101
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Chen Q, Zeng Y, Kang J, Hu M, Li N, Sun K, Zhao Y. Enhancer RNAs in transcriptional regulation: recent insights. Front Cell Dev Biol 2023; 11:1205540. [PMID: 37266452 PMCID: PMC10229774 DOI: 10.3389/fcell.2023.1205540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 05/09/2023] [Indexed: 06/03/2023] Open
Abstract
Enhancers are a class of cis-regulatory elements in the genome that instruct the spatiotemporal transcriptional program. Last decade has witnessed an exploration of non-coding transcripts pervasively transcribed from active enhancers in diverse contexts, referred to as enhancer RNAs (eRNAs). Emerging evidence unequivocally suggests eRNAs are an important layer in transcriptional regulation. In this mini-review, we summarize the well-established regulatory models for eRNA actions and highlight the recent insights into the structure and chemical modifications of eRNAs underlying their functions. We also explore the potential roles of eRNAs in transcriptional condensates.
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Affiliation(s)
- Qi Chen
- The Eighth Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
| | - Yaxin Zeng
- Molecular Cancer Research Center, School of Medicine, Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
| | - Jinjin Kang
- Molecular Cancer Research Center, School of Medicine, Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
| | - Minghui Hu
- Molecular Cancer Research Center, School of Medicine, Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
| | - Nianle Li
- Molecular Cancer Research Center, School of Medicine, Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
| | - Kun Sun
- Institute of Cancer Research, Shenzhen Bay Laboratory, Shenzhen, China
| | - Yu Zhao
- Molecular Cancer Research Center, School of Medicine, Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
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102
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Yoshida SR, Maity BK, Chong S. Visualizing Protein Localizations in Fixed Cells: Caveats and the Underlying Mechanisms. J Phys Chem B 2023; 127:4165-4173. [PMID: 37161904 DOI: 10.1021/acs.jpcb.3c01658] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Fluorescence microscopy techniques have been widely adopted in biology for their ability to visualize the structure and dynamics of a wide range of cellular and subcellular processes. The specificity and sensitivity that these techniques afford have made them primary tools in the characterization of protein localizations within cells. Many of the fluorescence microscopy techniques require cells to be fixed via chemical or alternative methods before being imaged. However, some fixation methods have been found to induce the redistribution of particular proteins in the cell, resulting in artifacts in the characterization of protein localizations and functions under physiological conditions. Here, we review the ability of commonly used cell fixation methods to faithfully preserve the localizations of proteins that bind to chromatin, undergo liquid-liquid phase separation (LLPS), and are involved in the formation of various membrane-bound organelles. We also review the mechanisms underlying various fixation artifacts and discuss potential alternative fixation methods to minimize the artifacts while investigating different proteins and cellular structures. Overall, fixed-cell fluorescence microscopy is a very powerful tool in biomedical research; however, each experiment demands the careful selection of an appropriate fixation method to avoid potential artifacts and may benefit from live-cell imaging validation.
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Affiliation(s)
- Shawn R Yoshida
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Barun K Maity
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Shasha Chong
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
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103
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Shi Y, Liao Y, Liu Q, Ni Z, Zhang Z, Shi M, Li P, Li H, Rao Y. BRD4-targeting PROTAC as a unique tool to study biomolecular condensates. Cell Discov 2023; 9:47. [PMID: 37156794 PMCID: PMC10167318 DOI: 10.1038/s41421-023-00544-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 03/14/2023] [Indexed: 05/10/2023] Open
Abstract
Biomolecular condensates play key roles in various biological processes. However, specific condensation modulators are currently lacking. PROTAC is a new technology that can use small molecules to degrade target proteins specifically. PROTAC molecules are expected to regulate biomolecular condensates dynamically by degrading/recovering key molecules in biomolecular condensates. In this study, we employed a BRD4-targeting PROTAC molecule to regulate the super-enhancer (SE) condensate and monitored the changes of SE condensate under PROTAC treatment using live-cell imaging and high-throughput sequencing technologies. As a result, we found that BRD4-targeting PROTACs can significantly reduce the BRD4 condensates, and we established a quantitative method for tracking BRD4 condensates by PROTAC and cellular imaging. Surprisingly and encouragingly, BRD4 condensates were observed to preferentially form and play specialized roles in biological process regulation for the first time. Additionally, BRD4 PROTAC makes it possible to observe the dynamics of other condensate components under the continued disruption of BRD4 condensates. Together, these results shed new light on research methods for liquid-liquid phase separation (LLPS), and specifically demonstrate that PROTAC presents a powerful and distinctive tool for the study of biomolecular condensates.
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Affiliation(s)
- Yi Shi
- MOE Key Laboratory of Protein Sciences, School of Pharmaceutical Sciences, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing, China
- Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing, China
| | - Yuan Liao
- Ministry of Education Key Laboratory of Protein Sciences, Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing, China
- Peking University-Tsinghua University-National Institute of Biological Sciences Joint Graduate Program, Beijing, China
| | - Qianlong Liu
- MOE Key Laboratory of Protein Sciences, School of Pharmaceutical Sciences, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing, China
- Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing, China
| | - Zhihao Ni
- MOE Key Laboratory of Protein Sciences, School of Pharmaceutical Sciences, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing, China
| | - Zhenzhen Zhang
- Ministry of Education Key Laboratory of Protein Sciences, Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing, China
| | - Minglei Shi
- MOE Key Laboratory of Bioinformatics, Bioinformatics Division and Center for Synthetic & Systems Biology, BNRist, School of Medicine, Tsinghua University, Beijing, China
| | - Pilong Li
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China.
| | - Haitao Li
- Ministry of Education Key Laboratory of Protein Sciences, Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing, China.
| | - Yu Rao
- MOE Key Laboratory of Protein Sciences, School of Pharmaceutical Sciences, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing, China.
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104
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Dall'Agnese G, Dall'Agnese A, Banani SF, Codrich M, Malfatti MC, Antoniali G, Tell G. Role of condensates in modulating DNA repair pathways and its implication for chemoresistance. J Biol Chem 2023:104800. [PMID: 37164156 DOI: 10.1016/j.jbc.2023.104800] [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: 11/22/2022] [Revised: 05/03/2023] [Accepted: 05/04/2023] [Indexed: 05/12/2023] Open
Abstract
For cells, it is important to repair DNA damage, such as double strand and single strand DNA breaks, because unrepaired DNA can compromise genetic integrity, potentially leading to cell death or cancer. Cells have multiple DNA damage repair pathways that have been the subject of detailed genetic, biochemical, and structural studies. Recently, the scientific community has started to gain evidence that the repair of DNA double strand breaks may occur within biomolecular condensates and that condensates may also contribute to DNA damage through concentrating genotoxic agents used to treat various cancers. Here, we summarize key features of biomolecular condensates and note where they have been implicated in the repair of DNA double strand breaks. We also describe evidence suggesting that condensates may be involved in the repair of other types of DNA damage, including single strand DNA breaks, nucleotide modifications (e.g., mismatch and oxidized bases) and bulky lesions, among others. Finally, we discuss old and new mysteries that could now be addressed considering the properties of condensates, including chemoresistance mechanisms.
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Affiliation(s)
- Giuseppe Dall'Agnese
- Laboratory of Molecular Biology and DNA repair, Department of Medicine, University of Udine, 33100 Udine, Italy; Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA
| | | | - Salman F Banani
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA; Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Marta Codrich
- Laboratory of Molecular Biology and DNA repair, Department of Medicine, University of Udine, 33100 Udine, Italy
| | - Matilde Clarissa Malfatti
- Laboratory of Molecular Biology and DNA repair, Department of Medicine, University of Udine, 33100 Udine, Italy
| | - Giulia Antoniali
- Laboratory of Molecular Biology and DNA repair, Department of Medicine, University of Udine, 33100 Udine, Italy
| | - Gianluca Tell
- Laboratory of Molecular Biology and DNA repair, Department of Medicine, University of Udine, 33100 Udine, Italy.
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105
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Pappu R, Farag M, Borcherds W, Bremer A, Mittag T. Phase Separation in Mixtures of Prion-Like Low Complexity Domains is Driven by the Interplay of Homotypic and Heterotypic Interactions. RESEARCH SQUARE 2023:rs.3.rs-2870258. [PMID: 37205474 PMCID: PMC10187436 DOI: 10.21203/rs.3.rs-2870258/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Prion-like low-complexity domains (PLCDs) are involved in the formation and regulation of distinct biomolecular condensates that form via coupled associative and segregative phase transitions. We previously deciphered how evolutionarily conserved sequence features drive phase separation of PLCDs through homotypic interactions. However, condensates typically encompass a diverse mixture of proteins with PLCDs. Here, we combine simulations and experiments to study mixtures of PLCDs from two RNA binding proteins namely, hnRNPA1 and FUS. We find that 1:1 mixtures of the A1-LCD and FUS-LCD undergo phase separation more readily than either of the PLCDs on their own. The enhanced driving forces for phase separation of mixtures of A1-LCD and FUS-LCD arise partly from complementary electrostatic interactions between the two proteins. This complex coacervation-like mechanism adds to complementary interactions among aromatic residues. Further, tie line analysis shows that stoichiometric ratios of different components and their sequence-encoded interactions jointly contribute to the driving forces for condensate formation. These results highlight how expression levels might be tuned to regulate the driving forces for condensate formation in vivo . Simulations also show that the organization of PLCDs within condensates deviates from expectations based on random mixture models. Instead, spatial organization within condensates will reflect the relative strengths of homotypic versus heterotypic interactions. We also uncover rules for how interaction strengths and sequence lengths modulate conformational preferences of molecules at interfaces of condensates formed by mixtures of proteins. Overall, our findings emphasize the network-like organization of molecules within multicomponent condensates, and the distinctive, composition-specific conformational features of condensate interfaces.
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106
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Salataj E, Spilianakis CG, Chaumeil J. Single-cell detection of primary transcripts, their genomic loci and nuclear factors by 3D immuno-RNA/DNA FISH in T cells. Front Immunol 2023; 14:1156077. [PMID: 37215121 PMCID: PMC10193148 DOI: 10.3389/fimmu.2023.1156077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 04/12/2023] [Indexed: 05/24/2023] Open
Abstract
Over the past decades, it has become increasingly clear that higher order chromatin folding and organization within the nucleus is involved in the regulation of genome activity and serves as an additional epigenetic mechanism that modulates cellular functions and gene expression programs in diverse biological processes. In particular, dynamic allelic interactions and nuclear locations can be of functional importance during the process of lymphoid differentiation and the regulation of immune responses. Analyses of the proximity between chromatin and/or nuclear regions can be performed on populations of cells with high-throughput sequencing approaches such as chromatin conformation capture ("3C"-based) or DNA adenine methyltransferase identification (DamID) methods, or, in individual cells, by the simultaneous visualization of genomic loci, their primary transcripts and nuclear compartments within the 3-dimensional nuclear space using Fluorescence In Situ Hybridization (FISH) and immunostaining. Here, we present a detailed protocol to simultaneously detect nascent RNA transcripts (3D RNA FISH), their genomic loci (3D DNA FISH) and/or their chromosome territories (CT paint DNA FISH) combined with the antibody-based detection of various nuclear factors (immunofluorescence). We delineate the application and effectiveness of this robust and reproducible protocol in several murine T lymphocyte subtypes (from differentiating thymic T cells, to activated splenic and peripheral T cells) as well as other murine cells, including embryonic stem cells, B cells, megakaryocytes and macrophages.
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Affiliation(s)
- Eralda Salataj
- Université Paris Cité, Institut Cochin, INSERM, CNRS, Paris, France
- Institute of Molecular Biology and Biotechnology-Foundation for Research and Technology Hellas, Heraklion, Crete, Greece
| | - Charalampos G. Spilianakis
- Institute of Molecular Biology and Biotechnology-Foundation for Research and Technology Hellas, Heraklion, Crete, Greece
- Department of Biology, University of Crete, Heraklion, Crete, Greece
| | - Julie Chaumeil
- Université Paris Cité, Institut Cochin, INSERM, CNRS, Paris, France
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107
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Cermakova K, Hodges HC. Interaction modules that impart specificity to disordered protein. Trends Biochem Sci 2023; 48:477-490. [PMID: 36754681 PMCID: PMC10106370 DOI: 10.1016/j.tibs.2023.01.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 01/09/2023] [Accepted: 01/12/2023] [Indexed: 02/09/2023]
Abstract
Intrinsically disordered regions (IDRs) are especially enriched among proteins that regulate chromatin and transcription. As a result, mechanisms that influence specificity of IDR-driven interactions have emerged as exciting unresolved issues for understanding gene regulation. We review the molecular elements frequently found within IDRs that confer regulatory specificity. In particular, we summarize the differing roles of disordered low-complexity regions (LCRs) and short linear motifs (SLiMs) towards selective nuclear regulation. Examination of IDR-driven interactions highlights SLiMs as organizers of selectivity, with widespread roles in gene regulation and integration of cellular signals. Analysis of recurrent interactions between SLiMs and folded domains suggests diverse avenues for SLiMs to influence phase-separated condensates and highlights opportunities to manipulate these interactions for control of biological activity.
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Affiliation(s)
- Katerina Cermakova
- Department of Molecular and Cellular Biology, Center for Precision Environmental Health, Baylor College of Medicine, Houston, TX, USA
| | - H Courtney Hodges
- Department of Molecular and Cellular Biology, Center for Precision Environmental Health, Baylor College of Medicine, Houston, TX, USA; Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, USA; Department of Bioengineering, Rice University, Houston, TX, USA; Center for Cancer Epigenetics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
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108
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Dai Y, You L, Chilkoti A. Engineering synthetic biomolecular condensates. NATURE REVIEWS BIOENGINEERING 2023; 1:1-15. [PMID: 37359769 PMCID: PMC10107566 DOI: 10.1038/s44222-023-00052-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 03/06/2023] [Indexed: 06/28/2023]
Abstract
The concept of phase-separation-mediated formation of biomolecular condensates provides a new framework to understand cellular organization and cooperativity-dependent cellular functions. With growing understanding of how biological systems drive phase separation and how cellular functions are encoded by biomolecular condensates, opportunities have emerged for cellular control through engineering of synthetic biomolecular condensates. In this Review, we discuss how to construct synthetic biomolecular condensates and how they can regulate cellular functions. We first describe the fundamental principles by which biomolecular components can drive phase separation. Next, we discuss the relationship between the properties of condensates and their cellular functions, which informs the design of components to create programmable synthetic condensates. Finally, we describe recent applications of synthetic biomolecular condensates for cellular control and discuss some of the design considerations and prospective applications.
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Affiliation(s)
- Yifan Dai
- Department of Biomedical Engineering, Duke University, Durham, NC USA
| | - Lingchong You
- Department of Biomedical Engineering, Duke University, Durham, NC USA
| | - Ashutosh Chilkoti
- Department of Biomedical Engineering, Duke University, Durham, NC USA
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109
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Ramabadran R, Wang JH, Reyes JM, Guzman AG, Gupta S, Rosas C, Brunetti L, Gundry MC, Tovy A, Long H, Gu T, Cullen SM, Tyagi S, Rux D, Kim JJ, Kornblau SM, Kyba M, Stossi F, Rau RE, Takahashi K, Westbrook TF, Goodell MA. DNMT3A-coordinated splicing governs the stem state switch towards differentiation in embryonic and haematopoietic stem cells. Nat Cell Biol 2023; 25:528-539. [PMID: 37024683 PMCID: PMC10337578 DOI: 10.1038/s41556-023-01109-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 02/17/2023] [Indexed: 04/08/2023]
Abstract
Upon stimulation by extrinsic stimuli, stem cells initiate a programme that enables differentiation or self-renewal. Disruption of the stem state exit has catastrophic consequences for embryogenesis and can lead to cancer. While some elements of this stem state switch are known, major regulatory mechanisms remain unclear. Here we show that this switch involves a global increase in splicing efficiency coordinated by DNA methyltransferase 3α (DNMT3A), an enzyme typically involved in DNA methylation. Proper activation of murine and human embryonic and haematopoietic stem cells depends on messenger RNA processing, influenced by DNMT3A in response to stimuli. DNMT3A coordinates splicing through recruitment of the core spliceosome protein SF3B1 to RNA polymerase and mRNA. Importantly, the DNA methylation function of DNMT3A is not required and loss of DNMT3A leads to impaired splicing during stem cell turnover. Finally, we identify the spliceosome as a potential therapeutic target in DNMT3A-mutated leukaemias. Together, our results reveal a modality through which DNMT3A and the spliceosome govern exit from the stem state towards differentiation.
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Affiliation(s)
- Raghav Ramabadran
- Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
- Interdepartmental Program in Integrative Molecular and Biomedical Sciences, Baylor College of Medicine, Houston, TX, USA
| | - Jarey H Wang
- Medical Scientist Training Program, Baylor College of Medicine, Houston, TX, USA
- Verna & Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Jaime M Reyes
- Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Anna G Guzman
- Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Sinjini Gupta
- Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Carina Rosas
- Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Lorenzo Brunetti
- Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX, USA
| | - Michael C Gundry
- Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX, USA
- Medical Scientist Training Program, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Ayala Tovy
- Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Hali Long
- Interdepartmental Program in Integrative Molecular and Biomedical Sciences, Baylor College of Medicine, Houston, TX, USA
| | - Tianpeng Gu
- Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Sean M Cullen
- Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX, USA
- Medical Scientist Training Program, Baylor College of Medicine, Houston, TX, USA
| | - Siddhartha Tyagi
- Verna & Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Danielle Rux
- Lillehei Heart Institute and Department of Pediatrics, University of Minnesota, Minneapolis, MN, USA
| | - Jean J Kim
- Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX, USA
| | - Steven M Kornblau
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Michael Kyba
- Lillehei Heart Institute and Department of Pediatrics, University of Minnesota, Minneapolis, MN, USA
| | - Fabio Stossi
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Rachel E Rau
- Department of Pediatrics, Baylor College of Medicine and Texas Children's Hospital, Houston, TX, USA
| | - Koichi Takahashi
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Thomas F Westbrook
- Verna & Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Therapeutic Innovation Center, Baylor College of Medicine, Houston, TX, USA
| | - Margaret A Goodell
- Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX, USA.
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA.
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110
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Rogalska ME, Vivori C, Valcárcel J. Regulation of pre-mRNA splicing: roles in physiology and disease, and therapeutic prospects. Nat Rev Genet 2023; 24:251-269. [PMID: 36526860 DOI: 10.1038/s41576-022-00556-8] [Citation(s) in RCA: 50] [Impact Index Per Article: 50.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/10/2022] [Indexed: 12/23/2022]
Abstract
The removal of introns from mRNA precursors and its regulation by alternative splicing are key for eukaryotic gene expression and cellular function, as evidenced by the numerous pathologies induced or modified by splicing alterations. Major recent advances have been made in understanding the structures and functions of the splicing machinery, in the description and classification of physiological and pathological isoforms and in the development of the first therapies for genetic diseases based on modulation of splicing. Here, we review this progress and discuss important remaining challenges, including predicting splice sites from genomic sequences, understanding the variety of molecular mechanisms and logic of splicing regulation, and harnessing this knowledge for probing gene function and disease aetiology and for the design of novel therapeutic approaches.
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Affiliation(s)
- Malgorzata Ewa Rogalska
- Genome Biology Program, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Claudia Vivori
- Genome Biology Program, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain
- Department of Medicine and Life Sciences, Universitat Pompeu Fabra (UPF), Barcelona, Spain
- The Francis Crick Institute, London, UK
| | - Juan Valcárcel
- Genome Biology Program, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain.
- Department of Medicine and Life Sciences, Universitat Pompeu Fabra (UPF), Barcelona, Spain.
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain.
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111
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Cui H, Diedrich JK, Wu DC, Lim JJ, Nottingham RM, Moresco JJ, Yates JR, Blencowe BJ, Lambowitz AM, Schimmel P. Arg-tRNA synthetase links inflammatory metabolism to RNA splicing and nuclear trafficking via SRRM2. Nat Cell Biol 2023; 25:592-603. [PMID: 37059883 DOI: 10.1038/s41556-023-01118-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 02/27/2023] [Indexed: 04/16/2023]
Abstract
Cells respond to perturbations such as inflammation by sensing changes in metabolite levels. Especially prominent is arginine, which has known connections to the inflammatory response. Aminoacyl-tRNA synthetases, enzymes that catalyse the first step of protein synthesis, can also mediate cell signalling. Here we show that depletion of arginine during inflammation decreased levels of nuclear-localized arginyl-tRNA synthetase (ArgRS). Surprisingly, we found that nuclear ArgRS interacts and co-localizes with serine/arginine repetitive matrix protein 2 (SRRM2), a spliceosomal and nuclear speckle protein, and that decreased levels of nuclear ArgRS correlated with changes in condensate-like nuclear trafficking of SRRM2 and splice-site usage in certain genes. These splice-site usage changes cumulated in the synthesis of different protein isoforms that altered cellular metabolism and peptide presentation to immune cells. Our findings uncover a mechanism whereby an aminoacyl-tRNA synthetase cognate to a key amino acid that is metabolically controlled during inflammation modulates the splicing machinery.
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Affiliation(s)
- Haissi Cui
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Jolene K Diedrich
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Douglas C Wu
- Institute for Cellular and Molecular Biology and Departments of Molecular Biosciences and Oncology, University of Texas at Austin, Austin, TX, USA
| | - Justin J Lim
- The Donnelly Centre, University of Toronto, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Ryan M Nottingham
- Institute for Cellular and Molecular Biology and Departments of Molecular Biosciences and Oncology, University of Texas at Austin, Austin, TX, USA
| | - James J Moresco
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
- Center for the Genetics of Host Defense, UT Southwestern Medical Center, Dallas, TX, USA
| | - John R Yates
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Benjamin J Blencowe
- The Donnelly Centre, University of Toronto, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Alan M Lambowitz
- Institute for Cellular and Molecular Biology and Departments of Molecular Biosciences and Oncology, University of Texas at Austin, Austin, TX, USA.
| | - Paul Schimmel
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA.
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112
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Tehrani N, Mitra RM. Plant pathogens and symbionts target the plant nucleus. Curr Opin Microbiol 2023; 72:102284. [PMID: 36868049 DOI: 10.1016/j.mib.2023.102284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 01/20/2023] [Accepted: 01/24/2023] [Indexed: 03/05/2023]
Abstract
In plant-microbe interactions, symbionts and pathogens live within plants and attempt to avoid triggering plant defense responses. In order to do so, these microbes have evolved multiple mechanisms that target components of the plant cell nucleus. Rhizobia-induced symbiotic signaling requires the function of specific legume nucleoporins within the nuclear pore complex. Symbiont and pathogen effectors harbor nuclear localization sequences that facilitate movement across nuclear pores, allowing these proteins to target transcription factors that function in defense. Oomycete pathogens introduce proteins that interact with plant pre-mRNA splicing components in order to alter host splicing of defense-related transcripts. Together, these functions indicate that the nucleus is an active site of symbiotic and pathogenic functioning in plant-microbe interactions.
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Suzuki H, Furugori K, Abe R, Ogawa S, Ito S, Akiyama T, Horiuchi K, Takahashi H. MED26-containing Mediator may orchestrate multiple transcription processes through organization of nuclear bodies. Bioessays 2023; 45:e2200178. [PMID: 36852638 DOI: 10.1002/bies.202200178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 02/04/2023] [Accepted: 02/06/2023] [Indexed: 03/01/2023]
Abstract
Mediator is a coregulatory complex that plays essential roles in multiple processes of transcription regulation. One of the human Mediator subunits, MED26, has a role in recruitment of the super elongation complex (SEC) to polyadenylated genes and little elongation complex (LEC) to non-polyadenylated genes, including small nuclear RNAs (snRNAs) and replication-dependent histone (RDH) genes. MED26-containing Mediator plays a role in 3' Pol II pausing at the proximal region of transcript end sites in RDH genes through recruitment of Cajal bodies (CBs) to histone locus bodies (HLBs). This finding suggests that Mediator is involved in the association of CBs with HLBs to facilitate 3' Pol II pausing and subsequent 3'-end processing by supplying 3'-end processing factors from CBs. Thus, we argue the possibility that Mediator is involved in the organization of nuclear bodies to orchestrate multiple processes of gene transcription.
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Affiliation(s)
- Hidefumi Suzuki
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Kanagawa, Japan
| | - Kazuki Furugori
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Kanagawa, Japan
| | - Ryota Abe
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Kanagawa, Japan
| | - Shintaro Ogawa
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Kanagawa, Japan
| | - Sayaka Ito
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Kanagawa, Japan
| | - Tomohiko Akiyama
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Kanagawa, Japan
| | - Keiko Horiuchi
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Kanagawa, Japan
| | - Hidehisa Takahashi
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Kanagawa, Japan
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114
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Niu X, Zhang L, Wu Y, Zong Z, Wang B, Liu J, Zhang L, Zhou F. Biomolecular condensates: Formation mechanisms, biological functions, and therapeutic targets. MedComm (Beijing) 2023; 4:e223. [PMID: 36875159 PMCID: PMC9974629 DOI: 10.1002/mco2.223] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Revised: 01/20/2023] [Accepted: 02/02/2023] [Indexed: 03/06/2023] Open
Abstract
Biomolecular condensates are cellular structures composed of membraneless assemblies comprising proteins or nucleic acids. The formation of these condensates requires components to change from a state of solubility separation from the surrounding environment by undergoing phase transition and condensation. Over the past decade, it has become widely appreciated that biomolecular condensates are ubiquitous in eukaryotic cells and play a vital role in physiological and pathological processes. These condensates may provide promising targets for the clinic research. Recently, a series of pathological and physiological processes have been found associated with the dysfunction of condensates, and a range of targets and methods have been demonstrated to modulate the formation of these condensates. A more extensive description of biomolecular condensates is urgently needed for the development of novel therapies. In this review, we summarized the current understanding of biomolecular condensates and the molecular mechanisms of their formation. Moreover, we reviewed the functions of condensates and therapeutic targets for diseases. We further highlighted the available regulatory targets and methods, discussed the significance and challenges of targeting these condensates. Reviewing the latest developments in biomolecular condensate research could be essential in translating our current knowledge on the use of condensates for clinical therapeutic strategies.
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Affiliation(s)
- Xin Niu
- Department of Otolaryngology Head and Neck Surgery The First Affiliated Hospital of Soochow University Suzhou China.,MOE Laboratory of Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network Life Sciences Institute Zhejiang University Hangzhou China
| | - Lei Zhang
- Department of Orthopedics The First Affiliated Hospital of Wenzhou Medical University Wenzhou China
| | - Yuchen Wu
- Department of Clinical Medicine, The First School of Medicine Wenzhou Medical University Wenzhou China
| | - Zhi Zong
- MOE Laboratory of Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network Life Sciences Institute Zhejiang University Hangzhou China
| | - Bin Wang
- MOE Laboratory of Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network Life Sciences Institute Zhejiang University Hangzhou China
| | - Jisheng Liu
- Department of Otolaryngology Head and Neck Surgery The First Affiliated Hospital of Soochow University Suzhou China
| | - Long Zhang
- MOE Laboratory of Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network Life Sciences Institute Zhejiang University Hangzhou China
| | - Fangfang Zhou
- Institutes of Biology and Medical Science Soochow University Suzhou China
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115
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Kim YJ, Lee M, Lee YT, Jing J, Sanders JT, Botten GA, He L, Lyu J, Zhang Y, Mettlen M, Ly P, Zhou Y, Xu J. Light-activated macromolecular phase separation modulates transcription by reconfiguring chromatin interactions. SCIENCE ADVANCES 2023; 9:eadg1123. [PMID: 37000871 PMCID: PMC10065442 DOI: 10.1126/sciadv.adg1123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 02/28/2023] [Indexed: 06/19/2023]
Abstract
Biomolecular condensates participate in the regulation of gene transcription, yet the relationship between nuclear condensation and transcriptional activation remains elusive. Here, we devised a biotinylated CRISPR-dCas9-based optogenetic method, light-activated macromolecular phase separation (LAMPS), to enable inducible formation, affinity purification, and multiomic dissection of nuclear condensates at the targeted genomic loci. LAMPS-induced condensation at enhancers and promoters activates endogenous gene transcription by chromatin reconfiguration, causing increased chromatin accessibility and de novo formation of long-range chromosomal loops. Proteomic profiling of light-induced condensates by dCas9-mediated affinity purification uncovers multivalent interaction-dependent remodeling of macromolecular composition, resulting in the selective enrichment of transcriptional coactivators and chromatin structure proteins. Our findings support a model whereby the formation of nuclear condensates at native genomic loci reconfigures chromatin architecture and multiprotein assemblies to modulate gene transcription. Hence, LAMPS facilitates mechanistic interrogation of the relationship between nuclear condensation, genome structure, and gene transcription in living cells.
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Affiliation(s)
- Yoon Jung Kim
- Children’s Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Department of Pediatrics, Harold C. Simmons Comprehensive Cancer Center, and Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Michael Lee
- Children’s Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Department of Pediatrics, Harold C. Simmons Comprehensive Cancer Center, and Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Yi-Tsang Lee
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX 77030, USA
| | - Ji Jing
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX 77030, USA
| | - Jacob T. Sanders
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Giovanni A. Botten
- Children’s Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Department of Pediatrics, Harold C. Simmons Comprehensive Cancer Center, and Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Lian He
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX 77030, USA
| | - Junhua Lyu
- Children’s Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Department of Pediatrics, Harold C. Simmons Comprehensive Cancer Center, and Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Yuannyu Zhang
- Children’s Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Department of Pediatrics, Harold C. Simmons Comprehensive Cancer Center, and Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Marcel Mettlen
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Peter Ly
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Yubin Zhou
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX 77030, USA
- Department of Translational Medical Sciences, College of Medicine, Texas A&M University, Houston, TX 77030, USA
| | - Jian Xu
- Children’s Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Department of Pediatrics, Harold C. Simmons Comprehensive Cancer Center, and Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
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116
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Zhou P, Liu H, Meng X, Zuo H, Qi M, Guo L, Gao C, Song W, Wu J, Chen X, Chen W, Liu L. Engineered Artificial Membraneless Organelles in Saccharomyces cerevisiae To Enhance Chemical Production. Angew Chem Int Ed Engl 2023; 62:e202215778. [PMID: 36762978 DOI: 10.1002/anie.202215778] [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: 10/27/2022] [Revised: 02/09/2023] [Accepted: 02/10/2023] [Indexed: 02/11/2023]
Abstract
Microbial cell factories provide a green and sustainable opportunity to produce value-added products from renewable feedstock. However, the leakage of toxic or volatile intermediates decreases the efficiency of microbial cell factories. In this study, membraneless organelles (MLOs) were reconstructed in Saccharomyces cerevisiae by the disordered protein sequence A-IDPs. A regulation system was designed to spatiotemporally regulate the size and rigidity of MLOs. Manipulating the MLO size of strain ZP03-FM, the amounts of assimilated methanol and malate were increased by 162 % and 61 %, respectively. Furthermore, manipulating the MLO rigidity in strain ZP04-RB made acetyl-coA synthesis from oxidative glycolysis change to non-oxidative glycolysis; consequently, CO2 release decreased by 35 % and the n-butanol yield increased by 20 %. This artificial MLO provides a strategy for the co-localization of enzymes to channel C1 starting materials into value-added chemicals.
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Affiliation(s)
- Pei Zhou
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
| | - Hui Liu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
| | - Xin Meng
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
| | - Huiyun Zuo
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
| | - Mengya Qi
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
| | - Liang Guo
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
| | - Cong Gao
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
| | - Wei Song
- School of Life Sciences and Health Engineering, Jiangnan University, Wuxi, 214122, China
| | - Jing Wu
- School of Life Sciences and Health Engineering, Jiangnan University, Wuxi, 214122, China
| | - Xiulai Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
| | - Wei Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
| | - Liming Liu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
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117
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Farag M, Borcherds WM, Bremer A, Mittag T, Pappu RV. Phase Separation in Mixtures of Prion-Like Low Complexity Domains is Driven by the Interplay of Homotypic and Heterotypic Interactions. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.15.532828. [PMID: 36993212 PMCID: PMC10055064 DOI: 10.1101/2023.03.15.532828] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Prion-like low-complexity domains (PLCDs) are involved in the formation and regulation of distinct biomolecular condensates that form via coupled associative and segregative phase transitions. We previously deciphered how evolutionarily conserved sequence features drive phase separation of PLCDs through homotypic interactions. However, condensates typically encompass a diverse mixture of proteins with PLCDs. Here, we combine simulations and experiments to study mixtures of PLCDs from two RNA binding proteins namely, hnRNPA1 and FUS. We find that 1:1 mixtures of the A1-LCD and FUS-LCD undergo phase separation more readily than either of the PLCDs on their own. The enhanced driving forces for phase separation of mixtures of A1-LCD and FUS-LCD arise partly from complementary electrostatic interactions between the two proteins. This complex coacervation-like mechanism adds to complementary interactions among aromatic residues. Further, tie line analysis shows that stoichiometric ratios of different components and their sequence-encoded interactions jointly contribute to the driving forces for condensate formation. These results highlight how expression levels might be tuned to regulate the driving forces for condensate formation in vivo . Simulations also show that the organization of PLCDs within condensates deviates from expectations based on random mixture models. Instead, spatial organization within condensates will reflect the relative strengths of homotypic versus heterotypic interactions. We also uncover rules for how interaction strengths and sequence lengths modulate conformational preferences of molecules at interfaces of condensates formed by mixtures of proteins. Overall, our findings emphasize the network-like organization of molecules within multicomponent condensates, and the distinctive, composition-specific conformational features of condensate interfaces. Significance Statement Biomolecular condensates are mixtures of different protein and nucleic acid molecules that organize biochemical reactions in cells. Much of what we know about how condensates form comes from studies of phase transitions of individual components of condensates. Here, we report results from studies of phase transitions of mixtures of archetypal protein domains that feature in distinct condensates. Our investigations, aided by a blend of computations and experiments, show that the phase transitions of mixtures are governed by a complex interplay of homotypic and heterotypic interactions. The results point to how expression levels of different protein components can be tuned in cells to modulate internal structures, compositions, and interfaces of condensates, thus affording distinct ways to control the functions of condensates.
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118
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Li Y, Huang J, Bao L, Zhu J, Duan W, Zheng H, Wang H, Jiang Y, Liu W, Zhang M, Yu Y, Yi C, Ji X. RNA Pol II preferentially regulates ribosomal protein expression by trapping disassociated subunits. Mol Cell 2023; 83:1280-1297.e11. [PMID: 36924766 DOI: 10.1016/j.molcel.2023.02.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 12/12/2022] [Accepted: 02/23/2023] [Indexed: 03/17/2023]
Abstract
RNA polymerase II (RNA Pol II) has been recognized as a passively regulated multi-subunit holoenzyme. However, the extent to which RNA Pol II subunits might be important beyond the RNA Pol II complex remains unclear. Here, fractions containing disassociated RPB3 (dRPB3) were identified by size exclusion chromatography in various cells. Through a unique strategy, i.e., "specific degradation of disassociated subunits (SDDS)," we demonstrated that dRPB3 functions as a regulatory component of RNA Pol II to enable the preferential control of 3' end processing of ribosomal protein genes directly through its N-terminal domain. Machine learning analysis of large-scale genomic features revealed that the little elongation complex (LEC) helps to specialize the functions of dRPB3. Mechanistically, dRPB3 facilitates CBC-PCF11 axis activity to increase the efficiency of 3' end processing. Furthermore, RPB3 is dynamically regulated during development and diseases. These findings suggest that RNA Pol II gains specific regulatory functions by trapping disassociated subunits in mammalian cells.
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Affiliation(s)
- Yuanjun Li
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Jie Huang
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Lijun Bao
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Junyi Zhu
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Wenjia Duan
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Haonan Zheng
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Hui Wang
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Yongpeng Jiang
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Weiwei Liu
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Meiling Zhang
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Department of Chemical Biology and Synthetic and Functional Biomolecules Center, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Yang Yu
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Chengqi Yi
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Department of Chemical Biology and Synthetic and Functional Biomolecules Center, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Xiong Ji
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China.
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119
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Rawat P, Sawarkar R. SPTing across condensates: SEC-mediated translocation of SPT complex from pausing condensates to elongation condensates. EMBO Rep 2023; 24:e56810. [PMID: 36762438 PMCID: PMC9986807 DOI: 10.15252/embr.202356810] [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: 01/11/2023] [Accepted: 01/31/2023] [Indexed: 02/11/2023] Open
Abstract
Several independent studies in the last few years have suggested that phase separation and biomolecular condensation play a critical role in regulating different transcription steps from initiation to pausing and elongation. However, how components of the transcription machinery translocate among different types of condensates during transcription remains poorly understood. Guo et al have now identified a potential mechanism underlying translocation of the DSIF complex from pausing to elongation condensates during promoter pause release, as reported in this issue of EMBO reports.
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Affiliation(s)
- Prashant Rawat
- Institute of BiochemistrySwiss Federal Institute of Technology (ETH)ZurichSwitzerland
| | - Ritwick Sawarkar
- Medical Research Council (MRC), Department of GeneticsUniversity of CambridgeCambridgeUK
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120
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Guo C, Zhang Y, Shuai S, Sigbessia A, Hao S, Xie P, Jiang X, Luo Z, Lin C. The super elongation complex (SEC) mediates phase transition of SPT5 during transcriptional pause release. EMBO Rep 2023; 24:e55699. [PMID: 36629390 PMCID: PMC9986819 DOI: 10.15252/embr.202255699] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 12/12/2022] [Accepted: 12/14/2022] [Indexed: 01/12/2023] Open
Abstract
Release of promoter-proximally paused RNA Pol II into elongation is a tightly regulated and rate-limiting step in metazoan gene transcription. However, the biophysical mechanism underlying pause release remains unclear. Here, we demonstrate that the pausing and elongation regulator SPT5 undergoes phase transition during transcriptional pause release. SPT5 per se is prone to form clusters. The disordered domain in SPT5 is required for pause release and gene activation. During early elongation, the super elongation complex (SEC) induces SPT5 transition into elongation droplets. Depletion of SEC increases SPT5 pausing clusters. Furthermore, disease-associated SEC mutations impair phase properties of elongation droplets and transcription. Our study suggests that SEC-mediated SPT5 phase transition might be essential for pause release and early elongation and that aberrant phase properties could contribute to transcription abnormality in diseases.
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Affiliation(s)
- Chenghao Guo
- Key Laboratory of Developmental Genes and Human Disease, School of Life Science and TechnologySoutheast UniversityNanjingChina
- Co‐innovation Center of NeuroregenerationNantong UniversityNantongChina
| | - Yadi Zhang
- Key Laboratory of Developmental Genes and Human Disease, School of Life Science and TechnologySoutheast UniversityNanjingChina
| | - Shimin Shuai
- Key Laboratory of Developmental Genes and Human Disease, School of Life Science and TechnologySoutheast UniversityNanjingChina
| | - Abire Sigbessia
- Key Laboratory of Developmental Genes and Human Disease, School of Life Science and TechnologySoutheast UniversityNanjingChina
| | - Shaohua Hao
- Key Laboratory of Developmental Genes and Human Disease, School of Life Science and TechnologySoutheast UniversityNanjingChina
| | - Peng Xie
- Southeast University‐Allen Institute Joint Center, Institute for Brain and IntelligenceSoutheast UniversityNanjingChina
| | - Xu Jiang
- Key Laboratory of Developmental Genes and Human Disease, School of Life Science and TechnologySoutheast UniversityNanjingChina
| | - Zhuojuan Luo
- Key Laboratory of Developmental Genes and Human Disease, School of Life Science and TechnologySoutheast UniversityNanjingChina
- Co‐innovation Center of NeuroregenerationNantong UniversityNantongChina
- Shenzhen Research InstituteSoutheast UniversityShenzhenChina
- Jiangsu Provincial Key Laboratory of Critical Care Medicine, School of Life Science and TechnologySoutheast UniversityNanjingChina
| | - Chengqi Lin
- Key Laboratory of Developmental Genes and Human Disease, School of Life Science and TechnologySoutheast UniversityNanjingChina
- Co‐innovation Center of NeuroregenerationNantong UniversityNantongChina
- Shenzhen Research InstituteSoutheast UniversityShenzhenChina
- Jiangsu Provincial Key Laboratory of Critical Care Medicine, School of Life Science and TechnologySoutheast UniversityNanjingChina
- Key Laboratory of Technical Evaluation of Fertility Regulation of Non‐human primate, Fujian Provincial Maternity and Children's HospitalAffiliated Hospital of Fujian Medical UniversityFuzhouChina
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121
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Ji J, Wang W, Chen C. Single-molecule techniques to visualize and to characterize liquid-liquid phase separation and phase transition. Acta Biochim Biophys Sin (Shanghai) 2023; 55:1023-1033. [PMID: 36876423 PMCID: PMC10415186 DOI: 10.3724/abbs.2023028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 01/09/2023] [Indexed: 02/23/2023] Open
Abstract
Biomolecules forming membraneless structures via liquid-liquid phase separation (LLPS) is a common event in living cells. Some liquid-like condensates can convert into solid-like aggregations, and such a phase transition process is related to some neurodegenerative diseases. Liquid-like condensates and solid-like aggregations usually exhibit distinctive fluidity and are commonly distinguished via their morphology and dynamic properties identified through ensemble methods. Emerging single-molecule techniques are a group of highly sensitive techniques, which can offer further mechanistic insights into LLPS and phase transition at the molecular level. Here, we summarize the working principles of several commonly used single-molecule techniques and demonstrate their unique power in manipulating LLPS, examining mechanical properties at the nanoscale, and monitoring dynamic and thermodynamic properties at the molecular level. Thus, single-molecule techniques are unique tools to characterize LLPS and liquid-to-solid phase transition under close-to-physiological conditions.
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Affiliation(s)
- Jinyao Ji
- School of Life SciencesBeijing Advanced Innovation Center for Structural BiologyBeijing Frontier Research Center of Biological StructureTsinghua UniversityBeijing100084China
| | - Wenjuan Wang
- School of Life SciencesTechnology Center for Protein SciencesTsinghua UniversityBeijing100084China
| | - Chunlai Chen
- School of Life SciencesBeijing Advanced Innovation Center for Structural BiologyBeijing Frontier Research Center of Biological StructureTsinghua UniversityBeijing100084China
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122
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Sagan SM, Weber SC. Let's phase it: viruses are master architects of biomolecular condensates. Trends Biochem Sci 2023; 48:229-243. [PMID: 36272892 DOI: 10.1016/j.tibs.2022.09.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Revised: 09/23/2022] [Accepted: 09/26/2022] [Indexed: 11/15/2022]
Abstract
Viruses compartmentalize their replication and assembly machinery to both evade detection and concentrate the viral proteins and nucleic acids necessary for genome replication and virion production. Accumulating evidence suggests that diverse RNA and DNA viruses form replication organelles and nucleocapsid assembly sites using phase separation. In general, the biogenesis of these compartments is regulated by two types of viral protein, collectively known as antiterminators and nucleocapsid proteins, respectively. Herein, we discuss how RNA viruses establish replication organelles and nucleocapsid assembly sites, and the evidence that these compartments form through phase separation. While this review focuses on RNA viruses, accumulating evidence suggests that all viruses rely on phase separation and form biomolecular condensates important for completing the infectious cycle.
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Affiliation(s)
- Selena M Sagan
- Department of Microbiology & Immunology, McGill University, Montreal, QC, Canada; Department of Biochemistry, McGill University, Montreal, QC, Canada.
| | - Stephanie C Weber
- Department of Biology, McGill University, Montreal, QC, Canada; Department of Physics, McGill University, Montreal, QC, Canada
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123
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Chen Q, Wu Y, Dai Z, Zhang Z, Yang X. Phosphorylation and specific DNA improved the incorporation ability of p53 into functional condensates. Int J Biol Macromol 2023; 230:123221. [PMID: 36634798 DOI: 10.1016/j.ijbiomac.2023.123221] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 12/26/2022] [Accepted: 01/07/2023] [Indexed: 01/11/2023]
Abstract
The transcription factor p53 acted as a critical tumor suppressor by activating the expression of various target genes to regulate diverse cellular responses. The phosphorylation of p53 influenced the binding of p53 to promotor-specific DNA and the choice of cell fate. In this study, we found that full-length wild-type p53 and pol II CTD could form heterotypic phase separation condensates in vitro. The heterotypic condensates of p53 and pol II CTD were mediated by electrostatic and hydrophobic interactions between pol II CTD and multiple domains of p53. The mobility of heterotypic p53 and pol II CTD droplets was significantly higher than that of p53 droplet. The phosphorylation promoted p53 to be recruited into pol II CTD droplets and transcription condensates. The specific DNA could further enhance the incorporation ability of p53 into functional condensates. Therefore, we proposed that the p53 droplet might be in a mediate state, the mutations resulting in p53 mutants with gain-of-function impelled the aggregate of p53, while the phosphorylation promoted p53 to be recruited into functional condensates as a client molecule to exert its function. This study might provide insights into the regulation mechanism that the phosphorylation and nuclei acid affected the phase behavior of p53.
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Affiliation(s)
- Qunyang Chen
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, Guangdong Province 510006, PR China
| | - Yiping Wu
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, Guangdong Province 510006, PR China
| | - Zhuojun Dai
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, Guangdong Province 510006, PR China
| | - Zhuqing Zhang
- College of life sciences, University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Xiaorong Yang
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, Guangdong Province 510006, PR China; Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development, Guangzhou 510640, PR China.
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124
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Boumpas P, Merabet S, Carnesecchi J. Integrating transcription and splicing into cell fate: Transcription factors on the block. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 14:e1752. [PMID: 35899407 DOI: 10.1002/wrna.1752] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 06/22/2022] [Accepted: 07/01/2022] [Indexed: 11/10/2022]
Abstract
Transcription factors (TFs) are present in all life forms and conserved across great evolutionary distances in eukaryotes. From yeast to complex multicellular organisms, they are pivotal players of cell fate decision by orchestrating gene expression at diverse molecular layers. Notably, TFs fine-tune gene expression by coordinating RNA fate at both the expression and splicing levels. They regulate alternative splicing, an essential mechanism for cell plasticity, allowing the production of many mRNA and protein isoforms in precise cell and tissue contexts. Despite this apparent role in splicing, how TFs integrate transcription and splicing to ultimately orchestrate diverse cell functions and cell fate decisions remains puzzling. We depict substantial studies in various model organisms underlining the key role of TFs in alternative splicing for promoting tissue-specific functions and cell fate. Furthermore, we emphasize recent advances describing the molecular link between the transcriptional and splicing activities of TFs. As TFs can bind both DNA and/or RNA to regulate transcription and splicing, we further discuss their flexibility and compatibility for DNA and RNA substrates. Finally, we propose several models integrating transcription and splicing activities of TFs in the coordination and diversification of cell and tissue identities. This article is categorized under: RNA Processing > Splicing Regulation/Alternative Splicing RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications RNA Processing > Splicing Mechanisms.
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Affiliation(s)
- Panagiotis Boumpas
- Institut de Génomique Fonctionnelle de Lyon, UMR5242, Ecole Normale Supérieure de Lyon, Centre National de la Recherche Scientifique, Université Claude Bernard-Lyon 1, Lyon, France
| | - Samir Merabet
- Institut de Génomique Fonctionnelle de Lyon, UMR5242, Ecole Normale Supérieure de Lyon, Centre National de la Recherche Scientifique, Université Claude Bernard-Lyon 1, Lyon, France
| | - Julie Carnesecchi
- Institut de Génomique Fonctionnelle de Lyon, UMR5242, Ecole Normale Supérieure de Lyon, Centre National de la Recherche Scientifique, Université Claude Bernard-Lyon 1, Lyon, France
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125
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Staples MI, Frazer C, Fawzi NL, Bennett RJ. Phase separation in fungi. Nat Microbiol 2023; 8:375-386. [PMID: 36782025 PMCID: PMC10081517 DOI: 10.1038/s41564-022-01314-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 12/16/2022] [Indexed: 02/15/2023]
Abstract
Phase separation, in which macromolecules partition into a concentrated phase that is immiscible with a dilute phase, is involved with fundamental cellular processes across the tree of life. We review the principles of phase separation and highlight how it impacts diverse processes in the fungal kingdom. These include the regulation of autophagy, cell signalling pathways, transcriptional circuits and the establishment of asymmetry in fungal cells. We describe examples of stable, phase-separated assemblies including membraneless organelles such as the nucleolus as well as transient condensates that also arise through phase separation and enable cells to rapidly and reversibly respond to important environmental cues. We showcase how research into phase separation in model yeasts, such as Saccharomyces cerevisiae and Schizosaccharomyces pombe, in conjunction with that in plant and human fungal pathogens, such as Ashbya gossypii and Candida albicans, is continuing to enrich our understanding of fundamental molecular processes.
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Affiliation(s)
- Mae I Staples
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI, USA
| | - Corey Frazer
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI, USA
| | - Nicolas L Fawzi
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, USA
| | - Richard J Bennett
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI, USA.
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126
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Akcan TS, Vilov S, Heinig M. Predictive model of transcriptional elongation control identifies trans regulatory factors from chromatin signatures. Nucleic Acids Res 2023; 51:1608-1624. [PMID: 36727445 PMCID: PMC9976927 DOI: 10.1093/nar/gkac1272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 12/09/2022] [Accepted: 01/12/2023] [Indexed: 02/03/2023] Open
Abstract
Promoter-proximal Polymerase II (Pol II) pausing is a key rate-limiting step for gene expression. DNA and RNA-binding trans-acting factors regulating the extent of pausing have been identified. However, we lack a quantitative model of how interactions of these factors determine pausing, therefore the relative importance of implicated factors is unknown. Moreover, previously unknown regulators might exist. Here we address this gap with a machine learning model that accurately predicts the extent of promoter-proximal Pol II pausing from large-scale genome and transcriptome binding maps and gene annotation and sequence composition features. We demonstrate high accuracy and generalizability of the model by validation on an independent cell line which reveals the model's cell line agnostic character. Model interpretation in light of prior knowledge about molecular functions of regulatory factors confirms the interconnection of pausing with other RNA processing steps. Harnessing underlying feature contributions, we assess the relative importance of each factor, quantify their predictive effects and systematically identify previously unknown regulators of pausing. We additionally identify 16 previously unknown 7SK ncRNA interacting RNA-binding proteins predictive of pausing. Our work provides a framework to further our understanding of the regulation of the critical early steps in transcriptional elongation.
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Affiliation(s)
- Toray S Akcan
- Institute of Computational Biology, Helmholtz Zentrum München Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Ingolstädter Landstraße 1, 85764 Neuherberg, Germany.,Department of Computer Science, TUM School of Computation, Information and Technology, Technical University Munich, Munich, Germany
| | - Sergey Vilov
- Institute of Computational Biology, Helmholtz Zentrum München Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
| | - Matthias Heinig
- Institute of Computational Biology, Helmholtz Zentrum München Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Ingolstädter Landstraße 1, 85764 Neuherberg, Germany.,Department of Computer Science, TUM School of Computation, Information and Technology, Technical University Munich, Munich, Germany.,DZHK (German Centre for Cardiovascular Research), Munich Heart Association, Partner Site Munich, 10785 Berlin, Germany
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127
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Balaban C, Sztacho M, Antiga L, Miladinović A, Harata M, Hozák P. PIP2-Effector Protein MPRIP Regulates RNA Polymerase II Condensation and Transcription. Biomolecules 2023; 13:biom13030426. [PMID: 36979361 PMCID: PMC10046169 DOI: 10.3390/biom13030426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 02/17/2023] [Accepted: 02/21/2023] [Indexed: 03/02/2023] Open
Abstract
The specific post-translational modifications of the C-terminal domain (CTD) of the Rpb1 subunit of RNA polymerase II (RNAPII) correlate with different stages of transcription. The phosphorylation of the Ser5 residues of this domain associates with the initiation condensates, which are formed through liquid-liquid phase separation (LLPS). The subsequent Tyr1 phosphorylation of the CTD peaks at the promoter-proximal region and is involved in the pause-release of RNAPII. By implementing super-resolution microscopy techniques, we previously reported that the nuclear Phosphatidylinositol 4,5-bisphosphate (PIP2) associates with the Ser5-phosphorylated-RNAPII complex and facilitates the RNAPII transcription. In this study, we identified Myosin Phosphatase Rho-Interacting Protein (MPRIP) as a novel regulator of the RNAPII transcription that recruits Tyr1-phosphorylated CTD (Tyr1P-CTD) to nuclear PIP2-containing structures. The depletion of MPRIP increases the number of the initiation condensates, indicating a defect in the transcription. We hypothesize that MPRIP regulates the condensation and transcription through affecting the association of the RNAPII complex with nuclear PIP2-rich structures. The identification of Tyr1P-CTD as an interactor of PIP2 and MPRIP further points to a regulatory role in RNAPII pause-release, where the susceptibility of the transcriptional complex to leave the initiation condensate depends on its association with nuclear PIP2-rich structures. Moreover, the N-terminal domain of MPRIP, which is responsible for the interaction with the Tyr1P-CTD, contains an F-actin binding region that offers an explanation of how nuclear F-actin formations can affect the RNAPII transcription and condensation. Overall, our findings shed light on the role of PIP2 in RNAPII transcription through identifying the F-actin binding protein MPRIP as a transcription regulator and a determinant of the condensation of RNAPII.
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Affiliation(s)
- Can Balaban
- Department of Biology of the Cell Nucleus, Institute of Molecular Genetics of the Czech Academy of Sciences, 142 20 Prague, Czech Republic
| | - Martin Sztacho
- Department of Biology of the Cell Nucleus, Institute of Molecular Genetics of the Czech Academy of Sciences, 142 20 Prague, Czech Republic
- Correspondence: (M.S.); (P.H.)
| | - Ludovica Antiga
- Department of Biology of the Cell Nucleus, Institute of Molecular Genetics of the Czech Academy of Sciences, 142 20 Prague, Czech Republic
| | - Ana Miladinović
- Department of Biology of the Cell Nucleus, Institute of Molecular Genetics of the Czech Academy of Sciences, 142 20 Prague, Czech Republic
| | - Masahiko Harata
- Laboratory of Molecular Biochemistry, Division of Life Science, Graduate School of Agricultural Science, Tohoku University, 468-1, Aramaki Aza Aoba, Aoba-ku, Sendai 980-0845, Japan
| | - Pavel Hozák
- Department of Biology of the Cell Nucleus, Institute of Molecular Genetics of the Czech Academy of Sciences, 142 20 Prague, Czech Republic
- Correspondence: (M.S.); (P.H.)
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128
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The circadian demethylation of a unique intronic deoxymethylCpG-rich island boosts the transcription of its cognate circadian clock output gene. Proc Natl Acad Sci U S A 2023; 120:e2214062120. [PMID: 36791105 PMCID: PMC9974474 DOI: 10.1073/pnas.2214062120] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023] Open
Abstract
We demonstrate that there is a tight functional relationship between two highly evolutionary conserved cell processes, i.e., the circadian clock (CC) and the circadian DNA demethylation-methylation of cognate deoxyCpG-rich islands. We have discovered that every circadian clock-controlled output gene (CCG), but not the core clock nor its immediate-output genes, contains a single cognate intronic deoxyCpG-rich island, the demethylation-methylation of which is controlled by the CC. During the transcriptional activation period, these intronic islands are demethylated and, upon dimerization of two YY1 protein binding sites located upstream to the transcriptional enhancer and downstream from the deoxyCpG-rich island, store activating components initially assembled on a cognate active enhancer (a RORE, a D-box or an E-box), in keeping with the generation of a transcriptionally active condensate that boosts the initiation of transcription of their cognate pre-mRNAs. We report how these single intronic deoxyCpG-rich islands are instrumental in such a circadian activation/repression transcriptional process.
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129
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Li X, An Z, Zhang W, Li F. Phase Separation: Direct and Indirect Driving Force for High-Order Chromatin Organization. Genes (Basel) 2023; 14:499. [PMID: 36833426 PMCID: PMC9956262 DOI: 10.3390/genes14020499] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 02/09/2023] [Accepted: 02/14/2023] [Indexed: 02/18/2023] Open
Abstract
The multi-level spatial chromatin organization in the nucleus is closely related to chromatin activity. The mechanism of chromatin organization and remodeling attract much attention. Phase separation describes the biomolecular condensation which is the basis for membraneless compartments in cells. Recent research shows that phase separation is a key aspect to drive high-order chromatin structure and remodeling. In addition, chromatin functional compartmentalization in the nucleus which is formed by phase separation also plays an important role in overall chromatin structure. In this review, we summarized the latest work about the role of phase separation in spatial chromatin organization, focusing on direct and indirect effects of phase separation on 3D chromatin organization and its impact on transcription regulation.
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Affiliation(s)
- Xiaoli Li
- Division of Cell, Developmental and Integrative Biology, School of Medicine, South China University of Technology, Guangzhou 510006, China
- Department of Cell Biology and Genetics, Core Facility of Developmental Biology, Chongqing Medical University, Chongqing 400016, China
| | - Ziyang An
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Wenqing Zhang
- Division of Cell, Developmental and Integrative Biology, School of Medicine, South China University of Technology, Guangzhou 510006, China
| | - Feifei Li
- Division of Cell, Developmental and Integrative Biology, School of Medicine, South China University of Technology, Guangzhou 510006, China
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130
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Unveiling the Machinery behind Chromosome Folding by Polymer Physics Modeling. Int J Mol Sci 2023; 24:ijms24043660. [PMID: 36835064 PMCID: PMC9967178 DOI: 10.3390/ijms24043660] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Revised: 02/06/2023] [Accepted: 02/09/2023] [Indexed: 02/16/2023] Open
Abstract
Understanding the mechanisms underlying the complex 3D architecture of mammalian genomes poses, at a more fundamental level, the problem of how two or multiple genomic sites can establish physical contacts in the nucleus of the cells. Beyond stochastic and fleeting encounters related to the polymeric nature of chromatin, experiments have revealed specific, privileged patterns of interactions that suggest the existence of basic organizing principles of folding. In this review, we focus on two major and recently proposed physical processes of chromatin organization: loop-extrusion and polymer phase-separation, both supported by increasing experimental evidence. We discuss their implementation into polymer physics models, which we test against available single-cell super-resolution imaging data, showing that both mechanisms can cooperate to shape chromatin structure at the single-molecule level. Next, by exploiting the comprehension of the underlying molecular mechanisms, we illustrate how such polymer models can be used as powerful tools to make predictions in silico that can complement experiments in understanding genome folding. To this aim, we focus on recent key applications, such as the prediction of chromatin structure rearrangements upon disease-associated mutations and the identification of the putative chromatin organizing factors that orchestrate the specificity of DNA regulatory contacts genome-wide.
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131
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Zhang S, Cooper JAL, Chong YS, Naveed A, Mayoh C, Jayatilleke N, Liu T, Amos S, Kobelke S, Marshall AC, Meers O, Choi YS, Bond CS, Fox AH. NONO enhances mRNA processing of super-enhancer-associated GATA2 and HAND2 genes in neuroblastoma. EMBO Rep 2023; 24:e54977. [PMID: 36416237 PMCID: PMC9900351 DOI: 10.15252/embr.202254977] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 11/02/2022] [Accepted: 11/07/2022] [Indexed: 11/24/2022] Open
Abstract
High-risk neuroblastoma patients have poor survival rates and require better therapeutic options. High expression of a multifunctional DNA and RNA-binding protein, NONO, in neuroblastoma is associated with poor patient outcome; however, there is little understanding of the mechanism of NONO-dependent oncogenic gene regulatory activity in neuroblastoma. Here, we used cell imaging, biochemical and genome-wide molecular analysis to reveal complex NONO-dependent regulation of gene expression. NONO forms RNA- and DNA-tethered condensates throughout the nucleus and undergoes phase separation in vitro, modulated by nucleic acid binding. CLIP analyses show that NONO mainly binds to the 5' end of pre-mRNAs and modulates pre-mRNA processing, dependent on its RNA-binding activity. NONO regulates super-enhancer-associated genes, including HAND2 and GATA2. Abrogating NONO RNA binding, or phase separation activity, results in decreased expression of HAND2 and GATA2. Thus, future development of agents that target RNA-binding activity of NONO may have therapeutic potential in this cancer context.
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Affiliation(s)
- Song Zhang
- School of Human SciencesThe University of Western AustraliaCrawleyWAAustralia
| | - Jack AL Cooper
- School of Human SciencesThe University of Western AustraliaCrawleyWAAustralia
| | - Yee Seng Chong
- School of Molecular SciencesThe University of Western AustraliaCrawleyWAAustralia
| | - Alina Naveed
- School of Human SciencesThe University of Western AustraliaCrawleyWAAustralia
| | - Chelsea Mayoh
- Children's Cancer Institute AustraliaRandwickNSWAustralia
- Centre for Childhood Cancer ResearchUNSW SydneyKensingtonNSWAustralia
- School of Women's and Children's HealthUNSW SydneyKensingtonNSWAustralia
| | - Nisitha Jayatilleke
- Children's Cancer Institute AustraliaRandwickNSWAustralia
- Centre for Childhood Cancer ResearchUNSW SydneyKensingtonNSWAustralia
| | - Tao Liu
- Children's Cancer Institute AustraliaRandwickNSWAustralia
- Centre for Childhood Cancer ResearchUNSW SydneyKensingtonNSWAustralia
| | - Sebastian Amos
- School of Human SciencesThe University of Western AustraliaCrawleyWAAustralia
| | - Simon Kobelke
- School of Human SciencesThe University of Western AustraliaCrawleyWAAustralia
| | - Andrew C Marshall
- School of Molecular SciencesThe University of Western AustraliaCrawleyWAAustralia
| | - Oliver Meers
- School of Human SciencesThe University of Western AustraliaCrawleyWAAustralia
| | - Yu Suk Choi
- School of Human SciencesThe University of Western AustraliaCrawleyWAAustralia
| | - Charles S Bond
- School of Molecular SciencesThe University of Western AustraliaCrawleyWAAustralia
| | - Archa H Fox
- School of Human SciencesThe University of Western AustraliaCrawleyWAAustralia
- School of Molecular SciencesThe University of Western AustraliaCrawleyWAAustralia
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132
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Regulation of ribosomal RNA gene copy number, transcription and nucleolus organization in eukaryotes. Nat Rev Mol Cell Biol 2023; 24:414-429. [PMID: 36732602 DOI: 10.1038/s41580-022-00573-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/14/2022] [Indexed: 02/04/2023]
Abstract
One of the first biological machineries to be created seems to have been the ribosome. Since then, organisms have dedicated great efforts to optimize this apparatus. The ribosomal RNA (rRNA) contained within ribosomes is crucial for protein synthesis and maintenance of cellular function in all known organisms. In eukaryotic cells, rRNA is produced from ribosomal DNA clusters of tandem rRNA genes, whose organization in the nucleolus, maintenance and transcription are strictly regulated to satisfy the substantial demand for rRNA required for ribosome biogenesis. Recent studies have elucidated mechanisms underlying the integrity of ribosomal DNA and regulation of its transcription, including epigenetic mechanisms and a unique recombination and copy-number control system to stably maintain high rRNA gene copy number. In this Review, we disucss how the crucial maintenance of rRNA gene copy number through control of gene amplification and of rRNA production by RNA polymerase I are orchestrated. We also discuss how liquid-liquid phase separation controls the architecture and function of the nucleolus and the relationship between rRNA production, cell senescence and disease.
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133
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van Mierlo G, Pushkarev O, Kribelbauer JF, Deplancke B. Chromatin modules and their implication in genomic organization and gene regulation. Trends Genet 2023; 39:140-153. [PMID: 36549923 DOI: 10.1016/j.tig.2022.11.003] [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: 06/08/2022] [Revised: 11/04/2022] [Accepted: 11/27/2022] [Indexed: 12/24/2022]
Abstract
Regulation of gene expression is a complex but highly guided process. While genomic technologies and computational approaches have allowed high-throughput mapping of cis-regulatory elements (CREs) and their interactions in 3D, their precise role in regulating gene expression remains obscure. Recent complementary observations revealed that interactions between CREs frequently result in the formation of small-scale functional modules within topologically associating domains. Such chromatin modules likely emerge from a complex interplay between regulatory machineries assembled at CREs, including site-specific binding of transcription factors. Here, we review the methods that allow identifying chromatin modules, summarize possible mechanisms that steer CRE interactions within these modules, and discuss outstanding challenges to uncover how chromatin modules fit in our current understanding of the functional 3D genome.
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Affiliation(s)
- Guido van Mierlo
- Laboratory of Systems Biology and Genetics, Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland; Swiss Institute of Bioinformatics (SIB), Lausanne, Switzerland
| | - Olga Pushkarev
- Laboratory of Systems Biology and Genetics, Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland; Swiss Institute of Bioinformatics (SIB), Lausanne, Switzerland
| | - Judith F Kribelbauer
- Laboratory of Systems Biology and Genetics, Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland; Swiss Institute of Bioinformatics (SIB), Lausanne, Switzerland
| | - Bart Deplancke
- Laboratory of Systems Biology and Genetics, Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland; Swiss Institute of Bioinformatics (SIB), Lausanne, Switzerland.
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134
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Hao Y, Cai T, Liu C, Zhang X, Fu XD. Sequential Polyadenylation to Enable Alternative mRNA 3' End Formation. Mol Cells 2023; 46:57-64. [PMID: 36697238 PMCID: PMC9880608 DOI: 10.14348/molcells.2023.2176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 11/21/2022] [Accepted: 11/22/2022] [Indexed: 01/27/2023] Open
Abstract
In eukaryotic cells, a key RNA processing step to generate mature mRNA is the coupled reaction for cleavage and polyadenylation (CPA) at the 3' end of individual transcripts. Many transcripts are alternatively polyadenylated (APA) to produce mRNAs with different 3' ends that may either alter protein coding sequence (CDS-APA) or create different lengths of 3'UTR (tandem-APA). As the CPA reaction is intimately associated with transcriptional termination, it has been widely assumed that APA is regulated cotranscriptionally. Isoforms terminated at different regions may have distinct RNA stability under different conditions, thus altering the ratio of APA isoforms. Such differential impacts on different isoforms have been considered as post-transcriptional APA, but strictly speaking, this can only be considered "apparent" APA, as the choice is not made during the CPA reaction. Interestingly, a recent study reveals sequential APA as a new mechanism for post-transcriptional APA. This minireview will focus on this new mechanism to provide insights into various documented regulatory paradigms.
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Affiliation(s)
- Yajing Hao
- Department of Cellular and Molecular Medicine, Institute of Genomic Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Ting Cai
- Department of Cellular and Molecular Medicine, Institute of Genomic Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Chang Liu
- Department of Cellular and Molecular Medicine, Institute of Genomic Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Xuan Zhang
- Department of Cellular and Molecular Medicine, Institute of Genomic Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Xiang-Dong Fu
- Department of Cellular and Molecular Medicine, Institute of Genomic Medicine, University of California San Diego, La Jolla, CA 92093, USA
- Present address: Westlake Laboratory of Life Sciences and Biomedicine, School of Life Sciences, Westlake University, Hangzhou 310024, China
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135
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Lyons H, Veettil RT, Pradhan P, Fornero C, De La Cruz N, Ito K, Eppert M, Roeder RG, Sabari BR. Functional partitioning of transcriptional regulators by patterned charge blocks. Cell 2023; 186:327-345.e28. [PMID: 36603581 PMCID: PMC9910284 DOI: 10.1016/j.cell.2022.12.013] [Citation(s) in RCA: 82] [Impact Index Per Article: 82.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 10/15/2022] [Accepted: 12/07/2022] [Indexed: 01/05/2023]
Abstract
Components of transcriptional machinery are selectively partitioned into specific condensates, often mediated by protein disorder, yet we know little about how this specificity is achieved. Here, we show that condensates composed of the intrinsically disordered region (IDR) of MED1 selectively partition RNA polymerase II together with its positive allosteric regulators while excluding negative regulators. This selective compartmentalization is sufficient to activate transcription and is required for gene activation during a cell-state transition. The IDRs of partitioned proteins are necessary and sufficient for selective compartmentalization and require alternating blocks of charged amino acids. Disrupting this charge pattern prevents partitioning, whereas adding the pattern to proteins promotes partitioning with functional consequences for gene activation. IDRs with similar patterned charge blocks show similar partitioning and function. These findings demonstrate that disorder-mediated interactions can selectively compartmentalize specific functionally related proteins from a complex mixture of biomolecules, leading to regulation of a biochemical pathway.
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Affiliation(s)
- Heankel Lyons
- Laboratory of Nuclear Organization, Cecil H. and Ida Green Center for Reproductive Biology Sciences, Division of Basic Research, Department of Obstetrics and Gynecology, Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Reshma T Veettil
- Laboratory of Nuclear Organization, Cecil H. and Ida Green Center for Reproductive Biology Sciences, Division of Basic Research, Department of Obstetrics and Gynecology, Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Prashant Pradhan
- Laboratory of Nuclear Organization, Cecil H. and Ida Green Center for Reproductive Biology Sciences, Division of Basic Research, Department of Obstetrics and Gynecology, Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Christy Fornero
- Laboratory of Nuclear Organization, Cecil H. and Ida Green Center for Reproductive Biology Sciences, Division of Basic Research, Department of Obstetrics and Gynecology, Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Nancy De La Cruz
- Laboratory of Nuclear Organization, Cecil H. and Ida Green Center for Reproductive Biology Sciences, Division of Basic Research, Department of Obstetrics and Gynecology, Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Keiichi Ito
- Laboratory of Biochemistry and Molecular Biology, the Rockefeller University, New York, NY 10065, USA
| | - Mikayla Eppert
- Laboratory of Nuclear Organization, Cecil H. and Ida Green Center for Reproductive Biology Sciences, Division of Basic Research, Department of Obstetrics and Gynecology, Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Robert G Roeder
- Laboratory of Biochemistry and Molecular Biology, the Rockefeller University, New York, NY 10065, USA
| | - Benjamin R Sabari
- Laboratory of Nuclear Organization, Cecil H. and Ida Green Center for Reproductive Biology Sciences, Division of Basic Research, Department of Obstetrics and Gynecology, Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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136
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André AAM, Yewdall NA, Spruijt E. Crowding-induced phase separation and gelling by co-condensation of PEG in NPM1-rRNA condensates. Biophys J 2023; 122:397-407. [PMID: 36463407 PMCID: PMC9892608 DOI: 10.1016/j.bpj.2022.12.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 11/11/2022] [Accepted: 11/30/2022] [Indexed: 12/12/2022] Open
Abstract
The crowdedness of the cell calls for adequate intracellular organization. Biomolecular condensates, formed by liquid-liquid phase separation of intrinsically disordered proteins and nucleic acids, are important organizers of cellular fluids. To underpin the molecular mechanisms of protein condensation, cell-free studies are often used where the role of crowding is not investigated in detail. Here, we investigate the effects of macromolecular crowding on the formation and material properties of a model heterotypic biomolecular condensate, consisting of nucleophosmin (NPM1) and ribosomal RNA (rRNA). We studied the effect of the macromolecular crowding agent poly(ethylene glycol) (PEG), which is often considered an inert crowding agent. We observed that PEG could induce both homotypic and heterotypic phase separation of NPM1 and NPM1-rRNA, respectively. Crowding increases the condensed concentration of NPM1 and decreases its equilibrium dilute phase concentration, although no significant change in the concentration of rRNA in the dilute phase was observed. Interestingly, the crowder itself is concentrated in the condensates, suggesting that co-condensation rather than excluded volume interactions underlie the enhanced phase separation by PEG. Fluorescence recovery after photobleaching measurements indicated that both NPM1 and rRNA become immobile at high PEG concentrations, indicative of a liquid-to-gel transition. Together, these results provide more insight into the role of synthetic crowding agents in phase separation and demonstrate that condensate properties determined in vitro depend strongly on the addition of crowding agents.
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Affiliation(s)
- Alain A M André
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, the Netherlands
| | - N Amy Yewdall
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, the Netherlands
| | - Evan Spruijt
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, the Netherlands.
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137
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Lambert É, Puwakdandawa K, Tao YF, Robert F. From structure to molecular condensates: emerging mechanisms for Mediator function. FEBS J 2023; 290:286-309. [PMID: 34698446 DOI: 10.1111/febs.16250] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 10/15/2021] [Accepted: 10/25/2021] [Indexed: 02/05/2023]
Abstract
Mediator is a large modular protein assembly whose function as a coactivator of transcription is conserved in all eukaryotes. The Mediator complex can integrate and relay signals from gene-specific activators bound at enhancers to activate the general transcription machinery located at promoters. It has thus been described as a bridge between these elements during initiation of transcription. Here, we review recent studies on Mediator relating to its structure, gene specificity and general requirement, roles in chromatin architecture as well as novel concepts involving phase separation and transcriptional bursting. We revisit the mechanism of action of Mediator and ultimately put forward models for its mode of action in gene activation.
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Affiliation(s)
- Élie Lambert
- Institut de recherches cliniques de Montréal, Canada
| | | | - Yi Fei Tao
- Institut de recherches cliniques de Montréal, Canada
| | - François Robert
- Institut de recherches cliniques de Montréal, Canada.,Département de Médecine, Faculté de Médecine, Université de Montréal, Canada
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138
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Pinheiro EDS, Preato AM, Petrucci TVB, dos Santos LS, Glezer I. Phase-separation: a possible new layer for transcriptional regulation by glucocorticoid receptor. Front Endocrinol (Lausanne) 2023; 14:1160238. [PMID: 37124728 PMCID: PMC10145926 DOI: 10.3389/fendo.2023.1160238] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 03/20/2023] [Indexed: 05/02/2023] Open
Abstract
Glucocorticoids (GCs) are hormones involved in circadian adaptation and stress response, and it is also noteworthy that these steroidal molecules present potent anti-inflammatory action through GC receptors (GR). Upon ligand-mediated activation, GR translocates to the nucleus, and regulates gene expression related to metabolism, acute-phase response and innate immune response. GR field of research has evolved considerably in the last decades, providing varied mechanisms that contributed to the understanding of transcriptional regulation and also impacted drug design for treating inflammatory diseases. Liquid-liquid phase separation (LLPS) in cellular processes represents a recent topic in biology that conceptualizes membraneless organelles and microenvironments that promote, or inhibit, chemical reactions and interactions of protein or nucleic acids. The formation of these molecular condensates has been implicated in gene expression control, and recent evidence shows that GR and other steroid receptors can nucleate phase separation (PS). Here we briefly review the varied mechanisms of transcriptional control by GR, which are largely studied in the context of inflammation, and further present how PS can be involved in the control of gene expression. Lastly, we consider how the reported advances on LLPS during transcription control, specially for steroid hormone receptors, could impact the different modalities of GR action on gene expression, adding a new plausible molecular event in glucocorticoid signal transduction.
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139
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Pandey G, Budhathoki A, Spille JH. Characterizing Properties of Biomolecular Condensates Below the Diffraction Limit In Vivo. Methods Mol Biol 2023; 2563:425-445. [PMID: 36227487 DOI: 10.1007/978-1-0716-2663-4_22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Fluorescence microscopy assays enable the investigation of endogenous biomolecular condensates directly in their cellular context. With appropriate experimental designs, these assays yield quantitative information on condensate material properties and inform on biophysical mechanisms of condensate formation. Single-molecule super-resolution and tracking experiments grant access to the smallest condensates and early condensation stages not resolved by conventional imaging approaches. Here, we discuss considerations for using single-molecule assays to extract quantitative information about biomolecular condensates directly in their cellular context.
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Affiliation(s)
- Ganesh Pandey
- Department of Physics, University of Illinois at Chicago, Chicago, IL, USA
| | - Alisha Budhathoki
- Department of Physics, University of Illinois at Chicago, Chicago, IL, USA
| | - Jan-Hendrik Spille
- Department of Physics, University of Illinois at Chicago, Chicago, IL, USA.
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140
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Ohishi H, Shimada S, Uchino S, Li J, Sato Y, Shintani M, Owada H, Ohkawa Y, Pertsinidis A, Yamamoto T, Kimura H, Ochiai H. STREAMING-tag system reveals spatiotemporal relationships between transcriptional regulatory factors and transcriptional activity. Nat Commun 2022; 13:7672. [PMID: 36539402 PMCID: PMC9768169 DOI: 10.1038/s41467-022-35286-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 11/25/2022] [Indexed: 12/24/2022] Open
Abstract
Transcription is a dynamic process. To detect the dynamic relationship among protein clusters of RNA polymerase II and coactivators, gene loci, and transcriptional activity, we insert an MS2 repeat, a TetO repeat, and inteins with a selection marker just downstream of the transcription start site. By optimizing the individual elements, we develop the Spliced TetO REpeAt, MS2 repeat, and INtein sandwiched reporter Gene tag (STREAMING-tag) system. Clusters of RNA polymerase II and BRD4 are observed proximal to the transcription start site of Nanog when the gene is transcribed in mouse embryonic stem cells. In contrast, clusters of MED19 and MED22 tend to be located near the transcription start site, even without transcription activity. Thus, the STREAMING-tag system reveals the spatiotemporal relationships between transcriptional activity and protein clusters near the gene. This powerful tool is useful for quantitatively understanding transcriptional regulation in living cells.
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Affiliation(s)
- Hiroaki Ohishi
- grid.257022.00000 0000 8711 3200Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, 739-0046 Japan
| | - Seiru Shimada
- grid.257022.00000 0000 8711 3200Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, 739-0046 Japan
| | - Satoshi Uchino
- grid.32197.3e0000 0001 2179 2105School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, 226-8501 Japan
| | - Jieru Li
- grid.51462.340000 0001 2171 9952Structural Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065 USA
| | - Yuko Sato
- grid.32197.3e0000 0001 2179 2105School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, 226-8501 Japan ,grid.32197.3e0000 0001 2179 2105Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, 226-8503 Japan
| | - Manabu Shintani
- grid.257022.00000 0000 8711 3200Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, 739-0046 Japan
| | - Hitoshi Owada
- grid.257022.00000 0000 8711 3200Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, 739-0046 Japan
| | - Yasuyuki Ohkawa
- grid.177174.30000 0001 2242 4849Division of Transcriptomics, Medical Institute of Bioregulation, Kyushu University, Fukuoka, 812-8582 Japan
| | - Alexandros Pertsinidis
- grid.51462.340000 0001 2171 9952Structural Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065 USA
| | - Takashi Yamamoto
- grid.257022.00000 0000 8711 3200Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, 739-0046 Japan
| | - Hiroshi Kimura
- grid.32197.3e0000 0001 2179 2105School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, 226-8501 Japan ,grid.32197.3e0000 0001 2179 2105Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, 226-8503 Japan
| | - Hiroshi Ochiai
- grid.257022.00000 0000 8711 3200Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, 739-0046 Japan
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141
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Ibrahim Z, Wang T, Destaing O, Salvi N, Hoghoughi N, Chabert C, Rusu A, Gao J, Feletto L, Reynoird N, Schalch T, Zhao Y, Blackledge M, Khochbin S, Panne D. Structural insights into p300 regulation and acetylation-dependent genome organisation. Nat Commun 2022; 13:7759. [PMID: 36522330 PMCID: PMC9755262 DOI: 10.1038/s41467-022-35375-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 11/29/2022] [Indexed: 12/23/2022] Open
Abstract
Histone modifications are deposited by chromatin modifying enzymes and read out by proteins that recognize the modified state. BRD4-NUT is an oncogenic fusion protein of the acetyl lysine reader BRD4 that binds to the acetylase p300 and enables formation of long-range intra- and interchromosomal interactions. We here examine how acetylation reading and writing enable formation of such interactions. We show that NUT contains an acidic transcriptional activation domain that binds to the TAZ2 domain of p300. We use NMR to investigate the structure of the complex and found that the TAZ2 domain has an autoinhibitory role for p300. NUT-TAZ2 interaction or mutations found in cancer that interfere with autoinhibition by TAZ2 allosterically activate p300. p300 activation results in a self-organizing, acetylation-dependent feed-forward reaction that enables long-range interactions by bromodomain multivalent acetyl-lysine binding. We discuss the implications for chromatin organisation, gene regulation and dysregulation in disease.
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Affiliation(s)
- Ziad Ibrahim
- Leicester Institute of Structural and Chemical Biology, Department of Molecular and Cell Biology, University of Leicester, Leicester, UK
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, United States
| | - Tao Wang
- CNRS UMR 5309, INSERM U1209, Université Grenoble Alpes, Institute for Advanced Biosciences, Grenoble, France
| | - Olivier Destaing
- CNRS UMR 5309, INSERM U1209, Université Grenoble Alpes, Institute for Advanced Biosciences, Grenoble, France
| | - Nicola Salvi
- Institut de Biologie Structurale, CNRS, CEA, UGA, Grenoble, France
| | - Naghmeh Hoghoughi
- CNRS UMR 5309, INSERM U1209, Université Grenoble Alpes, Institute for Advanced Biosciences, Grenoble, France
| | - Clovis Chabert
- CNRS UMR 5309, INSERM U1209, Université Grenoble Alpes, Institute for Advanced Biosciences, Grenoble, France
| | - Alexandra Rusu
- Leicester Institute of Structural and Chemical Biology, Department of Molecular and Cell Biology, University of Leicester, Leicester, UK
| | - Jinjun Gao
- Ben May Department of Cancer Research, The University of Chicago, Chicago, IL, 60637, USA
| | - Leonardo Feletto
- Leicester Institute of Structural and Chemical Biology, Department of Molecular and Cell Biology, University of Leicester, Leicester, UK
| | - Nicolas Reynoird
- CNRS UMR 5309, INSERM U1209, Université Grenoble Alpes, Institute for Advanced Biosciences, Grenoble, France
| | - Thomas Schalch
- Leicester Institute of Structural and Chemical Biology, Department of Molecular and Cell Biology, University of Leicester, Leicester, UK
| | - Yingming Zhao
- Ben May Department of Cancer Research, The University of Chicago, Chicago, IL, 60637, USA
| | | | - Saadi Khochbin
- CNRS UMR 5309, INSERM U1209, Université Grenoble Alpes, Institute for Advanced Biosciences, Grenoble, France
| | - Daniel Panne
- Leicester Institute of Structural and Chemical Biology, Department of Molecular and Cell Biology, University of Leicester, Leicester, UK.
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142
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Amankwaa B, Schoborg T, Labrador M. Drosophila insulator proteins exhibit in vivo liquid-liquid phase separation properties. Life Sci Alliance 2022; 5:5/12/e202201536. [PMID: 35853678 PMCID: PMC9297610 DOI: 10.26508/lsa.202201536] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 07/05/2022] [Accepted: 07/06/2022] [Indexed: 11/24/2022] Open
Abstract
Drosophila insulator proteins and the cohesin subunit Rad21 coalesce in vivo to form liquid-droplet condensates, suggesting that liquid–liquid phase separation mediates their function in 3D genome organization. Mounting evidence implicates liquid–liquid phase separation (LLPS), the condensation of biomolecules into liquid-like droplets in the formation and dissolution of membraneless intracellular organelles (MLOs). Cells use MLOs or condensates for various biological processes, including emergency signaling and spatiotemporal control over steady-state biochemical reactions and heterochromatin formation. Insulator proteins are architectural elements involved in establishing independent domains of transcriptional activity within eukaryotic genomes. In Drosophila, insulator proteins form nuclear foci known as insulator bodies in response to osmotic stress. However, the mechanism through which insulator proteins assemble into bodies is yet to be investigated. Here, we identify signatures of LLPS by insulator bodies, including high disorder tendency in insulator proteins, scaffold–client–dependent assembly, extensive fusion behavior, sphericity, and sensitivity to 1,6-hexanediol. We also show that the cohesin subunit Rad21 is a component of insulator bodies, adding to the known insulator protein constituents and γH2Av. Our data suggest a concerted role of cohesin and insulator proteins in insulator body formation and under physiological conditions. We propose a mechanism whereby these architectural proteins modulate 3D genome organization through LLPS.
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Affiliation(s)
- Bright Amankwaa
- Department of Biochemistry and Cellular and Molecular Biology, The University of Tennessee, Knoxville, TN, USA
| | - Todd Schoborg
- Department of Biochemistry and Cellular and Molecular Biology, The University of Tennessee, Knoxville, TN, USA
| | - Mariano Labrador
- Department of Biochemistry and Cellular and Molecular Biology, The University of Tennessee, Knoxville, TN, USA
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143
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Kitamura K, Suzuki H, Abe R, Inohara H, Kaneda Y, Takahashi H, Nimura K. Dual function of SF3B2 on chromatin and RNA to regulate transcription in head and neck squamous cell carcinoma. Cell Biosci 2022; 12:92. [PMID: 35715826 PMCID: PMC9206271 DOI: 10.1186/s13578-022-00812-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Accepted: 05/11/2022] [Indexed: 11/13/2022] Open
Abstract
RNA is spliced concomitantly with transcription and the process is organized by RNA splicing factors, transcriptional regulators, and chromatin regulators. RNA is spliced in close proximity to transcription machinery. Hence, some RNA splicing factors may play a role in transcription. Here, we show that the splicing factor SF3B2 binds to gene regulatory elements and mRNA to modulate transcription and RNA stability in head and neck squamous cell carcinoma cells. High SF3B2 expression leads to poor prognosis in patients with head and neck squamous cell carcinoma and to progression of tumor growth in mice. SF3B2 promotes tumor growth, owing to its involvement in activation of gene expression associated with mitochondrial electron transport and transcription regulatory region DNA binding. SF3B2 is enriched around the promoter element on chromatin and the transcription termination site on RNA. SF3B2 is involved in the regulation of RNA stability. According to the SF3B2-binding profile, SF3B2 regulates RNA polymerase II activity, in addition to regulating RNA splicing. Mechanistically, SF3B2 promotes the binding of structural maintenance of chromosomes 1A and CCCTC-binding factor (CTCF) to the SF3B2-binding genomic regions. SF3B2 also modulates CTCF transcriptional activity. Our findings indicate that SF3B2 has a dual function in both transcription and RNA stability, leading to head and neck squamous cell carcinoma progression.
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144
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Chowdhary S, Kainth AS, Paracha S, Gross DS, Pincus D. Inducible transcriptional condensates drive 3D genome reorganization in the heat shock response. Mol Cell 2022; 82:4386-4399.e7. [PMID: 36327976 PMCID: PMC9701134 DOI: 10.1016/j.molcel.2022.10.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 08/28/2022] [Accepted: 10/10/2022] [Indexed: 11/12/2022]
Abstract
Mammalian developmental and disease-associated genes concentrate large quantities of the transcriptional machinery by forming membrane-less compartments known as transcriptional condensates. However, it is unknown whether these structures are evolutionarily conserved or involved in 3D genome reorganization. Here, we identify inducible transcriptional condensates in the yeast heat shock response (HSR). HSR condensates are biophysically dynamic spatiotemporal clusters of the sequence-specific transcription factor heat shock factor 1 (Hsf1) with Mediator and RNA Pol II. Uniquely, HSR condensates drive the coalescence of multiple Hsf1 target genes, even those located on different chromosomes. Binding of the chaperone Hsp70 to a site on Hsf1 represses clustering, whereas an intrinsically disordered region on Hsf1 promotes condensate formation and intergenic interactions. Mutation of both Hsf1 determinants reprograms HSR condensates to become constitutively active without intergenic coalescence, which comes at a fitness cost. These results suggest that transcriptional condensates are ancient and flexible compartments of eukaryotic gene control.
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Affiliation(s)
- Surabhi Chowdhary
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA
| | - Amoldeep S Kainth
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, Shreveport, LA 71130, USA
| | - Sarah Paracha
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA
| | - David S Gross
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, Shreveport, LA 71130, USA.
| | - David Pincus
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA; Center for Physics of Evolving Systems, University of Chicago, Chicago, IL 60637, USA.
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145
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Song L, Yao X, Li H, Peng B, Boka AP, Liu Y, Chen G, Liu Z, Mathias KM, Xia L, Li Q, Mir M, Li Y, Li H, Wan L. Hotspot mutations in the structured ENL YEATS domain link aberrant transcriptional condensates and cancer. Mol Cell 2022; 82:4080-4098.e12. [PMID: 36272410 PMCID: PMC10071517 DOI: 10.1016/j.molcel.2022.09.034] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 08/04/2022] [Accepted: 09/28/2022] [Indexed: 11/06/2022]
Abstract
Growing evidence suggests prevalence of transcriptional condensates on chromatin, yet their mechanisms of formation and functional significance remain largely unclear. In human cancer, a series of mutations in the histone acetylation reader ENL create gain-of-function mutants with increased transcriptional activation ability. Here, we show that these mutations, clustered in ENL's structured acetyl-reading YEATS domain, trigger aberrant condensates at native genomic targets through multivalent homotypic and heterotypic interactions. Mechanistically, mutation-induced structural changes in the YEATS domain, ENL's two disordered regions of opposing charges, and the incorporation of extrinsic elongation factors are all required for ENL condensate formation. Extensive mutagenesis establishes condensate formation as a driver of oncogenic gene activation. Furthermore, expression of ENL mutants beyond the endogenous level leads to non-functional condensates. Our findings provide new mechanistic and functional insights into cancer-associated condensates and support condensate dysregulation as an oncogenic mechanism.
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Affiliation(s)
- Lele Song
- Department of Cancer Biology, Abramson Family Cancer Research Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Xinyi Yao
- MOE Key Laboratory of Protein Sciences, Beijing Frontier Research Center for Biological Structure, School of Medicine, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Hangpeng Li
- Department of Cancer Biology, Abramson Family Cancer Research Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Department of the School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Bo Peng
- MOE Key Laboratory of Protein Sciences, Beijing Frontier Research Center for Biological Structure, School of Medicine, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Alan P Boka
- Biochemistry and Molecular Biophysics Graduate Group, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Center for Computational and Genomic Medicine, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Yiman Liu
- Department of Cancer Biology, Abramson Family Cancer Research Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Guochao Chen
- MOE Key Laboratory of Protein Sciences, Beijing Frontier Research Center for Biological Structure, School of Medicine, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Zhenyang Liu
- MOE Key Laboratory of Protein Sciences, Beijing Frontier Research Center for Biological Structure, School of Medicine, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Kaeli M Mathias
- Department of Cancer Biology, Abramson Family Cancer Research Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Biochemistry and Molecular Biophysics Graduate Group, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Center for Computational and Genomic Medicine, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Lingbo Xia
- Department of Cancer Biology, Abramson Family Cancer Research Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Department of the School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Qinglan Li
- Department of Cancer Biology, Abramson Family Cancer Research Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Mustafa Mir
- Center for Computational and Genomic Medicine, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Epigenetics Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Institute for Regenerative Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Yuanyuan Li
- MOE Key Laboratory of Protein Sciences, Beijing Frontier Research Center for Biological Structure, School of Medicine, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China.
| | - Haitao Li
- MOE Key Laboratory of Protein Sciences, Beijing Frontier Research Center for Biological Structure, School of Medicine, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China.
| | - Liling Wan
- Department of Cancer Biology, Abramson Family Cancer Research Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Epigenetics Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Institute for Regenerative Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.
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146
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Lee PW, Marshall AC, Knott GJ, Kobelke S, Martelotto L, Cho E, McMillan PJ, Lee M, Bond CS, Fox AH. Paraspeckle subnuclear bodies depend on dynamic heterodimerisation of DBHS RNA-binding proteins via their structured domains. J Biol Chem 2022; 298:102563. [DOI: 10.1016/j.jbc.2022.102563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 09/23/2022] [Accepted: 09/26/2022] [Indexed: 11/06/2022] Open
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147
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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: 6] [Impact Index Per Article: 3.0] [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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148
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Richter WF, Nayak S, Iwasa J, Taatjes DJ. The Mediator complex as a master regulator of transcription by RNA polymerase II. Nat Rev Mol Cell Biol 2022; 23:732-749. [PMID: 35725906 PMCID: PMC9207880 DOI: 10.1038/s41580-022-00498-3] [Citation(s) in RCA: 71] [Impact Index Per Article: 35.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/17/2022] [Indexed: 02/08/2023]
Abstract
The Mediator complex, which in humans is 1.4 MDa in size and includes 26 subunits, controls many aspects of RNA polymerase II (Pol II) function. Apart from its size, a defining feature of Mediator is its intrinsic disorder and conformational flexibility, which contributes to its ability to undergo phase separation and to interact with a myriad of regulatory factors. In this Review, we discuss Mediator structure and function, with emphasis on recent cryogenic electron microscopy data of the 4.0-MDa transcription preinitiation complex. We further discuss how Mediator and sequence-specific DNA-binding transcription factors enable enhancer-dependent regulation of Pol II function at distal gene promoters, through the formation of molecular condensates (or transcription hubs) and chromatin loops. Mediator regulation of Pol II reinitiation is also discussed, in the context of transcription bursting. We propose a working model for Mediator function that combines experimental results and theoretical considerations related to enhancer-promoter interactions, which reconciles contradictory data regarding whether enhancer-promoter communication is direct or indirect. We conclude with a discussion of Mediator's potential as a therapeutic target and of future research directions.
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Affiliation(s)
- William F Richter
- Department of Biochemistry, University of Colorado, Boulder, CO, USA
| | - Shraddha Nayak
- Department of Biochemistry, University of Utah, Salt Lake City, UT, USA
| | - Janet Iwasa
- Department of Biochemistry, University of Utah, Salt Lake City, UT, USA
| | - Dylan J Taatjes
- Department of Biochemistry, University of Colorado, Boulder, CO, USA.
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149
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Ilık İA, Aktaş T. Nuclear speckles: dynamic hubs of gene expression regulation. FEBS J 2022; 289:7234-7245. [PMID: 34245118 DOI: 10.1111/febs.16117] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 06/13/2021] [Accepted: 07/08/2021] [Indexed: 01/13/2023]
Abstract
Complex, multistep biochemical reactions that routinely take place in our cells require high concentrations of enzymes, substrates, and other structural components to proceed efficiently and typically require chemical environments that can inhibit other reactions in their immediate vicinity. Eukaryotic cells solve these problems by restricting such reactions into diffusion-restricted compartments within the cell called organelles that can be separated from their environment by a lipid membrane, or into membrane-less compartments that form through liquid-liquid phase separation (LLPS). One of the most easily noticeable and the earliest discovered organelle is the nucleus, which harbors the genetic material in cells where transcription by RNA polymerases produces most of the messenger RNAs and a plethora of noncoding RNAs, which in turn are required for translation of mRNAs in the cytoplasm. The interior of the nucleus is not a uniform soup of biomolecules and rather consists of a variety of membrane-less bodies, such as the nucleolus, nuclear speckles (NS), paraspeckles, Cajal bodies, histone locus bodies, and more. In this review, we will focus on NS with an emphasis on recent developments including our own findings about the formation of NS by two large IDR-rich proteins SON and SRRM2.
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Affiliation(s)
| | - Tuğçe Aktaş
- Max Planck Institute for Molecular Genetics, Berlin, Germany
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150
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Johnstone CP, Galloway KE. Supercoiling-mediated feedback rapidly couples and tunes transcription. Cell Rep 2022; 41:111492. [PMID: 36261020 PMCID: PMC9624111 DOI: 10.1016/j.celrep.2022.111492] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 08/04/2022] [Accepted: 09/21/2022] [Indexed: 11/29/2022] Open
Abstract
Transcription induces a wave of DNA supercoiling, altering the binding affinity of RNA polymerases and reshaping the biochemical landscape of gene regulation. As supercoiling rapidly diffuses, transcription dynamically reshapes the regulation of proximal genes, forming a complex feedback loop. However, a theoretical framework is needed to integrate biophysical regulation with biochemical transcriptional regulation. To investigate the role of supercoiling-mediated feedback within multi-gene systems, we model transcriptional regulation under the influence of supercoiling-mediated polymerase dynamics, allowing us to identify patterns of expression that result from physical inter-gene coupling. We find that gene syntax—the relative ordering and orientation of genes—defines the expression profiles, variance, burst dynamics, and inter-gene correlation of two-gene systems. Furthermore, supercoiling can enhance or weaken biochemical regulation. Our results suggest that supercoiling couples behavior between neighboring genes, providing a regulatory mechanism that tunes transcriptional variance in engineered gene networks and explains the behavior of co-localized native circuits. Supercoiling-mediated feedback couples the transcription of proximal genes. Here, Johnstone and Galloway provide a framework for integrating biochemical gene regulation with the biophysical effects of DNA supercoiling. This unified model provides design principles for improving the performance of gene networks, developing novel regulatory functions, and accessing previously inaccessible regulatory dynamics.
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Affiliation(s)
| | - Kate E. Galloway
- Department of Chemical Engineering, MIT, 25 Ames St., Cambridge, MA 02139, USA,Lead contact,Correspondence:
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