tao Wang
- College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Jiangli Dong
- College of Biological Sciences, China Agricultural University, Beijing 100193, China.
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20
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Taneja I, Lasker K. Machine-learning-based methods to generate conformational ensembles of disordered proteins. Biophys J 2024; 123:101-113. [PMID: 38053335 PMCID: PMC10808026 DOI: 10.1016/j.bpj.2023.12.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 10/24/2023] [Accepted: 12/01/2023] [Indexed: 12/07/2023] Open
Abstract
Intrinsically disordered proteins are characterized by a conformational ensemble. While computational approaches such as molecular dynamics simulations have been used to generate such ensembles, their computational costs can be prohibitive. An alternative approach is to learn from data and train machine-learning models to generate conformational ensembles of disordered proteins. This has been a relatively unexplored approach, and in this work we demonstrate a proof-of-principle approach to do so. Specifically, we devised a two-stage computational pipeline: in the first stage, we employed supervised machine-learning models to predict ensemble-derived two-dimensional (2D) properties of a sequence, given the conformational ensemble of a closely related sequence. In the second stage, we used denoising diffusion models to generate three-dimensional (3D) coarse-grained conformational ensembles, given the two-dimensional predictions outputted by the first stage. We trained our models on a data set of coarse-grained molecular dynamics simulations of thousands of rationally designed synthetic sequences. The accuracy of our 2D and 3D predictions was validated across multiple metrics, and our work demonstrates the applicability of machine-learning techniques to predicting higher-dimensional properties of disordered proteins.
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Affiliation(s)
- Ishan Taneja
- Department of Integrative Structural and Computational Biology, Scripps Research, La Jolla, California
| | - Keren Lasker
- Department of Integrative Structural and Computational Biology, Scripps Research, La Jolla, California.
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21
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Marshall AC, Cummins J, Kobelke S, Zhu T, Widagdo J, Anggono V, Hyman A, Fox AH, Bond CS, Lee M. Different Low-complexity Regions of SFPQ Play Distinct Roles in the Formation of Biomolecular Condensates. J Mol Biol 2023; 435:168364. [PMID: 37952770 DOI: 10.1016/j.jmb.2023.168364] [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: 08/30/2023] [Revised: 11/02/2023] [Accepted: 11/07/2023] [Indexed: 11/14/2023]
Abstract
Demixing of proteins and nucleic acids into condensed liquid phases is rapidly emerging as a ubiquitous mechanism underlying the complex spatiotemporal organisation of molecules within the cell. Long disordered regions of low sequence complexity (LCRs) are a common feature of proteins that form liquid-like microscopic biomolecular condensates. In particular, RNA-binding proteins with prion-like regions have emerged as key drivers of liquid demixing to form condensates such as nucleoli, paraspeckles and stress granules. Splicing factor proline- and glutamine-rich (SFPQ) is an RNA- and DNA-binding protein essential for DNA repair and paraspeckle formation. SFPQ contains two LCRs of different length and composition. Here, we show that the shorter C-terminal LCR of SFPQ is the main region responsible for the condensation of SFPQ in vitro and in the cell nucleus. In contrast, we find that the longer N-terminal prion-like LCR of SFPQ attenuates condensation of the full-length protein, suggesting a more regulatory role in preventing aberrant condensate formation in the cell. The compositions of these respective LCRs are discussed with reference to current literature. Our data add nuance to the emerging understanding of biomolecular condensation, by providing the first example of a common multifunctional nucleic acid-binding protein with an extensive prion-like region that serves to regulate rather than drive condensate formation.
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Affiliation(s)
- Andrew C Marshall
- School of Molecular Sciences, The University of Western Australia, Crawley, WA 6009, Australia
| | - Jerry Cummins
- School of Molecular Sciences, The University of Western Australia, Crawley, WA 6009, Australia
| | - Simon Kobelke
- School of Human Sciences, The University of Western Australia, Crawley, WA 6009, Australia
| | - Tianyi Zhu
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Jocelyn Widagdo
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Victor Anggono
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Anthony Hyman
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Archa H Fox
- School of Human Sciences, The University of Western Australia, Crawley, WA 6009, Australia.
| | - Charles S Bond
- School of Molecular Sciences, The University of Western Australia, Crawley, WA 6009, Australia.
| | - Mihwa Lee
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia.
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22
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Moses D, Ginell GM, Holehouse AS, Sukenik S. Intrinsically disordered regions are poised to act as sensors of cellular chemistry. Trends Biochem Sci 2023; 48:1019-1034. [PMID: 37657994 PMCID: PMC10840941 DOI: 10.1016/j.tibs.2023.08.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 07/31/2023] [Accepted: 08/01/2023] [Indexed: 09/03/2023]
Abstract
Intrinsically disordered proteins and protein regions (IDRs) are abundant in eukaryotic proteomes and play a wide variety of essential roles. Instead of folding into a stable structure, IDRs exist in an ensemble of interconverting conformations whose structure is biased by sequence-dependent interactions. The absence of a stable 3D structure, combined with high solvent accessibility, means that IDR conformational biases are inherently sensitive to changes in their environment. Here, we argue that IDRs are ideally poised to act as sensors and actuators of cellular physicochemistry. We review the physical principles that underlie IDR sensitivity, the molecular mechanisms that translate this sensitivity to function, and recent studies where environmental sensing by IDRs may play a key role in their downstream function.
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Affiliation(s)
- David Moses
- Department of Chemistry and Biochemistry, University of California, Merced, CA, USA
| | - Garrett M Ginell
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, USA; Center for Biomolecular Condensates (CBC), Washington University in St. Louis, St. Louis, MO, USA
| | - Alex S Holehouse
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, USA; Center for Biomolecular Condensates (CBC), Washington University in St. Louis, St. Louis, MO, USA.
| | - Shahar Sukenik
- Department of Chemistry and Biochemistry, University of California, Merced, CA, USA; Quantitative Systems Biology Program, University of California, Merced, CA, USA.
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23
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Emenecker RJ, Guadalupe K, Shamoon NM, Sukenik S, Holehouse AS. Sequence-ensemble-function relationships for disordered proteins in live cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.29.564547. [PMID: 37961106 PMCID: PMC10634935 DOI: 10.1101/2023.10.29.564547] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Intrinsically disordered protein regions (IDRs) are ubiquitous across all kingdoms of life and play a variety of essential cellular roles. IDRs exist in a collection of structurally distinct conformers known as an ensemble. An IDR's amino acid sequence determines its ensemble, which in turn can play an important role in dictating molecular function. Yet a clear link connecting IDR sequence, its ensemble properties, and its molecular function in living cells has not been directly established. Here, we set out to test this sequence-ensemble-function paradigm using a novel computational method (GOOSE) that enables the rational design of libraries of IDRs by systematically varying specific sequence properties. Using ensemble FRET, we measured the ensemble dimensions of a library of rationally designed IDRs in human-derived cell lines, revealing how IDR sequence influences ensemble dimensions in situ. Furthermore, we show that the interplay between sequence and ensemble can tune an IDR's ability to sense changes in cell volume - a de novo molecular function for these synthetic sequences. Our results establish biophysical rules for intracellular sequence-ensemble relationships, enable a new route for understanding how IDR sequences map to function in live cells, and set the ground for the design of synthetic IDRs with de novo function.
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Affiliation(s)
- Ryan J. Emenecker
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO
- Center for Biomolecular Condensates (CBC), Washington University in St. Louis, St. Louis, MO
| | - Karina Guadalupe
- Department of Chemistry and Biochemistry, University of California, Merced, CA
- Center for Cellular and Biomolecular Machines, University of California, Merced, CA
| | - Nora M. Shamoon
- Center for Cellular and Biomolecular Machines, University of California, Merced, CA
- Quantitative Systems Biology Program, University of California, Merced, CA
| | - Shahar Sukenik
- Department of Chemistry and Biochemistry, University of California, Merced, CA
- Center for Cellular and Biomolecular Machines, University of California, Merced, CA
- Quantitative Systems Biology Program, University of California, Merced, CA
- Health Sciences Research Institute, University of California, Merced, CA
| | - Alex S. Holehouse
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO
- Center for Biomolecular Condensates (CBC), Washington University in St. Louis, St. Louis, MO
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24
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Holehouse A, Emenecker R, Guadalupe K, Shamoon N, Sukenik S. Sequence-ensemble-function relationships for disordered proteins in live cells. RESEARCH SQUARE 2023:rs.3.rs-3501110. [PMID: 37986812 PMCID: PMC10659550 DOI: 10.21203/rs.3.rs-3501110/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Intrinsically disordered protein regions (IDRs) are ubiquitous across all kingdoms of life and play a variety of essential cellular roles. IDRs exist in a collection of structurally distinct conformers known as an ensemble. IDR amino acid sequence determines its ensemble, which in turn can play an important role in dictating molecular function. Yet a clear link connecting IDR sequence, its ensemble properties, and its molecular function in living cells has not been systematically established. Here, we set out to test this sequence-ensemble-function paradigm using a novel computational method (GOOSE) that enables the rational design of libraries of IDRs by systematically varying specific sequence properties. Using ensemble FRET, we measured the ensemble dimensions of a library of rationally designed IDRs in human-derived cell lines, revealing how IDR sequence influences ensemble dimensions in situ. Furthermore, we show that the interplay between sequence and ensemble can tune an IDR's ability to sense changes in cell volume - a de novomolecular function for these synthetic sequences. Our results establish biophysical rules for intracellular sequence-ensemble relationships, enable a new route for understanding how IDR sequences map to function in live cells, and set the ground for the design of synthetic IDRs with de novo function.
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25
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Adhikari S, Mondal J. Machine Learning Subtle Conformational Change due to Phosphorylation in Intrinsically Disordered Proteins. J Phys Chem B 2023; 127:9433-9449. [PMID: 37905972 DOI: 10.1021/acs.jpcb.3c05136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
Phosphorylation of intrinsically disordered proteins/regions (IDPs/IDRs) has a profound effect in biological functions such as cell signaling, protein folding or unfolding, and long-range allosteric effects. However, here we focus on two IDPs, namely 83-residue IDR transcription factor Ash1 and 92-residue long N-terminal region of CDK inhibitor Sic1 protein, found in Saccharomyces cerevisiae, for which experimental measurements of average conformational properties, namely, radius of gyration and structure factor, indicate negligible changes upon phosphorylation. Here, we show that a judicious dissection of conformational ensemble via combination of unsupervised machine learning and extensive molecular dynamics (MD) trajectories can highlight key differences and similarities among the phosphorylated and wild-type IDP. In particular, we develop Markov state model (MSM) using the latent-space dimensions of an autoencoder, trained using multi-microsecond long MD simulation trajectories. Examination of structural changes among the states, prior to and upon phosphorylation, captured several similarities and differences in their backbone contact maps, secondary structure, and torsion angles. Hydrogen bonding analysis revealed that phosphorylation not only increases the number of hydrogen bonds but also switches the pattern of hydrogen bonding between the backbone and side chain atoms with the phosphorylated residues. We also observe that although phosphorylation introduces salt bridges, there is a loss of the cation-π interaction. Phosphorylation also improved the probability for long-range hydrophobic contacts and also enhanced interaction with water molecules and improved the local structure of water as evident from the geometric order parameters. The observations on these machine-learnt states gave important insights, as it would otherwise be difficult to determine experimentally which is important, if we were to understand the role of phosphorylation of IDPs in their biological functions.
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26
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Kotha SR, Staller MV. Clusters of acidic and hydrophobic residues can predict acidic transcriptional activation domains from protein sequence. Genetics 2023; 225:iyad131. [PMID: 37462277 PMCID: PMC10550315 DOI: 10.1093/genetics/iyad131] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 07/03/2023] [Indexed: 10/06/2023] Open
Abstract
Transcription factors activate gene expression in development, homeostasis, and stress with DNA binding domains and activation domains. Although there exist excellent computational models for predicting DNA binding domains from protein sequence, models for predicting activation domains from protein sequence have lagged, particularly in metazoans. We recently developed a simple and accurate predictor of acidic activation domains on human transcription factors. Here, we show how the accuracy of this human predictor arises from the clustering of aromatic, leucine, and acidic residues, which together are necessary for acidic activation domain function. When we combine our predictor with the predictions of convolutional neural network (CNN) models trained in yeast, the intersection is more accurate than individual models, emphasizing that each approach carries orthogonal information. We synthesize these findings into a new set of activation domain predictions on human transcription factors.
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Affiliation(s)
- Sanjana R Kotha
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
- Center for Computational Biology, University of California, Berkeley, CA 94720, USA
| | - Max Valentín Staller
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
- Center for Computational Biology, University of California, Berkeley, CA 94720, USA
- Chan Zuckerberg Biohub—San Francisco, San Francisco, CA 94158, USA
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27
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Hazra M, Levy Y. Cross-Talk of Cation-π Interactions with Electrostatic and Aromatic Interactions: A Salt-Dependent Trade-off in Biomolecular Condensates. J Phys Chem Lett 2023; 14:8460-8469. [PMID: 37721444 PMCID: PMC10544028 DOI: 10.1021/acs.jpclett.3c01642] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 09/13/2023] [Indexed: 09/19/2023]
Abstract
Biomolecular condensates are essential for cellular functionality, yet the complex interplay among the diverse molecular interactions that mediate their formation remains poorly understood. Here, using coarse-grained molecular dynamics simulations, we address the contribution of cation-π interactions to the stability of condensates formed via liquid-liquid phase separation. We found greater stabilization of up to 80% via cation-π interactions in condensates formed from peptides with higher aromatic residue content or less charge clustering. The contribution of cation-π interactions to droplet stability increases with increasing ionic strength, suggesting a trade-off between cation-π and electrostatic interactions. Cation-π interactions, therefore, can compensate for reduced electrostatic interactions, such as occurs at higher salt concentrations and in sequences with less charged residue content or clustering. Designing condensates with desired biophysical characteristics therefore requires quantification not only of the individual interactions but also cross-talks involving charge-charge, π-π, and cation-π interactions.
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Affiliation(s)
- Milan
Kumar Hazra
- Department of Chemical and
Structural Biology, Weizmann Institute of
Science, Rehovot 76100, Israel
| | - Yaakov Levy
- Department of Chemical and
Structural Biology, Weizmann Institute of
Science, Rehovot 76100, Israel
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28
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Tripathi S, Shirnekhi HK, Gorman SD, Chandra B, Baggett DW, Park CG, Somjee R, Lang B, Hosseini SMH, Pioso BJ, Li Y, Iacobucci I, Gao Q, Edmonson MN, Rice SV, Zhou X, Bollinger J, Mitrea DM, White MR, McGrail DJ, Jarosz DF, Yi SS, Babu MM, Mullighan CG, Zhang J, Sahni N, Kriwacki RW. Defining the condensate landscape of fusion oncoproteins. Nat Commun 2023; 14:6008. [PMID: 37770423 PMCID: PMC10539325 DOI: 10.1038/s41467-023-41655-2] [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: 11/10/2022] [Accepted: 09/13/2023] [Indexed: 09/30/2023] Open
Abstract
Fusion oncoproteins (FOs) arise from chromosomal translocations in ~17% of cancers and are often oncogenic drivers. Although some FOs can promote oncogenesis by undergoing liquid-liquid phase separation (LLPS) to form aberrant biomolecular condensates, the generality of this phenomenon is unknown. We explored this question by testing 166 FOs in HeLa cells and found that 58% formed condensates. The condensate-forming FOs displayed physicochemical features distinct from those of condensate-negative FOs and segregated into distinct feature-based groups that aligned with their sub-cellular localization and biological function. Using Machine Learning, we developed a predictor of FO condensation behavior, and discovered that 67% of ~3000 additional FOs likely form condensates, with 35% of those predicted to function by altering gene expression. 47% of the predicted condensate-negative FOs were associated with cell signaling functions, suggesting a functional dichotomy between condensate-positive and -negative FOs. Our Datasets and reagents are rich resources to interrogate FO condensation in the future.
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Affiliation(s)
- Swarnendu Tripathi
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Hazheen K Shirnekhi
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Scott D Gorman
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
- Arrakis Therapeutics, 830 Winter St, Waltham, MA, 02451, USA
| | - Bappaditya Chandra
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - David W Baggett
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Cheon-Gil Park
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Ramiz Somjee
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
- Rhodes College, Memphis, TN, USA
- Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO, 63110, USA
| | - Benjamin Lang
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
- Center of Excellence for Data-Driven Discovery, Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Seyed Mohammad Hadi Hosseini
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
- Center of Excellence for Data-Driven Discovery, Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Brittany J Pioso
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Yongsheng Li
- Livestrong Cancer Institutes, Department of Oncology, Dell Medical School, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Ilaria Iacobucci
- Department of Pathology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Qingsong Gao
- Department of Pathology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Michael N Edmonson
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Stephen V Rice
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Xin Zhou
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - John Bollinger
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Diana M Mitrea
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
- Dewpoint Therapeutics, 451 D Street, Suite 104, Boston, MA, 02210, USA
| | - Michael R White
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
- IDEXX Laboratories, Inc., One IDEXX Drive, Westbrook, ME, 04092, USA
| | - Daniel J McGrail
- Center for Immunotherapy and Precision Immuno-Oncology, Cleveland Clinic, Cleveland, OH, USA
- Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Daniel F Jarosz
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, USA
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - S Stephen Yi
- Livestrong Cancer Institutes, Department of Oncology, Dell Medical School, The University of Texas at Austin, Austin, TX, 78712, USA
- Department of Biomedical Engineering, and Oden Institute for Computational Engineering and Sciences, The University of Texas at Austin, Austin, TX, USA
| | - M Madan Babu
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
- Center of Excellence for Data-Driven Discovery, Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Charles G Mullighan
- Department of Pathology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Jinghui Zhang
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Nidhi Sahni
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Program in Quantitative and Computational Biosciences, Baylor College of Medicine, Houston, TX, USA
| | - Richard W Kriwacki
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA.
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Sciences Center, Memphis, TN, USA.
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29
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Hazra MK, Gilron Y, Levy Y. Not Only Expansion: Proline Content and Density Also Induce Disordered Protein Conformation Compaction. J Mol Biol 2023; 435:168196. [PMID: 37442414 DOI: 10.1016/j.jmb.2023.168196] [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: 03/25/2023] [Revised: 06/28/2023] [Accepted: 07/05/2023] [Indexed: 07/15/2023]
Abstract
Intrinsically disordered proteins (IDPs) adopt a wide array of different conformations that can be constrained by the presence of proline residues, which are frequently found in IDPs. To assess the effects of proline, we designed a series of peptides that differ with respect to the number of prolines in the sequence and their organization. Using high-resolution atomistic molecular dynamics simulations, we found that accounting for whether the proline residues are clustered or isolated contributed significantly to explaining deviations in the experimentally-determined gyration radii of IDPs from the values expected based on the Flory scaling-law. By contrast, total proline content makes smaller contribution to explaining the effect of prolines on IDP conformation. Proline residues exhibit opposing effects depending on their organizational pattern in the IDP sequence. Clustered prolines (i.e., prolines with ≤2 intervening non-proline residues) result in expanded peptide conformations whereas isolated prolines (i.e., prolines with >2 intervening non-proline residues) impose compacted conformations. Clustered prolines were estimated to induce an expansion of ∼20% in IDP dimension (via formation of PPII structural elements) whereas isolated prolines were estimated to induce a compaction of ∼10% in IDP dimension (via the formation of backbone turns). This dual role of prolines provides a mechanism for conformational switching that does not rely on the kinetically much slower isomerization of cis proline to the trans form. Bioinformatic analysis demonstrates high populations of both isolated and clustered prolines and implementing them in coarse-grained molecular dynamics models illustrates that they improve the characterization of the conformational ensembles of IDPs.
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Affiliation(s)
- Milan Kumar Hazra
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Yishai Gilron
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Yaakov Levy
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, Israel.
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30
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Tsangaris TE, Smyth S, Gomes GNW, Liu ZH, Milchberg M, Bah A, Wasney GA, Forman-Kay JD, Gradinaru CC. Delineating Structural Propensities of the 4E-BP2 Protein via Integrative Modeling and Clustering. J Phys Chem B 2023; 127:7472-7486. [PMID: 37595014 PMCID: PMC10858721 DOI: 10.1021/acs.jpcb.3c04052] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/20/2023]
Abstract
The intrinsically disordered 4E-BP2 protein regulates mRNA cap-dependent translation through interaction with the predominantly folded eukaryotic initiation factor 4E (eIF4E). Phosphorylation of 4E-BP2 dramatically reduces the level of eIF4E binding, in part by stabilizing a binding-incompatible folded domain. Here, we used a Rosetta-based sampling algorithm optimized for IDRs to generate initial ensembles for two phospho forms of 4E-BP2, non- and 5-fold phosphorylated (NP and 5P, respectively), with the 5P folded domain flanked by N- and C-terminal IDRs (N-IDR and C-IDR, respectively). We then applied an integrative Bayesian approach to obtain NP and 5P conformational ensembles that agree with experimental data from nuclear magnetic resonance, small-angle X-ray scattering, and single-molecule Förster resonance energy transfer (smFRET). For the NP state, inter-residue distance scaling and 2D maps revealed the role of charge segregation and pi interactions in driving contacts between distal regions of the chain (∼70 residues apart). The 5P ensemble shows prominent contacts of the N-IDR region with the two phosphosites in the folded domain, pT37 and pT46, and, to a lesser extent, delocalized interactions with the C-IDR region. Agglomerative hierarchical clustering led to partitioning of each of the two ensembles into four clusters with different global dimensions and contact maps. This helped delineate an NP cluster that, based on our smFRET data, is compatible with the eIF4E-bound state. 5P clusters were differentiated by interactions of C-IDR with the folded domain and of the N-IDR with the two phosphosites in the folded domain. Our study provides both a better visualization of fundamental structural poses of 4E-BP2 and a set of falsifiable insights on intrachain interactions that bias folding and binding of this protein.
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Affiliation(s)
- Thomas E Tsangaris
- Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
- Department of Chemical & Physical Sciences, University of Toronto Mississauga, Mississauga, Ontario L5L 1C6, Canada
| | - Spencer Smyth
- Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
- Department of Chemical & Physical Sciences, University of Toronto Mississauga, Mississauga, Ontario L5L 1C6, Canada
| | - Gregory-Neal W Gomes
- Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
- Department of Chemical & Physical Sciences, University of Toronto Mississauga, Mississauga, Ontario L5L 1C6, Canada
| | - Zi Hao Liu
- Program in Molecular Medicine, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Moses Milchberg
- Program in Molecular Medicine, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Alaji Bah
- Program in Molecular Medicine, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Gregory A Wasney
- Peter Gilgan Centre for Research and Learning, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | - Julie D Forman-Kay
- Program in Molecular Medicine, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Claudiu C Gradinaru
- Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
- Department of Chemical & Physical Sciences, University of Toronto Mississauga, Mississauga, Ontario L5L 1C6, Canada
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31
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Lalmansingh JM, Keeley AT, Ruff KM, Pappu RV, Holehouse AS. SOURSOP: A Python Package for the Analysis of Simulations of Intrinsically Disordered Proteins. J Chem Theory Comput 2023; 19:5609-5620. [PMID: 37463458 PMCID: PMC11188088 DOI: 10.1021/acs.jctc.3c00190] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
Conformational heterogeneity is a defining hallmark of intrinsically disordered proteins and protein regions (IDRs). The functions of IDRs and the emergent cellular phenotypes they control are associated with sequence-specific conformational ensembles. Simulations of conformational ensembles that are based on atomistic and coarse-grained models are routinely used to uncover the sequence-specific interactions that may contribute to IDR functions. These simulations are performed either independently or in conjunction with data from experiments. Functionally relevant features of IDRs can span a range of length scales. Extracting these features requires analysis routines that quantify a range of properties. Here, we describe a new analysis suite simulation analysis of unfolded regions of proteins (SOURSOP), an object-oriented and open-source toolkit designed for the analysis of simulated conformational ensembles of IDRs. SOURSOP implements several analysis routines motivated by principles in polymer physics, offering a unique collection of simple-to-use functions to characterize IDR ensembles. As an extendable framework, SOURSOP supports the development and implementation of new analysis routines that can be easily packaged and shared.
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Affiliation(s)
- Jared M. Lalmansingh
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
- Center for Biomolecular Condensates, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Alex T. Keeley
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
- Department of Chemistry, University of Illinois Urbana-Champaign, Urbana-Champaign, IL 61801, USA
| | - Kiersten M. Ruff
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
- Center for Biomolecular Condensates, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Rohit V. Pappu
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
- Center for Biomolecular Condensates, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Alex S. Holehouse
- Center for Biomolecular Condensates, Washington University in St. Louis, St. Louis, MO 63130, USA
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, 63110, USA
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32
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Flynn AJ, Miller K, Codjoe JM, King MR, Haswell ES. Mechanosensitive ion channels MSL8, MSL9, and MSL10 have environmentally sensitive intrinsically disordered regions with distinct biophysical characteristics in vitro. PLANT DIRECT 2023; 7:e515. [PMID: 37547488 PMCID: PMC10400277 DOI: 10.1002/pld3.515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 06/26/2023] [Accepted: 06/27/2023] [Indexed: 08/08/2023]
Abstract
Intrinsically disordered protein regions (IDRs) are highly dynamic sequences that rapidly sample a collection of conformations over time. In the past several decades, IDRs have emerged as a major component of many proteomes, comprising ~30% of all eukaryotic protein sequences. Proteins with IDRs function in a wide range of biological pathways and are notably enriched in signaling cascades that respond to environmental stresses. Here, we identify and characterize intrinsic disorder in the soluble cytoplasmic N-terminal domains of MSL8, MSL9, and MSL10, three members of the MscS-like (MSL) family of mechanosensitive ion channels. In plants, MSL channels are proposed to mediate cell and organelle osmotic homeostasis. Bioinformatic tools unanimously predicted that the cytosolic N-termini of MSL channels are intrinsically disordered. We examined the N-terminus of MSL10 (MSL10N) as an exemplar of these IDRs and circular dichroism spectroscopy confirms its disorder. MSL10N adopted a predominately helical structure when exposed to the helix-inducing compound trifluoroethanol (TFE). Furthermore, in the presence of molecular crowding agents, MSL10N underwent structural changes and exhibited alterations to its homotypic interaction favorability. Lastly, interrogations of collective behavior via in vitro imaging of condensates indicated that MSL8N, MSL9N, and MSL10N have sharply differing propensities for self-assembly into condensates, both inherently and in response to salt, temperature, and molecular crowding. Taken together, these data establish the N-termini of MSL channels as intrinsically disordered regions with distinct biophysical properties and the potential to respond uniquely to changes in their physiochemical environment.
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Affiliation(s)
- Aidan J. Flynn
- Department of BiologyWashington University in St. LouisSt. LouisMissouriUSA
- NSF Center for Engineering Mechanobiology, Department of BiologyWashington University in St. LouisSt. LouisMissouriUSA
- Department of Biochemistry and BiophysicsWashington University in St. LouisSt. LouisMissouriUSA
| | - Kari Miller
- Department of BiologyWashington University in St. LouisSt. LouisMissouriUSA
- NSF Center for Engineering Mechanobiology, Department of BiologyWashington University in St. LouisSt. LouisMissouriUSA
| | - Jennette M. Codjoe
- Department of BiologyWashington University in St. LouisSt. LouisMissouriUSA
- NSF Center for Engineering Mechanobiology, Department of BiologyWashington University in St. LouisSt. LouisMissouriUSA
| | - Matthew R. King
- Department of Biomedical EngineeringWashington University in St. LouisSt. LouisMissouriUSA
| | - Elizabeth S. Haswell
- Department of BiologyWashington University in St. LouisSt. LouisMissouriUSA
- NSF Center for Engineering Mechanobiology, Department of BiologyWashington University in St. LouisSt. LouisMissouriUSA
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33
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Alston JJ, Ginell GM, Soranno A, Holehouse AS. The Analytical Flory Random Coil Is a Simple-to-Use Reference Model for Unfolded and Disordered Proteins. J Phys Chem B 2023; 127:4746-4760. [PMID: 37200094 PMCID: PMC10875986 DOI: 10.1021/acs.jpcb.3c01619] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Denatured, unfolded, and intrinsically disordered proteins (collectively referred to here as unfolded proteins) can be described using analytical polymer models. These models capture various polymeric properties and can be fit to simulation results or experimental data. However, the model parameters commonly require users' decisions, making them useful for data interpretation but less clearly applicable as stand-alone reference models. Here we use all-atom simulations of polypeptides in conjunction with polymer scaling theory to parameterize an analytical model of unfolded polypeptides that behave as ideal chains (ν = 0.50). The model, which we call the analytical Flory random coil (AFRC), requires only the amino acid sequence as input and provides direct access to probability distributions of global and local conformational order parameters. The model defines a specific reference state to which experimental and computational results can be compared and normalized. As a proof-of-concept, we use the AFRC to identify sequence-specific intramolecular interactions in simulations of disordered proteins. We also use the AFRC to contextualize a curated set of 145 different radii of gyration obtained from previously published small-angle X-ray scattering experiments of disordered proteins. The AFRC is implemented as a stand-alone software package and is also available via a Google Colab notebook. In summary, the AFRC provides a simple-to-use reference polymer model that can guide intuition and aid in interpreting experimental or simulation results.
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Affiliation(s)
- Jhullian J. Alston
- 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
| | - Garrett M. Ginell
- 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
| | - Andrea Soranno
- 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
| | - 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
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Yu F, Sukenik S. Structural Preferences Shape the Entropic Force of Disordered Protein Ensembles. J Phys Chem B 2023; 127:4235-4244. [PMID: 37155239 DOI: 10.1021/acs.jpcb.3c00698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Intrinsically disordered protein regions (IDRs) make up over 30% of the human proteome and exist in a dynamic conformational ensemble instead of a native, well-folded structure. Tethering IDRs to a surface (for example, the surface of a well-folded region of the same protein) can reduce the number of accessible conformations in these ensembles. This reduces the ensemble's conformational entropy, generating an effective entropic force that pulls away from the point of tethering. Recent experimental work has shown that this entropic force causes measurable, physiologically relevant changes to protein function. But how the magnitude of this force depends on IDR sequence remains unexplored. Here, we use all-atom simulations to analyze how structural preferences in IDR ensembles contribute to the entropic force they exert upon tethering. We show that sequence-encoded structural preferences play an important role in determining the magnitude of this force: compact, spherical ensembles generate an entropic force that can be several times higher than more extended ensembles. We further show that changes in the surrounding solution's chemistry can modulate the IDR entropic force strength. We propose that the entropic force is a sequence-dependent, environmentally tunable property of terminal IDR sequences.
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Affiliation(s)
- Feng Yu
- Quantitative Systems Biology Program, University of California, Merced, California 95343, United States
| | - Shahar Sukenik
- Quantitative Systems Biology Program, University of California, Merced, California 95343, United States
- Department of Chemistry and Biochemistry, University of California, Merced, California 95343, United States
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35
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Gaalswyk K, Haider A, Ghosh K. Critical Assessment of Self-Consistency Checks in the All-Atom Molecular Dynamics Simulation of Intrinsically Disordered Proteins. J Chem Theory Comput 2023; 19:2973-2984. [PMID: 37133846 DOI: 10.1021/acs.jctc.2c01140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
All atom simulations can be used to quantify conformational properties of Intrinsically Disordered Proteins (IDP). However, simulations must satisfy convergence checks to ensure observables computed from simulation are reliable and reproducible. While absolute convergence is purely a theoretical concept requiring infinitely long simulation, a more practical, yet rigorous, approach is to impose Self Consistency Checks (SCCs) to gain confidence in the simulated data. Currently there is no study of SCCs in IDPs, unlike their folded counterparts. In this paper, we introduce different criteria for self-consistency checks for IDPs. Next, we impose these SCCs to critically assess the performance of different simulation protocols using the N terminal domain of HIV Integrase and the linker region of SARS-CoV-2 Nucleoprotein as two model IDPs. All simulation protocols begin with all-atom implicit solvent Monte Carlo (MC) simulation and subsequent clustering of MC generated conformations to create the representative structures of the IDPs. These representative structures serve as the initial structure for subsequent molecular dynamics (MD) runs with explicit solvent. We conclude that generating multiple short (∼3 μs) MD simulation trajectories─all starting from the most representative MC generated conformation─and merging them is the protocol of choice due to (i) its ability to satisfy multiple SCCs, (ii) consistently reproducing experimental data, and (iii) the efficiency of running independent trajectories in parallel by harnessing multiple cores available in modern GPU clusters. Running one long trajectory (greater than 20 μs) can also satisfy the first two criteria but is less desirable due to prohibitive computation time. These findings help resolve the challenge of identifying a usable starting configuration, provide an objective measure of SCC, and establish rigorous criteria to determine the minimum length (for one long simulation) or number of trajectories needed in all-atom simulation of IDPs.
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Affiliation(s)
- Kari Gaalswyk
- Department of Physics and Astronomy, University of Denver, Denver, Colorado 80208, United States
| | - Austin Haider
- Department of Molecular and Cellular Biophysics, University of Denver, Denver, Colorado 80208, United States
| | - Kingshuk Ghosh
- Department of Physics and Astronomy, University of Denver, Denver, Colorado 80208, United States
- Department of Molecular and Cellular Biophysics, University of Denver, Denver, Colorado 80208, United States
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36
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Menon S, Mondal J. Conformational Plasticity in α-Synuclein and How Crowded Environment Modulates It. J Phys Chem B 2023; 127:4032-4049. [PMID: 37114769 DOI: 10.1021/acs.jpcb.3c00982] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
A 140-residue intrinsically disordered protein (IDP), α-synuclein (αS), is known to adopt conformations that are vastly plastic and susceptible to environmental cues and crowders. However, the inherently heterogeneous nature of αS has precluded a clear demarcation of its monomeric precursor between aggregation-prone and functionally relevant aggregation-resistant states and how a crowded environment could modulate their mutual dynamic equilibrium. Here, we identify an optimal set of distinct metastable states of αS in aqueous media by dissecting a 73 μs-long molecular dynamics ensemble via building a comprehensive Markov state model (MSM). Notably, the most populated metastable state corroborates with the dimension obtained from PRE-NMR studies of αS monomer, and it undergoes kinetic transition at diverse time scales with a weakly populated random-coil-like ensemble and a globular protein-like state. However, subjecting αS to a crowded environment results in a nonmonotonic compaction of these metastable conformations, thereby skewing the ensemble by either introducing new tertiary contacts or by reinforcing the innate contacts. The early stage of dimerization process is found to be considerably expedited in the presence of crowders, albeit promoting nonspecific interactions. Together with this, using an extensively sampled ensemble of αS, this exposition demonstrates that crowded environments can potentially modulate the conformational preferences of IDP that can either promote or inhibit aggregation events.
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Affiliation(s)
- Sneha Menon
- Tata Institute of Fundamental Research Hyderabad, Telangana 500046, India
| | - Jagannath Mondal
- Tata Institute of Fundamental Research Hyderabad, Telangana 500046, India
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37
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Li T, Hendrix E, He Y. Simple and Effective Conformational Sampling Strategy for Intrinsically Disordered Proteins Using the UNRES Web Server. J Phys Chem B 2023; 127:2177-2186. [PMID: 36827446 DOI: 10.1021/acs.jpcb.2c08945] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Abstract
Intrinsically disordered proteins (IDPs) contain more charged amino acids than folded proteins, resulting in a lack of hydrophobic core(s) and a tendency to adopt rapidly interconverting structures rather than well-defined structures. The structural heterogeneity of IDPs, encoded by the amino acid sequence, is closely related to their unique roles in biological pathways, which require them to interact with different binding partners. Recently, Robustelli and co-workers have demonstrated that a balanced all-atom force field can be used to sample heterogeneous structures of disordered proteins ( Proc. Natl. Acad. Sci. U.S.A. 2018, 115, E4758-E4766). However, such a solution requires extensive computational resources, such as Anton supercomputers. Here, we propose a simple and effective solution to sample the conformational space of IDPs using a publicly available web server, namely, the UNited-RESidue (UNRES) web server. Our proposed solution requires no investment in computational resources and no prior knowledge of UNRES. UNRES Replica Exchange Molecular Dynamics (REMD) simulations were carried out on a set of eight disordered proteins at temperatures spanning from 270 to 430 K. Utilizing the latest UNRES force field designed for structured proteins, with proper selections of temperatures, we were able to produce comparable results to all-atom force fields as reported in work done by Robustelli and co-workers. In addition, NMR observables and the radius of gyration calculated from UNRES ensembles were directly compared with the experimental data to further evaluate the accuracy of the UNRES model at all temperatures. Our results suggest that carrying out the UNRES simulations at optimal temperatures using the UNRES web server can be a good alternative to sample heterogeneous structures of IDPs.
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Affiliation(s)
- Tongtong Li
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Emily Hendrix
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Yi He
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, United States.,Translational Informatics Division, Department of Internal Medicine, University of New Mexico, Albuquerque, New Mexico 87131, United States
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38
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Alston JJ, Ginell GM, Soranno A, Holehouse AS. The analytical Flory random coil is a simple-to-use reference model for unfolded and disordered proteins. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.12.531990. [PMID: 36993592 PMCID: PMC10054940 DOI: 10.1101/2023.03.12.531990] [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: 05/27/2023]
Abstract
Denatured, unfolded, and intrinsically disordered proteins (collectively referred to here as unfolded proteins) can be described using analytical polymer models. These models capture various polymeric properties and can be fit to simulation results or experimental data. However, the model parameters commonly require users' decisions, making them useful for data interpretation but less clearly applicable as stand-alone reference models. Here we use all-atom simulations of polypeptides in conjunction with polymer scaling theory to parameterize an analytical model of unfolded polypeptides that behave as ideal chains (ν = 0.50). The model, which we call the analytical Flory Random Coil (AFRC), requires only the amino acid sequence as input and provides direct access to probability distributions of global and local conformational order parameters. The model defines a specific reference state to which experimental and computational results can be compared and normalized. As a proof-of-concept, we use the AFRC to identify sequence-specific intramolecular interactions in simulations of disordered proteins. We also use the AFRC to contextualize a curated set of 145 different radii of gyration obtained from previously published small-angle X-ray scattering experiments of disordered proteins. The AFRC is implemented as a stand-alone software package and is also available via a Google colab notebook. In summary, the AFRC provides a simple-to-use reference polymer model that can guide intuition and aid in interpreting experimental or simulation results.
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Affiliation(s)
- Jhullian J. Alston
- 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
| | - Garrett M. Ginell
- 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
| | - Andrea Soranno
- 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
| | - 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
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39
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Lalmansingh JM, Keeley AT, Ruff KM, Pappu RV, Holehouse AS. SOURSOP: A Python package for the analysis of simulations of intrinsically disordered proteins. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.16.528879. [PMID: 36824878 PMCID: PMC9949127 DOI: 10.1101/2023.02.16.528879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
Conformational heterogeneity is a defining hallmark of intrinsically disordered proteins and protein regions (IDRs). The functions of IDRs and the emergent cellular phenotypes they control are associated with sequence-specific conformational ensembles. Simulations of conformational ensembles that are based on atomistic and coarse-grained models are routinely used to uncover the sequence-specific interactions that may contribute to IDR functions. These simulations are performed either independently or in conjunction with data from experiments. Functionally relevant features of IDRs can span a range of length scales. Extracting these features requires analysis routines that quantify a range of properties. Here, we describe a new analysis suite SOURSOP, an object-oriented and open-source toolkit designed for the analysis of simulated conformational ensembles of IDRs. SOURSOP implements several analysis routines motivated by principles in polymer physics, offering a unique collection of simple-to-use functions to characterize IDR ensembles. As an extendable framework, SOURSOP supports the development and implementation of new analysis routines that can be easily packaged and shared.
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40
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Gingerich MA, Liu X, Chai B, Pearson GL, Vincent MP, Stromer T, Zhu J, Sidarala V, Renberg A, Sahu D, Klionsky DJ, Schnell S, Soleimanpour SA. An intrinsically disordered protein region encoded by the human disease gene CLEC16A regulates mitophagy. Autophagy 2023; 19:525-543. [PMID: 35604110 PMCID: PMC9851259 DOI: 10.1080/15548627.2022.2080383] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
CLEC16A regulates mitochondrial health through mitophagy and is associated with over 20 human diseases. However, the key structural and functional regions of CLEC16A, and their relevance for human disease, remain unknown. Here, we report that a disease-associated CLEC16A variant lacks a C-terminal intrinsically disordered protein region (IDPR) that is critical for mitochondrial quality control. IDPRs comprise nearly half of the human proteome, yet their mechanistic roles in human disease are poorly understood. Using carbon detect NMR, we find that the CLEC16A C terminus lacks secondary structure, validating the presence of an IDPR. Loss of the CLEC16A C-terminal IDPR in vivo impairs mitophagy, mitochondrial function, and glucose-stimulated insulin secretion, ultimately causing glucose intolerance. Deletion of the CLEC16A C-terminal IDPR increases CLEC16A ubiquitination and degradation, thus impairing assembly of the mitophagy regulatory machinery. Importantly, CLEC16A stability is dependent on proline bias within the C-terminal IDPR, but not amino acid sequence order or charge. Together, we elucidate how an IDPR in CLEC16A regulates mitophagy and implicate pathogenic human gene variants that disrupt IDPRs as novel contributors to diabetes and other CLEC16A-associated diseases.Abbreviations : CAS: carbon-detect amino-acid specific; IDPR: intrinsically disordered protein region; MEFs: mouse embryonic fibroblasts; NMR: nuclear magnetic resonance.
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Affiliation(s)
- Morgan A. Gingerich
- Department of Internal Medicine and Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, MI, USA,Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, MI, USA
| | - Xueying Liu
- Department of Internal Medicine and Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, MI, USA,Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Biaoxin Chai
- Department of Internal Medicine and Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, MI, USA
| | - Gemma L. Pearson
- Department of Internal Medicine and Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, MI, USA
| | - Michael P. Vincent
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA,Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA
| | - Tracy Stromer
- Department of Internal Medicine and Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, MI, USA
| | - Jie Zhu
- Department of Internal Medicine and Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, MI, USA
| | - Vaibhav Sidarala
- Department of Internal Medicine and Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, MI, USA
| | - Aaron Renberg
- Department of Internal Medicine and Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, MI, USA
| | - Debashish Sahu
- BioNMR Core Facility, Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Daniel J. Klionsky
- Life Sciences Institute and Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Santiago Schnell
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA,Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA
| | - Scott A. Soleimanpour
- Department of Internal Medicine and Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, MI, USA,Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA,Medicine Service, Endocrinology and Metabolism Section, VA Ann Arbor Health Care System, Ann Arbor, MI, USA,CONTACT Scott A. Soleimanpour Department of Internal Medicine and Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Wall Street, Brehm Tower Room, Ann Arbor, MI, USA
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41
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Tesei G, Lindorff-Larsen K. Improved predictions of phase behaviour of intrinsically disordered proteins by tuning the interaction range. OPEN RESEARCH EUROPE 2023; 2:94. [PMID: 37645312 PMCID: PMC10450847 DOI: 10.12688/openreseurope.14967.2] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 12/16/2022] [Indexed: 08/31/2023]
Abstract
The formation and viscoelastic properties of condensates of intrinsically disordered proteins (IDPs) is dictated by amino acid sequence and solution conditions. Because of the involvement of biomolecular condensates in cell physiology and disease, advancing our understanding of the relationship between protein sequence and phase separation (PS) may have important implications in the formulation of new therapeutic hypotheses. Here, we present CALVADOS 2, a coarse-grained model of IDPs that accurately predicts conformational properties and propensities to undergo PS for diverse sequences and solution conditions. In particular, we systematically study the effect of varying the range of the nonionic interactions and use our findings to improve the temperature scale of the model. We further optimize the residue-specific model parameters against experimental data on the conformational properties of 55 proteins, while also leveraging 70 hydrophobicity scales from the literature to avoid overfitting the training data. Extensive testing shows that the model accurately predicts chain compaction and PS propensity for sequences of diverse length and charge patterning, as well as at different temperatures and salt concentrations.
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Affiliation(s)
- Giulio Tesei
- Structural Biology and NMR Laboratory & the Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Kresten Lindorff-Larsen
- Structural Biology and NMR Laboratory & the Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
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42
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Tesei G, Lindorff-Larsen K. Improved predictions of phase behaviour of intrinsically disordered proteins by tuning the interaction range. OPEN RESEARCH EUROPE 2023; 2:94. [PMID: 37645312 PMCID: PMC10450847 DOI: 10.12688/openreseurope.14967.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 12/16/2022] [Indexed: 02/13/2024]
Abstract
The formation and viscoelastic properties of condensates of intrinsically disordered proteins (IDPs) is dictated by amino acid sequence and solution conditions. Because of the involvement of biomolecular condensates in cell physiology and disease, advancing our understanding of the relationship between protein sequence and phase separation (PS) may have important implications in the formulation of new therapeutic hypotheses. Here, we present CALVADOS 2, a coarse-grained model of IDPs that accurately predicts conformational properties and propensities to undergo PS for diverse sequences and solution conditions. In particular, we systematically study the effect of varying the range of the nonionic interactions and use our findings to improve the temperature scale of the model. We further optimize the residue-specific model parameters against experimental data on the conformational properties of 55 proteins, while also leveraging 70 hydrophobicity scales from the literature to avoid overfitting the training data. Extensive testing shows that the model accurately predicts chain compaction and PS propensity for sequences of diverse length and charge patterning, as well as at different temperatures and salt concentrations.
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Affiliation(s)
- Giulio Tesei
- Structural Biology and NMR Laboratory & the Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Kresten Lindorff-Larsen
- Structural Biology and NMR Laboratory & the Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
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43
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Effects of Sequence Composition, Patterning and Hydrodynamics on the Conformation and Dynamics of Intrinsically Disordered Proteins. Int J Mol Sci 2023; 24:ijms24021444. [PMID: 36674958 PMCID: PMC9867189 DOI: 10.3390/ijms24021444] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 12/24/2022] [Accepted: 12/25/2022] [Indexed: 01/13/2023] Open
Abstract
Intrinsically disordered proteins (IDPs) and intrinsically disordered regions (IDRs) perform diverse functions in cellular organization, transport and signaling. Unlike the well-defined structures of the classical natively folded proteins, IDPs and IDRs dynamically span large conformational and structural ensembles. This dynamic disorder impedes the study of the relationship between the amino acid sequences of the IDPs and their spatial structures and dynamics, with different experimental techniques often offering seemingly contradictory results. Although experimental and theoretical evidence indicates that some IDP properties can be understood based on their average biophysical properties and amino acid composition, other aspects of IDP function are dictated by the specifics of the amino acid sequence. We investigate the effects of several key variables on the dimensions and the dynamics of IDPs using coarse-grained polymer models. We focus on the sequence "patchiness" informed by the sequence and biophysical properties of different classes of IDPs-and in particular FG nucleoporins of the nuclear pore complex (NPC). We show that the sequence composition and patterning are well reflected in the global conformational variables such as the radius of gyration and hydrodynamic radius, while the end-to-end distance and dynamics are highly sequence-specific. We find that in good solvent conditions highly heterogeneous sequences of IDPs can be well mapped onto averaged minimal polymer models for the purpose of prediction of the IDPs dimensions and dynamic relaxation times. The coarse-grained simulations are in a good agreement with the results of atomistic MD. We discuss the implications of these results for the interpretation of the recent experimental measurements, and for the further applications of mesoscopic models of FG nucleoporins and IDPs more broadly.
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44
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Sun B, Kekenes-Huskey PM. Myofilament-associated proteins with intrinsic disorder (MAPIDs) and their resolution by computational modeling. Q Rev Biophys 2023; 56:e2. [PMID: 36628457 PMCID: PMC11070111 DOI: 10.1017/s003358352300001x] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The cardiac sarcomere is a cellular structure in the heart that enables muscle cells to contract. Dozens of proteins belong to the cardiac sarcomere, which work in tandem to generate force and adapt to demands on cardiac output. Intriguingly, the majority of these proteins have significant intrinsic disorder that contributes to their functions, yet the biophysics of these intrinsically disordered regions (IDRs) have been characterized in limited detail. In this review, we first enumerate these myofilament-associated proteins with intrinsic disorder (MAPIDs) and recent biophysical studies to characterize their IDRs. We secondly summarize the biophysics governing IDR properties and the state-of-the-art in computational tools toward MAPID identification and characterization of their conformation ensembles. We conclude with an overview of future computational approaches toward broadening the understanding of intrinsic disorder in the cardiac sarcomere.
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Affiliation(s)
- Bin Sun
- Research Center for Pharmacoinformatics (The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Department of Medicinal Chemistry and Natural Medicine Chemistry, College of Pharmacy, Harbin Medical University, Harbin 150081, China
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Yarawsky AE, Ori AL, English LR, Whitten ST, Herr AB. Convergent behavior of extended stalk regions from staphylococcal surface proteins with widely divergent sequence patterns. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.06.523059. [PMID: 36711672 PMCID: PMC9881980 DOI: 10.1101/2023.01.06.523059] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Staphylococcus epidermidis and S. aureus are highly problematic bacteria in hospital settings. This stems, at least in part, from strong abilities to form biofilms on abiotic or biotic surfaces. Biofilms are well-organized multicellular aggregates of bacteria, which, when formed on indwelling medical devices, lead to infections that are difficult to treat. Cell wall-anchored (CWA) proteins are known to be important players in biofilm formation and infection. Many of these proteins have putative stalk-like regions or regions of low complexity near the cell wall-anchoring motif. Recent work demonstrated the strong propensity of the stalk region of the S. epidermidis accumulation-associated protein (Aap) to remain highly extended under solution conditions that typically induce compaction or other significant conformational changes. This behavior is consistent with the expected function of a stalk-like region that is covalently attached to the cell wall peptidoglycan and projects the adhesive domains of Aap away from the cell surface. In this study, we evaluate whether the ability to resist compaction is a common theme among stalk regions from various staphylococcal CWA proteins. Circular dichroism spectroscopy was used to examine secondary structure changes as a function of temperature and cosolvents along with sedimentation velocity analytical ultracentrifugation and SAXS to characterize structural characteristics in solution. All stalk regions tested are intrinsically disordered, lacking secondary structure beyond random coil and polyproline type II helix, and they all sample highly extended conformations. Remarkably, the Ser-Asp dipeptide repeat region of SdrC exhibited nearly identical behavior in solution when compared to the Aap Pro/Gly-rich region, despite highly divergent sequence patterns, indicating conservation of function by various distinct staphylococcal CWA protein stalk regions.
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Affiliation(s)
- Alexander E. Yarawsky
- Division of Immunobiology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Andrea L. Ori
- Division of Immunobiology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA,Medical Sciences Baccalaureate Program, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Lance R. English
- Department of Chemistry and Biochemistry, Texas State University, San Marcos, TX 78666, USA
| | - Steven T. Whitten
- Department of Chemistry and Biochemistry, Texas State University, San Marcos, TX 78666, USA
| | - Andrew B. Herr
- Division of Immunobiology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA,Division of Infectious Diseases, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
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Buholzer KJ, McIvor J, Zosel F, Teppich C, Nettels D, Mercadante D, Schuler B. Multilayered allosteric modulation of coupled folding and binding by phosphorylation, peptidyl-prolyl cis/trans isomerization, and diversity of interaction partners. J Chem Phys 2022; 157:235102. [PMID: 36550025 DOI: 10.1063/5.0128273] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Intrinsically disordered proteins (IDPs) play key roles in cellular regulation, including signal transduction, transcription, and cell-cycle control. Accordingly, IDPs can commonly interact with numerous different target proteins, and their interaction networks are expected to be highly regulated. However, many of the underlying regulatory mechanisms have remained unclear. Here, we examine the representative case of the nuclear coactivator binding domain (NCBD) of the large multidomain protein CBP, a hub in transcriptional regulation, and the interaction with several of its binding partners. Single-molecule Förster resonance energy transfer measurements show that phosphorylation of NCBD reduces its binding affinity, with effects that vary depending on the binding partner and the site and number of modifications. The complexity of the interaction is further increased by the dependence of the affinities on peptidyl-prolyl cis/trans isomerization in NCBD. Overall, our results reveal the potential for allosteric regulation on at least three levels: the different affinities of NCBD for its different binding partners, the differential modulation of these affinities by phosphorylation, and the effect of peptidyl-prolyl cis/trans isomerization on binding.
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Affiliation(s)
- Karin J Buholzer
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Jordan McIvor
- School of Chemical Sciences, The University of Auckland, Auckland, New Zealand
| | - Franziska Zosel
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Christian Teppich
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Daniel Nettels
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Davide Mercadante
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Benjamin Schuler
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
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Unveiling the Metal-Dependent Aggregation Properties of the C-terminal Region of Amyloidogenic Intrinsically Disordered Protein Isoforms DPF3b and DPF3a. Int J Mol Sci 2022; 23:ijms232315291. [PMID: 36499617 PMCID: PMC9738585 DOI: 10.3390/ijms232315291] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 11/24/2022] [Accepted: 12/01/2022] [Indexed: 12/12/2022] Open
Abstract
Double-PHD fingers 3 (DPF3) is a BAF-associated human epigenetic regulator, which is increasingly recognised as a major contributor to various pathological contexts, such as cardiac defects, cancer, and neurodegenerative diseases. Recently, we unveiled that its two isoforms (DPF3b and DPF3a) are amyloidogenic intrinsically disordered proteins. DPF3 isoforms differ from their C-terminal region (C-TERb and C-TERa), containing zinc fingers and disordered domains. Herein, we investigated the disorder aggregation properties of C-TER isoforms. In agreement with the predictions, spectroscopy highlighted a lack of a highly ordered structure, especially for C-TERa. Over a few days, both C-TERs were shown to spontaneously assemble into similar antiparallel and parallel β-sheet-rich fibrils. Altered metal homeostasis being a neurodegeneration hallmark, we also assessed the influence of divalent metal cations, namely Cu2+, Mg2+, Ni2+, and Zn2+, on the C-TER aggregation pathway. Circular dichroism revealed that metal binding does not impair the formation of β-sheets, though metal-specific tertiary structure modifications were observed. Through intrinsic and extrinsic fluorescence, we found that metal cations differently affect C-TERb and C-TERa. Cu2+ and Ni2+ have a strong inhibitory effect on the aggregation of both isoforms, whereas Mg2+ impedes C-TERb fibrillation and, on the contrary, enhances that of C-TERa. Upon Zn2+ binding, C-TERb aggregation is also hindered, and the amyloid autofluorescence of C-TERa is remarkably red-shifted. Using electron microscopy, we confirmed that the metal-induced spectral changes are related to the morphological diversity of the aggregates. While metal-treated C-TERb formed breakable and fragmented filaments, C-TERa fibrils retained their flexibility and packing properties in the presence of Mg2+ and Zn2+ cations.
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The biophysics of disordered proteins from the point of view of single-molecule fluorescence spectroscopy. Essays Biochem 2022; 66:875-890. [PMID: 36416865 PMCID: PMC9760427 DOI: 10.1042/ebc20220065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 10/10/2022] [Accepted: 10/11/2022] [Indexed: 11/24/2022]
Abstract
Intrinsically disordered proteins (IDPs) and regions (IDRs) have emerged as key players across many biological functions and diseases. Differently from structured proteins, disordered proteins lack stable structure and are particularly sensitive to changes in the surrounding environment. Investigation of disordered ensembles requires new approaches and concepts for quantifying conformations, dynamics, and interactions. Here, we provide a short description of the fundamental biophysical properties of disordered proteins as understood through the lens of single-molecule fluorescence observations. Single-molecule Förster resonance energy transfer (FRET) and fluorescence correlation spectroscopy (FCS) provides an extensive and versatile toolbox for quantifying the characteristics of conformational distributions and the dynamics of disordered proteins across many different solution conditions, both in vitro and in living cells.
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How phosphorylation impacts intrinsically disordered proteins and their function. Essays Biochem 2022; 66:901-913. [PMID: 36350035 PMCID: PMC9760426 DOI: 10.1042/ebc20220060] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 10/14/2022] [Accepted: 10/17/2022] [Indexed: 11/10/2022]
Abstract
Phosphorylation is the most common post-translational modification (PTM) in eukaryotes, occurring particularly frequently in intrinsically disordered proteins (IDPs). These proteins are highly flexible and dynamic by nature. Thus, it is intriguing that the addition of a single phosphoryl group to a disordered chain can impact its function so dramatically. Furthermore, as many IDPs carry multiple phosphorylation sites, the number of possible states increases, enabling larger complexities and novel mechanisms. Although a chemically simple and well-understood process, the impact of phosphorylation on the conformational ensemble and molecular function of IDPs, not to mention biological output, is highly complex and diverse. Since the discovery of the first phosphorylation site in proteins 75 years ago, we have come to a much better understanding of how this PTM works, but with the diversity of IDPs and their capacity for carrying multiple phosphoryl groups, the complexity grows. In this Essay, we highlight some of the basic effects of IDP phosphorylation, allowing it to serve as starting point when embarking on studies into this topic. We further describe how recent complex cases of multisite phosphorylation of IDPs have been instrumental in widening our view on the effect of protein phosphorylation. Finally, we put forward perspectives on the phosphorylation of IDPs, both in relation to disease and in context of other PTMs; areas where deep insight remains to be uncovered.
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Samulevich ML, Shamilov R, Aneskievich BJ. Thermostable Proteins from HaCaT Keratinocytes Identify a Wide Breadth of Intrinsically Disordered Proteins and Candidates for Liquid-Liquid Phase Separation. Int J Mol Sci 2022; 23:ijms232214323. [PMID: 36430801 PMCID: PMC9692912 DOI: 10.3390/ijms232214323] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 11/08/2022] [Accepted: 11/16/2022] [Indexed: 11/22/2022] Open
Abstract
Intrinsically disordered proteins (IDPs) move through an ensemble of conformations which allows multitudinous roles within a cell. Keratinocytes, the predominant cell type in mammalian epidermis, have had only a few individual proteins assessed for intrinsic disorder and its possible contribution to liquid-liquid phase separation (LLPS), especially in regard to what functions or structures these proteins provide. We took a holistic approach to keratinocyte IDPs starting with enrichment via the isolation of thermostable proteins. The keratinocyte protein involucrin, known for its resistance to heat denaturation, served as a marker. It and other thermostable proteins were identified by liquid chromatography tandem mass spectrometry and subjected to extensive bioinformatic analysis covering gene ontology, intrinsic disorder, and potential for LLPS. Numerous proteins unique to keratinocytes and other proteins with shared expression in multiple cell types were identified to have IDP traits (e.g., compositional bias, nucleic acid binding, and repeat motifs). Among keratinocyte-specific proteins, many that co-assemble with involucrin into the cell-specific structure known as the cornified envelope scored highly for intrinsic disorder and potential for LLPS. This suggests intrinsic disorder and LLPS are previously unrecognized traits for assembly of the cornified envelope, echoing the contribution of intrinsic disorder and LLPS to more widely encountered features such as stress granules and PML bodies.
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Affiliation(s)
- Michael L. Samulevich
- Graduate Program in Pharmacology & Toxicology, Department of Pharmaceutical Sciences, University of Connecticut, 69 North Eagleville Road, Storrs, CT 06292-3092, USA
| | - Rambon Shamilov
- Graduate Program in Pharmacology & Toxicology, Department of Pharmaceutical Sciences, University of Connecticut, 69 North Eagleville Road, Storrs, CT 06292-3092, USA
| | - Brian J. Aneskievich
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Connecticut, 69 North Eagleville Road, Storrs, CT 06269-3092, USA
- Correspondence: ; Tel.: +1-860-486-3053; Fax: +1-860-486-5792
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