51
|
Liu J, Zhorabek F, Zhang T, Lam JWY, Tang BZ, Chau Y. Multifaceted Cargo Recruitment and Release from Artificial Membraneless Organelles. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2201721. [PMID: 35596607 DOI: 10.1002/smll.202201721] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 04/15/2022] [Indexed: 06/15/2023]
Abstract
Liquid-liquid phase separation (LLPS) drives membraneless organelles (MLOs) formation for organizing biomolecules. Artificial MLOs (AMLOs) have been constructed mostly via the LLPS of engineered proteins capable of regulating limited types of biomolecules. Here, leveraging a minimalist AMLO, driven by LLPS of polymer-oligopeptide hybrids, enrichment, recruitment, and release of multifaceted cargoes are quantitatively shown, including small fluorescent molecules, fluorophore-containing macromolecules, proteins, DNAs, and RNAs. Cargoes show up to 105 -fold enrichment, whilst recruitment and release are triggered by variations of temperature, pH, and/or ionic strength. Also, the first efficacious, rapid, and reversible control of aggregation-induced emission with over 30 folds of modulation of overall fluorescence intensity is achieved, by intensifying the aggregation of luminogens in AMLO. The AMLO is a simple yet versatile platform for potential drug delivery and biosensor applications.
Collapse
Affiliation(s)
- Jianhui Liu
- Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, P. R. China
| | - Fariza Zhorabek
- Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, P. R. China
| | - Tianfu Zhang
- Department of Chemistry and Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, P. R. China
| | - Jacky W Y Lam
- Department of Chemistry and Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, P. R. China
| | - Ben Zhong Tang
- Department of Chemistry and Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, P. R. China
- School of Science and Engineering, Shenzhen Key Laboratory of Functional Aggregate Materials, The Chinese University of Hong Kong, Shenzhen, Shenzhen City, Guangdong, 518172, P. R. China
| | - Ying Chau
- Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, P. R. China
| |
Collapse
|
52
|
Guéguen N, Maréchal E. Origin of cyanobacterial thylakoids via a non-vesicular glycolipid phase transition and their impact on the Great Oxygenation Event. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:2721-2734. [PMID: 35560194 DOI: 10.1093/jxb/erab429] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 09/16/2021] [Indexed: 06/15/2023]
Abstract
The appearance of oxygenic photosynthesis in cyanobacteria is a major event in evolution. It had an irreversible impact on the Earth, promoting the Great Oxygenation Event (GOE) ~2.4 billion years ago. Ancient cyanobacteria predating the GOE were Gloeobacter-type cells lacking thylakoids, which hosted photosystems in their cytoplasmic membrane. The driver of the GOE was proposed to be the transition from unicellular to filamentous cyanobacteria. However, the appearance of thylakoids expanded the photosynthetic surface to such an extent that it introduced a multiplier effect, which would be more coherent with an impact on the atmosphere. Primitive thylakoids self-organize as concentric parietal uninterrupted multilayers. There is no robust evidence for an origin of thylakoids via a vesicular-based scenario. This review reports studies supporting that hexagonal II-forming glucolipids and galactolipids at the periphery of the cytosolic membrane could be turned, within nanoseconds and without any external source of energy, into membrane multilayers. Comparison of lipid biosynthetic pathways shows that ancient cyanobacteria contained only one anionic lamellar-forming lipid, phosphatidylglycerol. The acquisition of sulfoquinovosyldiacylglycerol biosynthesis correlates with thylakoid emergence, possibly enabling sufficient provision of anionic lipids to trigger a hexagonal II-to-lamellar phase transition. With this non-vesicular lipid-phase transition, a framework is also available to re-examine the role of companion proteins in thylakoid biogenesis.
Collapse
Affiliation(s)
- Nolwenn Guéguen
- Laboratoire de Physiologie Cellulaire et Végétale; INRAE, CNRS, CEA, Université Grenoble Alpes; IRIG; CEA Grenoble, 17 rue des Martyrs, 38000 Grenoble, France
| | - Eric Maréchal
- Laboratoire de Physiologie Cellulaire et Végétale; INRAE, CNRS, CEA, Université Grenoble Alpes; IRIG; CEA Grenoble, 17 rue des Martyrs, 38000 Grenoble, France
| |
Collapse
|
53
|
Nguyen HT, Hori N, Thirumalai D. Condensates in RNA repeat sequences are heterogeneously organized and exhibit reptation dynamics. Nat Chem 2022; 14:775-785. [PMID: 35501484 DOI: 10.1038/s41557-022-00934-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 03/24/2022] [Indexed: 12/21/2022]
Abstract
Although it is known that RNA undergoes liquid-liquid phase separation, the interplay between the molecular driving forces and the emergent features of the condensates, such as their morphologies and dynamic properties, is not well understood. We introduce a coarse-grained model to simulate phase separation of trinucleotide repeat RNAs, which are implicated in neurological disorders. After establishing that the simulations reproduce key experimental findings, we show that once recruited inside the liquid droplets, the monomers transition from hairpin-like structures to extended states. Interactions between the monomers in the condensates result in the formation of an intricate and dense intermolecular network, which severely restrains the fluctuations and mobilities of the RNAs inside large droplets. In the largest densely packed high-viscosity droplets, the mobility of RNA chains is best characterized by reptation, reminiscent of the dynamics in polymer melts. Our work provides a microscopic framework for understanding liquid-liquid phase separation in RNA, which is not easily discernible in current experiments.
Collapse
Affiliation(s)
- Hung T Nguyen
- Department of Chemistry, The University of Texas at Austin, Austin, TX, USA
| | - Naoto Hori
- School of Pharmacy, University of Nottingham, Nottingham, UK
| | - D Thirumalai
- Department of Chemistry, The University of Texas at Austin, Austin, TX, USA.
| |
Collapse
|
54
|
Ahn SY, Kim J, Vellampatti S, Oh S, Lim YT, Park SH, Luo D, Chung J, Um SH. Protein-Encoding Free-Standing RNA Hydrogel for Sub-Compartmentalized Translation. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2110424. [PMID: 35263477 DOI: 10.1002/adma.202110424] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 02/20/2022] [Indexed: 06/14/2023]
Abstract
RNA can self-fold into complex structures that can serve as major biological regulators in protein synthesis and in catalysis. Due to the abundance of structural primitives and functional diversity, RNA has been utilized for designing nature-defined goals despite its intrinsic chemical instability and lack of technologies. Here, a robust, free-standing RNA hydrogel is developed through a sequential process involving both ligation and rolling circle transcription to form RNA G-quadruplexes, capable of both catalytic activity and enhancing expression of several proteins in sub-compartmentalized, phase-separated translation environments. The observations suggest that this hydrogel will expand RNA research and impact practical RNA principles and applications.
Collapse
Affiliation(s)
- So Yeon Ahn
- Progeneer Incorporation, 12, Digital-ro 31-gil, Guro-gu, Seoul, 08380, Korea
| | - Jeonghun Kim
- Progeneer Incorporation, 12, Digital-ro 31-gil, Guro-gu, Seoul, 08380, Korea
| | | | - Sung Oh
- Progeneer Incorporation, 12, Digital-ro 31-gil, Guro-gu, Seoul, 08380, Korea
| | - Yong Taik Lim
- School of Chemical Engineering, Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do, 16419, Korea
- SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do, 16419, Korea
| | - Sung Ha Park
- SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do, 16419, Korea
- Department of Physics, Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do, 16419, Korea
| | - Dan Luo
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY, 14850, USA
| | - Junho Chung
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, 03080, Korea
| | - Soong Ho Um
- Progeneer Incorporation, 12, Digital-ro 31-gil, Guro-gu, Seoul, 08380, Korea
- School of Chemical Engineering, Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do, 16419, Korea
- SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do, 16419, Korea
- Biomedical Institute for Convergence at SKKU (BICS), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do, 16419, Korea
- Institute of Quantum Biophysics (IQB), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do, 16419, Korea
| |
Collapse
|
55
|
Feric M, Misteli T. Function moves biomolecular condensates in phase space. Bioessays 2022; 44:e2200001. [PMID: 35243657 PMCID: PMC9277701 DOI: 10.1002/bies.202200001] [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: 01/03/2022] [Revised: 02/19/2022] [Accepted: 02/22/2022] [Indexed: 11/08/2022]
Abstract
Phase separation underlies the formation of biomolecular condensates. We hypothesize the cellular processes that occur within condensates shape their structural features. We use the example of transcription to discuss structure-function relationships in condensates. Various types of transcriptional condensates have been reported across the evolutionary spectrum in the cell nucleus as well as in mitochondrial and bacterial nucleoids. In vitro and in vivo observations suggest that transcriptional activity of condensates influences their supramolecular structure, which in turn affects their function. Condensate organization thus becomes driven by differences in miscibility among the DNA and proteins of the transcription machinery and the RNA transcripts they generate. These considerations are in line with the notion that cellular processes shape the structural properties of condensates, leading to a dynamic, mutual interplay between structure and function in the cell.
Collapse
Affiliation(s)
- Marina Feric
- National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Tom Misteli
- National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| |
Collapse
|
56
|
Dobrynin MA, Korchagina NM, Ponomartsev NV, Podgornaya OI, Enukashvily NI. Influence of Inactivation of Tandemly Repeated Pericentromeric DNA Transcription on the Formation of Membraneless Structures at the End of Oocyte Maturation. Russ J Dev Biol 2022. [DOI: 10.1134/s1062360422020059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
57
|
Hanselmann RG, Welter C. Origin of Cancer: Cell work is the Key to Understanding Cancer Initiation and Progression. Front Cell Dev Biol 2022; 10:787995. [PMID: 35300431 PMCID: PMC8921603 DOI: 10.3389/fcell.2022.787995] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 01/31/2022] [Indexed: 11/16/2022] Open
Abstract
The cell is the smallest unit of life. It is a structure that maintains order through self-organization, characterized by a high level of dynamism, which in turn is characterized by work. For this work to take place, a continuous high flow of energy is necessary. However, a focused view of the physical relationship between energy and work is inadequate for describing complex biological/medical mechanisms or systems. In this review, we try to make a connection between the fundamental laws of physics and the mechanisms and functions of biology, which are characterized by self-organization. Many different physical work processes (work) in human cells are called cell work and can be grouped into five forms: synthetic, mechanical, electrical, concentration, and heat generation cell work. In addition to the flow of energy, these cell functions are based on fundamental processes of self-organization that we summarize with the term Entirety of molecular interaction (EoMI). This illustrates that cell work is caused by numerous molecular reactions, flow equilibrium, and mechanisms. Their number and interactions are so complex that they elude our perception in their entirety. To be able to describe cell functions in a biological/medical context, the parameters influencing cell work should be summarized in overarching influencing variables. These are “biological” energy, information, matter, and cell mechanics (EMIM). This makes it possible to describe and characterize the cell work involved in cell systems (e.g., respiratory chain, signal transmission, cell structure, or inheritance processes) and to demonstrate changes. If cell work and the different influencing parameters (EMIM influencing variables) are taken as the central property of the cell, specific gene mutations cannot be regarded as the sole cause for the initiation and progression of cancer. This reductionistic monocausal view does not do justice to the dynamic and highly complex system of a cell. Therefore, we postulate that each of the EMIM influencing variables described above is capable of changing the cell work and thus the order of a cell in such a way that it can develop into a cancer cell.
Collapse
|
58
|
Rhine K, Dasovich M, Yoniles J, Badiee M, Skanchy S, Ganser L, Ge Y, Fare CM, Shorter J, Leung AKL, Myong S. Poly(ADP-ribose) drives condensation of FUS via a transient interaction. Mol Cell 2022; 82:969-985.e11. [PMID: 35182479 PMCID: PMC9330637 DOI: 10.1016/j.molcel.2022.01.018] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 11/20/2021] [Accepted: 01/20/2022] [Indexed: 02/08/2023]
Abstract
Poly(ADP-ribose) (PAR) is an RNA-like polymer that regulates an increasing number of biological processes. Dysregulation of PAR is implicated in neurodegenerative diseases characterized by abnormal protein aggregation, including amyotrophic lateral sclerosis (ALS). PAR forms condensates with FUS, an RNA-binding protein linked with ALS, through an unknown mechanism. Here, we demonstrate that a strikingly low concentration of PAR (1 nM) is sufficient to trigger condensation of FUS near its physiological concentration (1 μM), which is three orders of magnitude lower than the concentration at which RNA induces condensation (1 μM). Unlike RNA, which associates with FUS stably, PAR interacts with FUS transiently, triggering FUS to oligomerize into condensates. Moreover, inhibition of a major PAR-synthesizing enzyme, PARP5a, diminishes FUS condensation in cells. Despite their structural similarity, PAR and RNA co-condense with FUS, driven by disparate modes of interaction with FUS. Thus, we uncover a mechanism by which PAR potently seeds FUS condensation.
Collapse
Affiliation(s)
- Kevin Rhine
- Program in Cell, Molecular, Developmental Biology, and Biophysics, Johns Hopkins University, Baltimore, MD 21218, USA.,Department of Biology, Johns Hopkins University, Baltimore, MD 21218
| | - Morgan Dasovich
- Chemistry-Biology Interface Program, Johns Hopkins University, Baltimore, MD 21218, USA.,Department of Chemistry, Johns Hopkins University, Baltimore, MD 21218, USA.,Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Joey Yoniles
- Department of Biophysics, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Mohsen Badiee
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Sophie Skanchy
- Department of Biophysics, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Laura Ganser
- Department of Biophysics, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Yingda Ge
- Department of Biophysics, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Charlotte M. Fare
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - James Shorter
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Anthony K. L. Leung
- Chemistry-Biology Interface Program, Johns Hopkins University, Baltimore, MD 21218, USA.,Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA.,Department of Molecular Biology and Genetics, School of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA.,Department of Oncology, School of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA.,Corresponding Authors; &
| | - Sua Myong
- Program in Cell, Molecular, Developmental Biology, and Biophysics, Johns Hopkins University, Baltimore, MD 21218, USA; Department of Biophysics, Johns Hopkins University, Baltimore, MD 21218, USA; Physics Frontier Center (Center for the Physics of Living Cells), University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
| |
Collapse
|
59
|
Jiang LL, Guan WL, Wang JY, Zhang SX, Hu HY. RNA-assisted sequestration of RNA-binding proteins by cytoplasmic inclusions of the C-terminal 35-kDa fragment of TDP-43. J Cell Sci 2022; 135:274331. [PMID: 35142363 DOI: 10.1242/jcs.259380] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 01/31/2022] [Indexed: 11/20/2022] Open
Abstract
TDP-43 is a nuclear splicing factor functioning in pre-mRNA processing. Its C-terminal 35-kDa fragment (TDP-35) forms inclusions or aggregates in cytoplasm, and sequesters full-length TDP-43 into the inclusions through binding with RNA. We extended the research to investigate whether TDP-35 inclusions sequester other RNA-binding proteins (RBPs) and how RNA-binding specificity exerts the function in this sequestration process. We have characterized TIA1 (T-cell restricted intracellular antigen-1) and other RBPs that can be sequestered into the TDP-35 inclusions through specific RNA binding, and found that this sequestration leads to dysfunction of TIA1 in maturation of target pre-mRNA. Moreover, we directly visualized the dynamic sequestration of TDP-43 by the cytoplasmic TDP-35 inclusions by live-cell imaging. Our results demonstrate that TDP-35 sequesters some specific RBPs and this sequestration is assisted by binding with sequence-specific RNA. This study provides further evidence in supporting the hijacking hypothesis for RNA-assisted sequestration and will be beneficial to further understanding of the TDP-43 proteinopathies.
Collapse
Affiliation(s)
- Lei-Lei Jiang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, P. R. China
| | - Wen-Liang Guan
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, P. R. China.,University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Jian-Yang Wang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, P. R. China.,University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Shu-Xian Zhang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, P. R. China.,University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Hong-Yu Hu
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, P. R. China
| |
Collapse
|
60
|
Geiger F, Acker J, Papa G, Wang X, Arter WE, Saar KL, Erkamp NA, Qi R, Bravo JPK, Strauss S, Krainer G, Burrone OR, Jungmann R, Knowles TPJ, Engelke H, Borodavka A. Liquid-liquid phase separation underpins the formation of replication factories in rotaviruses. EMBO J 2021; 40:e107711. [PMID: 34524703 PMCID: PMC8561643 DOI: 10.15252/embj.2021107711] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 08/23/2021] [Accepted: 08/27/2021] [Indexed: 12/29/2022] Open
Abstract
RNA viruses induce the formation of subcellular organelles that provide microenvironments conducive to their replication. Here we show that replication factories of rotaviruses represent protein-RNA condensates that are formed via liquid-liquid phase separation of the viroplasm-forming proteins NSP5 and rotavirus RNA chaperone NSP2. Upon mixing, these proteins readily form condensates at physiologically relevant low micromolar concentrations achieved in the cytoplasm of virus-infected cells. Early infection stage condensates could be reversibly dissolved by 1,6-hexanediol, as well as propylene glycol that released rotavirus transcripts from these condensates. During the early stages of infection, propylene glycol treatments reduced viral replication and phosphorylation of the condensate-forming protein NSP5. During late infection, these condensates exhibited altered material properties and became resistant to propylene glycol, coinciding with hyperphosphorylation of NSP5. Some aspects of the assembly of cytoplasmic rotavirus replication factories mirror the formation of other ribonucleoprotein granules. Such viral RNA-rich condensates that support replication of multi-segmented genomes represent an attractive target for developing novel therapeutic approaches.
Collapse
Affiliation(s)
- Florian Geiger
- Department of ChemistryLudwig‐Maximilians‐Universität MünchenMunichGermany
| | - Julia Acker
- Department of BiochemistryUniversity of CambridgeCambridgeUK
| | - Guido Papa
- International Center for Genetic Engineering and BiotechnologyTriesteItaly
- Present address:
Medical Research Council Laboratory of Molecular Biology (MRC LMB)CambridgeUK
| | - Xinyu Wang
- Department of BiochemistryUniversity of CambridgeCambridgeUK
| | | | - Kadi L Saar
- Department of ChemistryUniversity of CambridgeCambridgeUK
| | - Nadia A Erkamp
- Department of ChemistryUniversity of CambridgeCambridgeUK
| | - Runzhang Qi
- Department of ChemistryUniversity of CambridgeCambridgeUK
| | - Jack PK Bravo
- Department of BiochemistryUniversity of CambridgeCambridgeUK
- Present address:
Department of Molecular BiosciencesUniversity of Texas at AustinAustinTXUSA
| | - Sebastian Strauss
- Department of Physics and Center for NanoscienceMax Planck Institute of BiochemistryMunichGermany
| | - Georg Krainer
- Department of ChemistryUniversity of CambridgeCambridgeUK
| | - Oscar R Burrone
- International Center for Genetic Engineering and BiotechnologyTriesteItaly
| | - Ralf Jungmann
- Department of Physics and Center for NanoscienceMax Planck Institute of BiochemistryMunichGermany
| | | | - Hanna Engelke
- Department of ChemistryLudwig‐Maximilians‐Universität MünchenMunichGermany
- Institute of Pharmaceutical SciencesKarl‐Franzens‐Universität GrazGrazAustria
| | - Alexander Borodavka
- Department of ChemistryLudwig‐Maximilians‐Universität MünchenMunichGermany
- Department of BiochemistryUniversity of CambridgeCambridgeUK
- Department of Physics and Center for NanoscienceMax Planck Institute of BiochemistryMunichGermany
| |
Collapse
|
61
|
Fassler JS, Skuodas S, Weeks DL, Phillips BT. Protein Aggregation and Disaggregation in Cells and Development. J Mol Biol 2021; 433:167215. [PMID: 34450138 PMCID: PMC8530975 DOI: 10.1016/j.jmb.2021.167215] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 08/01/2021] [Accepted: 08/18/2021] [Indexed: 12/12/2022]
Abstract
Protein aggregation is a feature of numerous neurodegenerative diseases. However, regulated, often reversible, formation of protein aggregates, also known as condensates, helps control a wide range of cellular activities including stress response, gene expression, memory, cell development and differentiation. This review presents examples of aggregates found in biological systems, how they are used, and cellular strategies that control aggregation and disaggregation. We include features of the aggregating proteins themselves, environmental factors, co-aggregates, post-translational modifications and well-known aggregation-directed activities that influence their formation, material state, stability and dissolution. We highlight the emerging roles of biomolecular condensates in early animal development, and disaggregation processing proteins that have recently been shown to play key roles in gametogenesis and embryogenesis.
Collapse
Affiliation(s)
- Jan S Fassler
- Department of Biology, University of Iowa, Iowa City, IA 52242, United States.
| | - Sydney Skuodas
- Department of Biology, University of Iowa, Iowa City, IA 52242, United States. https://twitter.com/@sskuodas
| | - Daniel L Weeks
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, United States
| | - Bryan T Phillips
- Department of Biology, University of Iowa, Iowa City, IA 52242, United States. https://twitter.com/@bt4phillips
| |
Collapse
|
62
|
Ishiguro A, Lu J, Ozawa D, Nagai Y, Ishihama A. ALS-linked FUS mutations dysregulate G-quadruplex-dependent liquid-liquid phase separation and liquid-to-solid transition. J Biol Chem 2021; 297:101284. [PMID: 34624313 PMCID: PMC8567205 DOI: 10.1016/j.jbc.2021.101284] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 09/29/2021] [Accepted: 10/04/2021] [Indexed: 01/15/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by the accumulation of protein aggregates in motor neurons. Recent discoveries of genetic mutations in ALS patients promoted research into the complex molecular mechanisms underlying ALS. FUS (fused in sarcoma) is a representative ALS-linked RNA-binding protein (RBP) that specifically recognizes G-quadruplex (G4)-DNA/RNAs. However, the effects of ALS-linked FUS mutations on the G4-RNA-binding activity and the phase behavior have never been investigated. Using the purified full-length FUS, we analyzed the molecular mechanisms of multidomain structures consisting of multiple functional modules that bind to G4. Here we succeeded to observe the liquid–liquid phase separation (LLPS) of FUS condensate formation and subsequent liquid-to-solid transition (LST) leading to the formation of FUS aggregates. This process was markedly promoted through FUS interaction with G4-RNA. To further investigate, we selected a total of eight representative ALS-linked FUS mutants within multidomain structures and purified these proteins. The regulation of G4-RNA-dependent LLPS and LST pathways was lost for all ALS-linked FUS mutants defective in G4-RNA recognition tested, supporting the essential role of G4-RNA in this process. Noteworthy, the P525L mutation that causes juvenile ALS exhibited the largest effect on both G4-RNA binding and FUS aggregation. The findings described herein could provide a clue to the hitherto undefined connection between protein aggregation and dysfunction of RBPs in the complex pathway of ALS pathogenesis.
Collapse
Affiliation(s)
- Akira Ishiguro
- Research Center for Micro-Nano Technology, Hosei University, Koganei, Tokyo, Japan.
| | - Jun Lu
- Medical Examination Center, National Center for Global Health and Medicine, Shinjuku-ku, Tokyo, Japan
| | - Daisaku Ozawa
- Department of Neurotherapeutics, Osaka University Graduate School of Medicine, Suita, Osaka, Japan; Department of Neurology, Kindai University Faculty of Medicine, Osaka-Sayama, Osaka, Japan
| | - Yoshitaka Nagai
- Department of Neurotherapeutics, Osaka University Graduate School of Medicine, Suita, Osaka, Japan; Department of Neurology, Kindai University Faculty of Medicine, Osaka-Sayama, Osaka, Japan
| | - Akira Ishihama
- Research Center for Micro-Nano Technology, Hosei University, Koganei, Tokyo, Japan
| |
Collapse
|
63
|
Malik I, Kelley CP, Wang ET, Todd PK. Molecular mechanisms underlying nucleotide repeat expansion disorders. Nat Rev Mol Cell Biol 2021; 22:589-607. [PMID: 34140671 PMCID: PMC9612635 DOI: 10.1038/s41580-021-00382-6] [Citation(s) in RCA: 131] [Impact Index Per Article: 43.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/30/2021] [Indexed: 02/05/2023]
Abstract
The human genome contains over one million short tandem repeats. Expansion of a subset of these repeat tracts underlies over fifty human disorders, including common genetic causes of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (C9orf72), polyglutamine-associated ataxias and Huntington disease, myotonic dystrophy, and intellectual disability disorders such as Fragile X syndrome. In this Review, we discuss the four major mechanisms by which expansion of short tandem repeats causes disease: loss of function through transcription repression, RNA-mediated gain of function through gelation and sequestration of RNA-binding proteins, gain of function of canonically translated repeat-harbouring proteins, and repeat-associated non-AUG translation of toxic repeat peptides. Somatic repeat instability amplifies these mechanisms and influences both disease age of onset and tissue specificity of pathogenic features. We focus on the crosstalk between these disease mechanisms, and argue that they often synergize to drive pathogenesis. We also discuss the emerging native functions of repeat elements and how their dynamics might contribute to disease at a larger scale than currently appreciated. Lastly, we propose that lynchpins tying these disease mechanisms and native functions together offer promising therapeutic targets with potential shared applications across this class of human disorders.
Collapse
Affiliation(s)
- Indranil Malik
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA
| | - Chase P Kelley
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics, Genetics Institute, University of Florida, Gainesville, FL, USA
- Genetics and Genomics Graduate Program, University of Florida, Gainesville, FL, USA
| | - Eric T Wang
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics, Genetics Institute, University of Florida, Gainesville, FL, USA.
| | - Peter K Todd
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA.
- VA Ann Arbor Healthcare System, Ann Arbor, MI, USA.
| |
Collapse
|
64
|
Zhou G, Niu R, Zhou Y, Luo M, Peng Y, Wang H, Wang Z, Xu G. Proximity editing to identify RNAs in phase-separated RNA binding protein condensates. Cell Discov 2021; 7:72. [PMID: 34426573 PMCID: PMC8382829 DOI: 10.1038/s41421-021-00288-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 06/03/2021] [Indexed: 11/09/2022] Open
Affiliation(s)
- Guilong Zhou
- State Key Laboratory of Hybrid Rice, Institute for Advanced Studies (IAS), Wuhan University, 430072, Wuhan, Hubei, China
| | - Ruixia Niu
- State Key Laboratory of Hybrid Rice, Institute for Advanced Studies (IAS), Wuhan University, 430072, Wuhan, Hubei, China
| | - Yulu Zhou
- State Key Laboratory of Hybrid Rice, Institute for Advanced Studies (IAS), Wuhan University, 430072, Wuhan, Hubei, China
| | - Ming Luo
- State Key Laboratory of Hybrid Rice, Institute for Advanced Studies (IAS), Wuhan University, 430072, Wuhan, Hubei, China
| | - Yao Peng
- State Key Laboratory of Hybrid Rice, Institute for Advanced Studies (IAS), Wuhan University, 430072, Wuhan, Hubei, China
| | - Hui Wang
- State Key Laboratory of Hybrid Rice, Institute for Advanced Studies (IAS), Wuhan University, 430072, Wuhan, Hubei, China
| | - Zhao Wang
- State Key Laboratory of Hybrid Rice, Institute for Advanced Studies (IAS), Wuhan University, 430072, Wuhan, Hubei, China
| | - Guoyong Xu
- State Key Laboratory of Hybrid Rice, Institute for Advanced Studies (IAS), Wuhan University, 430072, Wuhan, Hubei, China.
| |
Collapse
|
65
|
Mukherjee A, de Izarra A, Degrouard J, Olive E, Maiti PK, Jang YH, Lansac Y. Protamine-Controlled Reversible DNA Packaging: A Molecular Glue. ACS NANO 2021; 15:13094-13104. [PMID: 34328301 DOI: 10.1021/acsnano.1c02337] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Packaging paternal genome into tiny sperm nuclei during spermatogenesis requires 106-fold compaction of DNA, corresponding to a 10-20 times higher compaction than in somatic cells. While such a high level of compaction involves protamine, a small arginine-rich basic protein, the precise mechanism at play is still unclear. Effective pair potential calculations and large-scale molecular dynamics simulations using a simple idealized model incorporating solely electrostatic and steric interactions clearly demonstrate a reversible control on DNA condensates formation by varying the protamine-to-DNA ratio. Microscopic states and condensate structures occurring in semidilute solutions of short DNA fragments are in good agreement with experimental phase diagram and cryoTEM observations. The reversible microscopic mechanisms induced by protamination modulation should provide valuable information to improve a mechanistic understanding of early and intermediate stages of spermatogenesis where an interplay between condensation and liquid-liquid phase separation triggered by protamine expression and post-translational regulation might occur. Moreover, recent vaccines to prevent virus infections and cancers using protamine as a packaging and depackaging agent might be fine-tuned for improved efficiency using a protamination control.
Collapse
Affiliation(s)
- Arnab Mukherjee
- GREMAN, CNRS UMR 7347, Université de Tours, 37200 Tours, France
| | - Ambroise de Izarra
- GREMAN, CNRS UMR 7347, Université de Tours, 37200 Tours, France
- Department of Energy Science and Engineering, DGIST, Daegu 42988, Korea
| | - Jeril Degrouard
- Laboratoire de Physique des Solides, CNRS UMR 8502, Université Paris-Saclay, 91405 Orsay, France
| | - Enrick Olive
- GREMAN, CNRS UMR 7347, Université de Tours, 37200 Tours, France
| | - Prabal K Maiti
- Center for Condensed Matter Theory, Indian Institute of Science, Bangalore 560012, India
| | - Yun Hee Jang
- Department of Energy Science and Engineering, DGIST, Daegu 42988, Korea
| | - Yves Lansac
- GREMAN, CNRS UMR 7347, Université de Tours, 37200 Tours, France
- Department of Energy Science and Engineering, DGIST, Daegu 42988, Korea
- Laboratoire de Physique des Solides, CNRS UMR 8502, Université Paris-Saclay, 91405 Orsay, France
| |
Collapse
|
66
|
Wang D, Huang X, Yan L, Zhou L, Yan C, Wu J, Su Z, Huang Y. The Structure Biology of Tau and Clue for Aggregation Inhibitor Design. Protein J 2021; 40:656-668. [PMID: 34401998 DOI: 10.1007/s10930-021-10017-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/12/2021] [Indexed: 12/22/2022]
Abstract
Tau is a microtubule-associated protein that is mainly expressed in central and peripheral nerve systems. Tau binds to tubulin and regulates assembly and stabilization of microtubule, thus playing a critical role in neuron morphology, axon development and navigation. Tau is highly stable under normal conditions; however, there are several factors that can induce or promote aggregation of tau, forming neurofibrillary tangles. Neurofibrillary tangles are toxic to neurons, which may be related to a series of neurodegenerative diseases including Alzheimer's disease. Thus, tau is widely accepted as an important therapeutic target for neurodegenerative diseases. While the monomeric structure of tau is highly disordered, the aggregate structure of tau is formed by closed packing of β-stands. Studies on the structure of tau and the structural transition mechanism provide valuable information on the occurrence, development, and therapy of tauopathies. In this review, we summarize recent progress on the structural investigation of tau and based on which we discuss aggregation inhibitor design.
Collapse
Affiliation(s)
- Dan Wang
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan, 430068, China.,Hubei Key Laboratory of Industrial Microbiology, Department of Biological Engineering, Hubei University of Technology, Wuhan, 430068, Hubei, China
| | - Xianlong Huang
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan, 430068, China.,Hubei Key Laboratory of Industrial Microbiology, Department of Biological Engineering, Hubei University of Technology, Wuhan, 430068, Hubei, China
| | - Lu Yan
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan, 430068, China.,Hubei Key Laboratory of Industrial Microbiology, Department of Biological Engineering, Hubei University of Technology, Wuhan, 430068, Hubei, China
| | - Luoqi Zhou
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan, 430068, China.,Hubei Key Laboratory of Industrial Microbiology, Department of Biological Engineering, Hubei University of Technology, Wuhan, 430068, Hubei, China
| | - Chang Yan
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan, 430068, China.,Hubei Key Laboratory of Industrial Microbiology, Department of Biological Engineering, Hubei University of Technology, Wuhan, 430068, Hubei, China
| | - Jinhu Wu
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan, 430068, China.,Hubei Key Laboratory of Industrial Microbiology, Department of Biological Engineering, Hubei University of Technology, Wuhan, 430068, Hubei, China
| | - Zhengding Su
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan, 430068, China.,Hubei Key Laboratory of Industrial Microbiology, Department of Biological Engineering, Hubei University of Technology, Wuhan, 430068, Hubei, China
| | - Yongqi Huang
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan, 430068, China. .,Hubei Key Laboratory of Industrial Microbiology, Department of Biological Engineering, Hubei University of Technology, Wuhan, 430068, Hubei, China.
| |
Collapse
|
67
|
Ambroggio EE, Costa Navarro GS, Pérez Socas LB, Bagatolli LA, Gamarnik AV. Dengue and Zika virus capsid proteins bind to membranes and self-assemble into liquid droplets with nucleic acids. J Biol Chem 2021; 297:101059. [PMID: 34375636 PMCID: PMC8397897 DOI: 10.1016/j.jbc.2021.101059] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 08/03/2021] [Accepted: 08/05/2021] [Indexed: 11/02/2022] Open
Abstract
Dengue virus (DENV) and Zika virus (ZIKV) capsid proteins efficiently recruit and surround the viral RNA at the endoplasmic reticulum (ER) membrane to yield nascent viral particles. However, little is known either about the molecular mechanisms by which multiple copies of capsid proteins assemble into nucleocapsids (NCs) or how the NC is recruited and wrapped by the ER membrane during particle morphogenesis. Here, we measured relevant interactions concerning this viral process using purified DENV and ZIKV capsid proteins, membranes mimicking the ER lipid composition, and nucleic acids in in vitro conditions to understand the biophysical properties of the RNA genome encapsidation process. We found that both ZIKV and DENV capsid proteins bound to liposomes at liquid-disordered phase regions, docked exogenous membranes, and RNA molecules. Liquid-liquid phase separation is prone to occur when positively charged proteins interact with nucleic acids, which is indeed the case for the studied capsids. We characterized these liquid condensates by measuring nucleic acid partition constants and the extent of water dipolar relaxation, observing a cooperative process for the formation of the new phase that involves a distinct water organization. Our data support a new model in which capsid-RNA complexes directly bind the ER membrane, seeding the process of RNA recruitment for viral particle assembly. These results contribute to our understanding of the viral NC formation as a stable liquid-liquid phase transition, which could be relevant for dengue and Zika gemmation, opening new avenues for antiviral intervention.
Collapse
Affiliation(s)
- Ernesto E Ambroggio
- Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, CIQUIBIC, CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina.
| | | | - Luis Benito Pérez Socas
- Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, CIQUIBIC, CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Luis A Bagatolli
- Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC (CONICET), Universidad Nacional de Córdoba, Córdoba, Argentina; Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | | |
Collapse
|
68
|
Razin SV, Gavrilov AA. Non-coding RNAs in chromatin folding and nuclear organization. Cell Mol Life Sci 2021; 78:5489-5504. [PMID: 34117518 PMCID: PMC11072467 DOI: 10.1007/s00018-021-03876-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 04/24/2021] [Accepted: 06/05/2021] [Indexed: 12/19/2022]
Abstract
One of the most intriguing questions facing modern biology concerns how the genome directs the construction of cells, tissues, and whole organisms. It is tempting to suggest that the part of the genome that does not encode proteins contains architectural plans. We are still far from understanding how these plans work at the level of building tissues and the body as a whole. However, the results of recent studies demonstrate that at the cellular level, special non-coding RNAs serve as scaffolds for the construction of various intracellular structures. The term "architectural RNAs" was proposed to designate this subset of non-coding RNAs. In this review, we discuss the role of architectural RNAs in the construction of the cell nucleus and maintenance of the three-dimensional organization of the genome.
Collapse
Affiliation(s)
- Sergey V Razin
- Institute of Gene Biology, Russian Academy of Sciences, 119334, Moscow, Russia.
- Faculty of Biology, M. V. Lomonosov Moscow State University, 119234, Moscow, Russia.
| | - Alexey A Gavrilov
- Institute of Gene Biology, Russian Academy of Sciences, 119334, Moscow, Russia
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, 119334, Moscow, Russia
| |
Collapse
|
69
|
Fare CM, Villani A, Drake LE, Shorter J. Higher-order organization of biomolecular condensates. Open Biol 2021; 11:210137. [PMID: 34129784 PMCID: PMC8205532 DOI: 10.1098/rsob.210137] [Citation(s) in RCA: 73] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
A guiding principle of biology is that biochemical reactions must be organized in space and time. One way this spatio-temporal organization is achieved is through liquid–liquid phase separation (LLPS), which generates biomolecular condensates. These condensates are dynamic and reactive, and often contain a complex mixture of proteins and nucleic acids. In this review, we discuss how underlying physical and chemical processes generate internal condensate architectures. We then outline the diverse condensate architectures that are observed in biological systems. Finally, we discuss how specific condensate organization is critical for specific biological functions.
Collapse
Affiliation(s)
- Charlotte M Fare
- Department of Biochemistry and Biophysics, and.,Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | | | | | - James Shorter
- Department of Biochemistry and Biophysics, and.,Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| |
Collapse
|
70
|
Ishiguro T, Nagai Y, Ishikawa K. Insight Into Spinocerebellar Ataxia Type 31 (SCA31) From Drosophila Model. Front Neurosci 2021; 15:648133. [PMID: 34113230 PMCID: PMC8185138 DOI: 10.3389/fnins.2021.648133] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 03/31/2021] [Indexed: 11/13/2022] Open
Abstract
Spinocerebellar ataxia type 31 (SCA31) is a progressive neurodegenerative disease characterized by degeneration of Purkinje cells in the cerebellum. Its genetic cause is a 2.5- to 3.8-kb-long complex pentanucleotide repeat insertion containing (TGGAA)n, (TAGAA)n, (TAAAA)n, and (TAAAATAGAA)n located in an intron shared by two different genes: brain expressed associated with NEDD4-1 (BEAN1) and thymidine kinase 2 (TK2). Among these repeat sequences, (TGGAA)n repeat was the only sequence segregating with SCA31, which strongly suggests its pathogenicity. In SCA31 patient brains, the mutant BEAN1 transcript containing expanded UGGAA repeats (UGGAAexp) was found to form abnormal RNA structures called RNA foci in cerebellar Purkinje cell nuclei. In addition, the deposition of pentapeptide repeat (PPR) proteins, poly(Trp-Asn-Gly-Met-Glu), translated from UGGAAexp RNA, was detected in the cytoplasm of Purkinje cells. To uncover the pathogenesis of UGGAAexp in SCA31, we generated Drosophila models of SCA31 expressing UGGAAexp RNA. The toxicity of UGGAAexp depended on its length and expression level, which was accompanied by the accumulation of RNA foci and translation of repeat-associated PPR proteins in Drosophila, consistent with the observation in SCA31 patient brains. We also revealed that TDP-43, FUS, and hnRNPA2B1, motor neuron disease–linked RNA-binding proteins bound to UGGAAexp RNA, act as RNA chaperones to regulate the formation of RNA foci and repeat-associated translation. Further research on the role of RNA-binding proteins as RNA chaperones may also provide a novel therapeutic strategy for other microsatellite repeat expansion diseases besides SCA31.
Collapse
Affiliation(s)
- Taro Ishiguro
- Department of Neurology and Neurological Science, Tokyo Medical and Dental University, Bunkyo City, Japan
| | - Yoshitaka Nagai
- Department of Neurotherapeutics, Osaka University Graduate School of Medicine, Suita, Japan
| | - Kinya Ishikawa
- Department of Neurology and Neurological Science, Tokyo Medical and Dental University, Bunkyo City, Japan.,Department of Personalized Genomic Medicine for Health, Graduate School, Tokyo Medical and Dental University, Bunkyo City, Japan
| |
Collapse
|
71
|
Ranganathan S, Shakhnovich E. Effect of RNA on Morphology and Dynamics of Membraneless Organelles. J Phys Chem B 2021; 125:5035-5044. [PMID: 33969989 DOI: 10.1021/acs.jpcb.1c02286] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Membraneless organelles (MLOs) are spatiotemporally regulated structures that concentrate multivalent proteins or RNA, often in response to stress. The proteins enriched within MLOs are often classified as high-valency "scaffolds" or low-valency "clients", with the former being associated with a phase-separation promoting role. In this study, we employ a minimal model for P-body components, with a defined protein-protein interaction network, to study their phase separation at biologically realistic low protein concentrations. Without RNA, multivalent proteins can assemble into solid-like clusters only in the regime of high concentration and stable interactions. RNA molecules promote cluster formation in an RNA-length-dependent manner, even in the regime of weak interactions and low protein volume fraction. Our simulations reveal that long RNA chains act as superscaffolds that stabilize large RNA-protein clusters by recruiting low-valency proteins within them while also ensuring functional "liquid-like" turnover of components. Our results suggest that RNA-mediated phase separation could be a plausible mechanism for spatiotemporally regulated phase separation in the cell.
Collapse
Affiliation(s)
- Srivastav Ranganathan
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Eugene Shakhnovich
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| |
Collapse
|
72
|
Sanulli S, Narlikar GJ. Generation and Biochemical Characterization of Phase-Separated Droplets Formed by Nucleic Acid Binding Proteins: Using HP1 as a Model System. Curr Protoc 2021; 1:e109. [PMID: 33950570 DOI: 10.1002/cpz1.109] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Liquid-liquid phase separation (LLPS) has been invoked as an underlying mechanism involved in the formation and function of several cellular membrane-less compartments. Given the explosion of studies in this field in recent years, it has become essential to converge on clear guidelines and methods to rigorously investigate LLPS and advance our understanding of this phenomenon. Here, we describe basic methods to (1) visualize droplets formed by nucleic acid binding proteins and (2) characterize the liquid-like nature of these droplets under controlled in vitro experimental conditions. We discuss the rationale behind these methods, as well as caveats and limitations. Our ultimate goal is to guide scientists interested in learning how to test for LLPS, while appreciating that the field is evolving rapidly and adjusting constantly to the growing knowledge. © 2021 Wiley Periodicals LLC. Basic Protocol 1: Observing phase-separated condensates by microscopy. Support Protocol: Coating of glass-bottom plates. Basic Protocol 2: Assessing condensate reversibility by changing ionic strength. Alternate Protocol 1: Assessing condensate reversibility by dilution. Alternate Protocol 2: Assessing condensate reversibility by altering temperature. Basic Protocol 3: Quantifying phase separation by centrifugation assay. Basic Protocol 4: Quantifying phase separation by turbidity assay.
Collapse
Affiliation(s)
- Serena Sanulli
- Department of Genetics, Stanford University, Palo Alto, California
| | - Geeta J Narlikar
- Department of Biochemistry and Biophysics, UCSF, San Francisco, California
| |
Collapse
|
73
|
Solomon DA, Smikle R, Reid MJ, Mizielinska S. Altered Phase Separation and Cellular Impact in C9orf72-Linked ALS/FTD. Front Cell Neurosci 2021; 15:664151. [PMID: 33967699 PMCID: PMC8096919 DOI: 10.3389/fncel.2021.664151] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 03/19/2021] [Indexed: 12/21/2022] Open
Abstract
Since the discovery of the C9orf72 repeat expansion mutation as causative for chromosome 9-linked amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) in 2011, a multitude of cellular pathways have been implicated. However, evidence has also been accumulating for a key mechanism of cellular compartmentalization—phase separation. Liquid-liquid phase separation (LLPS) is fundamental for the formation of membraneless organelles including stress granules, the nucleolus, Cajal bodies, nuclear speckles and the central channel of the nuclear pore. Evidence has now accumulated showing that the formation and function of these membraneless organelles is impaired by both the toxic arginine rich dipeptide repeat proteins (DPRs), translated from the C9orf72 repeat RNA transcript, and the repeat RNA itself. Both the arginine rich DPRs and repeat RNA themselves undergo phase separation and disrupt the physiological phase separation of proteins involved in the formation of these liquid-like organelles. Hence abnormal phase separation may explain a number of pathological cellular phenomena associated with C9orf72-ALS/FTD. In this review article, we will discuss the principles of phase separation, phase separation of the DPRs and repeat RNA themselves and how they perturb LLPS associated with membraneless organelles and the functional consequences of this. We will then discuss how phase separation may impact the major pathological feature of C9orf72-ALS/FTD, TDP-43 proteinopathy, and how LLPS may be targeted therapeutically in disease.
Collapse
Affiliation(s)
- Daniel A Solomon
- UK Dementia Research Institute at King's College London, London, United Kingdom.,Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, United Kingdom
| | - Rebekah Smikle
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, United Kingdom
| | - Matthew J Reid
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, United Kingdom
| | - Sarah Mizielinska
- UK Dementia Research Institute at King's College London, London, United Kingdom.,Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, United Kingdom
| |
Collapse
|
74
|
|
75
|
Chen X, Yang Z, Wang W, Qian K, Liu M, Wang J, Wang M. Structural basis for RNA recognition by the N-terminal tandem RRM domains of human RBM45. Nucleic Acids Res 2021; 49:2946-2958. [PMID: 33577684 PMCID: PMC7968997 DOI: 10.1093/nar/gkab075] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 01/16/2021] [Accepted: 01/28/2021] [Indexed: 12/20/2022] Open
Abstract
RBM45 is an RNA-binding protein involved in neural development, whose aggregation is associated with neurodegenerative diseases, such as amyotrophic lateral sclerosis (ALS) and frontotemporal lobar dementia (FTLD). However, the mechanisms of RNA-binding and aggregation of RBM45 remain unelucidated. Here, we report the crystal structure of the N-terminal tandem RRM domains of human RBM45 in complex with single-stranded DNA (ssDNA). Our structural and biochemical results revealed that both the RRM1 and RRM2 of RBM45 recognized the GAC sequence of RNA/ssDNA. Two aromatic residues and an arginine residue in each RRM were critical for RNA-binding, and the interdomain linker was also involved in RNA-binding. Two RRMs formed a pair of antiparallel RNA-binding sites, indicating that the N-terminal tandem RRM domains of RBM45 bound separate GAC motifs in one RNA strand or GAC motifs in different RNA strands. Our findings will be helpful in the identification of physiologic targets of RBM45 and provide evidence for understanding the physiologic and pathologic functions of RBM45.
Collapse
Affiliation(s)
- Xiaolei Chen
- Institutes of Physical Science and Information Technology, Anhui University, 111 Jiulong Road, Hefei 230601, Anhui, China.,School of Life Sciences, Anhui University, 111 Jiulong Road, Hefei 230601, Anhui, China
| | - Zhongmei Yang
- Institutes of Physical Science and Information Technology, Anhui University, 111 Jiulong Road, Hefei 230601, Anhui, China.,School of Life Sciences, Anhui University, 111 Jiulong Road, Hefei 230601, Anhui, China
| | - Wenfeng Wang
- Institutes of Physical Science and Information Technology, Anhui University, 111 Jiulong Road, Hefei 230601, Anhui, China.,School of Life Sciences, Anhui University, 111 Jiulong Road, Hefei 230601, Anhui, China
| | - Kaiyue Qian
- Institutes of Physical Science and Information Technology, Anhui University, 111 Jiulong Road, Hefei 230601, Anhui, China.,School of Life Sciences, Anhui University, 111 Jiulong Road, Hefei 230601, Anhui, China.,Key Laboratory of Human Microenvironment and Precision Medicine of Anhui Higher Education Institutes, Anhui University, 111 Jiulong Road, Hefei 230601, Anhui, China
| | - Mingjie Liu
- Institutes of Physical Science and Information Technology, Anhui University, 111 Jiulong Road, Hefei 230601, Anhui, China.,School of Life Sciences, Anhui University, 111 Jiulong Road, Hefei 230601, Anhui, China.,Key Laboratory of Human Microenvironment and Precision Medicine of Anhui Higher Education Institutes, Anhui University, 111 Jiulong Road, Hefei 230601, Anhui, China
| | - Junchao Wang
- Institutes of Physical Science and Information Technology, Anhui University, 111 Jiulong Road, Hefei 230601, Anhui, China.,School of Life Sciences, Anhui University, 111 Jiulong Road, Hefei 230601, Anhui, China.,Key Laboratory of Human Microenvironment and Precision Medicine of Anhui Higher Education Institutes, Anhui University, 111 Jiulong Road, Hefei 230601, Anhui, China
| | - Mingzhu Wang
- Institutes of Physical Science and Information Technology, Anhui University, 111 Jiulong Road, Hefei 230601, Anhui, China.,School of Life Sciences, Anhui University, 111 Jiulong Road, Hefei 230601, Anhui, China.,Key Laboratory of Human Microenvironment and Precision Medicine of Anhui Higher Education Institutes, Anhui University, 111 Jiulong Road, Hefei 230601, Anhui, China
| |
Collapse
|
76
|
Zeng Y, Yang J, Zhang B, Gao M, Su Z, Huang Y. The structure and phase of tau: from monomer to amyloid filament. Cell Mol Life Sci 2021; 78:1873-1886. [PMID: 33078207 PMCID: PMC11073437 DOI: 10.1007/s00018-020-03681-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 09/20/2020] [Accepted: 10/07/2020] [Indexed: 12/12/2022]
Abstract
Tau is a microtubule-associated protein involved in regulation of assembly and spatial organization of microtubule in neurons. However, in pathological conditions, tau monomers assemble into amyloid filaments characterized by the cross-β structures in a number of neurodegenerative diseases known as tauopathies. In this review, we summarize recent progression on the characterization of structures of tau monomer and filament, as well as the dynamic liquid droplet assembly. Our aim is to reveal how post-translational modifications, amino acid mutations, and interacting molecules modulate the conformational ensemble of tau monomer, and how they accelerate or inhibit tau assembly into aggregates. Structure-based aggregation inhibitor design is also discussed in the context of dynamics and heterogeneity of tau structures.
Collapse
Affiliation(s)
- Yifan Zeng
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan, China
- Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan, China
| | - Jing Yang
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan, China
- Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan, China
| | - Bailing Zhang
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan, China
- Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan, China
| | - Meng Gao
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan, China
- Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan, China
| | - Zhengding Su
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan, China
- Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan, China
| | - Yongqi Huang
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan, China.
- Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan, China.
| |
Collapse
|
77
|
Donsbach P, Klostermeier D. Regulation of RNA helicase activity: principles and examples. Biol Chem 2021; 402:529-559. [PMID: 33583161 DOI: 10.1515/hsz-2020-0362] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 01/29/2021] [Indexed: 12/16/2022]
Abstract
RNA helicases are a ubiquitous class of enzymes involved in virtually all processes of RNA metabolism, from transcription, mRNA splicing and export, mRNA translation and RNA transport to RNA degradation. Although ATP-dependent unwinding of RNA duplexes is their hallmark reaction, not all helicases catalyze unwinding in vitro, and some in vivo functions do not depend on duplex unwinding. RNA helicases are divided into different families that share a common helicase core with a set of helicase signature motives. The core provides the active site for ATP hydrolysis, a binding site for non-sequence-specific interaction with RNA, and in many cases a basal unwinding activity. Its activity is often regulated by flanking domains, by interaction partners, or by self-association. In this review, we summarize the regulatory mechanisms that modulate the activities of the helicase core. Case studies on selected helicases with functions in translation, splicing, and RNA sensing illustrate the various modes and layers of regulation in time and space that harness the helicase core for a wide spectrum of cellular tasks.
Collapse
Affiliation(s)
- Pascal Donsbach
- Institute for Physical Chemistry, University of Münster, Corrensstrasse 30, D-48149Münster, Germany
| | - Dagmar Klostermeier
- Institute for Physical Chemistry, University of Münster, Corrensstrasse 30, D-48149Münster, Germany
| |
Collapse
|
78
|
Joseph JA, Espinosa JR, Sanchez-Burgos I, Garaizar A, Frenkel D, Collepardo-Guevara R. Thermodynamics and kinetics of phase separation of protein-RNA mixtures by a minimal model. Biophys J 2021; 120:1219-1230. [PMID: 33571491 DOI: 10.1016/j.bpj.2021.01.031] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 11/11/2020] [Accepted: 01/20/2021] [Indexed: 12/20/2022] Open
Abstract
Intracellular liquid-liquid phase separation enables the formation of biomolecular condensates, such as ribonucleoprotein granules, which play a crucial role in the spatiotemporal organization of biomolecules (e.g., proteins and RNAs). Here, we introduce a patchy-particle polymer model to investigate liquid-liquid phase separation of protein-RNA mixtures. We demonstrate that at low to moderate concentrations, RNA enhances the stability of RNA-binding protein condensates because it increases the molecular connectivity of the condensed-liquid phase. Importantly, we find that RNA can also accelerate the nucleation stage of phase separation. Additionally, we assess how the capacity of RNA to increase the stability of condensates is modulated by the relative protein-protein/protein-RNA binding strengths. We find that phase separation and multiphase organization of multicomponent condensates is favored when the RNA binds with higher affinity to the lower-valency proteins in the mixture than to the cognate higher-valency proteins. Collectively, our results shed light on the roles of RNA in ribonucleoprotein granule formation and the internal structuring of stress granules.
Collapse
Affiliation(s)
- Jerelle A Joseph
- Maxwell Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge, United Kingdom; Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, United Kingdom; Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Jorge R Espinosa
- Maxwell Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge, United Kingdom; Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, United Kingdom; Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Ignacio Sanchez-Burgos
- Maxwell Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge, United Kingdom; Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, United Kingdom; Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Adiran Garaizar
- Maxwell Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge, United Kingdom; Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, United Kingdom; Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Daan Frenkel
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
| | - Rosana Collepardo-Guevara
- Maxwell Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge, United Kingdom; Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, United Kingdom; Department of Genetics, University of Cambridge, Cambridge, United Kingdom.
| |
Collapse
|
79
|
Enukashvily NI, Dobrynin MA, Chubar AV. RNA-seeded membraneless bodies: Role of tandemly repeated RNA. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2021; 126:151-193. [PMID: 34090614 DOI: 10.1016/bs.apcsb.2020.12.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/28/2023]
Abstract
Membraneless organelles (bodies, granules, etc.) are spatially distinct sub-nuclear and cytoplasmic foci involved in all the processes in a living cell, such as development, cell death, carcinogenesis, proliferation, and differentiation. Today the list of the membraneless organelles includes a wide spectrum of intranuclear and cytoplasmic bodies. Proteins with intrinsically disordered regions are the key players in the membraneless body assembly. However, recent data assume an important role of RNA molecules in the process of the liquid-liquid phase separation. High-level expression of RNA above a critical concentration threshold is mandatory to nucleate interactions with specific proteins and for seeding membraneless organelles. RNA components are considered by many authors as the principal determinants of organelle identity. Tandemly repeated (TR) DNA of big satellites (a TR family that includes centromeric and pericentromeric DNA sequences) was believed to be transcriptionally silent for a long period. Now we know about the TR transcription upregulation during gameto- and embryogenesis, carcinogenesis, stress response. In the review, we summarize the recent data about the involvement of TR RNA in the formation of nuclear membraneless granules, bodies, etc., with different functions being in some cases an initiator of the structures assembly. These RNP structures sequestrate and inactivate different proteins and transcripts. The TR induced sequestration is one of the key principles of nuclear architecture and genome functioning. Studying the role of the TR-based membraneless organelles in stress and disease will bring some new ideas for translational medicine.
Collapse
Affiliation(s)
- Natella I Enukashvily
- Institute of Cytology RAS, St. Petersburg, Russia; North-Western Medical State University named after I.I. Mechnikov, St. Petersburg, Russia.
| | | | | |
Collapse
|
80
|
Gerson JE, Linton H, Xing J, Sutter AB, Kakos FS, Ryou J, Liggans N, Sharkey LM, Safren N, Paulson HL, Ivanova MI. Shared and divergent phase separation and aggregation properties of brain-expressed ubiquilins. Sci Rep 2021; 11:287. [PMID: 33431932 PMCID: PMC7801659 DOI: 10.1038/s41598-020-78775-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 11/25/2020] [Indexed: 01/29/2023] Open
Abstract
The brain-expressed ubiquilins, UBQLNs 1, 2 and 4, are highly homologous proteins that participate in multiple aspects of protein homeostasis and are implicated in neurodegenerative diseases. Studies have established that UBQLN2 forms liquid-like condensates and accumulates in pathogenic aggregates, much like other proteins linked to neurodegenerative diseases. However, the relative condensate and aggregate formation of the three brain-expressed ubiquilins is unknown. Here we report that the three ubiquilins differ in aggregation propensity, revealed by in-vitro experiments, cellular models, and analysis of human brain tissue. UBQLN4 displays heightened aggregation propensity over the other ubiquilins and, like amyloids, UBQLN4 forms ThioflavinT-positive fibrils in vitro. Measuring fluorescence recovery after photobleaching (FRAP) of puncta in cells, we report that all three ubiquilins undergo liquid-liquid phase transition. UBQLN2 and 4 exhibit slower recovery than UBQLN1, suggesting the condensates formed by these brain-expressed ubiquilins have different compositions and undergo distinct internal rearrangements. We conclude that while all brain-expressed ubiquilins exhibit self-association behavior manifesting as condensates, they follow distinct courses of phase-separation and aggregation. We suggest that this variability among ubiquilins along the continuum from liquid-like to solid informs both the normal ubiquitin-linked functions of ubiquilins and their accumulation and potential contribution to toxicity in neurodegenerative diseases.
Collapse
Affiliation(s)
- Julia E Gerson
- Department of Neurology, University of Michigan, Ann Arbor, MI, 48109-2200, USA.
| | - Hunter Linton
- Department of Neurology, University of Michigan, Ann Arbor, MI, 48109-2200, USA
| | - Jiazheng Xing
- Department of Neurology, University of Michigan, Ann Arbor, MI, 48109-2200, USA
| | - Alexandra B Sutter
- Department of Neurology, University of Michigan, Ann Arbor, MI, 48109-2200, USA
- Neuroscience Graduate Program, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Fayth S Kakos
- Department of Neurology, University of Michigan, Ann Arbor, MI, 48109-2200, USA
| | - Jaimie Ryou
- Department of Neurology, University of Michigan, Ann Arbor, MI, 48109-2200, USA
| | - Nyjerus Liggans
- Department of Neurology, University of Michigan, Ann Arbor, MI, 48109-2200, USA
| | - Lisa M Sharkey
- Department of Neurology, University of Michigan, Ann Arbor, MI, 48109-2200, USA
| | - Nathaniel Safren
- Department of Neurology, University of Michigan, Ann Arbor, MI, 48109-2200, USA
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Henry L Paulson
- Department of Neurology, University of Michigan, Ann Arbor, MI, 48109-2200, USA.
| | - Magdalena I Ivanova
- Department of Neurology, University of Michigan, Ann Arbor, MI, 48109-2200, USA.
- Department of Neurology, Biophysics Program, University of Michigan, Ann Arbor, MI, 48109-2200, USA.
| |
Collapse
|
81
|
Laghmach R, Potoyan DA. Liquid-liquid phase separation driven compartmentalization of reactive nucleoplasm. Phys Biol 2021; 18:015001. [PMID: 33113512 PMCID: PMC8201646 DOI: 10.1088/1478-3975/abc5ad] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The nucleus of eukaryotic cells harbors active and out of equilibrium environments conducive to diverse gene regulatory processes. On a molecular scale, gene regulatory processes take place within hierarchically compartmentalized sub-nuclear bodies. While the impact of nuclear structure on gene regulation is widely appreciated, it has remained much less clear whether and how gene regulation is impacting nuclear order itself. Recently, the liquid-liquid phase separation emerged as a fundamental mechanism driving the formation of biomolecular condensates, including membrane-less organelles, chromatin territories, and transcriptional domains. The transience and environmental sensitivity of biomolecular condensation are strongly suggestive of kinetic gene-regulatory control of phase separation. To better understand kinetic aspects controlling biomolecular phase-separation, we have constructed a minimalist model of the reactive nucleoplasm. The model is based on the Cahn-Hilliard formulation of ternary protein-RNA-nucleoplasm components coupled to non-equilibrium and spatially dependent gene expression. We find a broad range of kinetic regimes through an extensive set of simulations where the interplay of phase separation and reactive timescales can generate heterogeneous multi-modal gene expression patterns. Furthermore, the significance of this finding is that heterogeneity of gene expression is linked directly with the heterogeneity of length-scales in phase-separated condensates.
Collapse
Affiliation(s)
- Rabia Laghmach
- Department of Chemistry, Iowa State University, Ames, IA 50011, United States of America. Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011, United States of America. Bioinformatics and Computational Biology program, Iowa State University, Ames, IA 50011, United States of America
| | | |
Collapse
|
82
|
Minehart JA, Speer CM. A Picture Worth a Thousand Molecules-Integrative Technologies for Mapping Subcellular Molecular Organization and Plasticity in Developing Circuits. Front Synaptic Neurosci 2021; 12:615059. [PMID: 33469427 PMCID: PMC7813761 DOI: 10.3389/fnsyn.2020.615059] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 12/07/2020] [Indexed: 12/23/2022] Open
Abstract
A key challenge in developmental neuroscience is identifying the local regulatory mechanisms that control neurite and synaptic refinement over large brain volumes. Innovative molecular techniques and high-resolution imaging tools are beginning to reshape our view of how local protein translation in subcellular compartments drives axonal, dendritic, and synaptic development and plasticity. Here we review recent progress in three areas of neurite and synaptic study in situ-compartment-specific transcriptomics/translatomics, targeted proteomics, and super-resolution imaging analysis of synaptic organization and development. We discuss synergies between sequencing and imaging techniques for the discovery and validation of local molecular signaling mechanisms regulating synaptic development, plasticity, and maintenance in circuits.
Collapse
Affiliation(s)
| | - Colenso M. Speer
- Department of Biology, University of Maryland, College Park, MD, United States
| |
Collapse
|
83
|
Rhine K, Makurath MA, Liu J, Skanchy S, Lopez C, Catalan KF, Ma Y, Fare CM, Shorter J, Ha T, Chemla YR, Myong S. ALS/FTLD-Linked Mutations in FUS Glycine Residues Cause Accelerated Gelation and Reduced Interactions with Wild-Type FUS. Mol Cell 2020; 80:666-681.e8. [PMID: 33159856 PMCID: PMC7688085 DOI: 10.1016/j.molcel.2020.10.014] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 08/06/2020] [Accepted: 10/09/2020] [Indexed: 12/12/2022]
Abstract
The RNA-binding protein fused in sarcoma (FUS) can form pathogenic inclusions in neurodegenerative diseases like amyotrophic lateral sclerosis (ALS) and frontotemporal lobar dementia (FTLD). Over 70 mutations in Fus are linked to ALS/FTLD. In patients, all Fus mutations are heterozygous, indicating that the mutant drives disease progression despite the presence of wild-type (WT) FUS. Here, we demonstrate that ALS/FTLD-linked FUS mutations in glycine (G) strikingly drive formation of droplets that do not readily interact with WT FUS, whereas arginine (R) mutants form mixed condensates with WT FUS. Remarkably, interactions between WT and G mutants are disfavored at the earliest stages of FUS nucleation. In contrast, R mutants physically interact with the WT FUS such that WT FUS recovers the mutant defects by reducing droplet size and increasing dynamic interactions with RNA. This result suggests disparate molecular mechanisms underlying ALS/FTLD pathogenesis and differing recovery potential depending on the type of mutation.
Collapse
Affiliation(s)
- Kevin Rhine
- Program in Cell, Molecular, Developmental Biology, and Biophysics, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA; Department of Biology, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA
| | - Monika A Makurath
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Department of Physics, Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - James Liu
- Department of Biology, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA; Medical Genetics and Ophthalmic Genomics Unit, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sophie Skanchy
- Department of Biophysics, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA
| | - Christian Lopez
- Department of Biology, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA
| | - Kevin F Catalan
- Program in Cell, Molecular, Developmental Biology, and Biophysics, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA; Department of Biology, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA
| | - Ye Ma
- Department of Biomedical Engineering, Johns Hopkins Medical Institute, 615 N Wolfe St, Baltimore, MD 21231, USA
| | - Charlotte M Fare
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - James Shorter
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Taekjip Ha
- Program in Cell, Molecular, Developmental Biology, and Biophysics, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA; Department of Physics, Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Department of Biophysics, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA; Department of Biomedical Engineering, Johns Hopkins Medical Institute, 615 N Wolfe St, Baltimore, MD 21231, USA; Howard Hughes Medical Institute, Baltimore, MD 21218, USA
| | - Yann R Chemla
- Department of Physics, Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Sua Myong
- Program in Cell, Molecular, Developmental Biology, and Biophysics, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA; Department of Physics, Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Department of Biophysics, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA.
| |
Collapse
|
84
|
Pessina F, Gioia U, Brandi O, Farina S, Ceccon M, Francia S, d'Adda di Fagagna F. DNA Damage Triggers a New Phase in Neurodegeneration. Trends Genet 2020; 37:337-354. [PMID: 33020022 DOI: 10.1016/j.tig.2020.09.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 08/28/2020] [Accepted: 09/03/2020] [Indexed: 12/21/2022]
Abstract
Subcellular compartmentalization contributes to the organization of a plethora of molecular events occurring within cells. This can be achieved in membraneless organelles generated through liquid-liquid phase separation (LLPS), a demixing process that separates and concentrates cellular reactions. RNA is often a critical factor in mediating LLPS. Recent evidence indicates that DNA damage response foci are membraneless structures formed via LLPS and modulated by noncoding transcripts synthesized at DNA damage sites. Neurodegeneration is often associated with DNA damage, and dysfunctional LLPS events can lead to the formation of toxic aggregates. In this review, we discuss those gene products involved in neurodegeneration that undergo LLPS and their involvement in the DNA damage response.
Collapse
Affiliation(s)
- Fabio Pessina
- IFOM Foundation - FIRC Institute of Molecular Oncology Foundation, 20139 Milan, Italy
| | - Ubaldo Gioia
- IFOM Foundation - FIRC Institute of Molecular Oncology Foundation, 20139 Milan, Italy
| | - Ornella Brandi
- Istituto di Genetica Molecolare 'Luigi Luca Cavalli-Sforza' CNR - Consiglio Nazionale delle Ricerche, 27100 Pavia, Italy
| | - Stefania Farina
- Istituto di Genetica Molecolare 'Luigi Luca Cavalli-Sforza' CNR - Consiglio Nazionale delle Ricerche, 27100 Pavia, Italy; University School for Advanced Studies IUSS, 27100 Pavia, Italy
| | - Marta Ceccon
- IFOM Foundation - FIRC Institute of Molecular Oncology Foundation, 20139 Milan, Italy
| | - Sofia Francia
- IFOM Foundation - FIRC Institute of Molecular Oncology Foundation, 20139 Milan, Italy; Istituto di Genetica Molecolare 'Luigi Luca Cavalli-Sforza' CNR - Consiglio Nazionale delle Ricerche, 27100 Pavia, Italy.
| | - Fabrizio d'Adda di Fagagna
- IFOM Foundation - FIRC Institute of Molecular Oncology Foundation, 20139 Milan, Italy; Istituto di Genetica Molecolare 'Luigi Luca Cavalli-Sforza' CNR - Consiglio Nazionale delle Ricerche, 27100 Pavia, Italy.
| |
Collapse
|
85
|
Dodson AE, Kennedy S. Phase Separation in Germ Cells and Development. Dev Cell 2020; 55:4-17. [PMID: 33007213 DOI: 10.1016/j.devcel.2020.09.004] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/28/2020] [Accepted: 09/05/2020] [Indexed: 12/20/2022]
Abstract
The animal germline is an immortal cell lineage that gives rise to eggs and/or sperm each generation. Fusion of an egg and sperm, or fertilization, sets off a cascade of developmental events capable of producing an array of different cell types and body plans. How germ cells develop, function, and eventually give rise to entirely new organisms is an important question in biology. A growing body of evidence suggests that phase separation events likely play a significant and multifaceted role in germ cells and development. Here, we discuss the organization, dynamics, and potential functions of phase-separated compartments in germ cells and examine the various ways in which phase separation might contribute to the development of multicellular organisms.
Collapse
Affiliation(s)
- Anne E Dodson
- Department of Genetics, Blavatnik Institute at Harvard Medical School, Boston, MA 02115, USA.
| | - Scott Kennedy
- Department of Genetics, Blavatnik Institute at Harvard Medical School, Boston, MA 02115, USA
| |
Collapse
|
86
|
Pattanayak GK, Liao Y, Wallace EWJ, Budnik B, Drummond DA, Rust MJ. Daily Cycles of Reversible Protein Condensation in Cyanobacteria. Cell Rep 2020; 32:108032. [PMID: 32814039 PMCID: PMC10005845 DOI: 10.1016/j.celrep.2020.108032] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 07/08/2020] [Accepted: 07/23/2020] [Indexed: 12/21/2022] Open
Abstract
An emerging principle of cell biology is the regulated conversion of macromolecules between soluble and condensed states. To screen for such regulation of the cyanobacterial proteome, we use quantitative mass spectrometry to identify proteins that change solubility during the day-night cycle. We find a set of night-insoluble proteins that includes many enzymes in essential metabolic pathways. Using time-lapse microscopy and isotope labeling, we show that these proteins reversibly transition between punctate structures at night and a soluble state during the day without substantial degradation. We find that the cyanobacterial circadian clock regulates the kinetics of puncta formation during the night and that the appearance of puncta indicates the metabolic status of the cell. Reversible condensation of specific enzymes is thus a regulated response to the day-night cycle and may reflect a general bacterial strategy used in fluctuating growth conditions.
Collapse
Affiliation(s)
- Gopal K Pattanayak
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA
| | - Yi Liao
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA
| | - Edward W J Wallace
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637, USA
| | - Bogdan Budnik
- Mass Spectrometry and Proteomics Resource Laboratory, FAS Division of Science, Harvard University, Cambridge, MA 02138, USA
| | - D Allan Drummond
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637, USA
| | - Michael J Rust
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA; Department of Physics, University of Chicago, Chicago, IL 60637, USA.
| |
Collapse
|
87
|
Tian S, Curnutte HA, Trcek T. RNA Granules: A View from the RNA Perspective. Molecules 2020; 25:E3130. [PMID: 32650583 PMCID: PMC7397151 DOI: 10.3390/molecules25143130] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 06/29/2020] [Accepted: 07/07/2020] [Indexed: 12/17/2022] Open
Abstract
RNA granules are ubiquitous. Composed of RNA-binding proteins and RNAs, they provide functional compartmentalization within cells. They are inextricably linked with RNA biology and as such are often referred to as the hubs for post-transcriptional regulation. Much of the attention has been given to the proteins that form these condensates and thus many fundamental questions about the biology of RNA granules remain poorly understood: How and which RNAs enrich in RNA granules, how are transcripts regulated in them, and how do granule-enriched mRNAs shape the biology of a cell? In this review, we discuss the imaging, genetic, and biochemical data, which have revealed that some aspects of the RNA biology within granules are carried out by the RNA itself rather than the granule proteins. Interestingly, the RNA structure has emerged as an important feature in the post-transcriptional control of granule transcripts. This review is part of the Special Issue in the Frontiers in RNA structure in the journal Molecules.
Collapse
Affiliation(s)
| | | | - Tatjana Trcek
- Homewood Campus, Department of Biology, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218, USA; (S.T.); (H.A.C.)
| |
Collapse
|