101
|
Fused in Sarcoma (FUS) in DNA Repair: Tango with Poly(ADP-ribose) Polymerase 1 and Compartmentalisation of Damaged DNA. Int J Mol Sci 2020; 21:ijms21197020. [PMID: 32987654 PMCID: PMC7582374 DOI: 10.3390/ijms21197020] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 09/20/2020] [Accepted: 09/21/2020] [Indexed: 12/18/2022] Open
Abstract
The fused in sarcoma (FUS) protein combines prion-like properties with a multifunctional DNA/RNA-binding domain and has functions spanning the regulation of RNA metabolism, including transcription, pre-mRNA splicing, mRNA transport and translation. In addition to its roles in RNA metabolism, FUS is implicated in the maintenance of DNA integrity. In this review, we examine the participation of FUS in major DNA repair pathways, focusing on DNA repair associated with poly(ADP-ribosyl)ation events and on how the interaction of FUS with poly(ADP-ribose) may orchestrate transient compartmentalisation of DNA strand breaks. Unravelling how prion-like RNA-binding proteins control DNA repair pathways will deepen our understanding of the pathogenesis of some neurological diseases and cancer as well as provide the basis for the development of relevant innovative therapeutic technologies. This knowledge may also extend the range of applications of poly(ADP-ribose) polymerase inhibitors to the treatment of neurodegenerative diseases related to RNA-binding proteins in the cell, e.g., amyotrophic lateral sclerosis and frontotemporal lobar degeneration.
Collapse
|
102
|
Owen I, Rhoads S, Yee D, Wyne H, Gery K, Hannula I, Sundrum M, Shewmaker F. The prion-like domain of Fused in Sarcoma is phosphorylated by multiple kinases affecting liquid- and solid-phase transitions. Mol Biol Cell 2020; 31:2522-2536. [PMID: 32877292 PMCID: PMC7851872 DOI: 10.1091/mbc.e20-05-0290] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Fused in Sarcoma (FUS) is a ubiquitously expressed protein that can phase-separate from nucleoplasm and cytoplasm into distinct liquid-droplet structures. It is predominantly nuclear and most of its functions are related to RNA and DNA metabolism. Excessive persistence of FUS within cytoplasmic phase-separated assemblies is implicated in the diseases amyotrophic lateral sclerosis and frontotemporal dementia. Phosphorylation of FUS’s prion-like domain (PrLD) by nuclear phosphatidylinositol 3-kinase-related kinase (PIKK)-family kinases following DNA damage was previously shown to alter FUS’s liquid-phase and solid-phase transitions in cell models and in vitro. However, proteomic data suggest that FUS’s PrLD is phosphorylated at numerous additional sites, and it is unknown if other non-PIKK and nonnuclear kinases might be influencing FUS’s phase transitions. Here we evaluate disease mutations and stress conditions that increase FUS accumulation into cytoplasmic phase-separated structures. We observed that cytoplasmic liquid-phase structures contain FUS phosphorylated at novel sites, which occurred independent of PIKK-family kinases. We engineered phosphomimetic substitutions within FUS’s PrLD and observed that mimicking a few phosphorylation sites strongly inhibited FUS solid-phase aggregation, while minimally altering liquid-phase condensation. These effects occurred independent of the exact location of the phosphomimetic substitutions, suggesting that modulation of PrLD phosphorylation may offer therapeutic strategies that are specific for solid-phase aggregation observed in disease.
Collapse
Affiliation(s)
- Izzy Owen
- Department of Biochemistry and Molecular Biology, Uniformed Services University, Bethesda, MD 20814
| | - Shannon Rhoads
- Department of Biochemistry and Molecular Biology, Uniformed Services University, Bethesda, MD 20814
| | - Debra Yee
- Department of Biochemistry and Molecular Biology, Uniformed Services University, Bethesda, MD 20814
| | - Hala Wyne
- Department of Biochemistry and Molecular Biology, Uniformed Services University, Bethesda, MD 20814
| | - Kevin Gery
- Department of Biochemistry and Molecular Biology, Uniformed Services University, Bethesda, MD 20814
| | - Isabelle Hannula
- Department of Biochemistry and Molecular Biology, Uniformed Services University, Bethesda, MD 20814
| | - Meenakshi Sundrum
- Department of Biochemistry and Molecular Biology, Uniformed Services University, Bethesda, MD 20814
| | - Frank Shewmaker
- Department of Biochemistry and Molecular Biology, Uniformed Services University, Bethesda, MD 20814
| |
Collapse
|
103
|
Paul T, Voter AF, Cueny RR, Gavrilov M, Ha T, Keck J, Myong S. E. coli Rep helicase and RecA recombinase unwind G4 DNA and are important for resistance to G4-stabilizing ligands. Nucleic Acids Res 2020; 48:6640-6653. [PMID: 32449930 PMCID: PMC7337899 DOI: 10.1093/nar/gkaa442] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 04/24/2020] [Accepted: 05/21/2020] [Indexed: 11/30/2022] Open
Abstract
G-quadruplex (G4) DNA structures can form physical barriers within the genome that must be unwound to ensure cellular genomic integrity. Here, we report unanticipated roles for the Escherichia coli Rep helicase and RecA recombinase in tolerating toxicity induced by G4-stabilizing ligands in vivo. We demonstrate that Rep and Rep-X (an enhanced version of Rep) display G4 unwinding activities in vitro that are significantly higher than the closely related UvrD helicase. G4 unwinding mediated by Rep involves repetitive cycles of G4 unfolding and refolding fueled by ATP hydrolysis. Rep-X and Rep also dislodge G4-stabilizing ligands, in agreement with our in vivo G4-ligand sensitivity result. We further demonstrate that RecA filaments disrupt G4 structures and remove G4 ligands in vitro, consistent with its role in countering cellular toxicity of G4-stabilizing ligands. Together, our study reveals novel genome caretaking functions for Rep and RecA in resolving deleterious G4 structures.
Collapse
Affiliation(s)
- Tapas Paul
- Department of Biophysics, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Andrew F Voter
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, USA
| | - Rachel R Cueny
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, USA
| | - Momčilo Gavrilov
- Department of Biophysics, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Taekjip Ha
- Department of Biophysics, Johns Hopkins University, Baltimore, MD 21218, USA
- Physics Frontier Center (Center for Physics of Living Cells), University of Illinois, 1110 W. Green St., Urbana, IL 61801, USA
- Howard Hughes Medical Institute, Johns Hopkins University, USA
| | - James L Keck
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, USA
| | - Sua Myong
- Department of Biophysics, Johns Hopkins University, Baltimore, MD 21218, USA
- Physics Frontier Center (Center for Physics of Living Cells), University of Illinois, 1110 W. Green St., Urbana, IL 61801, USA
| |
Collapse
|
104
|
Cupo RR, Shorter J. Skd3 (human ClpB) is a potent mitochondrial protein disaggregase that is inactivated by 3-methylglutaconic aciduria-linked mutations. eLife 2020; 9:e55279. [PMID: 32573439 PMCID: PMC7343390 DOI: 10.7554/elife.55279] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2020] [Accepted: 06/22/2020] [Indexed: 12/14/2022] Open
Abstract
Cells have evolved specialized protein disaggregases to reverse toxic protein aggregation and restore protein functionality. In nonmetazoan eukaryotes, the AAA+ disaggregase Hsp78 resolubilizes and reactivates proteins in mitochondria. Curiously, metazoa lack Hsp78. Hence, whether metazoan mitochondria reactivate aggregated proteins is unknown. Here, we establish that a mitochondrial AAA+ protein, Skd3 (human ClpB), couples ATP hydrolysis to protein disaggregation and reactivation. The Skd3 ankyrin-repeat domain combines with conserved AAA+ elements to enable stand-alone disaggregase activity. A mitochondrial inner-membrane protease, PARL, removes an autoinhibitory peptide from Skd3 to greatly enhance disaggregase activity. Indeed, PARL-activated Skd3 solubilizes α-synuclein fibrils connected to Parkinson's disease. Human cells lacking Skd3 exhibit reduced solubility of various mitochondrial proteins, including anti-apoptotic Hax1. Importantly, Skd3 variants linked to 3-methylglutaconic aciduria, a severe mitochondrial disorder, display diminished disaggregase activity (but not always reduced ATPase activity), which predicts disease severity. Thus, Skd3 is a potent protein disaggregase critical for human health.
Collapse
Affiliation(s)
- Ryan R Cupo
- Department of Biochemistry and Biophysics, Perelman School of Medicine at the University of PennsylvaniaPhiladelphiaUnited States
- Pharmacology Graduate Group, Perelman School of Medicine at the University of PennsylvaniaPhiladelphiaUnited States
| | - James Shorter
- Department of Biochemistry and Biophysics, Perelman School of Medicine at the University of PennsylvaniaPhiladelphiaUnited States
- Pharmacology Graduate Group, Perelman School of Medicine at the University of PennsylvaniaPhiladelphiaUnited States
| |
Collapse
|
105
|
Chou HY, Aksimentiev A. Single-Protein Collapse Determines Phase Equilibria of a Biological Condensate. J Phys Chem Lett 2020; 11:4923-4929. [PMID: 32426986 DOI: 10.1021/acs.jpclett.0c01222] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Recent advances in microscopy of living cells have established membraneless organelles as critical elements of diverse biological processes. The body of experimental work suggests that formation of such organelles is driven by liquid-liquid phase separation, a physical process that has been studied extensively for both simple liquids and mixtures of polymers. Here, we combine molecular dynamics simulations with polymer theory to show that the thermodynamic behavior of one particular biomolecular condensate-fused in sarcoma (FUS)-can be quantitatively accounted for at the level of the chain collapse theory. First, we show that a particle-based molecular dynamics model can reproduce known phase separation properties of a FUS condensate, including its critical concentration and susceptibility to mutations. Next, we obtain a polymer physics representation of a FUS condensate by examining the behavior of a single FUS protein as a function of temperature. We use the chain collapse theory to determine the thermodynamic properties of the condensate and to characterize changes in the single-chain conformation at the onset of phase separation. Altogether, our findings suggest that the phase behavior of FUS condensates can be explained by the properties of individual FUS proteins and that the change in the FUS conformation is the main force driving for the phase separation.
Collapse
Affiliation(s)
- Han-Yi Chou
- Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois 61801, United States
| | - Aleksei Aksimentiev
- Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois 61801, United States
| |
Collapse
|
106
|
Methods to Study Phase-Separated Condensates and the Underlying Molecular Interactions. Trends Biochem Sci 2020; 45:1004-1005. [PMID: 32561165 DOI: 10.1016/j.tibs.2020.05.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 05/19/2020] [Accepted: 05/20/2020] [Indexed: 11/23/2022]
|
107
|
Lau Y, Oamen HP, Caudron F. Protein Phase Separation during Stress Adaptation and Cellular Memory. Cells 2020; 9:cells9051302. [PMID: 32456195 PMCID: PMC7291175 DOI: 10.3390/cells9051302] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 05/14/2020] [Accepted: 05/21/2020] [Indexed: 12/13/2022] Open
Abstract
Cells need to organise and regulate their biochemical processes both in space and time in order to adapt to their surrounding environment. Spatial organisation of cellular components is facilitated by a complex network of membrane bound organelles. Both the membrane composition and the intra-organellar content of these organelles can be specifically and temporally controlled by imposing gates, much like bouncers controlling entry into night-clubs. In addition, a new level of compartmentalisation has recently emerged as a fundamental principle of cellular organisation, the formation of membrane-less organelles. Many of these structures are dynamic, rapidly condensing or dissolving and are therefore ideally suited to be involved in emergency cellular adaptation to stresses. Remarkably, the same proteins have also the propensity to adopt self-perpetuating assemblies which properties fit the needs to encode cellular memory. Here, we review some of the principles of phase separation and the function of membrane-less organelles focusing particularly on their roles during stress response and cellular memory.
Collapse
|
108
|
Tsai YL, Coady TH, Lu L, Zheng D, Alland I, Tian B, Shneider NA, Manley JL. ALS/FTD-associated protein FUS induces mitochondrial dysfunction by preferentially sequestering respiratory chain complex mRNAs. Genes Dev 2020; 34:785-805. [PMID: 32381627 PMCID: PMC7263147 DOI: 10.1101/gad.335836.119] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 04/09/2020] [Indexed: 12/12/2022]
Abstract
Dysregulation of the DNA/RNA-binding protein FUS causes certain subtypes of ALS/FTD by largely unknown mechanisms. Recent evidence has shown that FUS toxic gain of function due either to mutations or to increased expression can disrupt critical cellular processes, including mitochondrial functions. Here, we demonstrate that in human cells overexpressing wild-type FUS or expressing mutant derivatives, the protein associates with multiple mRNAs, and these are enriched in mRNAs encoding mitochondrial respiratory chain components. Notably, this sequestration leads to reduced levels of the encoded proteins, which is sufficient to bring about disorganized mitochondrial networks, reduced aerobic respiration and increased reactive oxygen species. We further show that mutant FUS associates with mitochondria and with mRNAs encoded by the mitochondrial genome. Importantly, similar results were also observed in fibroblasts derived from ALS patients with FUS mutations. Finally, we demonstrate that FUS loss of function does not underlie the observed mitochondrial dysfunction, and also provides a mechanism for the preferential sequestration of the respiratory chain complex mRNAs by FUS that does not involve sequence-specific binding. Together, our data reveal that respiratory chain complex mRNA sequestration underlies the mitochondrial defects characteristic of ALS/FTD and contributes to the FUS toxic gain of function linked to this disease spectrum.
Collapse
Affiliation(s)
- Yueh-Lin Tsai
- Department of Biological Sciences, Columbia University, New York, New York 10027, USA
| | - Tristan H Coady
- Department of Biological Sciences, Columbia University, New York, New York 10027, USA
| | - Lei Lu
- Center for Motor Neuron Biology and Disease, Columbia University, New York, New York 10027, USA
| | - Dinghai Zheng
- Department of Microbiology, Biochemistry, and Molecular Genetics, Rutgers New Jersey Medical School, Newark, New Jersey 07103, USA
| | - Isabel Alland
- Department of Biological Sciences, Columbia University, New York, New York 10027, USA
| | - Bin Tian
- Department of Microbiology, Biochemistry, and Molecular Genetics, Rutgers New Jersey Medical School, Newark, New Jersey 07103, USA
| | - Neil A Shneider
- Center for Motor Neuron Biology and Disease, Columbia University, New York, New York 10027, USA
| | - James L Manley
- Department of Biological Sciences, Columbia University, New York, New York 10027, USA
| |
Collapse
|
109
|
Ravnik-Glavač M, Glavač D. Circulating RNAs as Potential Biomarkers in Amyotrophic Lateral Sclerosis. Int J Mol Sci 2020; 21:ijms21051714. [PMID: 32138249 PMCID: PMC7084402 DOI: 10.3390/ijms21051714] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Revised: 02/27/2020] [Accepted: 02/29/2020] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a complex multi-system neurodegenerative disorder with currently limited diagnostic and no therapeutic options. Despite the intense efforts no clinically applicable biomarkers for ALS are yet established. Most current research is thus focused, in particular, in identifying potential non-invasive circulating biomarkers for more rapid and accurate diagnosis and monitoring of the disease. In this review, we have focused on messenger RNA (mRNA), non-coding RNAs (lncRNAs), micro RNAs (miRNAs) and circular RNA (circRNAs) as potential biomarkers for ALS in peripheral blood serum, plasma and cells. The most promising miRNAs include miR-206, miR-133b, miR-27a, mi-338-3p, miR-183, miR-451, let-7 and miR-125b. To test clinical potential of this miRNA panel, a useful approach may be to perform such analysis on larger multi-center scale using similar experimental design. However, other types of RNAs (lncRNAs, circRNAs and mRNAs) that, together with miRNAs, represent RNA networks, have not been yet extensively studied in blood samples of patients with ALS. Additional research has to be done in order to find robust circulating biomarkers and therapeutic targets that will distinguish key RNA interactions in specific ALS-types to facilitate diagnosis, predict progression and design therapy.
Collapse
Affiliation(s)
- Metka Ravnik-Glavač
- Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Vrazov trg 2, 1000 Ljubljana, Slovenia
- Correspondence: (M.R.-G.); (D.G.)
| | - Damjan Glavač
- Department of Molecular Genetics, Institute of Pathology, Faculty of Medicine, University of Ljubljana, Korytkova 2, 1000 Ljubljana, Slovenia
- Correspondence: (M.R.-G.); (D.G.)
| |
Collapse
|
110
|
Abramzon YA, Fratta P, Traynor BJ, Chia R. The Overlapping Genetics of Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Front Neurosci 2020; 14:42. [PMID: 32116499 PMCID: PMC7012787 DOI: 10.3389/fnins.2020.00042] [Citation(s) in RCA: 134] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Accepted: 01/13/2020] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are two diseases that form a broad neurodegenerative continuum. Considerable effort has been made to unravel the genetics of these disorders, and, based on this work, it is now clear that ALS and FTD have a significant genetic overlap. TARDBP, SQSTM1, VCP, FUS, TBK1, CHCHD10, and most importantly C9orf72, are the critical genetic players in these neurological disorders. Discoveries of these genes have implicated autophagy, RNA regulation, and vesicle and inclusion formation as the central pathways involved in neurodegeneration. Here we provide a summary of the significant genes identified in these two intrinsically linked neurodegenerative diseases and highlight the genetic and pathological overlaps.
Collapse
Affiliation(s)
- Yevgeniya A. Abramzon
- Neuromuscular Diseases Research Section, Laboratory of Neurogenetics, National Institute on Aging, NIH, Bethesda, MD, United States
- Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, London, United Kingdom
| | - Pietro Fratta
- Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, London, United Kingdom
| | - Bryan J. Traynor
- Neuromuscular Diseases Research Section, Laboratory of Neurogenetics, National Institute on Aging, NIH, Bethesda, MD, United States
- Department of Neurology, Brain Science Institute, Johns Hopkins University, Baltimore, MD, United States
| | - Ruth Chia
- Neuromuscular Diseases Research Section, Laboratory of Neurogenetics, National Institute on Aging, NIH, Bethesda, MD, United States
| |
Collapse
|