1
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King MR, Ruff KM, Pappu RV. Emergent microenvironments of nucleoli. Nucleus 2024; 15:2319957. [PMID: 38443761 PMCID: PMC10936679 DOI: 10.1080/19491034.2024.2319957] [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: 09/04/2023] [Accepted: 02/13/2024] [Indexed: 03/07/2024] Open
Abstract
In higher eukaryotes, the nucleolus harbors at least three sub-phases that facilitate multiple functionalities including ribosome biogenesis. The three prominent coexisting sub-phases are the fibrillar center (FC), the dense fibrillar component (DFC), and the granular component (GC). Here, we review recent efforts in profiling sub-phase compositions that shed light on the types of physicochemical properties that emerge from compositional biases and territorial organization of specific types of macromolecules. We highlight roles played by molecular grammars which refers to protein sequence features including the substrate binding domains, the sequence features of intrinsically disordered regions, and the multivalence of these distinct types of domains / regions. We introduce the concept of a barcode of emergent physicochemical properties of nucleoli. Although our knowledge of the full barcode remains incomplete, we hope that the concept prompts investigations into undiscovered emergent properties and engenders an appreciation for how and why unique microenvironments control biochemical reactions.
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Affiliation(s)
- Matthew R. King
- Department of Biomedical Engineering and Center for Biomolecular Condensates, Washington University in St. Louis, Campus, MO, USA
| | - Kiersten M. Ruff
- Department of Biomedical Engineering and Center for Biomolecular Condensates, Washington University in St. Louis, Campus, MO, USA
| | - Rohit V. Pappu
- Department of Biomedical Engineering and Center for Biomolecular Condensates, Washington University in St. Louis, Campus, MO, USA
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2
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Yan X, Kuster D, Mohanty P, Nijssen J, Pombo-García K, Rizuan A, Franzmann TM, Sergeeva A, Passos PM, George L, Wang SH, Shenoy J, Danielson HL, Honigmann A, Ayala YM, Fawzi NL, Mittal J, Alberti S, Hyman AA. Intra-condensate demixing of TDP-43 inside stress granules generates pathological aggregates. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.23.576837. [PMID: 38328053 PMCID: PMC10849624 DOI: 10.1101/2024.01.23.576837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Cytosolic aggregation of the nuclear protein TDP-43 is associated with many neurodegenerative diseases, but the triggers for TDP-43 aggregation are still debated. Here, we demonstrate that TDP-43 aggregation requires a double event. One is up-concentration in stress granules beyond a threshold, and the other is oxidative stress. These two events collectively induce intra-condensate demixing, giving rise to a dynamic TDP-43 enriched phase within stress granules, which subsequently transitions into pathological aggregates. Mechanistically, intra-condensate demixing is triggered by local unfolding of the RRM1 domain for intermolecular disulfide bond formation and by increased hydrophobic patch interactions in the C-terminal domain. By engineering TDP-43 variants resistant to intra-condensate demixing, we successfully eliminate pathological TDP-43 aggregates in cells. We conclude that up-concentration inside condensates and simultaneous exposure to environmental stress could be a general pathway for protein aggregation, with intra-condensate demixing constituting a key intermediate step.
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Affiliation(s)
- Xiao Yan
- Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG); Dresden, Saxony, 01307; Germany
| | - David Kuster
- Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG); Dresden, Saxony, 01307; Germany
- These authors contributed equally
| | - Priyesh Mohanty
- Artie McFerrin Department of Chemical Engineering, Texas A&M University; College Station, TX 77843; USA
- These authors contributed equally
| | - Jik Nijssen
- Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG); Dresden, Saxony, 01307; Germany
- These authors contributed equally
| | - Karina Pombo-García
- Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG); Dresden, Saxony, 01307; Germany
- These authors contributed equally
| | - Azamat Rizuan
- Artie McFerrin Department of Chemical Engineering, Texas A&M University; College Station, TX 77843; USA
| | - Titus M. Franzmann
- Biotechnology Center (BIOTEC), Center for Molecular and Cellular Bioengineering, Technische Universität Dresden; Dresden, Saxony, 01307; Germany
| | - Aleksandra Sergeeva
- Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG); Dresden, Saxony, 01307; Germany
- Biotechnology Center (BIOTEC), Center for Molecular and Cellular Bioengineering, Technische Universität Dresden; Dresden, Saxony, 01307; Germany
| | - Patricia M. Passos
- Edward Doisy Department of Biochemistry and Molecular Biology, Saint Louis University; St. Louis, MO 63104; USA
| | - Leah George
- Edward Doisy Department of Biochemistry and Molecular Biology, Saint Louis University; St. Louis, MO 63104; USA
| | - Szu-Huan Wang
- Department of Molecular Biology, Cell Biology & Biochemistry, Brown University; Providence, RI 02912; USA
| | - Jayakrishna Shenoy
- Department of Molecular Biology, Cell Biology & Biochemistry, Brown University; Providence, RI 02912; USA
| | - Helen L. Danielson
- Center for Biomedical Engineering, Brown University; Providence, RI 02912; USA
| | - Alf Honigmann
- Biotechnology Center (BIOTEC), Center for Molecular and Cellular Bioengineering, Technische Universität Dresden; Dresden, Saxony, 01307; Germany
| | - Yuna M. Ayala
- Edward Doisy Department of Biochemistry and Molecular Biology, Saint Louis University; St. Louis, MO 63104; USA
| | - Nicolas L. Fawzi
- Department of Molecular Biology, Cell Biology & Biochemistry, Brown University; Providence, RI 02912; USA
| | - Jeetain Mittal
- Artie McFerrin Department of Chemical Engineering, Texas A&M University; College Station, TX 77843; USA
- Department of Chemistry, Texas A&M University; College Station, TX 77843; USA
- Interdisciplinary Graduate Program in Genetics and Genomics, Texas A&M University; College Station, TX 77843; USA
| | - Simon Alberti
- Biotechnology Center (BIOTEC), Center for Molecular and Cellular Bioengineering, Technische Universität Dresden; Dresden, Saxony, 01307; Germany
| | - Anthony A. Hyman
- Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG); Dresden, Saxony, 01307; Germany
- Lead contact
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3
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Giudice J, Jiang H. Splicing regulation through biomolecular condensates and membraneless organelles. Nat Rev Mol Cell Biol 2024:10.1038/s41580-024-00739-7. [PMID: 38773325 DOI: 10.1038/s41580-024-00739-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/22/2024] [Indexed: 05/23/2024]
Abstract
Biomolecular condensates, sometimes also known as membraneless organelles (MLOs), can form through weak multivalent intermolecular interactions of proteins and nucleic acids, a process often associated with liquid-liquid phase separation. Biomolecular condensates are emerging as sites and regulatory platforms of vital cellular functions, including transcription and RNA processing. In the first part of this Review, we comprehensively discuss how alternative splicing regulates the formation and properties of condensates, and conversely the roles of biomolecular condensates in splicing regulation. In the second part, we focus on the spatial connection between splicing regulation and nuclear MLOs such as transcriptional condensates, splicing condensates and nuclear speckles. We then discuss key studies showing how splicing regulation through biomolecular condensates is implicated in human pathologies such as neurodegenerative diseases, different types of cancer, developmental disorders and cardiomyopathies, and conclude with a discussion of outstanding questions pertaining to the roles of condensates and MLOs in splicing regulation and how to experimentally study them.
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Affiliation(s)
- Jimena Giudice
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
- McAllister Heart Institute, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
| | - Hao Jiang
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA, USA.
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4
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Paul S, Arias MA, Wen L, Liao SE, Zhang J, Wang X, Regev O, Fei J. RNA molecules display distinctive organization at nuclear speckles. iScience 2024; 27:109603. [PMID: 38638569 PMCID: PMC11024929 DOI: 10.1016/j.isci.2024.109603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 01/05/2024] [Accepted: 03/25/2024] [Indexed: 04/20/2024] Open
Abstract
RNA molecules often play critical roles in assisting the formation of membraneless organelles in eukaryotic cells. Yet, little is known about the organization of RNAs within membraneless organelles. Here, using super-resolution imaging and nuclear speckles as a model system, we demonstrate that different sequence domains of RNA transcripts exhibit differential spatial distributions within speckles. Specifically, we image transcripts containing a region enriched in binding motifs of serine/arginine-rich (SR) proteins and another region enriched in binding motifs of heterogeneous nuclear ribonucleoproteins (hnRNPs). We show that these transcripts localize to the outer shell of speckles, with the SR motif-rich region localizing closer to the speckle center relative to the hnRNP motif-rich region. Further, we identify that this intra-speckle RNA organization is driven by the strength of RNA-protein interactions inside and outside speckles. Our results hint at novel functional roles of nuclear speckles and likely other membraneless organelles in organizing RNA substrates for biochemical reactions.
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Affiliation(s)
- Sneha Paul
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, USA
| | - Mauricio A. Arias
- Courant Institute of Mathematical Sciences, New York University, New York, NY 10012, USA
- Institute for System Genetics, NYU Langone Health, New York, NY 10016, USA
| | - Li Wen
- Department of Physics, The University of Chicago, Chicago, IL 60637, USA
| | - Susan E. Liao
- Courant Institute of Mathematical Sciences, New York University, New York, NY 10012, USA
| | - Jiacheng Zhang
- Graduate Program in Biophysical Sciences, The University of Chicago, Chicago, IL 60637, USA
| | - Xiaoshu Wang
- The College, The University of Chicago, Chicago, IL 60637, USA
| | - Oded Regev
- Courant Institute of Mathematical Sciences, New York University, New York, NY 10012, USA
| | - Jingyi Fei
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, USA
- Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL 60637, USA
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5
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Chakraborty S, Mishra J, Roy A, Niharika, Manna S, Baral T, Nandi P, Patra S, Patra SK. Liquid-liquid phase separation in subcellular assemblages and signaling pathways: Chromatin modifications induced gene regulation for cellular physiology and functions including carcinogenesis. Biochimie 2024; 223:74-97. [PMID: 38723938 DOI: 10.1016/j.biochi.2024.05.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 03/08/2024] [Accepted: 05/04/2024] [Indexed: 05/24/2024]
Abstract
Liquid-liquid phase separation (LLPS) describes many biochemical processes, including hydrogel formation, in the integrity of macromolecular assemblages and existence of membraneless organelles, including ribosome, nucleolus, nuclear speckles, paraspeckles, promyelocytic leukemia (PML) bodies, Cajal bodies (all exert crucial roles in cellular physiology), and evidence are emerging day by day. Also, phase separation is well documented in generation of plasma membrane subdomains and interplay between membranous and membraneless organelles. Intrinsically disordered regions (IDRs) of biopolymers/proteins are the most critical sticking regions that aggravate the formation of such condensates. Remarkably, phase separated condensates are also involved in epigenetic regulation of gene expression, chromatin remodeling, and heterochromatinization. Epigenetic marks on DNA and histones cooperate with RNA-binding proteins through their IDRs to trigger LLPS for facilitating transcription. How phase separation coalesces mutant oncoproteins, orchestrate tumor suppressor genes expression, and facilitated cancer-associated signaling pathways are unravelling. That autophagosome formation and DYRK3-mediated cancer stem cell modification also depend on phase separation is deciphered in part. In view of this, and to linchpin insight into the subcellular membraneless organelle assembly, gene activation and biological reactions catalyzed by enzymes, and the downstream physiological functions, and how all these events are precisely facilitated by LLPS inducing organelle function, epigenetic modulation of gene expression in this scenario, and how it goes awry in cancer progression are summarized and presented in this article.
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Affiliation(s)
- Subhajit Chakraborty
- Epigenetics and Cancer Research Laboratory, Biochemistry and Molecular Biology Group, Department of Life Science, National Institute of Technology, Rourkela, India
| | - Jagdish Mishra
- Epigenetics and Cancer Research Laboratory, Biochemistry and Molecular Biology Group, Department of Life Science, National Institute of Technology, Rourkela, India
| | - Ankan Roy
- Epigenetics and Cancer Research Laboratory, Biochemistry and Molecular Biology Group, Department of Life Science, National Institute of Technology, Rourkela, India
| | - Niharika
- Epigenetics and Cancer Research Laboratory, Biochemistry and Molecular Biology Group, Department of Life Science, National Institute of Technology, Rourkela, India
| | - Soumen Manna
- Epigenetics and Cancer Research Laboratory, Biochemistry and Molecular Biology Group, Department of Life Science, National Institute of Technology, Rourkela, India
| | - Tirthankar Baral
- Epigenetics and Cancer Research Laboratory, Biochemistry and Molecular Biology Group, Department of Life Science, National Institute of Technology, Rourkela, India
| | - Piyasa Nandi
- Epigenetics and Cancer Research Laboratory, Biochemistry and Molecular Biology Group, Department of Life Science, National Institute of Technology, Rourkela, India
| | - Subhajit Patra
- Department of Chemical Engineering, Maulana Azad National Institute of Technology, Bhopal, India
| | - Samir Kumar Patra
- Epigenetics and Cancer Research Laboratory, Biochemistry and Molecular Biology Group, Department of Life Science, National Institute of Technology, Rourkela, India.
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6
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Dion W, Tao Y, Chambers M, Zhao S, Arbuckle RK, Sun M, Kubra S, Nie Y, Ye M, Larsen MB, Camarco D, Ickes E, DuPont C, Wang H, Wang B, Liu S, Pi S, Chen BB, Chen Y, Chen X, Zhu B. Nuclear speckle rejuvenation alleviates proteinopathies at the expense of YAP1. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.18.590103. [PMID: 38659924 PMCID: PMC11042303 DOI: 10.1101/2024.04.18.590103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Current treatments targeting individual protein quality control have limited efficacy in alleviating proteinopathies, highlighting the prerequisite for a common upstream druggable target capable of global proteostasis modulation. Building on our prior research establishing nuclear speckles as pivotal organelles responsible for global proteostasis transcriptional control, we aim to alleviate proteinopathies through nuclear speckle rejuvenation. We identified pyrvinium pamoate as a small-molecule nuclear speckle rejuvenator that enhances protein quality control while suppressing YAP1 signaling via decreasing the surface tension of nuclear speckle condensates through interaction with the intrinsically disordered region of nuclear speckle scaffold protein SON. In pre-clinical models, pyrvinium pamoate reduced tauopathy and alleviated retina degeneration by promoting autophagy and ubiquitin-proteasome system. Aberrant nuclear speckle morphology, reduced protein quality control and increased YAP1 activity were also observed in human tauopathies. Our study uncovers novel therapeutic targets for tackling protein misfolding disorders within an expanded proteostasis framework encompassing nuclear speckles and YAP1.
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Affiliation(s)
- William Dion
- Aging Institute of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, PA, U.S.A
| | - Yuren Tao
- Department of Neuroscience, School of Medicine, University of California, San Diego, CA, U.S.A
| | - Maci Chambers
- Aging Institute of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, PA, U.S.A
| | - Shanshan Zhao
- Department of Neuroscience, School of Medicine, University of California, San Diego, CA, U.S.A
| | - Riley K. Arbuckle
- Department of Ophthalmology, University of Pittsburgh School of Medicine, PA, U.S.A
- Department of Human Genetics, University of Pittsburgh Graduate School of Public Health, Pittsburgh, PA, USA
| | - Michelle Sun
- Aging Institute of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, PA, U.S.A
| | - Syeda Kubra
- Aging Institute of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, PA, U.S.A
| | - Yuhang Nie
- Department of Neuroscience, School of Medicine, University of California, San Diego, CA, U.S.A
| | - Megan Ye
- Aging Institute of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, PA, U.S.A
| | - Mads B. Larsen
- Aging Institute of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, PA, U.S.A
| | - Daniel Camarco
- Aging Institute of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, PA, U.S.A
| | - Eleanor Ickes
- Aging Institute of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, PA, U.S.A
| | - Claire DuPont
- Aging Institute of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, PA, U.S.A
| | - Haokun Wang
- Aging Institute of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, PA, U.S.A
| | - Bingjie Wang
- Department of Ophthalmology, University of Pittsburgh School of Medicine, PA, U.S.A
| | - Silvia Liu
- Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, PA, U.S.A
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, U.S.A
| | - Shaohua Pi
- Department of Ophthalmology, University of Pittsburgh School of Medicine, PA, U.S.A
| | - Bill B Chen
- Aging Institute of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, PA, U.S.A
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, U.S.A
| | - Yuanyuan Chen
- Department of Ophthalmology, University of Pittsburgh School of Medicine, PA, U.S.A
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, PA, U.S.A
| | - Xu Chen
- Department of Neuroscience, School of Medicine, University of California, San Diego, CA, U.S.A
| | - Bokai Zhu
- Aging Institute of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, PA, U.S.A
- Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, PA, U.S.A
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, U.S.A
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7
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Zhang Z, Zhang J. Purification of SRSF1 from E. coli for Biophysical and Biochemical Assays. Curr Protoc 2024; 4:e1017. [PMID: 38578012 DOI: 10.1002/cpz1.1017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/06/2024]
Abstract
The Ser/Arg-rich splicing factors (SR proteins) constitute a crucial protein family in alternative splicing, comprising twelve members characterized by unique repetitive Arg-Ser dipeptide sequences (RS) and one to two RNA-recognition motifs (RRM). The RS regions of SR proteins undergo variable phosphorylation, resulting in unphosphorylated, partially phosphorylated, or hyper-phosphorylated states based on functional requirements. Despite the identification of the SR protein family over 30 years ago, the purification of native SR proteins in soluble form at large quantities has presented challenges due to their low solubility. This protocol delineates a method for acquiring soluble, full-length, unphosphorylated, hypo- and hyper-phosphorylated SRSF1, a prototypical SR family member. Notably, this protocol facilitates the purification of SRSF1 in ample quantities suitable for NMR, as well as various biophysical and biochemical studies. The methodologies and principles outlined herein are expected to extend beyond SRSF1 protein production and can be adapted for purifying other SR protein family members or SR-related proteins, such as snRNP70 and U2AF-35. Given the involvement of these proteins in numerous essential biological processes, this protocol will prove beneficial to researchers in related fields. © 2024 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Purification of SRSF1 from E. coli Support Protocol: Purification of ULP1 Basic Protocol 2: Purification of hypo-phosphorylated SRSF1 from E. coli Basic Protocol 3: Purification of hyper-phosphorylated SRSF1 from E. coli.
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Affiliation(s)
- Zihan Zhang
- Department of Chemistry, University of Alabama at Birmingham, Birmingham, Alabama
| | - Jun Zhang
- Department of Chemistry, University of Alabama at Birmingham, Birmingham, Alabama
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8
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Regan-Fendt KE, Izumi K. Nuclear speckleopathies: developmental disorders caused by variants in genes encoding nuclear speckle proteins. Hum Genet 2024; 143:529-544. [PMID: 36929417 DOI: 10.1007/s00439-023-02540-6] [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: 12/01/2022] [Accepted: 02/17/2023] [Indexed: 03/18/2023]
Abstract
Nuclear speckles are small, membrane-less organelles that reside within the nucleus. Nuclear speckles serve as a regulatory hub coordinating complex RNA metabolism steps including gene transcription, pre-mRNA splicing, RNA modifications, and mRNA nuclear export. Reflecting the importance of proper nuclear speckle function in regulating normal human development, an increasing number of genetic disorders have been found to result from mutations in the genes encoding nuclear speckle proteins. To denote this growing class of genetic disorders, we propose "nuclear speckleopathies". Notably, developmental disabilities are commonly seen in individuals with nuclear speckleopathies, suggesting the particular importance of nuclear speckles in ensuring normal neurocognitive development. In this review article, a general overview of nuclear speckle function, and the current knowledge of the mechanisms underlying some nuclear speckleopathies, such as ZTTK syndrome, NKAP-related syndrome, TARP syndrome, and TAR syndrome, are discussed. These nuclear speckleopathies represent valuable models to understand the basic function of nuclear speckles and how its functional defects result in human developmental disorders.
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Affiliation(s)
- Kelly E Regan-Fendt
- Division of Human Genetics, Department of Pediatrics, The Children's Hospital of Philadelphia, 3615 Civic Center Blvd., Philadelphia, PA, USA
| | - Kosuke Izumi
- Division of Human Genetics, Department of Pediatrics, The Children's Hospital of Philadelphia, 3615 Civic Center Blvd., Philadelphia, PA, USA.
- Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA.
- Laboratory of Rare Disease Research, Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, Japan.
- Division of Genetics and Metabolism, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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9
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Lotthammer JM, Ginell GM, Griffith D, Emenecker RJ, Holehouse AS. Direct prediction of intrinsically disordered protein conformational properties from sequence. Nat Methods 2024; 21:465-476. [PMID: 38297184 PMCID: PMC10927563 DOI: 10.1038/s41592-023-02159-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Accepted: 12/20/2023] [Indexed: 02/02/2024]
Abstract
Intrinsically disordered regions (IDRs) are ubiquitous across all domains of life and play a range of functional roles. While folded domains are generally well described by a stable three-dimensional structure, IDRs exist in a collection of interconverting states known as an ensemble. This structural heterogeneity means that IDRs are largely absent from the Protein Data Bank, contributing to a lack of computational approaches to predict ensemble conformational properties from sequence. Here we combine rational sequence design, large-scale molecular simulations and deep learning to develop ALBATROSS, a deep-learning model for predicting ensemble dimensions of IDRs, including the radius of gyration, end-to-end distance, polymer-scaling exponent and ensemble asphericity, directly from sequences at a proteome-wide scale. ALBATROSS is lightweight, easy to use and accessible as both a locally installable software package and a point-and-click-style interface via Google Colab notebooks. We first demonstrate the applicability of our predictors by examining the generalizability of sequence-ensemble relationships in IDRs. Then, we leverage the high-throughput nature of ALBATROSS to characterize the sequence-specific biophysical behavior of IDRs within and between proteomes.
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Affiliation(s)
- Jeffrey M Lotthammer
- 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
| | - Daniel Griffith
- 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
| | - Ryan J Emenecker
- 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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10
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Keber FC, Nguyen T, Mariossi A, Brangwynne CP, Wühr M. Evidence for widespread cytoplasmic structuring into mesoscale condensates. Nat Cell Biol 2024; 26:346-352. [PMID: 38424273 PMCID: PMC10981939 DOI: 10.1038/s41556-024-01363-5] [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] [Received: 01/31/2022] [Accepted: 01/23/2024] [Indexed: 03/02/2024]
Abstract
Compartmentalization is an essential feature of eukaryotic life and is achieved both via membrane-bound organelles, such as mitochondria, and membrane-less biomolecular condensates, such as the nucleolus. Known biomolecular condensates typically exhibit liquid-like properties and are visualized by microscopy on the scale of ~1 µm (refs. 1,2). They have been studied mostly by microscopy, examining select individual proteins. So far, several dozen biomolecular condensates are known, serving a multitude of functions, for example, in the regulation of transcription3, RNA processing4 or signalling5,6, and their malfunction can cause diseases7,8. However, it remains unclear to what extent biomolecular condensates are utilized in cellular organization and at what length scale they typically form. Here we examine native cytoplasm from Xenopus egg extract on a global scale with quantitative proteomics, filtration, size exclusion and dilution experiments. These assays reveal that at least 18% of the proteome is organized into mesoscale biomolecular condensates at the scale of ~100 nm and appear to be stabilized by RNA or gelation. We confirmed mesoscale sizes via imaging below the diffraction limit by investigating protein permeation into porous substrates with defined pore sizes. Our results show that eukaryotic cytoplasm organizes extensively via biomolecular condensates, but at surprisingly short length scales.
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Affiliation(s)
- Felix C Keber
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, USA
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Thao Nguyen
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, USA
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Andrea Mariossi
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Clifford P Brangwynne
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, USA.
- Howard Hughes Medical Institute, Princeton University, Princeton, NJ, USA.
- Omenn-Darling Bioengineering Institute, Princeton University, Princeton, NJ, USA.
| | - Martin Wühr
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA.
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, USA.
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA.
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11
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Lin AZ, Ruff KM, Dar F, Jalihal A, King MR, Lalmansingh JM, Posey AE, Erkamp NA, Seim I, Gladfelter AS, Pappu RV. Dynamical control enables the formation of demixed biomolecular condensates. Nat Commun 2023; 14:7678. [PMID: 37996438 PMCID: PMC10667521 DOI: 10.1038/s41467-023-43489-4] [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: 08/02/2023] [Accepted: 11/10/2023] [Indexed: 11/25/2023] Open
Abstract
Cellular matter can be organized into compositionally distinct biomolecular condensates. For example, in Ashbya gossypii, the RNA-binding protein Whi3 forms distinct condensates with different RNA molecules. Using criteria derived from a physical framework for explaining how compositionally distinct condensates can form spontaneously via thermodynamic considerations, we find that condensates in vitro form mainly via heterotypic interactions in binary mixtures of Whi3 and RNA. However, within these condensates, RNA molecules become dynamically arrested. As a result, in ternary systems, simultaneous additions of Whi3 and pairs of distinct RNA molecules lead to well-mixed condensates, whereas delayed addition of an RNA component results in compositional distinctness. Therefore, compositional identities of condensates can be achieved via dynamical control, being driven, at least partially, by the dynamical arrest of RNA molecules. Finally, we show that synchronizing the production of different RNAs leads to more well-mixed, as opposed to compositionally distinct condensates in vivo.
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Affiliation(s)
- Andrew Z Lin
- Division of Biology and Biomedical Sciences, Plant and Microbial Biosciences, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Kiersten M Ruff
- Department of Biomedical Engineering and Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Furqan Dar
- Department of Biomedical Engineering and Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Ameya Jalihal
- Department of Cell Biology, Duke University, Durham, NC, 27708, USA
| | - Matthew R King
- Department of Biomedical Engineering and Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Jared M Lalmansingh
- Department of Biomedical Engineering and Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Ammon E Posey
- Department of Biomedical Engineering and Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Nadia A Erkamp
- Department of Biomedical Engineering and Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA
- Yusuf Hamied Department of Chemistry, Centre for Misfolding Diseases, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Ian Seim
- Department of Cell Biology, Duke University, Durham, NC, 27708, USA
| | - Amy S Gladfelter
- Department of Cell Biology, Duke University, Durham, NC, 27708, USA.
| | - Rohit V Pappu
- Division of Biology and Biomedical Sciences, Plant and Microbial Biosciences, Washington University in St. Louis, St. Louis, MO, 63130, USA.
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12
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He C, Wu CY, Li W, Xu K. Multidimensional Super-Resolution Microscopy Unveils Nanoscale Surface Aggregates in the Aging of FUS Condensates. J Am Chem Soc 2023; 145:24240-24248. [PMID: 37782826 PMCID: PMC10691933 DOI: 10.1021/jacs.3c08674] [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] [Indexed: 10/04/2023]
Abstract
The intracellular liquid-liquid phase separation (LLPS) of biomolecules gives rise to condensates that act as membrane-less organelles with vital functions. FUS, an RNA-binding protein, natively forms condensates through LLPS and further provides a model system for the often disease-linked liquid-to-solid transition of biomolecular condensates during aging. However, the mechanism of such maturation processes, as well as the structural and physical properties of the system, remains unclear, partly attributable to difficulties in resolving the internal structures of the micrometer-sized condensates with diffraction-limited optical microscopy. Harnessing a set of multidimensional super-resolution microscopy tools that uniquely map out local physicochemical parameters through single-molecule spectroscopy, here, we uncover nanoscale heterogeneities in FUS condensates and elucidate their evolution over aging. Through spectrally resolved single-molecule localization microscopy (SR-SMLM) with a solvatochromic dye, we unveil distinct hydrophobic nanodomains at the condensate surface. Through SMLM with a fluorogenic amyloid probe, we identify these nanodomains as amyloid aggregates. Through single-molecule displacement/diffusivity mapping (SMdM), we show that such nanoaggregates drastically impede local diffusion. Notably, upon aging or mechanical shears, these nanoaggregates progressively expand on the condensate surface, thus leading to a growing low-diffusivity shell while leaving the condensate interior diffusion-permitting. Together, beyond uncovering fascinating structural arrangements and aging mechanisms in the single-component FUS condensates, the demonstrated synergy of multidimensional super-resolution approaches in this study opens new paths for understanding LLPS systems at the nanoscale.
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Affiliation(s)
- Changdong He
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Chun Ying Wu
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Wan Li
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Ke Xu
- Department of Chemistry, University of California, Berkeley, California 94720, United States
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13
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Kuang S, Pollard KS. Exploring the Roles of RNAs in Chromatin Architecture Using Deep Learning. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.22.563498. [PMID: 37961712 PMCID: PMC10634726 DOI: 10.1101/2023.10.22.563498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Recent studies have highlighted the impact of both transcription and transcripts on 3D genome organization, particularly its dynamics. Here, we propose a deep learning framework, called AkitaR, that leverages both genome sequences and genome-wide RNA-DNA interactions to investigate the roles of chromatin-associated RNAs (caRNAs) on genome folding in HFFc6 cells. In order to disentangle the cis- and trans-regulatory roles of caRNAs, we compared models with nascent transcripts, trans-located caRNAs, open chromatin data, or DNA sequence alone. Both nascent transcripts and trans-located caRNAs improved the models' predictions, especially at cell-type-specific genomic regions. Analyses of feature importance scores revealed the contribution of caRNAs at TAD boundaries, chromatin loops and nuclear sub-structures such as nuclear speckles and nucleoli to the models' predictions. Furthermore, we identified non-coding RNAs (ncRNAs) known to regulate chromatin structures, such as MALAT1 and NEAT1, as well as several novel RNAs, RNY5, RPPH1, POLG-DT and THBS1-IT, that might modulate chromatin architecture through trans-interactions in HFFc6. Our modeling also suggests that transcripts from Alus and other repetitive elements may facilitate chromatin interactions through trans R-loop formation. Our findings provide new insights and generate testable hypotheses about the roles of caRNAs in shaping chromatin organization.
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Affiliation(s)
- Shuzhen Kuang
- Gladstone Institute of Data Science and Biotechnology, San Francisco, CA
| | - Katherine S. Pollard
- Gladstone Institute of Data Science and Biotechnology, San Francisco, CA
- Department of Epidemiology & Biostatistics, University of California, San Francisco, CA
- Chan Zuckerberg Biohub, San Francisco, CA, USA
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14
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Huang L, Li G, Du C, Jia Y, Yang J, Fan W, Xu Y, Cheng H, Zhou Y. The polyA tail facilitates splicing of last introns with weak 3' splice sites via PABPN1. EMBO Rep 2023; 24:e57128. [PMID: 37661812 PMCID: PMC10561182 DOI: 10.15252/embr.202357128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 08/04/2023] [Accepted: 08/16/2023] [Indexed: 09/05/2023] Open
Abstract
The polyA tail of mRNAs is important for many aspects of RNA metabolism. However, whether and how it regulates pre-mRNA splicing is still unknown. Here, we report that the polyA tail acts as a splicing enhancer for the last intron via the nuclear polyA binding protein PABPN1 in HeLa cells. PABPN1-depletion induces the retention of a group of introns with a weaker 3' splice site, and they show a strong 3'-end bias and mainly locate in nuclear speckles. The polyA tail is essential for PABPN1-enhanced last intron splicing and functions in a length-dependent manner. Tethering PABPN1 to nonpolyadenylated transcripts also promotes splicing, suggesting a direct role for PABPN1 in splicing regulation. Using TurboID-MS, we construct the PABPN1 interactome, including many spliceosomal and RNA-binding proteins. Specifically, PABPN1 can recruit RBM26&27 to promote splicing by interacting with the coiled-coil and RRM domain of RBM27. PABPN1-regulated terminal intron splicing is conserved in mice. Together, our study establishes a novel mode of post-transcriptional splicing regulation via the polyA tail and PABPN1.
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Affiliation(s)
- Li Huang
- College of Life Sciences, TaiKang Center for Life and Medical Sciences, RNA InstituteWuhan UniversityWuhanChina
| | - Guangnan Li
- College of Life Sciences, TaiKang Center for Life and Medical Sciences, RNA InstituteWuhan UniversityWuhanChina
| | - Chen Du
- College of Life Sciences, TaiKang Center for Life and Medical Sciences, RNA InstituteWuhan UniversityWuhanChina
| | - Yu Jia
- College of Life Sciences, TaiKang Center for Life and Medical Sciences, RNA InstituteWuhan UniversityWuhanChina
| | - Jiayi Yang
- College of Life Sciences, TaiKang Center for Life and Medical Sciences, RNA InstituteWuhan UniversityWuhanChina
| | - Weiliang Fan
- College of Life Sciences, TaiKang Center for Life and Medical Sciences, RNA InstituteWuhan UniversityWuhanChina
| | - Yong‐Zhen Xu
- College of Life Sciences, TaiKang Center for Life and Medical Sciences, RNA InstituteWuhan UniversityWuhanChina
| | - Hong Cheng
- Key Laboratory of RNA Science and Engineering, Chinese Academy of Sciences, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of SciencesUniversity of Chinese Academy of SciencesShanghaiChina
| | - Yu Zhou
- College of Life Sciences, TaiKang Center for Life and Medical Sciences, RNA InstituteWuhan UniversityWuhanChina
- Frontier Science Center for Immunology and MetabolismWuhan UniversityWuhanChina
- Institute of Advanced StudiesWuhan UniversityWuhanChina
- State Key Laboratory of VirologyWuhan UniversityWuhanChina
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15
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He C, Wu CY, Li W, Xu K. Multidimensional super-resolution microscopy unveils nanoscale surface aggregates in the aging of FUS condensates. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.12.548239. [PMID: 37503034 PMCID: PMC10369965 DOI: 10.1101/2023.07.12.548239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
The intracellular liquid-liquid phase separation (LLPS) of biomolecules gives rise to condensates that act as membrane-less organelles with vital functions. FUS, an RNA-binding protein, natively forms condensates through LLPS and further provides a model system for the often disease-linked liquid-to-solid transition of biomolecular condensates during aging. However, the mechanism of such maturation processes, as well as the structural and physical properties of the system, remain unclear, partly attributable to difficulties in resolving the internal structures of the micrometer-sized condensates with diffraction-limited optical microscopy. Harnessing a set of multidimensional super-resolution microscopy tools that uniquely map out local physicochemical parameters through single-molecule spectroscopy, here we uncover nanoscale heterogeneities in the aging process of FUS condensates. Through spectrally resolved single-molecule localization microscopy (SR-SMLM) with a solvatochromic dye, we unveil distinct hydrophobic nanodomains at the condensate surface. Through SMLM with a fluorogenic amyloid probe, we identify these nanodomains as amyloid aggregates. Through single-molecule displacement/diffusivity mapping (SM d M), we show that such nanoaggregates drastically impede local diffusion. Notably, upon aging or mechanical shears, these nanoaggregates progressively expand on the condensate surface, thus leading to a growing low-diffusivity shell while leaving the condensate interior diffusion-permitting. Together, beyond uncovering fascinating nanoscale structural arrangements and aging mechanisms in the single-component FUS condensates, the demonstrated synergy of multidimensional super-resolution approaches in this study opens new paths for understanding LLPS systems.
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16
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Wakao S, Saitoh N, Awazu A. Mathematical model of structural changes in nuclear speckle. Biophys Physicobiol 2023; 20:e200020. [PMID: 38496241 PMCID: PMC10941963 DOI: 10.2142/biophysico.bppb-v20.0020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 04/26/2023] [Indexed: 03/19/2024] Open
Abstract
Nuclear speckles are nuclear bodies consisting of populations of small and irregularly shaped droplet-like molecular condensates that contain various splicing factors. Recent experiments have revealed the following structural features of nuclear speckles: (I) Each molecular condensate contains SON and SRRM2 proteins, and MALAT1 non-coding RNA surrounds these condensates; (II) During normal interphase of the cell cycle in multicellular organisms, these condensates are broadly distributed throughout the nucleus. In contrast, when cell transcription is suppressed, the condensates fuse and form strongly condensed spherical droplets; (III) SON is dispersed spatially in MALAT1 knocked-down cells and MALAT1 is dispersed in SON knocked-down cells because of the collapse of the nuclear speckles. However, the detailed interactions among the molecules that are mechanistically responsible for the structural variation remain unknown. In this study, a coarse-grained molecular dynamics model of the nuclear speckle was developed by considering the dynamics of SON, SRRM2, MALAT1, and pre-mRNA as representative components of the condensates. The simulations reproduced the structural changes, which were used to predict the interaction network among the representative components of the condensates.
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Affiliation(s)
- Shingo Wakao
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashihiroshima, Hiroshima 739-8526, Japan
| | - Noriko Saitoh
- Division of Cancer Biology, The Cancer Institute of Japanese Foundation for Cancer Research, Koto-ku, Tokyo 135-8550, Japan
| | - Akinori Awazu
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashihiroshima, Hiroshima 739-8526, Japan
- Research Center for the Mathematics on Chromatin Live Dynamics, Hiroshima University, Higashihiroshima, Hiroshima 739-8526, Japan
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17
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Kim T, Yoo J, Do S, Hwang DS, Park Y, Shin Y. RNA-mediated demixing transition of low-density condensates. Nat Commun 2023; 14:2425. [PMID: 37105967 PMCID: PMC10140143 DOI: 10.1038/s41467-023-38118-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 04/17/2023] [Indexed: 04/29/2023] Open
Abstract
Biomolecular condensates play a key role in organizing cellular reactions by concentrating a specific set of biomolecules. However, whether condensate formation is accompanied by an increase in the total mass concentration within condensates or by the demixing of already highly crowded intracellular components remains elusive. Here, using refractive index imaging, we quantify the mass density of several condensates, including nucleoli, heterochromatin, nuclear speckles, and stress granules. Surprisingly, the latter two condensates exhibit low densities with a total mass concentration similar to the surrounding cyto- or nucleoplasm. Low-density condensates display higher permeability to cellular protein probes. We find that RNA tunes the biomolecular density of condensates. Moreover, intracellular structures such as mitochondria heavily influence the way phase separation proceeds, impacting the localization, morphology, and growth of condensates. These findings favor a model where segregative phase separation driven by non-associative or repulsive molecular interactions together with RNA-mediated selective association of specific components can give rise to low-density condensates in the crowded cellular environment.
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Affiliation(s)
- Taehyun Kim
- Department of Mechanical Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Jaeyoon Yoo
- Department of Mechanical Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Sungho Do
- Department of Mechanical Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Dong Soo Hwang
- Division of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - YongKeun Park
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
- KAIST Institute for Health Science and Technology, Daejeon, 34141, Republic of Korea
- Tomocube Inc, Daejeon, 34109, South Korea
| | - Yongdae Shin
- Department of Mechanical Engineering, Seoul National University, Seoul, 08826, Republic of Korea.
- Interdisciplinary Program in Bioengineering, Seoul National University, Seoul, 08826, Korea.
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18
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Abstract
Multivalent proteins and nucleic acids, collectively referred to as multivalent associative biomacromolecules, provide the driving forces for the formation and compositional regulation of biomolecular condensates. Here, we review the key concepts of phase transitions of aqueous solutions of associative biomacromolecules, specifically proteins that include folded domains and intrinsically disordered regions. The phase transitions of these systems come under the rubric of coupled associative and segregative transitions. The concepts underlying these processes are presented, and their relevance to biomolecular condensates is discussed.
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Affiliation(s)
- Rohit V Pappu
- Department of Biomedical Engineering, Center for Biomolecular Condensates (CBC), Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Samuel R Cohen
- Department of Biomedical Engineering, Center for Biomolecular Condensates (CBC), Washington University in St. Louis, St. Louis, Missouri 63130, United States.,Center of Regenerative Medicine, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Furqan Dar
- Department of Biomedical Engineering, Center for Biomolecular Condensates (CBC), Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Mina Farag
- Department of Biomedical Engineering, Center for Biomolecular Condensates (CBC), Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Mrityunjoy Kar
- Max Planck Institute of Cell Biology and Genetics, 01307 Dresden, Germany
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19
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Fargason T, De Silva NIU, King E, Zhang Z, Paul T, Shariq J, Zaharias S, Zhang J. Peptides that Mimic RS repeats modulate phase separation of SRSF1, revealing a reliance on combined stacking and electrostatic interactions. eLife 2023; 12:84412. [PMID: 36862748 PMCID: PMC10023157 DOI: 10.7554/elife.84412] [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: 10/24/2022] [Accepted: 03/01/2023] [Indexed: 03/03/2023] Open
Abstract
Phase separation plays crucial roles in both sustaining cellular function and perpetuating disease states. Despite extensive studies, our understanding of this process is hindered by low solubility of phase-separating proteins. One example of this is found in SR and SR-related proteins. These proteins are characterized by domains rich in arginine and serine (RS domains), which are essential to alternative splicing and in vivo phase separation. However, they are also responsible for a low solubility that has made these proteins difficult to study for decades. Here, we solubilize the founding member of the SR family, SRSF1, by introducing a peptide mimicking RS repeats as a co-solute. We find that this RS-mimic peptide forms interactions similar to those of the protein's RS domain. Both interact with a combination of surface-exposed aromatic residues and acidic residues on SRSF1's RNA Recognition Motifs (RRMs) through electrostatic and cation-pi interactions. Analysis of RRM domains from human SR proteins indicates that these sites are conserved across the protein family. In addition to opening an avenue to previously unavailable proteins, our work provides insight into how SR proteins phase separate and participate in nuclear speckles.
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Affiliation(s)
- Talia Fargason
- Department of Chemistry, University of Alabama at BirminghamBirminghamUnited States
| | | | - Erin King
- Department of Chemistry, University of Alabama at BirminghamBirminghamUnited States
| | - Zihan Zhang
- Department of Chemistry, University of Alabama at BirminghamBirminghamUnited States
| | - Trenton Paul
- Department of Chemistry, University of Alabama at BirminghamBirminghamUnited States
| | - Jamal Shariq
- Department of Chemistry, University of Alabama at BirminghamBirminghamUnited States
| | - Steve Zaharias
- Department of Chemistry, University of Alabama at BirminghamBirminghamUnited States
| | - Jun Zhang
- Department of Chemistry, University of Alabama at BirminghamBirminghamUnited States
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20
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Asher G, Zhu B. Beyond circadian rhythms: emerging roles of ultradian rhythms in control of liver functions. Hepatology 2023; 77:1022-1035. [PMID: 35591797 PMCID: PMC9674798 DOI: 10.1002/hep.32580] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 04/26/2022] [Accepted: 04/28/2022] [Indexed: 12/08/2022]
Abstract
The mammalian liver must cope with various metabolic and physiological changes that normally recur every day and primarily stem from daily cycles of rest-activity and fasting-feeding. Although a large body of evidence supports the reciprocal regulation of circadian rhythms and liver function, the research on the hepatic ultradian rhythms have largely been lagging behind. However, with the advent of more cost-effective high-throughput omics technologies, high-resolution time-lapse imaging, and more robust and powerful mathematical tools, several recent studies have shed new light on the presence and functions of hepatic ultradian rhythms. In this review, we will first very briefly discuss the basic principles of circadian rhythms, and then cover in greater details the recent literature related to ultradian rhythms. Specifically, we will highlight the prevalence and mechanisms of hepatic 12-h rhythms, and 8-h rhythms, which cycle at the second and third harmonics of circadian frequency. Finally, we also refer to ultradian rhythms with other frequencies and examine the limitations of the current approaches as well as the challenges related to identifying ultradian rhythm and addressing their molecular underpinnings.
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Affiliation(s)
- Gad Asher
- Department of Biomolecular Sciences, Weizmann Institute of Science, 7610001, Rehovot, Israel
| | - Bokai Zhu
- Aging Institute of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Pittsburgh Liver Research Center, University of Pittsburgh, Pennsylvania, USA
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, School of Medicine, Pittsburgh, Pennsylvania, USA
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21
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Petrunina NA, Shtork AS, Lukina MM, Tsvetkov VB, Khodarovich YM, Feofanov AV, Moysenovich AM, Maksimov EG, Shipunova VO, Zatsepin TS, Bogomazova AN, Shender VO, Aralov AV, Lagarkova MA, Varizhuk AM. Ratiometric i-Motif-Based Sensor for Precise Long-Term Monitoring of pH Micro Alterations in the Nucleoplasm and Interchromatin Granules. ACS Sens 2023; 8:619-629. [PMID: 36662613 DOI: 10.1021/acssensors.2c01813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
DNA-intercalated motifs (iMs) are facile scaffolds for the design of various pH-responsive nanomachines, including biocompatible pH sensors. First, DNA pH sensors relied on complex intermolecular scaffolds. Here, we used a simple unimolecular dual-labeled iM scaffold and minimized it by replacing the redundant loop nucleosides with abasic or alkyl linkers. These modifications improved the thermal stability of the iM and increased the rates of its pH-induced conformational transitions. The best effects were obtained upon the replacement of all three native loops with short and flexible linkers, such as the propyl one. The resulting sensor showed a pH transition value equal to 6.9 ± 0.1 and responded rapidly to minor acidification (tau1/2 <1 s for 7.2 → 6.6 pH jump). We demonstrated the applicability of this sensor for pH measurements in the nuclei of human lung adenocarcinoma cells (pH = 7.4 ± 0.2) and immortalized embryonic kidney cells (pH = 7.0 ± 0.2). The sensor stained diffusely the nucleoplasm and piled up in interchromatin granules. These findings highlight the prospects of iMs in the studies of normal and pathological pH-dependent processes in the nucleus, including the formation of biomolecular condensates.
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Affiliation(s)
- Nataliia A Petrunina
- Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow119435, Russia
| | - Alina S Shtork
- Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow119435, Russia
| | - Maria M Lukina
- Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow119435, Russia.,Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow119435, Russia
| | - Vladimir B Tsvetkov
- Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow119435, Russia.,Institute of Biodesign and Complex System Modeling, I.M. Sechenov First Moscow State Medical University, Moscow119991, Russia.,A.V. Topchiev Institute of Petrochemical Synthesis RAS, Leninsky Prospect Str. 29, Moscow119991, Russia
| | - Yuri M Khodarovich
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow117997, Russia.,The Peoples' Friendship University of Russia, 117198Moscow, Russia
| | - Alexey V Feofanov
- Biological Faculty, Lomonosov Moscow State University, Moscow119992, Russia.,Institute of Gene Biology RAS, Russian Academy of Sciences, Moscow119334, Russia
| | | | - Eugene G Maksimov
- Biological Faculty, Lomonosov Moscow State University, Moscow119992, Russia
| | - Victoria O Shipunova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow117997, Russia
| | - Timofei S Zatsepin
- Department of Chemistry, Lomonosov Moscow State University, Moscow119992, Russia
| | - Alexandra N Bogomazova
- Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow119435, Russia.,Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow119435, Russia
| | - Victoria O Shender
- Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow119435, Russia.,Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow119435, Russia.,Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow117997, Russia
| | - Andrey V Aralov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow117997, Russia
| | - Maria A Lagarkova
- Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow119435, Russia.,Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow119435, Russia
| | - Anna M Varizhuk
- Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow119435, Russia.,Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow119435, Russia.,G4_Interact, USERN, University of Pavia, 27100Pavia, Italy
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22
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Lin AZ, Ruff KM, Jalihal A, Dar F, King MR, Lalmansingh JM, Posey AE, Seim I, Gladfelter AS, Pappu RV. Dynamical control enables the formation of demixed biomolecular condensates. RESEARCH SQUARE 2023:rs.3.rs-2440278. [PMID: 36798397 PMCID: PMC9934772 DOI: 10.21203/rs.3.rs-2440278/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Macromolecular phase separation underlies the regulated formation and dissolution of biomolecular condensates. What is unclear is how condensates of distinct and shared macromolecular compositions form and coexist within cellular milieus. Here, we use theory and computation to establish thermodynamic criteria that must be satisfied to achieve compositionally distinct condensates. We applied these criteria to an archetypal ribonucleoprotein condensate and discovered that demixing into distinct protein-RNA condensates cannot be the result of purely thermodynamic considerations. Instead, demixed, compositionally distinct condensates arise due to asynchronies in timescales that emerge from differences in long-lived protein-RNA and RNA-RNA crosslinks. This type of dynamical control is also found to be active in live cells whereby asynchronous production of molecules is required for realizing demixed protein-RNA condensates. We find that interactions that exert dynamical control provide a versatile and generalizable way to influence the compositions of coexisting condensates in live cells.
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Affiliation(s)
- Andrew Z Lin
- Division of Biology and Biomedical Sciences, Plant and Microbial Biosciences, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Kiersten M Ruff
- Department of Biomedical Engineering and Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Ameya Jalihal
- Department of Biology, University of North Carolina, Chapel Hill, NC
| | - Furqan Dar
- Department of Biomedical Engineering and Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Matthew R King
- Department of Biomedical Engineering and Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Jared M Lalmansingh
- Department of Biomedical Engineering and Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Ammon E Posey
- Department of Biomedical Engineering and Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Ian Seim
- Department of Biology, University of North Carolina, Chapel Hill, NC
| | - Amy S Gladfelter
- Department of Biology, University of North Carolina, Chapel Hill, NC
| | - Rohit V Pappu
- Department of Biomedical Engineering and Center for Biomolecular Condensates, James F. McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
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23
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Kumar A, Schrader AW, Boroojeny AE, Asadian M, Lee J, Song YJ, Zhao SD, Han HS, Sinha S. Intracellular Spatial Transcriptomic Analysis Toolkit (InSTAnT). RESEARCH SQUARE 2023:rs.3.rs-2481749. [PMID: 36747718 PMCID: PMC9901031 DOI: 10.21203/rs.3.rs-2481749/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Imaging-based spatial transcriptomics technologies such as MERFISH offer snapshots of cellular processes in unprecedented detail, but new analytic tools are needed to realize their full potential. We present InSTAnT, a computational toolkit for extracting molecular relationships from spatial transcriptomics data at the intra-cellular resolution. InSTAnT detects gene pairs and modules with interesting patterns of mutual co-localization within and across cells, using specialized statistical tests and graph mining. We showcase the toolkit on datasets profiling a human cancer cell line and hypothalamic preoptic region of mouse brain. We performed rigorous statistical assessment of discovered co-localization patterns, found supporting evidence from databases and RNA interactions, and identified subcellular domains associated with RNA-colocalization. We identified several novel cell type-specific gene co-localizations in the brain. Intra-cellular spatial patterns discovered by InSTAnT mirror diverse molecular relationships, including RNA interactions and shared sub-cellular localization or function, providing a rich compendium of testable hypotheses regarding molecular functions.
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Affiliation(s)
- Anurendra Kumar
- College of Computing, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Alex W. Schrader
- Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA
| | | | - Marisa Asadian
- Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA
| | - Juyeon Lee
- Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA
| | - You Jin Song
- Department of Cell and Developmental Biology, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA
| | - Sihai Dave Zhao
- Department of Statistics, University of Illinois Urbana-Champaign, Urbana, IL, 61820, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA
| | - Hee-Sun Han
- Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA
| | - Saurabh Sinha
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA
- H. Milton Stewart School of Industrial & Systems Engineering, Georgia Institute of Technology, Atlanta, GA, 30318, USA
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24
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Lin AZ, Ruff KM, Jalihal A, Dar F, King MR, Lalmansingh JM, Posey AE, Seim I, Gladfelter AS, Pappu RV. Dynamical control enables the formation of demixed biomolecular condensates. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.04.522702. [PMID: 36711465 PMCID: PMC9881950 DOI: 10.1101/2023.01.04.522702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Macromolecular phase separation underlies the regulated formation and dissolution of biomolecular condensates. What is unclear is how condensates of distinct and shared macromolecular compositions form and coexist within cellular milieus. Here, we use theory and computation to establish thermodynamic criteria that must be satisfied to achieve compositionally distinct condensates. We applied these criteria to an archetypal ribonucleoprotein condensate and discovered that demixing into distinct protein-RNA condensates cannot be the result of purely thermodynamic considerations. Instead, demixed, compositionally distinct condensates arise due to asynchronies in timescales that emerge from differences in long-lived protein-RNA and RNA-RNA crosslinks. This type of dynamical control is also found to be active in live cells whereby asynchronous production of molecules is required for realizing demixed protein-RNA condensates. We find that interactions that exert dynamical control provide a versatile and generalizable way to influence the compositions of coexisting condensates in live cells.
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25
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Zhu H, Narita M, Joseph JA, Krainer G, Arter WE, Olan I, Saar KL, Ermann N, Espinosa JR, Shen Y, Kuri MA, Qi R, Welsh TJ, Collepardo‐Guevara R, Narita M, Knowles TPJ. The Chromatin Regulator HMGA1a Undergoes Phase Separation in the Nucleus. Chembiochem 2023; 24:e202200450. [PMID: 36336658 PMCID: PMC10098602 DOI: 10.1002/cbic.202200450] [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: 08/04/2022] [Revised: 10/20/2022] [Indexed: 11/09/2022]
Abstract
The protein high mobility group A1 (HMGA1) is an important regulator of chromatin organization and function. However, the mechanisms by which it exerts its biological function are not fully understood. Here, we report that the HMGA isoform, HMGA1a, nucleates into foci that display liquid-like properties in the nucleus, and that the protein readily undergoes phase separation to form liquid condensates in vitro. By bringing together machine-leaning modelling, cellular and biophysical experiments and multiscale simulations, we demonstrate that phase separation of HMGA1a is promoted by protein-DNA interactions, and has the potential to be modulated by post-transcriptional effects such as phosphorylation. We further show that the intrinsically disordered C-terminal tail of HMGA1a significantly contributes to its phase separation through electrostatic interactions via AT hooks 2 and 3. Our work sheds light on HMGA1 phase separation as an emergent biophysical factor in regulating chromatin structure.
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Affiliation(s)
- Hongjia Zhu
- Centre for Misfolding DiseasesYusuf Hamied Department of ChemistryUniversity of CambridgeCambridgeUK
| | - Masako Narita
- Cancer Research UK Cambridge InstituteLi Ka Shing CentreUniversity of CambridgeCambridgeUK
| | - Jerelle A. Joseph
- Department of GeneticsUniversity of CambridgeCambridgeUK
- Cavendish LaboratoryDepartment of PhysicsUniversity of CambridgeJJ Thomson AvenueCambridgeUK
- Yusuf Hamied Department of ChemistryUniversity of CambridgeCambridgeUK
| | - Georg Krainer
- Centre for Misfolding DiseasesYusuf Hamied Department of ChemistryUniversity of CambridgeCambridgeUK
| | - William E. Arter
- Centre for Misfolding DiseasesYusuf Hamied Department of ChemistryUniversity of CambridgeCambridgeUK
- Transition Bio Ltd., Maxwell CentreJJ Thomson AvenueCambridgeUK
| | - Ioana Olan
- Cancer Research UK Cambridge InstituteLi Ka Shing CentreUniversity of CambridgeCambridgeUK
| | - Kadi L. Saar
- Centre for Misfolding DiseasesYusuf Hamied Department of ChemistryUniversity of CambridgeCambridgeUK
- Transition Bio Ltd., Maxwell CentreJJ Thomson AvenueCambridgeUK
| | - Niklas Ermann
- Transition Bio Ltd., Maxwell CentreJJ Thomson AvenueCambridgeUK
| | - Jorge R. Espinosa
- Cavendish LaboratoryDepartment of PhysicsUniversity of CambridgeJJ Thomson AvenueCambridgeUK
| | - Yi Shen
- School of Chemical and Biomolecular EngineeringThe University of SydneySydneyAustralia
| | - Masami Ando Kuri
- Cancer Research UK Cambridge InstituteLi Ka Shing CentreUniversity of CambridgeCambridgeUK
| | - Runzhang Qi
- Centre for Misfolding DiseasesYusuf Hamied Department of ChemistryUniversity of CambridgeCambridgeUK
| | - Timothy J. Welsh
- Centre for Misfolding DiseasesYusuf Hamied Department of ChemistryUniversity of CambridgeCambridgeUK
| | - Rosana Collepardo‐Guevara
- Department of GeneticsUniversity of CambridgeCambridgeUK
- Cavendish LaboratoryDepartment of PhysicsUniversity of CambridgeJJ Thomson AvenueCambridgeUK
- Yusuf Hamied Department of ChemistryUniversity of CambridgeCambridgeUK
| | - Masashi Narita
- Cancer Research UK Cambridge InstituteLi Ka Shing CentreUniversity of CambridgeCambridgeUK
| | - Tuomas P. J. Knowles
- Centre for Misfolding DiseasesYusuf Hamied Department of ChemistryUniversity of CambridgeCambridgeUK
- Cavendish LaboratoryDepartment of PhysicsUniversity of CambridgeJJ Thomson AvenueCambridgeUK
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26
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Ginell GM, Holehouse AS. An Introduction to the Stickers-and-Spacers Framework as Applied to Biomolecular Condensates. Methods Mol Biol 2023; 2563:95-116. [PMID: 36227469 DOI: 10.1007/978-1-0716-2663-4_4] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Cellular organization is determined by a combination of membrane-bound and membrane-less biomolecular assemblies that range from clusters of tens of molecules to micrometer-sized cellular bodies. Over the last decade, membrane-less assemblies have come to be referred to as biomolecular condensates, reflecting their ability to condense specific molecules with respect to the remainder of the cell. In many cases, the physics of phase transitions provides a conceptual framework and a mathematical toolkit to describe the assembly, maintenance, and dissolution of biomolecular condensates. Among the various quantitative and qualitative models applied to understand intracellular phase transitions, the stickers-and-spacers framework offers an intuitive yet rigorous means to map biomolecular sequences and structure to the driving forces needed for higher-order assembly. This chapter introduces the fundamental concepts behind the stickers-and-spacers model, considers its application to different biological systems, and discusses limitations and misconceptions around the model.
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Affiliation(s)
- Garrett M Ginell
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, USA
- Center for Science & Engineering of Living Systems (CSELS), 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 Science & Engineering of Living Systems (CSELS), Washington University in St. Louis, St. Louis, MO, USA.
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27
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Latham AP, Zhang B. Molecular Determinants for the Layering and Coarsening of Biological Condensates. AGGREGATE (HOBOKEN, N.J.) 2022; 3:e306. [PMID: 37065433 PMCID: PMC10101022 DOI: 10.1002/agt2.306] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/18/2023]
Abstract
Many membraneless organelles, or biological condensates, form through phase separation, and play key roles in signal sensing and transcriptional regulation. While the functional importance of these condensates has inspired many studies to characterize their stability and spatial organization, the underlying principles that dictate these emergent properties are still being uncovered. In this review, we examine recent work on biological condensates, especially multicomponent systems. We focus on connecting molecular factors such as binding energy, valency, and stoichiometry with the interfacial tension, explaining the nontrivial interior organization in many condensates. We further discuss mechanisms that arrest condensate coalescence by lowering the surface tension or introducing kinetic barriers to stabilize the multidroplet state.
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Affiliation(s)
- Andrew P Latham
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, 02139
- Department of Bioengineering and Therapeutic Sciences, University of California at San Francisco, San Francisco, CA 94143
| | - Bin Zhang
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, 02139
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28
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MacPherson RA, Shankar V, Sunkara LT, Hannah RC, Campbell MR, Anholt RRH, Mackay TFC. Pleiotropic fitness effects of the lncRNA Uhg4 in Drosophila melanogaster. BMC Genomics 2022; 23:781. [PMID: 36451091 PMCID: PMC9710044 DOI: 10.1186/s12864-022-08972-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 10/26/2022] [Indexed: 12/05/2022] Open
Abstract
BACKGROUND Long noncoding RNAs (lncRNAs) are a diverse class of RNAs that are critical for gene regulation, DNA repair, and splicing, and have been implicated in development, stress response, and cancer. However, the functions of many lncRNAs remain unknown. In Drosophila melanogaster, U snoRNA host gene 4 (Uhg4) encodes an antisense long noncoding RNA that is host to seven small nucleolar RNAs (snoRNAs). Uhg4 is expressed ubiquitously during development and in all adult tissues, with maximal expression in ovaries; however, it has no annotated function(s). RESULTS We used CRISPR-Cas9 germline gene editing to generate multiple deletions spanning the promoter region and first exon of Uhg4. Females showed arrested egg development and both males and females were sterile. In addition, Uhg4 deletion mutants showed delayed development and decreased viability, and changes in sleep and responses to stress. Whole-genome RNA sequencing of Uhg4 deletion flies and their controls identified co-regulated genes and genetic interaction networks associated with Uhg4. Gene ontology analyses highlighted a broad spectrum of biological processes, including regulation of transcription and translation, morphogenesis, and stress response. CONCLUSION Uhg4 is a lncRNA essential for reproduction with pleiotropic effects on multiple fitness traits.
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Affiliation(s)
- Rebecca A MacPherson
- Center for Human Genetics and Department of Genetics and Biochemistry, Clemson University, 114 Gregor Mendel Circle, Greenwood, SC, 29646, USA
| | - Vijay Shankar
- Center for Human Genetics and Department of Genetics and Biochemistry, Clemson University, 114 Gregor Mendel Circle, Greenwood, SC, 29646, USA
| | - Lakshmi T Sunkara
- Present adress: Clemson Veterinary Diagnostic Center, Livestock Poultry Health, Clemson University, 500 Clemson Road, Columbia, SC, 29229, USA
| | - Rachel C Hannah
- Center for Human Genetics and Department of Genetics and Biochemistry, Clemson University, 114 Gregor Mendel Circle, Greenwood, SC, 29646, USA
| | - Marion R Campbell
- Center for Human Genetics and Department of Genetics and Biochemistry, Clemson University, 114 Gregor Mendel Circle, Greenwood, SC, 29646, USA
| | - Robert R H Anholt
- Center for Human Genetics and Department of Genetics and Biochemistry, Clemson University, 114 Gregor Mendel Circle, Greenwood, SC, 29646, USA.
| | - Trudy F C Mackay
- Center for Human Genetics and Department of Genetics and Biochemistry, Clemson University, 114 Gregor Mendel Circle, Greenwood, SC, 29646, USA.
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29
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Yuan Y, Padilla MA, Clark D, Yadlapalli S. Streamlined single-molecule RNA-FISH of core clock mRNAs in clock neurons in whole mount Drosophila brains. Front Physiol 2022; 13:1051544. [PMID: 36439243 PMCID: PMC9682093 DOI: 10.3389/fphys.2022.1051544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 10/17/2022] [Indexed: 11/10/2022] Open
Abstract
Circadian clocks are ∼24-h timekeepers that control rhythms in almost all aspects of our behavior and physiology. While it is well known that subcellular localization of core clock proteins plays a critical role in circadian regulation, very little is known about the spatiotemporal organization of core clock mRNAs and its role in generating ∼24-h circadian rhythms. Here we describe a streamlined single molecule Fluorescence In Situ Hybridization (smFISH) protocol and a fully automated analysis pipeline to precisely quantify the number and subcellular location of mRNAs of Clock, a core circadian transcription factor, in individual clock neurons in whole mount Drosophila adult brains. Specifically, we used ∼48 fluorescent oligonucleotide probes that can bind to an individual Clock mRNA molecule, which can then be detected as a diffraction-limited spot. Further, we developed a machine learning-based approach for 3-D cell segmentation, based on a pretrained encoder-decoder convolutional neural network, to automatically identify the cytoplasm and nuclei of clock neurons. We combined our segmentation model with a spot counting algorithm to detect Clock mRNA spots in individual clock neurons. Our results demonstrate that the number of Clock mRNA molecules cycle in large ventral lateral clock neurons (lLNvs) with peak levels at ZT4 (4 h after lights are turned on) with ∼80 molecules/neuron and trough levels at ZT16 with ∼30 molecules/neuron. Our streamlined smFISH protocol and deep learning-based analysis pipeline can be employed to quantify the number and subcellular location of any mRNA in individual clock neurons in Drosophila brains. Further, this method can open mechanistic and functional studies into how spatiotemporal localization of clock mRNAs affect circadian rhythms.
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Affiliation(s)
- Ye Yuan
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI, United States
- *Correspondence: Ye Yuan, ; Swathi Yadlapalli,
| | - Marc-Antonio Padilla
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, United States
| | - Dunham Clark
- Cell and Developmental Biology Department, University of Michigan, Ann Arbor, MI, United States
| | - Swathi Yadlapalli
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI, United States
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, United States
- Cell and Developmental Biology Department, University of Michigan, Ann Arbor, MI, United States
- *Correspondence: Ye Yuan, ; Swathi Yadlapalli,
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30
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Mitrea DM, Mittasch M, Gomes BF, Klein IA, Murcko MA. Modulating biomolecular condensates: a novel approach to drug discovery. Nat Rev Drug Discov 2022; 21:841-862. [PMID: 35974095 PMCID: PMC9380678 DOI: 10.1038/s41573-022-00505-4] [Citation(s) in RCA: 73] [Impact Index Per Article: 36.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/08/2022] [Indexed: 12/12/2022]
Abstract
In the past decade, membraneless assemblies known as biomolecular condensates have been reported to play key roles in many cellular functions by compartmentalizing specific proteins and nucleic acids in subcellular environments with distinct properties. Furthermore, growing evidence supports the view that biomolecular condensates often form by phase separation, in which a single-phase system demixes into a two-phase system consisting of a condensed phase and a dilute phase of particular biomolecules. Emerging understanding of condensate function in normal and aberrant cellular states, and of the mechanisms of condensate formation, is providing new insights into human disease and revealing novel therapeutic opportunities. In this Perspective, we propose that such insights could enable a previously unexplored drug discovery approach based on identifying condensate-modifying therapeutics (c-mods), and we discuss the strategies, techniques and challenges involved.
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31
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Ren J, Zhang Z, Zong Z, Zhang L, Zhou F. Emerging Implications of Phase Separation in Cancer. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2202855. [PMID: 36117111 PMCID: PMC9631093 DOI: 10.1002/advs.202202855] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Revised: 08/26/2022] [Indexed: 05/19/2023]
Abstract
In eukaryotic cells, biological activities are executed in distinct cellular compartments or organelles. Canonical organelles with membrane-bound structures are well understood. Cells also inherently contain versatile membrane-less organelles (MLOs) that feature liquid or gel-like bodies. A biophysical process termed liquid-liquid phase separation (LLPS) elucidates how MLOs form through dynamic biomolecule assembly. LLPS-related molecules often have multivalency, which is essential for low-affinity inter- or intra-molecule interactions to trigger phase separation. Accumulating evidence shows that LLPS concentrates and organizes desired molecules or segregates unneeded molecules in cells. Thus, MLOs have tunable functional specificity in response to environmental stimuli and metabolic processes. Aberrant LLPS is widely associated with several hallmarks of cancer, including sustained proliferative signaling, growth suppressor evasion, cell death resistance, telomere maintenance, DNA damage repair, etc. Insights into the molecular mechanisms of LLPS provide new insights into cancer therapeutics. Here, the current understanding of the emerging concepts of LLPS and its involvement in cancer are comprehensively reviewed.
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Affiliation(s)
- Jiang Ren
- School of MedicineZhejiang University City CollegeHangzhou215123China
- The Eighth Affiliated HospitalSun Yat‐sen UniversityShenzhen518033China
| | - Zhenyu Zhang
- Department of NeurosurgeryThe First Affiliated Hospital of Zhengzhou UniversityZhengzhouHenan450003China
| | - Zhi Zong
- MOE Key Laboratory of Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling NetworkLife Sciences InstituteZhejiang UniversityHangzhou310058China
| | - Long Zhang
- MOE Key Laboratory of Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling NetworkLife Sciences InstituteZhejiang UniversityHangzhou310058China
- International Biomed‐X Research Center, Second Affiliated Hospital of Zhejiang University School of MedicineZhejiang UniversityHangzhouChina
- Cancer CenterZhejiang UniversityHangzhou215123China
| | - Fangfang Zhou
- School of MedicineZhejiang University City CollegeHangzhou215123China
- Institutes of Biology and Medical SciencesSoochow UniversitySuzhou215123China
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32
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Lacroix E, Audas TE. Keeping up with the condensates: The retention, gain, and loss of nuclear membrane-less organelles. Front Mol Biosci 2022; 9:998363. [PMID: 36203874 PMCID: PMC9530788 DOI: 10.3389/fmolb.2022.998363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 08/19/2022] [Indexed: 12/04/2022] Open
Abstract
In recent decades, a growing number of biomolecular condensates have been identified in eukaryotic cells. These structures form through phase separation and have been linked to a diverse array of cellular processes. While a checklist of established membrane-bound organelles is present across the eukaryotic domain, less is known about the conservation of membrane-less subcellular structures. Many of these structures can be seen throughout eukaryotes, while others are only thought to be present in metazoans or a limited subset of species. In particular, the nucleus is a hub of biomolecular condensates. Some of these subnuclear domains have been found in a broad range of organisms, which is a characteristic often attributed to essential functionality. However, this does not always appear to be the case. For example, the nucleolus is critical for ribosomal biogenesis and is present throughout the eukaryotic domain, while the Cajal bodies are believed to be similarly conserved, yet these structures are dispensable for organismal survival. Likewise, depletion of the Drosophila melanogaster omega speckles reduces viability, despite the apparent absence of this domain in higher eukaryotes. By reviewing primary research that has analyzed the presence of specific condensates (nucleoli, Cajal bodies, amyloid bodies, nucleolar aggresomes, nuclear speckles, nuclear paraspeckles, nuclear stress bodies, PML bodies, omega speckles, NUN bodies, mei2 dots) in a cross-section of organisms (e.g., human, mouse, D. melanogaster, Caenorhabditis elegans, yeast), we adopt a human-centric view to explore the emergence, retention, and absence of a subset of nuclear biomolecular condensates. This overview is particularly important as numerous biomolecular condensates have been linked to human disease, and their presence in additional species could unlock new and well characterized model systems for health research.
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Affiliation(s)
- Emma Lacroix
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
- Centre for Cell Biology, Development, and Disease, Simon Fraser University, Burnaby, BC, Canada
| | - Timothy E. Audas
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
- Centre for Cell Biology, Development, and Disease, Simon Fraser University, Burnaby, BC, Canada
- *Correspondence: Timothy E. Audas,
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Lee B, Jaberi-Lashkari N, Calo E. A unified view of low complexity regions (LCRs) across species. eLife 2022; 11:e77058. [PMID: 36098382 PMCID: PMC9470157 DOI: 10.7554/elife.77058] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 08/17/2022] [Indexed: 11/13/2022] Open
Abstract
Low complexity regions (LCRs) play a role in a variety of important biological processes, yet we lack a unified view of their sequences, features, relationships, and functions. Here, we use dotplots and dimensionality reduction to systematically define LCR type/copy relationships and create a map of LCR sequence space capable of integrating LCR features and functions. By defining LCR relationships across the proteome, we provide insight into how LCR type and copy number contribute to higher order assemblies, such as the importance of K-rich LCR copy number for assembly of the nucleolar protein RPA43 in vivo and in vitro. With LCR maps, we reveal the underlying structure of LCR sequence space, and relate differential occupancy in this space to the conservation and emergence of higher order assemblies, including the metazoan extracellular matrix and plant cell wall. Together, LCR relationships and maps uncover and identify scaffold-client relationships among E-rich LCR-containing proteins in the nucleolus, and revealed previously undescribed regions of LCR sequence space with signatures of higher order assemblies, including a teleost-specific T/H-rich sequence space. Thus, this unified view of LCRs enables discovery of how LCRs encode higher order assemblies of organisms.
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Affiliation(s)
- Byron Lee
- Department of Biology, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Nima Jaberi-Lashkari
- Department of Biology, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Eliezer Calo
- Department of Biology, Massachusetts Institute of TechnologyCambridgeUnited States
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of TechnologyCambridgeUnited States
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34
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Zhu B. Logic of the Temporal Compartmentalization of the Hepatic Metabolic Cycle. Physiology (Bethesda) 2022; 37:0. [PMID: 35658626 PMCID: PMC9394779 DOI: 10.1152/physiol.00003.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 05/05/2022] [Accepted: 05/28/2022] [Indexed: 12/25/2022] Open
Abstract
The mammalian liver must cope with various metabolic and physiological changes that normally recur every day and result primarily from rest-activity and fasting-feeding cycles. In this article, I present evidence supporting a temporal compartmentalization of rhythmic hepatic metabolic processes into four main clusters: regulation of energy homeostasis, maintenance of information integrity, immune response, and genetic information flow. I further review literatures and discuss how both the circadian and the newly discovered 12-h ultradian clock work together to regulate these four temporally separated processes in mouse liver, which, interestingly, is largely uncoupled from the liver zonation regulation.
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Affiliation(s)
- Bokai Zhu
- Aging Institute of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
- Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
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35
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Gouveia B, Kim Y, Shaevitz JW, Petry S, Stone HA, Brangwynne CP. Capillary forces generated by biomolecular condensates. Nature 2022; 609:255-264. [PMID: 36071192 DOI: 10.1038/s41586-022-05138-6] [Citation(s) in RCA: 63] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Accepted: 07/25/2022] [Indexed: 12/21/2022]
Abstract
Liquid-liquid phase separation and related phase transitions have emerged as generic mechanisms in living cells for the formation of membraneless compartments or biomolecular condensates. The surface between two immiscible phases has an interfacial tension, generating capillary forces that can perform work on the surrounding environment. Here we present the physical principles of capillarity, including examples of how capillary forces structure multiphase condensates and remodel biological substrates. As with other mechanisms of intracellular force generation, for example, molecular motors, capillary forces can influence biological processes. Identifying the biomolecular determinants of condensate capillarity represents an exciting frontier, bridging soft matter physics and cell biology.
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Affiliation(s)
- Bernardo Gouveia
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, USA
| | - Yoonji Kim
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | | | - Sabine Petry
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | - Howard A Stone
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ, USA.
| | - Clifford P Brangwynne
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, USA. .,The Howard Hughes Medical Institute, Princeton, NJ, USA.
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36
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Bechara ST, Kabbani LES, Maurer-Alcalá XX, Nowacki M. Identification of novel, functional, long noncoding RNAs involved in programmed, large-scale genome rearrangements. RNA (NEW YORK, N.Y.) 2022; 28:1110-1127. [PMID: 35680167 PMCID: PMC9297840 DOI: 10.1261/rna.079134.122] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 05/26/2022] [Indexed: 06/15/2023]
Abstract
Noncoding RNAs (ncRNAs) make up to ∼98% percent of the transcriptome of a given organism. In recent years, one relatively new class of ncRNAs, long noncoding RNAs (lncRNAs), were shown to be more than mere by-products of gene expression and regulation. The unicellular eukaryote Paramecium tetraurelia is a member of the ciliate phylum, an extremely heterogeneous group of organisms found in most bodies of water across the globe. A hallmark of ciliate genetics is nuclear dimorphism and programmed elimination of transposons and transposon-derived DNA elements, the latter of which is essential for the maintenance of the somatic genome. Paramecium and ciliates in general harbor a plethora of different ncRNA species, some of which drive the process of large-scale genome rearrangements, including DNA elimination, during sexual development. Here, we identify and validate the first known functional lncRNAs in ciliates to date. Using deep-sequencing and subsequent bioinformatic processing and experimental validation, we show that Paramecium expresses at least 15 lncRNAs. These candidates were predicted by a highly conservative pipeline, and informatic analyses hint at differential expression during development. Depletion of two lncRNAs, lnc1 and lnc15, resulted in clear phenotypes, decreased survival, morphological impairment, and a global effect on DNA elimination.
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Affiliation(s)
- Sebastian T Bechara
- Institute of Cell Biology, University of Bern, Bern 3012, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern 3012, Switzerland
| | - Lyna E S Kabbani
- Institute of Cell Biology, University of Bern, Bern 3012, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern 3012, Switzerland
| | - Xyrus X Maurer-Alcalá
- Institute of Cell Biology, University of Bern, Bern 3012, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern 3012, Switzerland
| | - Mariusz Nowacki
- Institute of Cell Biology, University of Bern, Bern 3012, Switzerland
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37
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Xu Y, Zhu H, Denduluri A, Ou Y, Erkamp NA, Qi R, Shen Y, Knowles TPJ. Recent Advances in Microgels: From Biomolecules to Functionality. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2200180. [PMID: 35790106 DOI: 10.1002/smll.202200180] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 03/15/2022] [Indexed: 06/15/2023]
Abstract
The emerging applications of hydrogel materials at different length scales, in areas ranging from sustainability to health, have driven the progress in the design and manufacturing of microgels. Microgels can provide miniaturized, monodisperse, and regulatable compartments, which can be spatially separated or interconnected. These microscopic materials provide novel opportunities for generating biomimetic cell culture environments and are thus key to the advances of modern biomedical research. The evolution of the physical and chemical properties has, furthermore, highlighted the potentials of microgels in the context of materials science and bioengineering. This review describes the recent research progress in the fabrication, characterization, and applications of microgels generated from biomolecular building blocks. A key enabling technology allowing the tailoring of the properties of microgels is their synthesis through microfluidic technologies, and this paper highlights recent advances in these areas and their impact on expanding the physicochemical parameter space accessible using microgels. This review finally discusses the emerging roles that microgels play in liquid-liquid phase separation, micromechanics, biosensors, and regenerative medicine.
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Affiliation(s)
- Yufan Xu
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK
| | - Hongjia Zhu
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK
| | - Akhila Denduluri
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK
| | - Yangteng Ou
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK
| | - Nadia A Erkamp
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK
| | - Runzhang Qi
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK
| | - Yi Shen
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK
- School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, NSW, 2006, Australia
- The University of Sydney Nano Institute, University of Sydney, Sydney, NSW, 2006, Australia
| | - Tuomas P J Knowles
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK
- Cavendish Laboratory, University of Cambridge, Cambridge, CB3 0HE, UK
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38
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Abstract
Phase separation has emerged as an essential concept for the spatial organization inside biological cells. However, despite the clear relevance to virtually all physiological functions, we understand surprisingly little about what phases form in a system of many interacting components, like in cells. Here we introduce a numerical method based on physical relaxation dynamics to study the coexisting phases in such systems. We use our approach to optimize interactions between components, similar to how evolution might have optimized the interactions of proteins. These evolved interactions robustly lead to a defined number of phases, despite substantial uncertainties in the initial composition, while random or designed interactions perform much worse. Moreover, the optimized interactions are robust to perturbations, and they allow fast adaption to new target phase counts. We thus show that genetically encoded interactions of proteins provide versatile control of phase behavior. The phases forming in our system are also a concrete example of a robust emergent property that does not rely on fine-tuning the parameters of individual constituents.
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39
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The Association of MEG3 lncRNA with Nuclear Speckles in Living Cells. Cells 2022; 11:cells11121942. [PMID: 35741072 PMCID: PMC9221825 DOI: 10.3390/cells11121942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 06/12/2022] [Accepted: 06/13/2022] [Indexed: 02/04/2023] Open
Abstract
Nuclear speckles are nuclear bodies containing RNA-binding proteins as well as RNAs including long non-coding RNAs (lncRNAs). Maternally expressed gene 3 (MEG3) is a nuclear retained lncRNA found to associate with nuclear speckles. To understand the association dynamics of MEG3 lncRNA with nuclear speckles in living cells, we generated a fluorescently tagged MEG3 transcript that could be detected in real time. Under regular conditions, transient association of MEG3 with nuclear speckles was observed, including a nucleoplasmic fraction. Transcription or splicing inactivation conditions, known to affect nuclear speckle structure, showed prominent and increased association of MEG3 lncRNA with the nuclear speckles, specifically forming a ring-like structure around the nuclear speckles. This contrasted with metastasis-associated lung adenocarcinoma (MALAT1) lncRNA that is normally highly associated with nuclear speckles, which was released and dispersed in the nucleoplasm. Under normal conditions, MEG3 dynamically associated with the periphery of the nuclear speckles, but under transcription or splicing inhibition, MEG3 could also enter the center of the nuclear speckle. Altogether, using live-cell imaging approaches, we find that MEG3 lncRNA is a transient resident of nuclear speckles and that its association with this nuclear body is modulated by the levels of transcription and splicing activities in the cell.
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40
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Lee DSW, Strom AR, Brangwynne CP. The mechanobiology of nuclear phase separation. APL Bioeng 2022; 6:021503. [PMID: 35540725 PMCID: PMC9054271 DOI: 10.1063/5.0083286] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 04/19/2022] [Indexed: 02/06/2023] Open
Abstract
The cell nucleus can be thought of as a complex, dynamic, living material, which functions to organize and protect the genome and coordinate gene expression. These functions are achieved via intricate mechanical and biochemical interactions among its myriad components, including the nuclear lamina, nuclear bodies, and the chromatin itself. While the biophysical organization of the nuclear lamina and chromatin have been thoroughly studied, the concept that liquid–liquid phase separation and related phase transitions play a role in establishing nuclear structure has emerged only recently. Phase transitions are likely to be intimately coupled to the mechanobiology of structural elements in the nucleus, but their interplay with one another is still not understood. Here, we review recent developments on the role of phase separation and mechanics in nuclear organization and discuss the functional implications in cell physiology and disease states.
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Affiliation(s)
- Daniel S. W. Lee
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey 08544, USA
| | - Amy R. Strom
- Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, USA
| | - Clifford P. Brangwynne
- Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, USA
- Princeton Institute for the Science and Technology of Materials, Princeton University, Princeton, New Jersey 08544, USA
- Howard Hughes Medical Institute, Princeton University, Princeton, New Jersey 08544, USA
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41
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Mazarakos K, Zhou HX. Multiphase Organization Is a Second Phase Transition Within Multi-Component Biomolecular Condensates. J Chem Phys 2022; 156:191104. [DOI: 10.1063/5.0088004] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present a mean-field theoretical model, along with molecular dynamics simulations, to show that the multiphase organization of multi-component condensates is a second phase transition. Whereas the first phase transition that leads to the separation of condensates from the bulk phase is driven by overall attraction among the macromolecular components, the second phase transition can be driven by the disparity in strength between self and cross-species attraction. At a fixed level of disparity in interaction strengths, both of the phase transitions can be observed by decreasing temperature, leading first to the separation of condensates from the bulk phase and then to component demixing inside condensates. The existence of a critical temperature for demixing and predicted binodals are verified by molecular dynamics simulations of model mixtures.
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Affiliation(s)
| | - Huan-Xiang Zhou
- Department of Chemistry and Department of Physics, University of Illinois at Chicago, United States of America
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42
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Bencivenga D, Stampone E, Vastante A, Barahmeh M, Della Ragione F, Borriello A. An Unanticipated Modulation of Cyclin-Dependent Kinase Inhibitors: The Role of Long Non-Coding RNAs. Cells 2022; 11:cells11081346. [PMID: 35456025 PMCID: PMC9028986 DOI: 10.3390/cells11081346] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Revised: 04/08/2022] [Accepted: 04/11/2022] [Indexed: 12/13/2022] Open
Abstract
It is now definitively established that a large part of the human genome is transcribed. However, only a scarce percentage of the transcriptome (about 1.2%) consists of RNAs that are translated into proteins, while the large majority of transcripts include a variety of RNA families with different dimensions and functions. Within this heterogeneous RNA world, a significant fraction consists of sequences with a length of more than 200 bases that form the so-called long non-coding RNA family. The functions of long non-coding RNAs range from the regulation of gene transcription to the changes in DNA topology and nucleosome modification and structural organization, to paraspeckle formation and cellular organelles maturation. This review is focused on the role of long non-coding RNAs as regulators of cyclin-dependent kinase inhibitors’ (CDKIs) levels and activities. Cyclin-dependent kinases are enzymes necessary for the tuned progression of the cell division cycle. The control of their activity takes place at various levels. Among these, interaction with CDKIs is a vital mechanism. Through CDKI modulation, long non-coding RNAs implement control over cellular physiology and are associated with numerous pathologies. However, although there are robust data in the literature, the role of long non-coding RNAs in the modulation of CDKIs appears to still be underestimated, as well as their importance in cell proliferation control.
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43
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Decker CJ, Burke JM, Mulvaney PK, Parker R. RNA is required for the integrity of multiple nuclear and cytoplasmic membrane-less RNP granules. EMBO J 2022; 41:e110137. [PMID: 35355287 PMCID: PMC9058542 DOI: 10.15252/embj.2021110137] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Revised: 03/03/2022] [Accepted: 03/14/2022] [Indexed: 12/22/2022] Open
Abstract
Numerous membrane‐less organelles, composed of a combination of RNA and proteins, are observed in the nucleus and cytoplasm of eukaryotic cells. These RNP granules include stress granules (SGs), processing bodies (PBs), Cajal bodies, and nuclear speckles. An unresolved question is how frequently RNA molecules are required for the integrity of RNP granules in either the nucleus or cytosol. To address this issue, we degraded intracellular RNA in either the cytosol or the nucleus by the activation of RNase L and examined the impact of RNA loss on several RNP granules. We find the majority of RNP granules, including SGs, Cajal bodies, nuclear speckles, and the nucleolus, are altered by the degradation of their RNA components. In contrast, PBs and super‐enhancer complexes were largely not affected by RNA degradation in their respective compartments. RNA degradation overall led to the apparent dissolution of some membrane‐less organelles, whereas others reorganized into structures with altered morphology. These findings highlight a critical and widespread role of RNA in the organization of several RNP granules.
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Affiliation(s)
- Carolyn J Decker
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA.,Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, CO, USA
| | - James M Burke
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA
| | - Patrick K Mulvaney
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA
| | - Roy Parker
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA.,Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, CO, USA.,BioFrontiers Institute, University of Colorado Boulder, Boulder, CO, USA
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44
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Dion W, Ballance H, Lee J, Pan Y, Irfan S, Edwards C, Sun M, Zhang J, Zhang X, Liu S, Zhu B. Four-dimensional nuclear speckle phase separation dynamics regulate proteostasis. SCIENCE ADVANCES 2022; 8:eabl4150. [PMID: 34985945 PMCID: PMC8730402 DOI: 10.1126/sciadv.abl4150] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 11/15/2021] [Indexed: 05/15/2023]
Abstract
Phase separation and biorhythms control biological processes in the spatial and temporal dimensions, respectively, but mechanisms of four-dimensional integration remain elusive. Here, we identified an evolutionarily conserved XBP1s-SON axis that establishes a cell-autonomous mammalian 12-hour ultradian rhythm of nuclear speckle liquid-liquid phase separation (LLPS) dynamics, separate from both the 24-hour circadian clock and the cell cycle. Higher expression of nuclear speckle scaffolding protein SON, observed at early morning/early afternoon, generates diffuse and fluid nuclear speckles, increases their interactions with chromatin proactively, transcriptionally amplifies the unfolded protein response, and protects against proteome stress, whereas the opposites are observed following reduced SON level at early evening/late morning. Correlative Son and proteostasis gene expression dynamics are further observed across the entire mouse life span. Our results suggest that by modulating the temporal dynamics of proteostasis, the nuclear speckle LLPS may represent a previously unidentified (chrono)-therapeutic target for pathologies associated with dysregulated proteostasis.
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Affiliation(s)
- William Dion
- Aging Institute of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Heather Ballance
- Aging Institute of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Jane Lee
- Aging Institute of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | | | - Saad Irfan
- Aging Institute of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Casey Edwards
- Aging Institute of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Michelle Sun
- Aging Institute of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Jing Zhang
- Aging Institute of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Xin Zhang
- Department of Chemistry, The Pennsylvania State University, University Park, PA, USA
| | - Silvia Liu
- Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Bokai Zhu
- Aging Institute of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, PA, USA
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh
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45
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Zhao M, Xia T, Xing J, Yin L, Li X, Pan J, Liu J, Sun L, Wang M, Li T, Mao J, Han Q, Xue W, Cai H, Wang K, Xu X, Li T, He K, Wang N, Li A, Zhou T, Zhang X, Li W, Li T. The stress granule protein G3BP1 promotes pre-condensation of cGAS to allow rapid responses to DNA. EMBO Rep 2022; 23:e53166. [PMID: 34779554 PMCID: PMC8728604 DOI: 10.15252/embr.202153166] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 10/11/2021] [Accepted: 10/15/2021] [Indexed: 01/07/2023] Open
Abstract
Cyclic GMP-AMP synthase (cGAS) functions as a key sensor for microbial invasion and cellular damage by detecting emerging cytosolic DNA. Here, we report that GTPase-activating protein-(SH3 domain)-binding protein 1 (G3BP1) primes cGAS for its prompt activation by engaging cGAS in a primary liquid-phase condensation state. Using high-resolution microscopy, we show that in resting cells, cGAS exhibits particle-like morphological characteristics, which are markedly weakened when G3BP1 is deleted. Upon DNA challenge, the pre-condensed cGAS undergoes liquid-liquid phase separation (LLPS) more efficiently. Importantly, G3BP1 deficiency or its inhibition dramatically diminishes DNA-induced LLPS and the subsequent activation of cGAS. Interestingly, RNA, previously reported to form condensates with cGAS, does not activate cGAS. Accordingly, we find that DNA - but not RNA - treatment leads to the dissociation of G3BP1 from cGAS. Taken together, our study shows that the primary condensation state of cGAS is critical for its rapid response to DNA.
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Affiliation(s)
- Ming Zhao
- State Key Laboratory of ProteomicsNational Center of Biomedical AnalysisBeijingChina
| | - Tian Xia
- State Key Laboratory of ProteomicsNational Center of Biomedical AnalysisBeijingChina
| | - Jia‐Qing Xing
- State Key Laboratory of ProteomicsNational Center of Biomedical AnalysisBeijingChina
| | - Le‐Hua Yin
- State Key Laboratory of ProteomicsNational Center of Biomedical AnalysisBeijingChina
| | - Xiao‐Wei Li
- State Key Laboratory of ProteomicsNational Center of Biomedical AnalysisBeijingChina
| | - Jie Pan
- State Key Laboratory of ProteomicsNational Center of Biomedical AnalysisBeijingChina
| | - Jia‐Yu Liu
- State Key Laboratory of ProteomicsNational Center of Biomedical AnalysisBeijingChina
| | - Li‐Ming Sun
- State Key Laboratory of ProteomicsNational Center of Biomedical AnalysisBeijingChina
| | - Miao Wang
- State Key Laboratory of ProteomicsNational Center of Biomedical AnalysisBeijingChina
| | - Tingting Li
- State Key Laboratory of ProteomicsNational Center of Biomedical AnalysisBeijingChina
- Nanhu LaboratoryJiaxingChina
| | - Jie Mao
- State Key Laboratory of ProteomicsNational Center of Biomedical AnalysisBeijingChina
| | - Qiu‐Ying Han
- State Key Laboratory of ProteomicsNational Center of Biomedical AnalysisBeijingChina
- Nanhu LaboratoryJiaxingChina
| | - Wen Xue
- State Key Laboratory of ProteomicsNational Center of Biomedical AnalysisBeijingChina
- Nanhu LaboratoryJiaxingChina
| | - Hong Cai
- State Key Laboratory of ProteomicsNational Center of Biomedical AnalysisBeijingChina
| | - Kai Wang
- State Key Laboratory of ProteomicsNational Center of Biomedical AnalysisBeijingChina
| | - Xin Xu
- State Key Laboratory of ProteomicsNational Center of Biomedical AnalysisBeijingChina
| | - Teng Li
- State Key Laboratory of ProteomicsNational Center of Biomedical AnalysisBeijingChina
| | - Kun He
- State Key Laboratory of ProteomicsNational Center of Biomedical AnalysisBeijingChina
| | - Na Wang
- State Key Laboratory of ProteomicsNational Center of Biomedical AnalysisBeijingChina
| | - Ai‐Ling Li
- State Key Laboratory of ProteomicsNational Center of Biomedical AnalysisBeijingChina
- Nanhu LaboratoryJiaxingChina
| | - Tao Zhou
- State Key Laboratory of ProteomicsNational Center of Biomedical AnalysisBeijingChina
- Nanhu LaboratoryJiaxingChina
| | - Xue‐Min Zhang
- State Key Laboratory of ProteomicsNational Center of Biomedical AnalysisBeijingChina
- Nanhu LaboratoryJiaxingChina
- School of Basic Medical SciencesFudan UniversityShanghaiChina
| | - Wei‐Hua Li
- State Key Laboratory of ProteomicsNational Center of Biomedical AnalysisBeijingChina
| | - Tao Li
- State Key Laboratory of ProteomicsNational Center of Biomedical AnalysisBeijingChina
- Nanhu LaboratoryJiaxingChina
- School of Basic Medical SciencesFudan UniversityShanghaiChina
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46
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Zhang D, Xue J, Peng F. The regulatory activities of MALAT1 in the development of bone and cartilage diseases. Front Endocrinol (Lausanne) 2022; 13:1054827. [PMID: 36452326 PMCID: PMC9701821 DOI: 10.3389/fendo.2022.1054827] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 11/01/2022] [Indexed: 11/15/2022] Open
Abstract
Long non-coding RNAs (lncRNAs) have been comprehensively implicated in various cellular functions by mediating transcriptional or post-transcriptional activities. MALAT1 is involved in the differentiation, proliferation, and apoptosis of multiple cell lines, including BMSCs, osteoblasts, osteoclasts, and chondrocytes. Interestingly, MALAT1 may interact with RNAs or proteins, regulating cellular processes. Recently, MALAT1 has been reported to be associated with the development of bone and cartilage diseases by orchestrating the signaling network. The involvement of MALAT1 in the pathological development of bone and cartilage diseases makes it available to be a potential biomarker for clinical diagnosis or prognosis. Although the potential mechanisms of MALAT1 in mediating the cellular processes of bone and cartilage diseases are still needed for further elucidation, MALAT1 shows great promise for drug development.
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Affiliation(s)
- Di Zhang
- Department of Medical Imaging, First Affiliated Hospital of Gannan Medical University, Ganzhou, China
| | - Jinhua Xue
- School of Basic Medicine, Gannan Medical University, Ganzhou, China
| | - Fang Peng
- Department of Pathology, Ganzhou People’s Hospital, Ganzhou, China
- *Correspondence: Fang Peng,
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47
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Measuring Cytological Proximity of Chromosomal Loci to Defined Nuclear Compartments with TSA-seq. Methods Mol Biol 2022; 2532:145-186. [PMID: 35867249 DOI: 10.1007/978-1-0716-2497-5_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Distinct nuclear structures and bodies are involved in genome intranuclear positioning. Measuring proximity and relative distances of genomic loci to these nuclear compartments, and correlating this chromosome intranuclear positioning with epigenetic marks and functional readouts genome-wide, will be required to appreciate the true extent to which this nuclear compartmentalization contributes to regulation of genome functions. Here we present detailed protocols for TSA-seq, the first sequencing-based method for estimation of cytological proximity of chromosomal loci to spatially discrete nuclear structures, such as nuclear bodies or the nuclear lamina. TSA-seq uses Tyramide Signal Amplification (TSA) of immunostained cells to create a concentration gradient of tyramide-biotin free radicals which decays exponentially as a function of distance from a point-source target. Reaction of these free radicals with DNA deposits tyramide-biotin onto DNA as a function of distance from the point source. The relative enrichment of this tyramide-labeled DNA versus input DNA, revealed by DNA sequencing, can then be used as a "cytological ruler" to infer relative, or even absolute, mean chromosomal distances from immunostained nuclear compartments. TSA-seq mapping is highly reproducible and largely independent of the target protein or antibody choice for labeling a particular nuclear compartment. Our protocols include variations in TSA labeling conditions to provide varying spatial resolution as well as enhanced sensitivity. Our most streamlined protocol produces TSA-seq spatial mapping over a distance range of ~1 micron from major nuclear compartments using ~10-20 million cells.
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48
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Gao Y, Liu C, Wu T, Liu R, Mao W, Gan X, Lu X, Liu Y, Wan L, Xu B, Chen M. Current status and perspectives of non-coding RNA and phase separation interactions. Biosci Trends 2022; 16:330-345. [DOI: 10.5582/bst.2022.01304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Yue Gao
- Surgical Research Center, Institute of Urology, Medical School of Southeast University, Nanjing, Jiangsu, China
| | - Chunhui Liu
- Department of Urology, Affiliated Zhongda Hospital of Southeast University, Nanjing, Jiangsu, China
| | - Tiange Wu
- Surgical Research Center, Institute of Urology, Medical School of Southeast University, Nanjing, Jiangsu, China
| | - Ruiji Liu
- Surgical Research Center, Institute of Urology, Medical School of Southeast University, Nanjing, Jiangsu, China
| | - Weipu Mao
- Surgical Research Center, Institute of Urology, Medical School of Southeast University, Nanjing, Jiangsu, China
| | - Xinqiang Gan
- Surgical Research Center, Institute of Urology, Medical School of Southeast University, Nanjing, Jiangsu, China
| | - Xun Lu
- Surgical Research Center, Institute of Urology, Medical School of Southeast University, Nanjing, Jiangsu, China
| | - Yifan Liu
- Surgical Research Center, Institute of Urology, Medical School of Southeast University, Nanjing, Jiangsu, China
| | - Lilin Wan
- Surgical Research Center, Institute of Urology, Medical School of Southeast University, Nanjing, Jiangsu, China
| | - Bin Xu
- Department of Urology, Affiliated Zhongda Hospital of Southeast University, Nanjing, Jiangsu, China
| | - Ming Chen
- Department of Urology, Affiliated Zhongda Hospital of Southeast University, Nanjing, Jiangsu, China
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49
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Kelley FM, Favetta B, Regy RM, Mittal J, Schuster BS. Amphiphilic proteins coassemble into multiphasic condensates and act as biomolecular surfactants. Proc Natl Acad Sci U S A 2021; 118:e2109967118. [PMID: 34916288 PMCID: PMC8713756 DOI: 10.1073/pnas.2109967118] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/03/2021] [Indexed: 12/14/2022] Open
Abstract
Cells contain membraneless compartments that assemble due to liquid-liquid phase separation, including biomolecular condensates with complex morphologies. For instance, certain condensates are surrounded by a film of distinct composition, such as Ape1 condensates coated by a layer of Atg19, required for selective autophagy in yeast. Other condensates are multiphasic, with nested liquid phases of distinct compositions and functions, such as in the case of ribosome biogenesis in the nucleolus. The size and structure of such condensates must be regulated for proper biological function. We leveraged a bioinspired approach to discover how amphiphilic, surfactant-like proteins may contribute to the structure and size regulation of biomolecular condensates. We designed and examined families of amphiphilic proteins comprising one phase-separating domain and one non-phase-separating domain. In particular, these proteins contain the soluble structured domain glutathione S-transferase (GST) or maltose binding protein (MBP), fused to the intrinsically disordered RGG domain from P granule protein LAF-1. When one amphiphilic protein is mixed in vitro with RGG-RGG, the proteins assemble into enveloped condensates, with RGG-RGG at the core and the amphiphilic protein forming the surface film layer. Importantly, we found that MBP-based amphiphiles are surfactants and influence droplet size, with increasing surfactant concentration resulting in smaller droplet radii. In contrast, GST-based amphiphiles at increased concentrations coassemble with RGG-RGG into multiphasic structures. We propose a mechanism for these experimental observations, supported by molecular simulations of a minimalist model. We speculate that surfactant proteins may play a significant role in regulating the structure and function of biomolecular condensates.
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Affiliation(s)
- Fleurie M Kelley
- Department of Chemical and Biochemical Engineering, Rutgers, the State University of New Jersey, Piscataway, NJ 08854
| | - Bruna Favetta
- Department of Biomedical Engineering, Rutgers, the State University of New Jersey, Piscataway, NJ 08854
| | - Roshan Mammen Regy
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX 77843
| | - Jeetain Mittal
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX 77843
| | - Benjamin S Schuster
- Department of Chemical and Biochemical Engineering, Rutgers, the State University of New Jersey, Piscataway, NJ 08854;
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50
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Naz F, Tariq I, Ali S, Somaida A, Preis E, Bakowsky U. The Role of Long Non-Coding RNAs (lncRNAs) in Female Oriented Cancers. Cancers (Basel) 2021; 13:6102. [PMID: 34885213 PMCID: PMC8656502 DOI: 10.3390/cancers13236102] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 11/14/2021] [Accepted: 11/30/2021] [Indexed: 12/15/2022] Open
Abstract
Recent advances in molecular biology have discovered the mysterious role of long non-coding RNAs (lncRNAs) as potential biomarkers for cancer diagnosis and targets for advanced cancer therapy. Studies have shown that lncRNAs take part in the incidence and development of cancers in humans. However, previously they were considered as mere RNA noise or transcription byproducts lacking any biological function. In this article, we present a summary of the progress on ascertaining the biological functions of five lncRNAs (HOTAIR, NEAT1, H19, MALAT1, and MEG3) in female-oriented cancers, including breast and gynecological cancers, with the perspective of carcinogenesis, cancer proliferation, and metastasis. We provide the current state of knowledge from the past five years of the literature to discuss the clinical importance of such lncRNAs as therapeutic targets or early diagnostic biomarkers. We reviewed the consequences, either oncogenic or tumor-suppressing features, of their aberrant expression in female-oriented cancers. We tried to explain the established mechanism by which they regulate cancer proliferation and metastasis by competing with miRNAs and other mechanisms involved via regulating genes and signaling pathways. In addition, we revealed the association between stated lncRNAs and chemo-resistance or radio-resistance and their potential clinical applications and future perspectives.
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Affiliation(s)
- Faiza Naz
- Punjab University College of Pharmacy, Allama Iqbal Campus, University of the Punjab, Lahore 54000, Pakistan;
| | - Imran Tariq
- Punjab University College of Pharmacy, Allama Iqbal Campus, University of the Punjab, Lahore 54000, Pakistan;
- Department of Pharmaceutics and Biopharmaceutics, University of Marburg, Robert-Koch-Str. 4, 35037 Marburg, Germany or (S.A.); (A.S.); (E.P.)
| | - Sajid Ali
- Department of Pharmaceutics and Biopharmaceutics, University of Marburg, Robert-Koch-Str. 4, 35037 Marburg, Germany or (S.A.); (A.S.); (E.P.)
- Angström Laboratory, Department of Chemistry, Uppsala University, 75123 Uppsala, Sweden
| | - Ahmed Somaida
- Department of Pharmaceutics and Biopharmaceutics, University of Marburg, Robert-Koch-Str. 4, 35037 Marburg, Germany or (S.A.); (A.S.); (E.P.)
| | - Eduard Preis
- Department of Pharmaceutics and Biopharmaceutics, University of Marburg, Robert-Koch-Str. 4, 35037 Marburg, Germany or (S.A.); (A.S.); (E.P.)
| | - Udo Bakowsky
- Department of Pharmaceutics and Biopharmaceutics, University of Marburg, Robert-Koch-Str. 4, 35037 Marburg, Germany or (S.A.); (A.S.); (E.P.)
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