251
|
Verma A, Sumi S, Seervi M. Heat shock proteins-driven stress granule dynamics: yet another avenue for cell survival. Apoptosis 2021; 26:371-384. [PMID: 33978921 DOI: 10.1007/s10495-021-01678-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/04/2021] [Indexed: 12/24/2022]
Abstract
Heat shock proteins (HSPs) are evolutionary conserved 'stress-response' proteins that facilitate cell survival against various adverse conditions. HSP-mediated cytoprotection was hitherto reported to occur principally in two ways. Firstly, HSPs interact directly or indirectly with apoptosis signaling components and suppress apoptosis. Secondly, through chaperon activity, HSPs suppress proteotoxicity and maintain protein-homeostasis. Recent studies highlight the interaction of HSPs with cytoplasmic stress granules (SGs). SGs are conserved cytoplasmic mRNPs granules that aid in cell survival under stressful conditions. We primarily aim to describe the distinct cell survival strategy mediated by HSPs as the crucial regulators of SGs assembly and disassembly. Based on the growing evidence, HSPs and associated co-chaperones act as important determinants of SG assembly, composition and dissolution. Under cellular stress, as a 'stress-coping mechanism', the formation of SGs reprograms protein translation machinery and modulates signaling pathways indispensable for cell survival. Besides their role in suppressing apoptosis, HSPs also regulate protein-homeostasis by their chaperone activity as well as by their tight regulation of SG dynamics. The intricate molecular signaling in and around the nexus of HSPs-SGs and its importance in diseases has to be unearthed. These studies have significant implications in the management of chronic diseases such as cancer and neurodegenerative diseases where SGs possess pathological functions.
Collapse
Affiliation(s)
- Akanksha Verma
- Department of Biotechnology, All India Institute of Medical Sciences (AIIMS), New Delhi, 110029, India
| | - S Sumi
- Cardiovascular Diseases and Diabetes Biology, Rajiv Gandhi Centre for Biotechnology (RGCB), Thiruvananthapuram, Kerala, India
| | - Mahendra Seervi
- Department of Biotechnology, All India Institute of Medical Sciences (AIIMS), New Delhi, 110029, India.
| |
Collapse
|
252
|
Connecting the "dots": RNP granule network in health and disease. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2021; 1868:119058. [PMID: 33989700 DOI: 10.1016/j.bbamcr.2021.119058] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 05/01/2021] [Accepted: 05/07/2021] [Indexed: 12/26/2022]
Abstract
All cells contain ribonucleoprotein (RNP) granules - large membraneless structures composed of RNA and proteins. Recent breakthroughs in RNP granule research have brought a new appreciation of their crucial role in organising virtually all cellular processes. Cells widely exploit the flexible, dynamic nature of RNP granules to adapt to a variety of functional states and the ever-changing environment. Constant exchange of molecules between the different RNP granules connects them into a network. This network controls basal cellular activities and is remodelled to enable efficient stress response. Alterations in RNP granule structure and regulation have been found to lead to fatal human diseases. The interconnectedness of RNP granules suggests that the RNP granule network as a whole becomes affected in disease states such as a representative neurodegenerative disease amyotrophic lateral sclerosis (ALS). In this review, we summarize available evidence on the communication between different RNP granules and on the RNP granule network disruption as a primary ALS pathomechanism.
Collapse
|
253
|
Tikhomirova MA, Sheval EV. Formation of Biomolecular Condensates: Regulation of Embryogenesis at the Cellular Level. Russ J Dev Biol 2021. [DOI: 10.1134/s1062360421020077] [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]
|
254
|
Jin X, Cao X, Liu S, Liu B. Functional Roles of Poly(ADP-Ribose) in Stress Granule Formation and Dynamics. Front Cell Dev Biol 2021; 9:671780. [PMID: 33981709 PMCID: PMC8107429 DOI: 10.3389/fcell.2021.671780] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 04/06/2021] [Indexed: 12/03/2022] Open
Abstract
Stress granules (SGs) are highly dynamic cytoplasmic foci formed in response to stress. The formation of SGs is reported to be regulated by diverse post-translational protein modifications (PTMs). Among them, ADP-ribosylation is of emerging interest due to its recently identified roles in SG organization. In this review, we summarized the latest advances on the roles of poly(ADP-ribose) (PAR) in the regulation of SG formation and dynamics, including its function in modulating nucleocytoplasmic trafficking and SG recruitment of SG components, as well as its effects on protein phase separation behavior. Moreover, the functional role of PAR chain diversity on dynamic of SG composition is also introduced. Potential future developments on investigating global ADP-ribosylation networks, individual roles of different PARPs, and interactions between ADP-ribosylation and other PTMs in SGs are also discussed.
Collapse
Affiliation(s)
- Xuejiao Jin
- State Key Laboratory of Subtropical Silviculture, School of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou, China
| | - Xiuling Cao
- State Key Laboratory of Subtropical Silviculture, School of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou, China
| | - Shenkui Liu
- State Key Laboratory of Subtropical Silviculture, School of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou, China
| | - Beidong Liu
- State Key Laboratory of Subtropical Silviculture, School of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou, China.,Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden.,Faculty of Science, Center for Large-Scale Cell-Based Screening, University of Gothenburg, Gothenburg, Sweden
| |
Collapse
|
255
|
Amen T, Kaganovich D. Small Molecule Screen Reveals Joint Regulation of Stress Granule Formation and Lipid Droplet Biogenesis. Front Cell Dev Biol 2021; 8:606111. [PMID: 33972926 PMCID: PMC8105174 DOI: 10.3389/fcell.2020.606111] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 12/21/2020] [Indexed: 01/22/2023] Open
Abstract
Metabolic regulation is a necessary component of all stress response pathways, because all different mechanisms of stress-adaptation place high-energy demands on the cell. Mechanisms that integrate diverse stress response pathways with their metabolic components are therefore of great interest, but few are known. We show that stress granule (SG) formation, a common adaptive response to a variety of stresses, is reciprocally regulated by the pathways inducing lipid droplet accumulation. Inability to upregulate lipid droplets reduces stress granule formation. Stress granule formation in turn drives lipid droplet clustering and fatty acid accumulation. Our findings reveal a novel connection between stress response pathways and new modifiers of stress granule formation.
Collapse
Affiliation(s)
- Triana Amen
- Department of Experimental Neurodegeneration, University Medical Center Göttingen, Göttingen, Germany
| | - Daniel Kaganovich
- Department of Experimental Neurodegeneration, University Medical Center Göttingen, Göttingen, Germany.,1Base Pharmaceuticals, Boston, MA, United States
| |
Collapse
|
256
|
Shuster SO, Lee JC. Tryptophan Probes of TDP-43 C-Terminal Domain Amyloid Formation. J Phys Chem B 2021; 125:3781-3789. [PMID: 33835818 DOI: 10.1021/acs.jpcb.1c00767] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Aggregated TAR DNA-binding protein 43 (TDP-43) forms the cytoplasmic hallmarks associated with patients suffering from amyotrophic lateral sclerosis and frontotemporal lobar degeneration with ubiquitin. Under normal conditions, TDP-43 is a 414-amino acid protein; however, aggregates are enriched with N-terminal truncations which contain residues 267-414, known as the C-terminal domain of TDP-43 (TDP-43CTD). To gain residue-specific information on the aggregation process of TDP-43CTD, we created three single-Trp containing mutants (W385F/W412F, W334F/W412F, and W334F/W385F) by substituting two of the three native Trp residues with Phe, yielding fluorescent probes at W334, W385, and W412, respectively. Aggregation kinetics, secondary structure, and fibril morphology were compared to the wild-type protein using thioflavin-T fluorescence, Raman spectroscopy, and transmission electron microscopy, respectively. While only W334 is determined to be in the proteinase-K resistant core, all three sites are sensitive reporters of aggregation, revealing site-specific differences. Interestingly, W334 exhibited unusual multistep Trp kinetics, pinpointing a distinctive role for W334 and its nearby region during aggregation. This behavior is retained even upon seeding, suggesting the observed spectral change is related to fibril growth. This work provides new insights into the aggregation mechanism of TDP-43CTD and exemplifies the advantages of Trp as a site-specific environmentally sensitive fluorescent probe.
Collapse
Affiliation(s)
- Sydney O Shuster
- Laboratory of Protein Conformation and Dynamics, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Jennifer C Lee
- Laboratory of Protein Conformation and Dynamics, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
| |
Collapse
|
257
|
Schnell HM, Jochem M, Micoogullari Y, Riggs CL, Ivanov P, Welsch H, Ravindran R, Anderson P, Robinson LC, Tatchell K, Hanna J. Reg1 and Snf1 regulate stress-induced relocalization of protein phosphatase-1 to cytoplasmic granules. FEBS J 2021; 288:4833-4848. [PMID: 33682330 DOI: 10.1111/febs.15802] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 02/22/2021] [Accepted: 03/03/2021] [Indexed: 11/26/2022]
Abstract
The compartmentalization of cellular function is achieved largely through the existence of membrane-bound organelles. However, recent work suggests a novel mechanism of compartmentalization mediated by membraneless structures that have liquid droplet-like properties and arise through phase separation. Cytoplasmic stress granules (SGs) are the best characterized and are induced by various stressors including arsenite, heat shock, and glucose deprivation. Current models suggest that SGs play an important role in protein homeostasis by mediating reversible translation attenuation. Protein phosphatase-1 (PP1) is a central cellular regulator responsible for most serine/threonine dephosphorylation. Here, we show that upon arsenite stress, PP1's catalytic subunit Glc7 relocalizes to punctate cytoplasmic granules. This altered localization requires PP1's recently described maturation pathway mediated by the multifunctional ATPase Cdc48 and PP1's regulatory subunit Ypi1. Glc7 relocalization is mediated by its regulatory subunit Reg1 and its target Snf1, the AMP-dependent protein kinase. Surprisingly, Glc7 granules are highly specific to arsenite and appear distinct from canonical SGs. Arsenite induces potent translational inhibition, and translational recovery is strongly dependent on Glc7, but independent of Glc7's well-established role in regulating eIF2α. These results suggest a novel form of stress-induced cytoplasmic granule and a new mode of translational control by Glc7.
Collapse
Affiliation(s)
- Helena Maria Schnell
- Department of Pathology, Harvard Medical School and Brigham and Women's Hospital, Boston, MA, USA
| | - Marco Jochem
- Department of Pathology, Harvard Medical School and Brigham and Women's Hospital, Boston, MA, USA
| | - Yagmur Micoogullari
- Department of Pathology, Harvard Medical School and Brigham and Women's Hospital, Boston, MA, USA
| | - Claire Louise Riggs
- Department of Rheumatology, Harvard Medical School and Brigham and Women's Hospital, Boston, MA, USA
| | - Pavel Ivanov
- Department of Rheumatology, Harvard Medical School and Brigham and Women's Hospital, Boston, MA, USA
| | - Hendrik Welsch
- Department of Pathology, Harvard Medical School and Brigham and Women's Hospital, Boston, MA, USA
| | - Rini Ravindran
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, Shreveport, LA, USA
| | - Paul Anderson
- Department of Rheumatology, Harvard Medical School and Brigham and Women's Hospital, Boston, MA, USA
| | - Lucy Christina Robinson
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, Shreveport, LA, USA
| | - Kelly Tatchell
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, Shreveport, LA, USA
| | - John Hanna
- Department of Pathology, Harvard Medical School and Brigham and Women's Hospital, Boston, MA, USA
| |
Collapse
|
258
|
Di Marco B, Dell'Albani P, D'Antoni S, Spatuzza M, Bonaccorso CM, Musumeci SA, Drago F, Bardoni B, Catania MV. Fragile X mental retardation protein (FMRP) and metabotropic glutamate receptor subtype 5 (mGlu5) control stress granule formation in astrocytes. Neurobiol Dis 2021; 154:105338. [PMID: 33775821 DOI: 10.1016/j.nbd.2021.105338] [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] [Received: 10/02/2020] [Revised: 03/12/2021] [Accepted: 03/17/2021] [Indexed: 12/18/2022] Open
Abstract
Fragile X syndrome (FXS) is a common form of intellectual disability and autism caused by the lack of Fragile X Mental Retardation Protein (FMRP), an RNA-binding protein involved in RNA transport and protein synthesis. Upon cellular stress, global protein synthesis is blocked and mRNAs are recruited into stress granules (SGs), together with RNA-binding proteins including FMRP. Activation of group-I metabotropic glutamate (mGlu) receptors stimulates FMRP-mediated mRNA transport and protein synthesis, but their role in SGs formation is unexplored. To this aim, we pre-treated wild type (WT) and Fmr1 knockout (KO) cultured astrocytes with the group-I-mGlu receptor agonist (S)-3,5-Dihydroxyphenylglycine (DHPG) and exposed them to sodium arsenite (NaAsO2), a widely used inducer of SGs formation. In WT cultures the activation of group-I mGlu receptors reduced SGs formation and recruitment of FMRP into SGs, and also attenuated phosphorylation of eIF2α, a key event crucially involved in SGs formation and inhibition of protein synthesis. In contrast, Fmr1 KO astrocytes, which exhibited a lower number of SGs than WT astrocytes, did not respond to agonist stimulation. Interestingly, the mGlu5 receptor negative allosteric modulator (NAM) 2-methyl-6-(phenylethynyl)pyridine (MPEP) antagonized DHPG-mediated SGs reduction in WT and reversed SGs formation in Fmr1 KO cultures. Our findings reveal a novel function of mGlu5 receptor as modulator of SGs formation and open new perspectives for understanding cellular response to stress in FXS pathophysiology.
Collapse
Affiliation(s)
- B Di Marco
- Institute for Biomedical Research and Innovation - The National Research Council of Italy (IRIB-CNR), Catania, Italy
| | - P Dell'Albani
- Institute for Biomedical Research and Innovation - The National Research Council of Italy (IRIB-CNR), Catania, Italy
| | - S D'Antoni
- Institute for Biomedical Research and Innovation - The National Research Council of Italy (IRIB-CNR), Catania, Italy
| | - M Spatuzza
- Oasi Research Institute - IRCCS, Troina, Italy
| | | | | | - F Drago
- Department of Biomedical and Biotecnological Sciences, University of Catania, Italy
| | - B Bardoni
- Université Côte d'Azur, Inserm, CNRS UMR7275, Institute of Molecular and Cellular Pharmacology, Valbonne 06560, France
| | - M V Catania
- Institute for Biomedical Research and Innovation - The National Research Council of Italy (IRIB-CNR), Catania, Italy; Oasi Research Institute - IRCCS, Troina, Italy.
| |
Collapse
|
259
|
Moon SL, Morisaki T, Stasevich TJ, Parker R. Coupling of translation quality control and mRNA targeting to stress granules. J Cell Biol 2021; 219:151851. [PMID: 32520986 PMCID: PMC7401812 DOI: 10.1083/jcb.202004120] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 05/05/2020] [Accepted: 05/06/2020] [Indexed: 02/07/2023] Open
Abstract
Stress granules are dynamic assemblies of proteins and nontranslating RNAs that form when translation is inhibited in response to diverse stresses. Defects in ubiquitin–proteasome system factors including valosin-containing protein (VCP) and the proteasome impact the kinetics of stress granule induction and dissolution as well as being implicated in neuropathogenesis. However, the impacts of dysregulated proteostasis on mRNA regulation and stress granules are not well understood. Using single mRNA imaging, we discovered ribosomes stall on some mRNAs during arsenite stress, and the release of transcripts from stalled ribosomes for their partitioning into stress granules requires the activities of VCP, components of the ribosome-associated quality control (RQC) complex, and the proteasome. This is an unexpected contribution of the RQC system in releasing mRNAs from translation under stress, thus identifying a new type of stress-activated RQC (saRQC) distinct from canonical RQC pathways in mRNA substrates, cellular context, and mRNA fate.
Collapse
Affiliation(s)
- Stephanie L Moon
- Department of Human Genetics, University of Michigan, Ann Arbor, MI.,Center for RNA Biomedicine, University of Michigan, Ann Arbor, MI
| | - Tatsuya Morisaki
- Department of Biochemistry, Colorado State University, Fort Collins, CO
| | - Timothy J Stasevich
- Department of Biochemistry, Colorado State University, Fort Collins, CO.,World Research Hub Initiative, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | - Roy Parker
- Department of Biochemistry, University of Colorado, Boulder, CO.,Howard Hughes Medical Institute, Chevy Chase, MD
| |
Collapse
|
260
|
Watanabe K, Morishita K, Zhou X, Shiizaki S, Uchiyama Y, Koike M, Naguro I, Ichijo H. Cells recognize osmotic stress through liquid-liquid phase separation lubricated with poly(ADP-ribose). Nat Commun 2021; 12:1353. [PMID: 33649309 PMCID: PMC7921423 DOI: 10.1038/s41467-021-21614-5] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 02/02/2021] [Indexed: 12/17/2022] Open
Abstract
Cells are under threat of osmotic perturbation; cell volume maintenance is critical in cerebral edema, inflammation and aging, in which prominent changes in intracellular or extracellular osmolality emerge. After osmotic stress-enforced cell swelling or shrinkage, the cells regulate intracellular osmolality to recover their volume. However, the mechanisms recognizing osmotic stress remain obscured. We previously clarified that apoptosis signal-regulating kinase 3 (ASK3) bidirectionally responds to osmotic stress and regulates cell volume recovery. Here, we show that macromolecular crowding induces liquid-demixing condensates of ASK3 under hyperosmotic stress, which transduce osmosensing signal into ASK3 inactivation. A genome-wide small interfering RNA (siRNA) screen identifies an ASK3 inactivation regulator, nicotinamide phosphoribosyltransferase (NAMPT), related to poly(ADP-ribose) signaling. Furthermore, we clarify that poly(ADP-ribose) keeps ASK3 condensates in the liquid phase and enables ASK3 to become inactivated under hyperosmotic stress. Our findings demonstrate that cells rationally incorporate physicochemical phase separation into their osmosensing systems.
Collapse
Affiliation(s)
- Kengo Watanabe
- Laboratory of Cell Signaling, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, 113-0033, Japan.
| | - Kazuhiro Morishita
- Laboratory of Cell Signaling, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Xiangyu Zhou
- Laboratory of Cell Signaling, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Shigeru Shiizaki
- Laboratory of Cell Signaling, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Yasuo Uchiyama
- Department of Cellular and Molecular Neuropathology, Juntendo University Graduate School of Medicine, Tokyo, 113-8421, Japan
| | - Masato Koike
- Department of Cell Biology and Neuroscience, Juntendo University Graduate School of Medicine, Tokyo, 113-8421, Japan
| | - Isao Naguro
- Laboratory of Cell Signaling, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Hidenori Ichijo
- Laboratory of Cell Signaling, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, 113-0033, Japan.
| |
Collapse
|
261
|
Abouward R, Schiavo G. Walking the line: mechanisms underlying directional mRNA transport and localisation in neurons and beyond. Cell Mol Life Sci 2021; 78:2665-2681. [PMID: 33341920 PMCID: PMC8004493 DOI: 10.1007/s00018-020-03724-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 11/02/2020] [Accepted: 11/25/2020] [Indexed: 12/21/2022]
Abstract
Messenger RNA (mRNA) localisation enables a high degree of spatiotemporal control on protein synthesis, which contributes to establishing the asymmetric protein distribution required to set up and maintain cellular polarity. As such, a tight control of mRNA localisation is essential for many biological processes during development and in adulthood, such as body axes determination in Drosophila melanogaster and synaptic plasticity in neurons. The mechanisms controlling how mRNAs are localised, including diffusion and entrapment, local degradation and directed active transport, are largely conserved across evolution and have been under investigation for decades in different biological models. In this review, we will discuss the standing of the field regarding directional mRNA transport in light of the recent discovery that RNA can hitchhike on cytoplasmic organelles, such as endolysosomes, and the impact of these transport modalities on our understanding of neuronal function during development, adulthood and in neurodegeneration.
Collapse
Affiliation(s)
- Reem Abouward
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, WC1N 3BG, UK
- UK Dementia Research Institute, University College London, London, WC1E 6BT, UK
- The Francis Crick Institute, 1 Midland Rd, London, NW1 1AT, UK
| | - Giampietro Schiavo
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, WC1N 3BG, UK.
- UK Dementia Research Institute, University College London, London, WC1E 6BT, UK.
| |
Collapse
|
262
|
Seo H, Lee H. Recent developments in microfluidic synthesis of artificial cell-like polymersomes and liposomes for functional bioreactors. BIOMICROFLUIDICS 2021; 15:021301. [PMID: 33833845 PMCID: PMC8012066 DOI: 10.1063/5.0048441] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 03/18/2021] [Indexed: 05/16/2023]
Abstract
Recent advances in droplet microfluidics have led to the fabrication of versatile vesicles with a structure that mimics the cellular membrane. These artificial cell-like vesicles including polymersomes and liposomes effectively enclose an aqueous core with well-defined size and composition from the surrounding environment to implement various biological reactions, serving as a diverse functional reactor. The advantage of realizing various biological phenomena within a compartment separated by a membrane that resembles a natural cell membrane is actively explored in the fields of synthetic biology as well as biomedical applications including drug delivery, biosensors, and bioreactors, to name a few. In this Perspective, we first summarize various methods utilized in producing these polymersomes and liposomes. Moreover, we will highlight some of the recent advances in the design of these artificial cell-like vesicles for functional bioreactors and discuss the current issues and future perspectives.
Collapse
Affiliation(s)
- Hanjin Seo
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 37673, South Korea
| | - Hyomin Lee
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 37673, South Korea
| |
Collapse
|
263
|
Jeon P, Lee JA. Dr. Jekyll and Mr. Hyde? Physiology and Pathology of Neuronal Stress Granules. Front Cell Dev Biol 2021; 9:609698. [PMID: 33718353 PMCID: PMC7947226 DOI: 10.3389/fcell.2021.609698] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 01/25/2021] [Indexed: 11/30/2022] Open
Abstract
Stress granules (SGs) are membraneless cytosolic granules containing dense aggregations of RNA-binding proteins and RNAs. They appear in the cytosol under stress conditions and inhibit the initiation of mRNA translation. SGs are dynamically assembled under stressful conditions and rapidly disassembled after stress removal. They are heterogeneous in their RNA and protein content and are cell type- and stress-specific. In post-mitotic neurons, which do not divide, the dynamics of neuronal SGs are tightly regulated, implying that their dysregulation leads to neurodegeneration. Mutations in RNA-binding proteins are associated with SGs. SG components accumulate in cytosolic inclusions in many neurodegenerative diseases, such as frontotemporal dementia and amyotrophic lateral sclerosis. Although SGs primarily mediate a pro-survival adaptive response to cellular stress, abnormal persistent SGs might develop into aggregates and link to the pathogenesis of diseases. In this review, we present recent advances in the study of neuronal SGs in physiology and pathology, and discuss potential therapeutic approaches to remove abnormal, persistent SGs associated with neurodegeneration.
Collapse
Affiliation(s)
- Pureum Jeon
- Department of Biotechnology and Biological Sciences, Hannam University, Daejeon, South Korea
| | - Jin A Lee
- Department of Biotechnology and Biological Sciences, Hannam University, Daejeon, South Korea
| |
Collapse
|
264
|
Polčic P, Machala Z. Effects of Non-Thermal Plasma on Yeast Saccharomyces cerevisiae. Int J Mol Sci 2021; 22:ijms22052247. [PMID: 33668158 PMCID: PMC7956799 DOI: 10.3390/ijms22052247] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 02/16/2021] [Accepted: 02/20/2021] [Indexed: 12/26/2022] Open
Abstract
Cold plasmas generated by various electrical discharges can affect cell physiology or induce cell damage that may often result in the loss of viability. Many cold plasma-based technologies have emerged in recent years that are aimed at manipulating the cells within various environments or tissues. These include inactivation of microorganisms for the purpose of sterilization, food processing, induction of seeds germination, but also the treatment of cells in the therapy. Mechanisms that underlie the plasma-cell interactions are, however, still poorly understood. Dissection of cellular pathways or structures affected by plasma using simple eukaryotic models is therefore desirable. Yeast Saccharomyces cerevisiae is a traditional model organism with unprecedented impact on our knowledge of processes in eukaryotic cells. As such, it had been also employed in studies of plasma-cell interactions. This review focuses on the effects of cold plasma on yeast cells.
Collapse
Affiliation(s)
- Peter Polčic
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Mlynská dolina CH1, Ilkovičova 6, 84215 Bratislava, Slovakia
- Correspondence: ; Tel.: +421-2-60296-398
| | - Zdenko Machala
- Division of Environmental Physics, Faculty of Mathematics, Physics, and Informatics, Comenius University in Bratislava, Mlynská dolina F2, 84248 Bratislava, Slovakia;
| |
Collapse
|
265
|
Gaete-Argel A, Velásquez F, Márquez CL, Rojas-Araya B, Bueno-Nieto C, Marín-Rojas J, Cuevas-Zúñiga M, Soto-Rifo R, Valiente-Echeverría F. Tellurite Promotes Stress Granules and Nuclear SG-Like Assembly in Response to Oxidative Stress and DNA Damage. Front Cell Dev Biol 2021; 9:622057. [PMID: 33681200 PMCID: PMC7928414 DOI: 10.3389/fcell.2021.622057] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 01/21/2021] [Indexed: 12/13/2022] Open
Abstract
Tellurium oxyanion, tellurite (TeO3–2), is a highly toxic compound for many organisms. Its presence in the environment has increased over the past years due to industrial manufacturing processes and has been associated with adverse effects on human health. Although tellurite induces the phosphorylation of eIF2α, DNA damage and oxidative stress, the molecular mechanisms related to the cellular responses to tellurite-induced stress are poorly understood. In this work, we evaluated the ability of tellurite to induce phosphorylation of eIF2α, stress granules (SGs) assembly and their relationship with DNA damage in U2OS cells. We demonstrate that tellurite promotes the assembly of bona fide cytoplasmic SGs. Unexpectedly, tellurite also induces the assembly of nuclear SGs. Interestingly, we observed that the presence of tellurite-induced nuclear SGs correlates with γH2AX foci. However, although H2O2 also induce DNA damage, no nuclear SGs were observed. Our data show that tellurite promotes the assembly of cytoplasmic and nuclear SGs in response to oxidative stress and DNA damage, revealing a new aspect of cellular stress response mediated by the assembly of nuclear stress granules.
Collapse
Affiliation(s)
- Aracelly Gaete-Argel
- Molecular and Cellular Virology Laboratory, Faculty of Medicine, Virology Program, Institute of Biomedical Sciences, Universidad de Chile, Santiago, Chile.,HIV/AIDS Workgroup, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Felipe Velásquez
- Molecular and Cellular Virology Laboratory, Faculty of Medicine, Virology Program, Institute of Biomedical Sciences, Universidad de Chile, Santiago, Chile.,HIV/AIDS Workgroup, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Chantal L Márquez
- Molecular and Cellular Virology Laboratory, Faculty of Medicine, Virology Program, Institute of Biomedical Sciences, Universidad de Chile, Santiago, Chile.,HIV/AIDS Workgroup, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Barbara Rojas-Araya
- HIV/AIDS Workgroup, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Constanza Bueno-Nieto
- Molecular and Cellular Virology Laboratory, Faculty of Medicine, Virology Program, Institute of Biomedical Sciences, Universidad de Chile, Santiago, Chile
| | - Josefina Marín-Rojas
- Molecular and Cellular Virology Laboratory, Faculty of Medicine, Virology Program, Institute of Biomedical Sciences, Universidad de Chile, Santiago, Chile.,HIV/AIDS Workgroup, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Miguel Cuevas-Zúñiga
- Molecular and Cellular Virology Laboratory, Faculty of Medicine, Virology Program, Institute of Biomedical Sciences, Universidad de Chile, Santiago, Chile
| | - Ricardo Soto-Rifo
- Molecular and Cellular Virology Laboratory, Faculty of Medicine, Virology Program, Institute of Biomedical Sciences, Universidad de Chile, Santiago, Chile.,HIV/AIDS Workgroup, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Fernando Valiente-Echeverría
- Molecular and Cellular Virology Laboratory, Faculty of Medicine, Virology Program, Institute of Biomedical Sciences, Universidad de Chile, Santiago, Chile.,HIV/AIDS Workgroup, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| |
Collapse
|
266
|
Mikhalkevich N, O’Carroll IP, Tkavc R, Lund K, Sukumar G, Dalgard CL, Johnson KR, Li W, Wang T, Nath A, Iordanskiy S. Response of human macrophages to gamma radiation is mediated via expression of endogenous retroviruses. PLoS Pathog 2021; 17:e1009305. [PMID: 33556144 PMCID: PMC7895352 DOI: 10.1371/journal.ppat.1009305] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 02/19/2021] [Accepted: 01/11/2021] [Indexed: 01/11/2023] Open
Abstract
Ionizing radiation-induced tissue damage recruits monocytes into the exposed area where they are differentiated to macrophages. These implement phagocytic removal of dying cells and elicit an acute inflammatory response, but can also facilitate tumorigenesis due to production of anti-inflammatory cytokines. Using primary human monocyte-derived macrophages (MDMs) and the THP1 monocytic cell line, we demonstrate that gamma radiation triggers monocyte differentiation toward the macrophage phenotype with increased expression of type I interferons (IFN-I) and both pro- and anti-inflammatory macrophage activation markers. We found that these changes correlate with significantly upregulated expression of 622 retroelements from various groups, particularly of several clades of human endogenous retroviruses (HERVs). Elevated transcription was detected in both sense and antisense directions in the HERV subgroups tested, including the most genetically homogeneous clade HML-2. The level of antisense transcription was three- to five-fold higher than of the sense strand levels. Using a proximity ligation assay and immunoprecipitation followed by RNA quantification, we identified an increased amount of the dsRNA receptors MDA-5 and TLR3 bound to an equivalent number of copies of sense and antisense chains of HERVK HML-2 RNA. This binding triggered MAVS-associated signaling pathways resulting in increased expression of IFN-I and inflammation related genes that enhanced the cumulative inflammatory effect of radiation-induced senescence. HML-2 knockdown was accompanied with reduced expression and secretion of IFNα, pro-inflammatory (IL-1β, IL-6, CCL2, CCL3, CCL8, and CCL20) and anti-inflammatory (IL10) modulators in irradiated monocytes and MDMs. Taken together, our data indicate that radiation stress-induced HERV expression enhances the IFN-I and cytokine response and results in increased levels of pro-inflammatory modulators along with expression of anti-inflammatory factors associated with the macrophage tumorigenic phenotype. Ionizing radiation is a powerful stressogenic factor that induces massive cell damage. The signals released from radiation-damaged tissues recruit the monocytes, which are differentiated into macrophages that remove dying cells via phagocytosis and facilitate inflammation but can also contribute to tumorigenesis through anti-inflammatory and regenerative activities. The mechanism of this dual response of macrophages to irradiation is not fully understood. Using primary human macrophages and a monocytic cell line, we demonstrated that gamma radiation doses activate expression of various human endogenous retroviruses (HERVs). At the molecular level, we have shown that increased numbers of sense and antisense transcripts of tested HERV subgroups bind to double-stranded RNA receptors inducing the expression of type I interferons, multiple pro-inflammatory and some anti-inflammatory factors. At the phenotypic level, polarized macrophages exhibit a potent inflammatory response along with potentially tumorigenic characteristics. Our data suggest that endogenous retroviruses represent an important contributor of the macrophage-mediated inflammation in response to radiation-induced stress but may also indirectly influence tumorigenesis via biased macrophage polarization.
Collapse
Affiliation(s)
- Natallia Mikhalkevich
- Department of Pharmacology & Molecular Therapeutics, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Ina P. O’Carroll
- Department of Chemistry, United States Naval Academy, Annapolis, Maryland, United States of America
| | - Rok Tkavc
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, Maryland, United States of America
| | - Kateryna Lund
- Biomedical Instrumentation Center, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Gauthaman Sukumar
- The American Genome Center (TAGC), Collaborative Health Initiative Research Program, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Clifton L. Dalgard
- The American Genome Center (TAGC), Collaborative Health Initiative Research Program, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
- Department of Anatomy, Physiology & Genetics, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Kory R. Johnson
- Bioinformatics Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Wenxue Li
- Section of Infections of the Nervous System, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Tongguang Wang
- Section of Infections of the Nervous System, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Avindra Nath
- Section of Infections of the Nervous System, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail: (AN); (SI)
| | - Sergey Iordanskiy
- Department of Pharmacology & Molecular Therapeutics, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
- * E-mail: (AN); (SI)
| |
Collapse
|
267
|
Boija A, Klein IA, Young RA. Biomolecular Condensates and Cancer. Cancer Cell 2021; 39:174-192. [PMID: 33417833 PMCID: PMC8721577 DOI: 10.1016/j.ccell.2020.12.003] [Citation(s) in RCA: 140] [Impact Index Per Article: 46.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 12/02/2020] [Accepted: 12/04/2020] [Indexed: 12/14/2022]
Abstract
Malignant transformation is characterized by dysregulation of diverse cellular processes that have been the subject of detailed genetic, biochemical, and structural studies, but only recently has evidence emerged that many of these processes occur in the context of biomolecular condensates. Condensates are membrane-less bodies, often formed by liquid-liquid phase separation, that compartmentalize protein and RNA molecules with related functions. New insights from condensate studies portend a profound transformation in our understanding of cellular dysregulation in cancer. Here we summarize key features of biomolecular condensates, note where they have been implicated-or will likely be implicated-in oncogenesis, describe evidence that the pharmacodynamics of cancer therapeutics can be greatly influenced by condensates, and discuss some of the questions that must be addressed to further advance our understanding and treatment of cancer.
Collapse
Affiliation(s)
- Ann Boija
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA.
| | - Isaac A Klein
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02215, USA.
| | - Richard A Young
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
| |
Collapse
|
268
|
Mechanism and effect of stress granule formation in cancer and its potential roles in breast cancer therapy. Genes Dis 2021; 9:659-667. [PMID: 35782985 PMCID: PMC9243343 DOI: 10.1016/j.gendis.2021.02.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 02/04/2021] [Accepted: 02/10/2021] [Indexed: 02/06/2023] Open
Abstract
Stress granules are non-membranous cytoplasmic foci induced by various stress conditions. It is a protective strategy used by cells to suppress overall translation during stress. In cancer cells, it was thought that the formation of stress granules could protect them from apoptosis and induces resistance towards anti-cancer drugs or radiation treatment which makes the stress granules a potential target for cancer treatment. However, most of our understanding of stress granules are still in the stage of molecular and cell biology, and a transitional gap for its actual effect on clinical settings remains. In this review, we summarize the mechanism and effect of stress granules formation in cancer and try to illuminate its potential applications in cancer therapy, using breast cancer as an example.
Collapse
|
269
|
Low YH, Asi Y, Foti SC, Lashley T. Heterogeneous Nuclear Ribonucleoproteins: Implications in Neurological Diseases. Mol Neurobiol 2021; 58:631-646. [PMID: 33000450 PMCID: PMC7843550 DOI: 10.1007/s12035-020-02137-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 09/17/2020] [Indexed: 12/13/2022]
Abstract
Heterogenous nuclear ribonucleoproteins (hnRNPs) are a complex and functionally diverse family of RNA binding proteins with multifarious roles. They are involved, directly or indirectly, in alternative splicing, transcriptional and translational regulation, stress granule formation, cell cycle regulation, and axonal transport. It is unsurprising, given their heavy involvement in maintaining functional integrity of the cell, that their dysfunction has neurological implications. However, compared to their more established roles in cancer, the evidence of hnRNP implication in neurological diseases is still in its infancy. This review aims to consolidate the evidences for hnRNP involvement in neurological diseases, with a focus on spinal muscular atrophy (SMA), Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), multiple sclerosis (MS), congenital myasthenic syndrome (CMS), and fragile X-associated tremor/ataxia syndrome (FXTAS). Understanding more about hnRNP involvement in neurological diseases can further elucidate the pathomechanisms involved in these diseases and perhaps guide future therapeutic advances.
Collapse
Affiliation(s)
- Yi-Hua Low
- The Queen Square Brain Bank for Neurological Disorders, Department of Clinical and Movement Disorders, UCL Queen Square Institute of Neurology, University College London, London, WC1N 3BG, UK
- Duke-NUS Medical School, Singapore, Singapore
| | - Yasmine Asi
- The Queen Square Brain Bank for Neurological Disorders, Department of Clinical and Movement Disorders, UCL Queen Square Institute of Neurology, University College London, London, WC1N 3BG, UK
| | - Sandrine C Foti
- The Queen Square Brain Bank for Neurological Disorders, Department of Clinical and Movement Disorders, UCL Queen Square Institute of Neurology, University College London, London, WC1N 3BG, UK
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Tammaryn Lashley
- The Queen Square Brain Bank for Neurological Disorders, Department of Clinical and Movement Disorders, UCL Queen Square Institute of Neurology, University College London, London, WC1N 3BG, UK.
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, University College London, London, UK.
| |
Collapse
|
270
|
Matheny T, Van Treeck B, Huynh TN, Parker R. RNA partitioning into stress granules is based on the summation of multiple interactions. RNA (NEW YORK, N.Y.) 2021; 27:174-189. [PMID: 33199441 PMCID: PMC7812873 DOI: 10.1261/rna.078204.120] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 10/28/2020] [Indexed: 05/28/2023]
Abstract
Stress granules (SGs) are stress-induced RNA-protein assemblies formed from a complex transcriptome of untranslating ribonucleoproteins (RNPs). Although RNAs can be either enriched or depleted from SGs, the rules that dictate RNA partitioning into SGs are unknown. We demonstrate that the SG-enriched NORAD RNA is sufficient to enrich a reporter RNA within SGs through the combined effects of multiple elements. Moreover, artificial tethering of G3BP1, TIA1, or FMRP can target mRNAs into SGs in a dose-dependent manner with numerous interactions required for efficient SG partitioning, which suggests individual protein interactions have small effects on the SG partitioning of mRNPs. This is supported by the observation that the SG transcriptome is largely unchanged in cell lines lacking the abundant SG RNA-binding proteins G3BP1 and G3BP2. We suggest the targeting of RNPs into SGs is due to a summation of potential RNA-protein, protein-protein, and RNA-RNA interactions with no single interaction dominating RNP recruitment into SGs.
Collapse
Affiliation(s)
- Tyler Matheny
- Department of Biochemistry, University of Colorado, Boulder, Colorado 80309, USA
| | - Briana Van Treeck
- Department of Biochemistry, University of Colorado, Boulder, Colorado 80309, USA
| | - Thao Ngoc Huynh
- Department of Biochemistry, University of Colorado, Boulder, Colorado 80309, USA
| | - Roy Parker
- Department of Biochemistry, University of Colorado, Boulder, Colorado 80309, USA
- Howard Hughes Medical Institute, Chevy Chase, Maryland 20815, USA
| |
Collapse
|
271
|
Zhang Y, Yue C, Krichevsky AM, Garkavtsev I. Repression of the stress granule protein G3BP2 inhibits immune checkpoint molecule PD-L1. Mol Oncol 2021. [PMID: 33525064 DOI: 10.1002/1878-0261.12915] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 10/21/2020] [Accepted: 01/29/2021] [Indexed: 11/05/2022] Open
Abstract
Mounting evidence suggests that cancer stemness and immunosuppression are related, but the underlying mechanisms behind these are not clear. We previously reported that the stress granule-associated protein G3BP2 is involved in the regulation of tumor-initiating (stem) cells. In this study, we show that this protein also upregulates the immune checkpoint molecule PD-L1 under conditions of stress in breast and glioblastoma cancer cells, revealing a previously unknown connection between stemness programs, stress responses, and immune checkpoint control. We also identified a significant correlation between G3BP2 and PD-L1 co-expression in tumor tissues from cancer patients. To assess the targetability of G3BP2, we employed a small molecule (C108) that binds G3BP2 and interferes with the stress response. Tumors treated with C108 had increased CD8 T-cell proliferation and infiltration. Moreover, treatment of breast tumor-bearing mice with C108 resulted in a significant survival benefit and long-term cures. Cancer cells treated with C108 or cancer cells with genetically repressed G3BP2 had decreased PD-L1 expression due to enhanced mRNA degradation. Our study provides a compelling mechanism linking stress granule formation and immune checkpoint program of cancer, suggesting this link may provide new opportunities for improving anticancer immunotherapy.
Collapse
Affiliation(s)
- Yanhong Zhang
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Department of Neurology, Ann Romney Center for Neurologic Diseases, Initiative for RNA Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Changli Yue
- Department of Pathology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Anna M Krichevsky
- Department of Neurology, Ann Romney Center for Neurologic Diseases, Initiative for RNA Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Igor Garkavtsev
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| |
Collapse
|
272
|
Angiogenin (ANG)-Ribonuclease Inhibitor (RNH1) System in Protein Synthesis and Disease. Int J Mol Sci 2021; 22:ijms22031287. [PMID: 33525475 PMCID: PMC7866052 DOI: 10.3390/ijms22031287] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/25/2021] [Accepted: 01/25/2021] [Indexed: 12/16/2022] Open
Abstract
Protein synthesis is a highly complex process executed by well-organized translation machinery. Ribosomes, tRNAs and mRNAs are the principal components of this machinery whereas RNA binding proteins and ribosome interacting partners act as accessory factors. Angiogenin (ANG)-Ribonuclease inhibitor (RNH1) system is one such accessory part of the translation machinery that came into focus afresh due to its unconventional role in the translation. ANG is conventionally known for its ability to induce blood vessel formation and RNH1 as a "sentry" to protect RNAs from extracellular RNases. However, recent studies suggest them to be important in translation regulation. During cell homeostasis, ANG in the nucleus promotes rRNA transcription. While under stress, ANG translocates to the cytosol and cleaves tRNA into fragments which inhibit ribosome biogenesis and protein synthesis. RNH1, which intimately interacts with ANG to inhibit its ribonucleolytic activity, can also bind to the 40S ribosomes and control translation by yet to be known mechanisms. Here, we review recent advancement in the knowledge of translation regulation by the ANG-RNH1 system. We also gather information about this system in cell homeostasis as well as in pathological conditions such as cancer and ribosomopathies. Additionally, we discuss the future research directions and therapeutic potential of this system.
Collapse
|
273
|
Reovirus and the Host Integrated Stress Response: On the Frontlines of the Battle to Survive. Viruses 2021; 13:v13020200. [PMID: 33525628 PMCID: PMC7910986 DOI: 10.3390/v13020200] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 01/22/2021] [Accepted: 01/26/2021] [Indexed: 12/17/2022] Open
Abstract
Cells are continually exposed to stressful events, which are overcome by the activation of a number of genetic pathways. The integrated stress response (ISR) is a large component of the overall cellular response to stress, which ultimately functions through the phosphorylation of the alpha subunit of eukaryotic initiation factor-2 (eIF2α) to inhibit the energy-taxing process of translation. This response is instrumental in the inhibition of viral infection and contributes to evolution in viruses. Mammalian orthoreovirus (MRV), an oncolytic virus that has shown promise in over 30 phase I–III clinical trials, has been shown to induce multiple arms within the ISR pathway, but it successfully evades, modulates, or subverts each cellular attempt to inhibit viral translation. MRV has not yet received Food and Drug Administration (FDA) approval for general use in the clinic; therefore, researchers continue to study virus interactions with host cells to identify circumstances where MRV effectiveness in tumor killing can be improved. In this review, we will discuss the ISR, MRV modulation of the ISR, and discuss ways in which MRV interaction with the ISR may increase the effectiveness of cancer therapeutics whose modes of action are altered by the ISR.
Collapse
|
274
|
Fomicheva A, Ross ED. From Prions to Stress Granules: Defining the Compositional Features of Prion-Like Domains That Promote Different Types of Assemblies. Int J Mol Sci 2021; 22:ijms22031251. [PMID: 33513942 PMCID: PMC7865556 DOI: 10.3390/ijms22031251] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/21/2021] [Accepted: 01/22/2021] [Indexed: 12/12/2022] Open
Abstract
Stress granules are ribonucleoprotein assemblies that form in response to cellular stress. Many of the RNA-binding proteins found in stress granule proteomes contain prion-like domains (PrLDs), which are low-complexity sequences that compositionally resemble yeast prion domains. Mutations in some of these PrLDs have been implicated in neurodegenerative diseases, including amyotrophic lateral sclerosis and frontotemporal dementia, and are associated with persistent stress granule accumulation. While both stress granules and prions are macromolecular assemblies, they differ in both their physical properties and complexity. Prion aggregates are highly stable homopolymeric solids, while stress granules are complex dynamic biomolecular condensates driven by multivalent homotypic and heterotypic interactions. Here, we use stress granules and yeast prions as a paradigm to examine how distinct sequence and compositional features of PrLDs contribute to different types of PrLD-containing assemblies.
Collapse
|
275
|
Brown SL, Kendrick S. The i-Motif as a Molecular Target: More Than a Complementary DNA Secondary Structure. Pharmaceuticals (Basel) 2021; 14:ph14020096. [PMID: 33513764 PMCID: PMC7911047 DOI: 10.3390/ph14020096] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 01/20/2021] [Accepted: 01/22/2021] [Indexed: 12/25/2022] Open
Abstract
Stretches of cytosine-rich DNA are capable of adopting a dynamic secondary structure, the i-motif. When within promoter regions, the i-motif has the potential to act as a molecular switch for controlling gene expression. However, i-motif structures in genomic areas of repetitive nucleotide sequences may play a role in facilitating or hindering expansion of these DNA elements. Despite research on the i-motif trailing behind the complementary G-quadruplex structure, recent discoveries including the identification of a specific i-motif antibody are pushing this field forward. This perspective reviews initial and current work characterizing the i-motif and providing insight into the biological function of this DNA structure, with a focus on how the i-motif can serve as a molecular target for developing new therapeutic approaches to modulate gene expression and extension of repetitive DNA.
Collapse
|
276
|
Lu S, Ye Q, Singh D, Cao Y, Diedrich JK, Yates JR, Villa E, Cleveland DW, Corbett KD. The SARS-CoV-2 nucleocapsid phosphoprotein forms mutually exclusive condensates with RNA and the membrane-associated M protein. Nat Commun 2021; 12:502. [PMID: 33479198 PMCID: PMC7820290 DOI: 10.1038/s41467-020-20768-y] [Citation(s) in RCA: 244] [Impact Index Per Article: 81.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 12/17/2020] [Indexed: 02/07/2023] Open
Abstract
The multifunctional nucleocapsid (N) protein in SARS-CoV-2 binds the ~30 kb viral RNA genome to aid its packaging into the 80-90 nm membrane-enveloped virion. The N protein is composed of N-terminal RNA-binding and C-terminal dimerization domains that are flanked by three intrinsically disordered regions. Here we demonstrate that the N protein's central disordered domain drives phase separation with RNA, and that phosphorylation of an adjacent serine/arginine rich region modulates the physical properties of the resulting condensates. In cells, N forms condensates that recruit the stress granule protein G3BP1, highlighting a potential role for N in G3BP1 sequestration and stress granule inhibition. The SARS-CoV-2 membrane (M) protein independently induces N protein phase separation, and three-component mixtures of N + M + RNA form condensates with mutually exclusive compartments containing N + M or N + RNA, including annular structures in which the M protein coats the outside of an N + RNA condensate. These findings support a model in which phase separation of the SARS-CoV-2 N protein contributes both to suppression of the G3BP1-dependent host immune response and to packaging genomic RNA during virion assembly.
Collapse
Affiliation(s)
- Shan Lu
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
- Ludwig Institute for Cancer Research, San Diego Branch, La Jolla, CA, 92093, USA
| | - Qiaozhen Ye
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Digvijay Singh
- Section of Molecular Biology, Division of Biological Sciences, University of California San Diego, La Jolla, CA, 92093, USA
| | - Yong Cao
- National Institute of Biological Sciences, 102206, Beijing, China
| | | | - John R Yates
- The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Elizabeth Villa
- Section of Molecular Biology, Division of Biological Sciences, University of California San Diego, La Jolla, CA, 92093, USA
| | - Don W Cleveland
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, 92093, USA.
- Ludwig Institute for Cancer Research, San Diego Branch, La Jolla, CA, 92093, USA.
| | - Kevin D Corbett
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, 92093, USA.
- Department of Chemistry & Biochemistry, University of California San Diego, La Jolla, CA, 92093, USA.
| |
Collapse
|
277
|
Luo L, Li Z, Zhao T, Ju X, Ma P, Jin B, Zhou Y, He S, Huang J, Xu X, Zou Y, Li P, Liang A, Liu J, Chi T, Huang X, Ding Q, Jin Z, Huang C, Zhang Y. SARS-CoV-2 nucleocapsid protein phase separates with G3BPs to disassemble stress granules and facilitate viral production. Sci Bull (Beijing) 2021; 66:1194-1204. [PMID: 33495715 PMCID: PMC7816596 DOI: 10.1016/j.scib.2021.01.013] [Citation(s) in RCA: 77] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 10/13/2020] [Accepted: 12/30/2020] [Indexed: 12/13/2022]
Abstract
A key to tackling the coronavirus disease 2019 (COVID-19) pandemic is to understand how severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) manages to outsmart host antiviral defense mechanisms. Stress granules (SGs), which are assembled during viral infection and function to sequester host and viral mRNAs and proteins, are part of the antiviral responses. Here, we show that the SARS-CoV-2 nucleocapsid (N) protein, an RNA binding protein essential for viral production, interacted with Ras-GTPase-activating protein SH3-domain-binding protein (G3BP) and disrupted SG assembly, both of which require intrinsically disordered region1 (IDR1) in N protein. The N protein partitioned into SGs through liquid-liquid phase separation with G3BP, and blocked the interaction of G3BP1 with other SG-related proteins. Moreover, the N protein domains important for phase separation with G3BP and SG disassembly were required for SARS-CoV-2 viral production. We propose that N protein-mediated SG disassembly is crucial for SARS-CoV-2 production.
Collapse
Affiliation(s)
- Lingling Luo
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Zhean Li
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai 201210, China
| | - Tiejun Zhao
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Xiaohui Ju
- Center for Infectious Disease Research, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Peixiang Ma
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai 201210, China
| | - Boxing Jin
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Yulin Zhou
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Su He
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Jinhua Huang
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Xun Xu
- Center for Infectious Disease Research, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Yan Zou
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai 201210, China
| | - Ping Li
- Department of Hematology, Tongji Hospital of Tongji University, Shanghai 200065, China
| | - Aibin Liang
- Department of Hematology, Tongji Hospital of Tongji University, Shanghai 200065, China
| | - Jia Liu
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai 201210, China
| | - Tian Chi
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Xingxu Huang
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Qiang Ding
- Center for Infectious Disease Research, School of Medicine, Tsinghua University, Beijing 100084, China
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua University, Beijing 100084, China
| | - Zhigang Jin
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Cheng Huang
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Yu Zhang
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| |
Collapse
|
278
|
Lee JW, Chun YL, Kim AY, Lloyd LT, Ko S, Yoon JH, Min KW. Accumulation of Mitochondrial RPPH1 RNA Is Associated with Cellular Senescence. Int J Mol Sci 2021; 22:ijms22020782. [PMID: 33466722 PMCID: PMC7828772 DOI: 10.3390/ijms22020782] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Accepted: 01/11/2021] [Indexed: 12/17/2022] Open
Abstract
Post-transcriptional gene regulation is an important step in the regulation of eukaryotic gene expression. Subcellular compartmentalization of RNA species plays a crucial role in the control of mRNA turnover, spatial restriction of protein synthesis, and the formation of macromolecular complexes. Although long noncoding RNAs (lncRNAs) are one of the key regulators of post-transcriptional gene expression, it is not heavily studied whether localization of lncRNAs in subcellular organelles has functional consequences. Here, we report on mitochondrial lncRNAs whose expression fluctuates in the process of cellular senescence. One of the mitochondrial lncRNAs, RPPH1 RNA, is overexpressed and accumulates in mitochondria of senescent fibroblasts, possibly modulated by the RNA-binding protein AUF1. In addition, RPPH1 RNA overexpression promotes spontaneous replicative cellular senescence in proliferating fibroblasts. Using MS2 aptamer-based RNA affinity purification strategy, we identified putative target mRNAs of RPPH1 RNA and revealed that partial complementarity of RPPH1 RNA to its target mRNAs prevents those mRNAs decay in proliferating fibroblasts. Altogether, our results demonstrate the role of mitochondrial noncoding RNA in the regulation of mRNA stability and cellular senescence.
Collapse
Affiliation(s)
- Ji Won Lee
- Department of Biology, College of Natural Sciences, Gangneung-Wonju National University, Gangneung 25457, Korea; (J.W.L.); (A.Y.K.)
| | - Yoo Lim Chun
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA; (Y.L.C.); (L.T.L.); (S.K.); (J.-H.Y.)
- Department of Anatomy and Neurobiology, College of Medicine, Kyung Hee University, 26, Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Korea
| | - Ah Young Kim
- Department of Biology, College of Natural Sciences, Gangneung-Wonju National University, Gangneung 25457, Korea; (J.W.L.); (A.Y.K.)
| | - Lawson T. Lloyd
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA; (Y.L.C.); (L.T.L.); (S.K.); (J.-H.Y.)
| | - Seungbeom Ko
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA; (Y.L.C.); (L.T.L.); (S.K.); (J.-H.Y.)
| | - Je-Hyun Yoon
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA; (Y.L.C.); (L.T.L.); (S.K.); (J.-H.Y.)
| | - Kyung-Won Min
- Department of Biology, College of Natural Sciences, Gangneung-Wonju National University, Gangneung 25457, Korea; (J.W.L.); (A.Y.K.)
- Correspondence:
| |
Collapse
|
279
|
Barraza CE, Solari CA, Rinaldi J, Ojeda L, Rossi S, Ashe MP, Portela P. A prion-like domain of Tpk2 catalytic subunit of protein kinase A modulates P-body formation in response to stress in budding yeast. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2021; 1868:118884. [PMID: 33039554 DOI: 10.1016/j.bbamcr.2020.118884] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Revised: 09/26/2020] [Accepted: 09/29/2020] [Indexed: 01/19/2023]
Abstract
Low complexity regions are involved in the assembly and disassembly of P-bodies (PBs). Saccharomyces cerevisiae contains three genes encoding the protein kinase A (PKA) catalytic subunit: TPK1, TPK2 and TPK3. Tpk2 and Tpk3 isoforms localize to PBs upon glucose starvation showing different mechanisms and kinetics of accumulation. In contrast to the other two isoforms, Tpk2 harbors a glutamine-rich prion-like domain (PrLD) at the N-terminus. Here we show that the appearance of Tpk2 foci in response to glucose starvation, heat stress or stationary phase was dependent on its PrLD. Moreover, the PrLD of Tpk2 was necessary for efficient PB and stress granule aggregation during stress conditions and in quiescent cells. Deletion of PrLD does not affect the in vitro and in vivo kinase activity of Tpk2 or its interaction with the regulatory subunit Bcy1. We present evidence that the PrLD of Tpk2 serves as a scaffold domain for PB assembly in a manner that is independent of Pat1 phosphorylation by PKA. In addition, a mutant strain where Tpk2 lacks PrLD showed a decrease of turnover of mRNA during glucose starvation. This work therefore provides new insight into the mechanism of stress-induced cytoplasmic mRNP assembly, and the role of isoform specific domains in the regulation of PKA catalytic subunit specificity and dynamic localization to cytoplasmic RNPs granules.
Collapse
Affiliation(s)
- Carla E Barraza
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Biológica, Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales-Consejo Nacional de Investigaciones Científicas y Técnicas (IQUIBICEN-CONICET). Buenos Aires, Argentina.
| | - Clara A Solari
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Biológica, Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales-Consejo Nacional de Investigaciones Científicas y Técnicas (IQUIBICEN-CONICET). Buenos Aires, Argentina.
| | - Jimena Rinaldi
- Fundación Instituto Leloir, IIBBA-CONICET, Buenos Aires, Argentina.
| | - Lucas Ojeda
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Biológica, Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales-Consejo Nacional de Investigaciones Científicas y Técnicas (IQUIBICEN-CONICET). Buenos Aires, Argentina.
| | - Silvia Rossi
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Biológica, Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales-Consejo Nacional de Investigaciones Científicas y Técnicas (IQUIBICEN-CONICET). Buenos Aires, Argentina.
| | - Mark P Ashe
- The Michael Smith Building, Faculty of Life Sciences, University of Manchester, Manchester, UK.
| | - Paula Portela
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Biológica, Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales-Consejo Nacional de Investigaciones Científicas y Técnicas (IQUIBICEN-CONICET). Buenos Aires, Argentina.
| |
Collapse
|
280
|
Wolff H, Jakoby M, Stephan L, Koebke E, Hülskamp M. Heat Stress-Dependent Association of Membrane Trafficking Proteins With mRNPs Is Selective. FRONTIERS IN PLANT SCIENCE 2021; 12:670499. [PMID: 34249042 PMCID: PMC8264791 DOI: 10.3389/fpls.2021.670499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Accepted: 05/27/2021] [Indexed: 05/03/2023]
Abstract
The Arabidopsis AAA ATPase SKD1 is essential for ESCRT-dependent endosomal sorting by mediating the disassembly of the ESCRTIII complex in an ATP-dependent manner. In this study, we show that SKD1 localizes to messenger ribonucleoprotein complexes upon heat stress. Consistent with this, the interactome of SKD1 revealed differential interactions under normal and stress conditions and included membrane transport proteins as well as proteins associated with RNA metabolism. Localization studies with selected interactome proteins revealed that not only RNA associated proteins but also several ESCRTIII and membrane trafficking proteins were recruited to messenger ribonucleoprotein granules after heat stress.
Collapse
Affiliation(s)
- Heike Wolff
- Cluster of Excellence on Plant Sciences (CEPLAS), Botanical Institute, Cologne University, Cologne, Germany
| | - Marc Jakoby
- Botanical Institute, Biocenter, Cologne University, Cologne, Germany
| | - Lisa Stephan
- Botanical Institute, Biocenter, Cologne University, Cologne, Germany
| | - Eva Koebke
- Botanical Institute, Biocenter, Cologne University, Cologne, Germany
| | - Martin Hülskamp
- Botanical Institute, Biocenter, Cologne University, Cologne, Germany
- *Correspondence: Martin Hülskamp
| |
Collapse
|
281
|
Brown NP, Vergara AM, Whelan AB, Guerra P, Bolger TA. Medulloblastoma-associated mutations in the DEAD-box RNA helicase DDX3X/DED1 cause specific defects in translation. J Biol Chem 2021; 296:100296. [PMID: 33460649 PMCID: PMC7949108 DOI: 10.1016/j.jbc.2021.100296] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 01/05/2021] [Accepted: 01/12/2021] [Indexed: 01/22/2023] Open
Abstract
Medulloblastoma is the most common pediatric brain cancer, and sequencing studies identified frequent mutations in DDX3X, a DEAD-box RNA helicase primarily implicated in translation. Forty-two different sites were identified, suggesting that the functional effects of the mutations are complex. To investigate how these mutations are affecting DDX3X cellular function, we constructed a full set of equivalent mutant alleles in DED1, the Saccharomyces cerevisiae ortholog of DDX3X, and characterized their effects in vivo and in vitro. Most of the medulloblastoma-associated mutants in DDX3X/DED1 (ded1-mam) showed substantial growth defects, indicating that functional effects are conserved in yeast. Further, while translation was affected in some mutants, translation defects affecting bulk mRNA were neither consistent nor correlated with the growth phenotypes. Likewise, increased formation of stress granules in ded1-mam mutants was common but did not correspond to the severity of the mutants' growth defects. In contrast, defects in translating mRNAs containing secondary structure in their 5' untranslated regions (UTRs) were found in almost all ded1-mam mutants and correlated well with growth phenotypes. We thus conclude that these specific translation defects, rather than generalized effects on translation, are responsible for the observed cellular phenotypes and likely contribute to DDX3X-mutant medulloblastoma. Examination of ATPase activity and RNA binding of recombinant mutant proteins also did not reveal a consistent defect, indicating that the translation defects are derived from multiple enzymatic deficiencies. This work suggests that future studies into medulloblastoma pathology should focus on this specific translation defect, while taking into account the wide spectrum of DDX3X mutations.
Collapse
Affiliation(s)
- Nicolette P Brown
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona, USA
| | - Ashley M Vergara
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona, USA
| | - Alisha B Whelan
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona, USA
| | - Paolo Guerra
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona, USA
| | - Timothy A Bolger
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona, USA.
| |
Collapse
|
282
|
Aoyama-Ishiwatari S, Okazaki T, Iemura SI, Natsume T, Okada Y, Gotoh Y. NUDT21 Links Mitochondrial IPS-1 to RLR-Containing Stress Granules and Activates Host Antiviral Defense. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2021; 206:154-163. [PMID: 33219146 DOI: 10.4049/jimmunol.2000306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 10/23/2020] [Indexed: 11/19/2022]
Abstract
Viral RNA in the cytoplasm of mammalian host cells is recognized by retinoic acid-inducible protein-I-like receptors (RLRs), which localize to cytoplasmic stress granules (SGs). Activated RLRs associate with the mitochondrial adaptor protein IPS-1, which activates antiviral host defense mechanisms, including type I IFN induction. It has remained unclear, however, how RLRs in SGs and IPS-1 in the mitochondrial outer membrane associate physically and engage in information transfer. In this study, we show that NUDT21, an RNA-binding protein that regulates alternative transcript polyadenylation, physically associates with IPS-1 and mediates its localization to SGs in response to transfection with polyinosinic-polycytidylic acid [poly(I:C)], a mimic of viral dsRNA. We found that despite its well-established function in the nucleus, a fraction of NUDT21 localizes to mitochondria in resting cells and becomes localized to SGs in response to poly(I:C) transfection. NUDT21 was also found to be required for efficient type I IFN induction in response to viral infection in both human HeLa cells and mouse macrophage cell line RAW264.7 cells. Our results together indicate that NUDT21 links RLRs in SGs to mitochondrial IPS-1 and thereby activates host defense responses to viral infection.
Collapse
Affiliation(s)
| | - Tomohiko Okazaki
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan;
| | - Shun-Ichiro Iemura
- Molecular Profiling Research Center for Drug Discovery, National Institute of Advanced Industrial Science and Technology, Tokyo 135-0064, Japan
| | - Tohru Natsume
- Molecular Profiling Research Center for Drug Discovery, National Institute of Advanced Industrial Science and Technology, Tokyo 135-0064, Japan
| | - Yasushi Okada
- Laboratory for Cell Dynamics Observation, Center for Biosystems Dynamics Research, RIKEN, Osaka 565-0874, Japan
- Department of Physics, Universal Biology Institute, Tokyo 113-0033, Japan; and
- International Research Center for Neurointelligence, World Premier International Research Center Initiative, The University of Tokyo, Tokyo 113-0033, Japan
| | - Yukiko Gotoh
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
- International Research Center for Neurointelligence, World Premier International Research Center Initiative, The University of Tokyo, Tokyo 113-0033, Japan
| |
Collapse
|
283
|
Weskamp K, Olwin BB, Parker R. Post-Transcriptional Regulation in Skeletal Muscle Development, Repair, and Disease. Trends Mol Med 2020; 27:469-481. [PMID: 33384234 DOI: 10.1016/j.molmed.2020.12.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 11/30/2020] [Accepted: 12/02/2020] [Indexed: 12/14/2022]
Abstract
Skeletal muscle formation is a complex process that requires tight spatiotemporal control of key myogenic factors. Emerging evidence suggests that RNA processing is crucial for the regulation of these factors, and that multiple post-transcriptional regulatory pathways work dependently and independently of one another to enable precise control of transcripts throughout muscle development and repair. Moreover, disruption of these pathways is implicated in neuromuscular disease, and the recent development of RNA-mediated therapies shows enormous promise in the treatment of these disorders. We discuss the overlapping post-transcriptional regulatory pathways that mediate muscle development, how these pathways are disrupted in neuromuscular disorders, and advances in RNA-mediated therapies that present a novel approach to the treatment of these diseases.
Collapse
Affiliation(s)
- Kaitlin Weskamp
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA.
| | - Bradley B Olwin
- Department of Molecular, Cellular and Developmental Biology, University of Colorado Boulder, Boulder, CO, USA
| | - Roy Parker
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA; Howard Hughes Medical Institute, Chevy Chase, MD, USA.
| |
Collapse
|
284
|
Kanakamani S, Suresh PS, Venkatesh T. Regulation of processing bodies: From viruses to cancer epigenetic machinery. Cell Biol Int 2020; 45:708-719. [PMID: 33325125 DOI: 10.1002/cbin.11527] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 10/17/2020] [Accepted: 12/13/2020] [Indexed: 11/08/2022]
Abstract
Processing bodies (PBs) are 100-300 nm cytoplasmic messenger ribonucleoprotein particle (mRNP) granules that regulate eukaryotic gene expression. These cytoplasmic compartments harbor messenger RNAs (mRNAs) and several proteins involved in mRNA decay, microRNA silencing, nonsense-mediated mRNA decay, and splicing. Though membrane-less, PB structures are maintained by RNA-protein and protein-protein interactions. PB proteins have intrinsically disordered regions and low complexity domains, which account for its liquid to liquid phase separation. In addition to being dynamic and actively involved in the exchange of materials with other mRNPs and organelles, they undergo changes on various cellular cues and environmental stresses, including viral infections. Interestingly, several PB proteins are individually implicated in cancer development, and no study has addressed the effects on PB dynamics after epigenetic modifications of cancer-associated PB genes. In the current review, we summarize modulations undergone by P bodies or P body components upon viral infections. Furthermore, we discuss the selective and widely investigated PB proteins that undergo methylation changes in cancer and their potential as biomarkers.
Collapse
Affiliation(s)
- Sunmathy Kanakamani
- Department of Biochemistry and Molecular Biology, Central University of Kerala, Kasargod, India
| | - Padmanaban S Suresh
- Department of Biotechnology, National Institute of Technology Calicut, Calicut, India
| | - Thejaswini Venkatesh
- Department of Biochemistry and Molecular Biology, Central University of Kerala, Kasargod, India
| |
Collapse
|
285
|
Roscoe S, Manni E, Roberts M, Ananvoranich S. Formation of mRNP granules in Toxoplasma gondii during the lytic cycle. Mol Biochem Parasitol 2020; 242:111349. [PMID: 33383066 DOI: 10.1016/j.molbiopara.2020.111349] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 12/18/2020] [Accepted: 12/21/2020] [Indexed: 12/01/2022]
Abstract
Two poly(A) binding proteins (PABPs) of Toxoplasma gondii, were identified and characterized. They were named TgPABPC and TgPABPN as they were found to localize in the cytoplasm and nucleus respectively. TgPABPC, which colocalizes with mRNA granules, is therefore used as a cellular marker of mRNP granules. We detected that the formation of mRNP granules was independent of polymerized microtubules, and that the granules were distributed stochastically within the cytosol. Formation of mRNP granules was found to occur prior to parasite egress when a Ca2+ ionophore is used to induce egress. It was also found that maturation of mRNP granules could be described as a two-phase process. First, prior to host cell lysis, mRNP granules were formed rapidly within the cytosol. Second, the mRNP granule load was reduced within 10 min post egress. To investigate the link between translational state and mRNP granule formation, treatments with salubrinal, nutrient deprivation, and pH stress were used. While salubrinal induced granule formation in tachyzoites, nutrient starvation and pH stress showed no induction effect on mRNP granule formation. Interestingly, salubrinal treatment in bradyzoites did not induce RNP granule formation, thus suggesting that mRNP granule formation is not a ubiquitous response or directly related to translational repression. Instead, mRNP granule formation is likely a response to the rapid increase in non-translating RNA brought on by sudden changes in translational state.
Collapse
Affiliation(s)
- Scott Roscoe
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, N9B3P4, Canada
| | - Emad Manni
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, N9B3P4, Canada
| | - Mikayla Roberts
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, N9B3P4, Canada
| | - Sirinart Ananvoranich
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, N9B3P4, Canada.
| |
Collapse
|
286
|
Lee J, Park J, Kim JH, Lee G, Park TE, Yoon KJ, Kim YK, Lim C. LSM12-EPAC1 defines a neuroprotective pathway that sustains the nucleocytoplasmic RAN gradient. PLoS Biol 2020; 18:e3001002. [PMID: 33362237 PMCID: PMC7757817 DOI: 10.1371/journal.pbio.3001002] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 11/19/2020] [Indexed: 02/07/2023] Open
Abstract
Nucleocytoplasmic transport (NCT) defects have been implicated in neurodegenerative diseases such as C9ORF72-associated amyotrophic lateral sclerosis and frontotemporal dementia (C9-ALS/FTD). Here, we identify a neuroprotective pathway of like-Sm protein 12 (LSM12) and exchange protein directly activated by cyclic AMP 1 (EPAC1) that sustains the nucleocytoplasmic RAN gradient and thereby suppresses NCT dysfunction by the C9ORF72-derived poly(glycine-arginine) protein. LSM12 depletion in human neuroblastoma cells aggravated poly(GR)-induced impairment of NCT and nuclear integrity while promoting the nuclear accumulation of poly(GR) granules. In fact, LSM12 posttranscriptionally up-regulated EPAC1 expression, whereas EPAC1 overexpression rescued the RAN gradient and NCT defects in LSM12-deleted cells. C9-ALS patient-derived neurons differentiated from induced pluripotent stem cells (C9-ALS iPSNs) displayed low expression of LSM12 and EPAC1. Lentiviral overexpression of LSM12 or EPAC1 indeed restored the RAN gradient, mitigated the pathogenic mislocalization of TDP-43, and suppressed caspase-3 activation for apoptosis in C9-ALS iPSNs. EPAC1 depletion biochemically dissociated RAN-importin β1 from the cytoplasmic nuclear pore complex, thereby dissipating the nucleocytoplasmic RAN gradient essential for NCT. These findings define the LSM12-EPAC1 pathway as an important suppressor of the NCT-related pathologies in C9-ALS/FTD. A post-transcriptional circuit comprising LSM12 and EPAC1 suppresses neurodegenerative pathologies in C9ORF72-associated amyotrophic lateral sclerosis by establishing the RAN gradient and sustaining nucleocytoplasmic transport.
Collapse
Affiliation(s)
- Jongbo Lee
- School of Life Sciences, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | - Jumin Park
- School of Life Sciences, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | - Ji-hyung Kim
- School of Life Sciences, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | - Giwook Lee
- School of Life Sciences, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | - Tae-Eun Park
- School of Life Sciences, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | - Ki-Jun Yoon
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
| | - Yoon Ki Kim
- Creative Research Initiatives Center for Molecular Biology of Translation, Korea University, Seoul, Republic of Korea
- Division of Life Sciences, Korea University, Seoul, Republic of Korea
| | - Chunghun Lim
- School of Life Sciences, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
- * E-mail:
| |
Collapse
|
287
|
Bader SB, Dewhirst MW, Hammond EM. Cyclic Hypoxia: An Update on Its Characteristics, Methods to Measure It and Biological Implications in Cancer. Cancers (Basel) 2020; 13:E23. [PMID: 33374581 PMCID: PMC7793090 DOI: 10.3390/cancers13010023] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 12/14/2020] [Accepted: 12/16/2020] [Indexed: 02/07/2023] Open
Abstract
Regions of hypoxia occur in most if not all solid cancers. Although the presence of tumor hypoxia is a common occurrence, the levels of hypoxia and proportion of the tumor that are hypoxic vary significantly. Importantly, even within tumors, oxygen levels fluctuate due to changes in red blood cell flux, vascular remodeling and thermoregulation. Together, this leads to cyclic or intermittent hypoxia. Tumor hypoxia predicts for poor patient outcome, in part due to increased resistance to all standard therapies. However, it is less clear how cyclic hypoxia impacts therapy response. Here, we discuss the causes of cyclic hypoxia and, importantly, which imaging modalities are best suited to detecting cyclic vs. chronic hypoxia. In addition, we provide a comparison of the biological response to chronic and cyclic hypoxia, including how the levels of reactive oxygen species and HIF-1 are likely impacted. Together, we highlight the importance of remembering that tumor hypoxia is not a static condition and that the fluctuations in oxygen levels have significant biological consequences.
Collapse
Affiliation(s)
- Samuel B. Bader
- Department of Oncology, The Oxford Institute for Radiation Oncology, Oxford University, Oxford OX3 7DQ, UK;
| | - Mark W. Dewhirst
- Radiation Oncology Department, Duke University School of Medicine, Durham, NC 27710, USA
| | - Ester M. Hammond
- Department of Oncology, The Oxford Institute for Radiation Oncology, Oxford University, Oxford OX3 7DQ, UK;
| |
Collapse
|
288
|
Marmor-Kollet H, Siany A, Kedersha N, Knafo N, Rivkin N, Danino YM, Moens TG, Olender T, Sheban D, Cohen N, Dadosh T, Addadi Y, Ravid R, Eitan C, Toth Cohen B, Hofmann S, Riggs CL, Advani VM, Higginbottom A, Cooper-Knock J, Hanna JH, Merbl Y, Van Den Bosch L, Anderson P, Ivanov P, Geiger T, Hornstein E. Spatiotemporal Proteomic Analysis of Stress Granule Disassembly Using APEX Reveals Regulation by SUMOylation and Links to ALS Pathogenesis. Mol Cell 2020; 80:876-891.e6. [PMID: 33217318 PMCID: PMC7816607 DOI: 10.1016/j.molcel.2020.10.032] [Citation(s) in RCA: 128] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 07/30/2020] [Accepted: 10/22/2020] [Indexed: 10/23/2022]
Abstract
Stress granules (SGs) are cytoplasmic assemblies of proteins and non-translating mRNAs. Whereas much has been learned about SG formation, a major gap remains in understanding the compositional changes SGs undergo during normal disassembly and under disease conditions. Here, we address this gap by proteomic dissection of the SG temporal disassembly sequence using multi-bait APEX proximity proteomics. We discover 109 novel SG proteins and characterize distinct SG substructures. We reveal dozens of disassembly-engaged proteins (DEPs), some of which play functional roles in SG disassembly, including small ubiquitin-like modifier (SUMO) conjugating enzymes. We further demonstrate that SUMOylation regulates SG disassembly and SG formation. Parallel proteomics with amyotrophic lateral sclerosis (ALS)-associated C9ORF72 dipeptides uncovered attenuated DEP recruitment during SG disassembly and impaired SUMOylation. Accordingly, SUMO activity ameliorated C9ORF72-ALS-related neurodegeneration in Drosophila. By dissecting the SG spatiotemporal proteomic landscape, we provide an in-depth resource for future work on SG function and reveal basic and disease-relevant mechanisms of SG disassembly.
Collapse
Affiliation(s)
- Hagai Marmor-Kollet
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Aviad Siany
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Nancy Kedersha
- Division of Rheumatology, Immunity, and Inflammation, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA; Harvard Medical School Initiative for RNA Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Naama Knafo
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Natalia Rivkin
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Yehuda M Danino
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Thomas G Moens
- KU Leuven - University of Leuven, Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), Leuven, Belgium; VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven, Belgium
| | - Tsviya Olender
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Daoud Sheban
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel; Department of Immunology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Nir Cohen
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Tali Dadosh
- Department of Chemical Research Support, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Yoseph Addadi
- Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Revital Ravid
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Chen Eitan
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Beata Toth Cohen
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Sarah Hofmann
- Division of Rheumatology, Immunity, and Inflammation, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA; Harvard Medical School Initiative for RNA Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Claire L Riggs
- Division of Rheumatology, Immunity, and Inflammation, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA; Harvard Medical School Initiative for RNA Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Vivek M Advani
- Division of Rheumatology, Immunity, and Inflammation, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA; Harvard Medical School Initiative for RNA Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Adrian Higginbottom
- Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield S10 2HQ, UK
| | - Johnathan Cooper-Knock
- Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield S10 2HQ, UK
| | - Jacob H Hanna
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Yifat Merbl
- Department of Immunology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Ludo Van Den Bosch
- KU Leuven - University of Leuven, Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), Leuven, Belgium; VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven, Belgium
| | - Paul Anderson
- Division of Rheumatology, Immunity, and Inflammation, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA; Harvard Medical School Initiative for RNA Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Pavel Ivanov
- Division of Rheumatology, Immunity, and Inflammation, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA; Harvard Medical School Initiative for RNA Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Tamar Geiger
- Harvard Medical School Initiative for RNA Medicine, Harvard Medical School, Boston, MA 02115, USA; Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel.
| | - Eran Hornstein
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel.
| |
Collapse
|
289
|
Attwood KM, Robichaud A, Westhaver LP, Castle EL, Brandman DM, Balgi AD, Roberge M, Colp P, Croul S, Kim I, McCormick C, Corcoran JA, Weeks A. Raloxifene prevents stress granule dissolution, impairs translational control and promotes cell death during hypoxia in glioblastoma cells. Cell Death Dis 2020; 11:989. [PMID: 33203845 PMCID: PMC7673037 DOI: 10.1038/s41419-020-03159-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 10/09/2020] [Accepted: 10/12/2020] [Indexed: 12/30/2022]
Abstract
Glioblastoma (GBM) is the most common primary malignant brain tumor, and it has a uniformly poor prognosis. Hypoxia is a feature of the GBM microenvironment, and previous work has shown that cancer cells residing in hypoxic regions resist treatment. Hypoxia can trigger the formation of stress granules (SGs), sites of mRNA triage that promote cell survival. A screen of 1120 FDA-approved drugs identified 129 candidates that delayed the dissolution of hypoxia-induced SGs following a return to normoxia. Amongst these candidates, the selective estrogen receptor modulator (SERM) raloxifene delayed SG dissolution in a dose-dependent manner. SG dissolution typically occurs by 15 min post-hypoxia, however pre-treatment of immortalized U251 and U3024 primary GBM cells with raloxifene prevented SG dissolution for up to 2 h. During this raloxifene-induced delay in SG dissolution, translational silencing was sustained, eIF2α remained phosphorylated and mTOR remained inactive. Despite its well-described role as a SERM, raloxifene-mediated delay in SG dissolution was unaffected by co-administration of β-estradiol, nor did β-estradiol alone have any effect on SGs. Importantly, the combination of raloxifene and hypoxia resulted in increased numbers of late apoptotic/necrotic cells. Raloxifene and hypoxia also demonstrated a block in late autophagy similar to the known autophagy inhibitor chloroquine (CQ). Genetic disruption of the SG-nucleating proteins G3BP1 and G3BP2 revealed that G3BP1 is required to sustain the raloxifene-mediated delay in SG dissolution. Together, these findings indicate that modulating the stress response can be used to exploit the hypoxic niche of GBM tumors, causing cell death by disrupting pro-survival stress responses and control of protein synthesis.
Collapse
Affiliation(s)
| | - Aaron Robichaud
- Department of Medical Neuroscience, Dalhousie University, Halifax, NS, Canada
- Division of Neurosurgery, Department of Surgery, Dalhousie University, Halifax, NS, Canada
| | | | - Elizabeth L Castle
- Department of Microbiology & Immunology, Dalhousie University, Halifax, NS, Canada
| | - David M Brandman
- Division of Neurosurgery, Department of Surgery, Dalhousie University, Halifax, NS, Canada
| | - Aruna D Balgi
- Department of Biochemistry & Molecular Biology, University of British Columbia, Vancouver, BC, Canada
| | - Michel Roberge
- Department of Biochemistry & Molecular Biology, University of British Columbia, Vancouver, BC, Canada
| | - Patricia Colp
- Department of Pathology, Dalhousie University, Halifax, NS, Canada
| | - Sidney Croul
- Department of Pathology, Dalhousie University, Halifax, NS, Canada
| | - Inhwa Kim
- Department of Medicine, Dalhousie University, Halifax, NS, Canada
| | - Craig McCormick
- Department of Microbiology & Immunology, Dalhousie University, Halifax, NS, Canada
| | - Jennifer A Corcoran
- Department of Microbiology, Immunology and Infectious Disease, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Adrienne Weeks
- Department of Surgery, Dalhousie University, Halifax, NS, Canada.
- Department of Medical Neuroscience, Dalhousie University, Halifax, NS, Canada.
- Division of Neurosurgery, Department of Surgery, Dalhousie University, Halifax, NS, Canada.
| |
Collapse
|
290
|
Dysregulated ribonucleoprotein granules promote cardiomyopathy in RBM20 gene-edited pigs. Nat Med 2020; 26:1788-1800. [PMID: 33188278 PMCID: PMC9270981 DOI: 10.1038/s41591-020-1087-x] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 08/21/2020] [Indexed: 12/12/2022]
Abstract
Ribonucleoprotein (RNP) granules are biomolecular condensates-liquid-liquid phase-separated droplets that organize and manage messenger RNA metabolism, cell signaling, biopolymer assembly, biochemical reactions and stress granule responses to cellular adversity. Dysregulated RNP granules drive neuromuscular degenerative disease but have not previously been linked to heart failure. By exploring the molecular basis of congenital dilated cardiomyopathy (DCM) in genome-edited pigs homozygous for an RBM20 allele encoding the pathogenic R636S variant of human RNA-binding motif protein-20 (RBM20), we discovered that RNP granules accumulated abnormally in the sarcoplasm, and we confirmed this finding in myocardium and reprogrammed cardiomyocytes from patients with DCM carrying the R636S allele. Dysregulated sarcoplasmic RBM20 RNP granules displayed liquid-like material properties, docked at precisely spaced intervals along cytoskeletal elements, promoted phase partitioning of cardiac biomolecules and fused with stress granules. Our results link dysregulated RNP granules to myocardial cellular pathobiology and heart failure in gene-edited pigs and patients with DCM caused by RBM20 mutation.
Collapse
|
291
|
Mateu-Regué À, Nielsen FC, Christiansen J. Cytoplasmic mRNPs revisited: Singletons and condensates. Bioessays 2020; 42:e2000097. [PMID: 33145808 DOI: 10.1002/bies.202000097] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 09/04/2020] [Indexed: 01/01/2023]
Abstract
Cytoplasmic messenger ribonucleoprotein particles (mRNPs) represent the cellular transcriptome, and recent data have challenged our current understanding of their architecture, transport, and complexity before translation. Pre-translational mRNPs are composed of a single transcript, whereas P-bodies and stress granules are condensates. Both pre-translational mRNPs and actively translating mRNPs seem to adopt a linear rather than a closed-loop configuration. Moreover, assembly of pre-translational mRNPs in physical RNA regulons is an unlikely event, and co-regulated translation may occur locally following extracellular cues. We envisage a stochastic mRNP transport mechanism where translational repression of single mRNPs-in combination with microtubule-mediated cytoplasmic streaming and docking events-are prerequisites for local translation, rather than direct transport.
Collapse
Affiliation(s)
| | | | - Jan Christiansen
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
292
|
Adjirackor NA, Harvey KE, Harvey SC. Eukaryotic response to hypothermia in relation to integrated stress responses. Cell Stress Chaperones 2020; 25:833-846. [PMID: 32676830 PMCID: PMC7591648 DOI: 10.1007/s12192-020-01135-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 06/29/2020] [Accepted: 07/01/2020] [Indexed: 12/25/2022] Open
Abstract
Eukaryotic cells respond to hypothermic stress through a series of regulatory mechanisms that preserve energy resources and prolong cell survival. These mechanisms include alterations in gene expression, attenuated global protein synthesis and changes in the lipid composition of the phospholipid bilayer. Cellular responses to hyperthermia, hypoxia, nutrient deprivation and oxidative stress have been comprehensively investigated, but studies of the cellular response to cold stress are more limited. Responses to cold stress are however of great importance both in the wild, where exposure to low and fluctuating environmental temperatures is common, and in medical and biotechnology settings where cells and tissues are frequently exposed to hypothermic stress and cryopreservation. This means that it is vitally important to understand how cells are impacted by low temperatures and by the decreases and subsequent increases in temperature associated with cold stress. Here, we review the ways in which eukaryotic cells respond to hypothermic stress and how these compare to the well-described and highly integrated stress response systems that govern the cellular response to other types of stress.
Collapse
Affiliation(s)
- Naki A Adjirackor
- School of Human and Life Sciences, Canterbury Christ Church University, Canterbury, CT1 1QU, UK.
| | - Katie E Harvey
- School of Human and Life Sciences, Canterbury Christ Church University, Canterbury, CT1 1QU, UK
| | - Simon C Harvey
- School of Human and Life Sciences, Canterbury Christ Church University, Canterbury, CT1 1QU, UK
| |
Collapse
|
293
|
Role of Chikungunya nsP3 in Regulating G3BP1 Activity, Stress Granule Formation and Drug Efficacy. Arch Med Res 2020; 52:48-57. [PMID: 33131924 DOI: 10.1016/j.arcmed.2020.10.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 07/30/2020] [Accepted: 10/01/2020] [Indexed: 01/23/2023]
Abstract
BACKGROUND Ras-GTPase activating protein SH3-domain-binding proteins (G3BP) are a small family of RNA-binding proteins implicated in regulating gene expression. Changes in expression of G3BPs are correlated to several cancers including thyroid, colon, pancreatic and breast cancer. G3BPs are important regulators of stress granule (SG) formation and function. SG are ribonucleoprotein (RNP) particles that respond to cellular stresses to triage mRNA resulting in transcripts being selectively degraded, stored or translated resulting in a change of gene expression which confers a survival response to the cell. These changes in gene expression contribute to the development of drug resistance. Many RNA viruses, including Chikungunya (and potentially Coronavirus), dismantle SG so that the cell cannot respond to the viral infection. Non-structural protein 3 (nsP3), from the Chikungunya virus, has been shown to translocate G3BP away from SG. Interestingly in cancer cells, the formation of SG is correlated to drug-resistance and blocking SG formation has been shown to reestablish the efficacy of the anticancer drug bortezomib. METHODS Chikungunya nsP3 was transfected into breast cancer cell lines T47D and MCF7 to disrupt SG formation. Changes in the cytotoxicity of bortezomib were measured. RESULTS Bortezomib cytotoxicity in breast cancer cell lines changed with a 22 fold decrease in its IC50 for T47D and a 7 fold decrease for MCF7 cells. CONCLUSIONS Chikungunya nsP3 disrupts SG formation. As a result, it increases the cytotoxicity of the FDA approved drug, bortezomib. In addition, the increased cytotoxicity appears to correlate to improved bortezomib selectivity when compared to control cell lines.
Collapse
|
294
|
Jeong SG, Ohn T, Jang CH, Vijayakumar K, Cho GW. The Role of Stress Granules in the Neuronal Differentiation of Stem Cells. Mol Cells 2020; 43:848-855. [PMID: 33028745 PMCID: PMC7604023 DOI: 10.14348/molcells.2020.0135] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 09/07/2020] [Accepted: 09/10/2020] [Indexed: 02/07/2023] Open
Abstract
creativecommons.org/licenses/by-nc-sa/3.0/. Cells assemble stress granules (SGs) to protect their RNAs from exposure to harmful chemical reactions induced by environmental stress. These SGs release RNAs, which resume translation once the stress is relieved. During stem cell differentiation, gene expression is altered to allow cells to adopt various functional and morphological features necessary to differentiate. This process induces stress within a cell, and cells that cannot overcome this stress die. Here, we investigated the role of SGs in the progression of stem cell differentiation. SGs aggregated during the neuronal differentiation of human bone marrow-mesenchymal stem cells, and not in cell lines that could not undergo differentiation. SGs were observed between one and three hours post-induction; RNA translation was restrained at the same time. Immediately after disassembly of SGs, the expression of the neuronal marker neurofilament-M (NFM) gradually increased. Assembled SGs that persisted in cells were exposed to salubrinal, which inhibited the dephosphorylation of eukaryotic translation initiation factor 2 subunit 1 (eIF2α), and in eIF2α/S51D mutant cells. When eIF2α/S51A mutant cells differentiated, SGs were not assembled. In all experiments, the disruption of SGs was accompanied by delayed NF-M expression and the number of neuronally differentiated cells was decreased. Decreased differentiation was accompanied by decreased cell viability, indicating the necessity of SGs for preventing cell death during neuronal differentiation. Collectively, these results demonstrate the essential role of SGs during the neuronal differentiation of stem cells.
Collapse
Affiliation(s)
- Sin-Gu Jeong
- Department of Biology, College of Natural Science, Chosun University, Gwangju 61452, Korea
- Department of Integrative Biological Science, BK21 FOUR Education Research Group for Age-Associated Disorder Control Technology, Chosun University, Gwangju 61452, Korea
- Department of Bio Research & Business Development, Biot Korea Inc., Gwangju 61001, Korea
| | - Takbum Ohn
- Department of Cellular & Molecular Medicine, College of Medicine, Chosun University, Gwangju 61452, Korea
| | - Chul Ho Jang
- Department of Otolaryngology, Chonnam National University Medical School, Gwangju 61469, Korea
| | - Karthikeyan Vijayakumar
- Department of Biology, College of Natural Science, Chosun University, Gwangju 61452, Korea
- Department of Integrative Biological Science, BK21 FOUR Education Research Group for Age-Associated Disorder Control Technology, Chosun University, Gwangju 61452, Korea
| | - Gwang-Won Cho
- Department of Biology, College of Natural Science, Chosun University, Gwangju 61452, Korea
- Department of Integrative Biological Science, BK21 FOUR Education Research Group for Age-Associated Disorder Control Technology, Chosun University, Gwangju 61452, Korea
| |
Collapse
|
295
|
Dhakal S, Macreadie I. Protein Homeostasis Networks and the Use of Yeast to Guide Interventions in Alzheimer's Disease. Int J Mol Sci 2020; 21:E8014. [PMID: 33126501 PMCID: PMC7662794 DOI: 10.3390/ijms21218014] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 10/24/2020] [Accepted: 10/26/2020] [Indexed: 12/12/2022] Open
Abstract
Alzheimer's Disease (AD) is a progressive multifactorial age-related neurodegenerative disorder that causes the majority of deaths due to dementia in the elderly. Although various risk factors have been found to be associated with AD progression, the cause of the disease is still unresolved. The loss of proteostasis is one of the major causes of AD: it is evident by aggregation of misfolded proteins, lipid homeostasis disruption, accumulation of autophagic vesicles, and oxidative damage during the disease progression. Different models have been developed to study AD, one of which is a yeast model. Yeasts are simple unicellular eukaryotic cells that have provided great insights into human cell biology. Various yeast models, including unmodified and genetically modified yeasts, have been established for studying AD and have provided significant amount of information on AD pathology and potential interventions. The conservation of various human biological processes, including signal transduction, energy metabolism, protein homeostasis, stress responses, oxidative phosphorylation, vesicle trafficking, apoptosis, endocytosis, and ageing, renders yeast a fascinating, powerful model for AD. In addition, the easy manipulation of the yeast genome and availability of methods to evaluate yeast cells rapidly in high throughput technological platforms strengthen the rationale of using yeast as a model. This review focuses on the description of the proteostasis network in yeast and its comparison with the human proteostasis network. It further elaborates on the AD-associated proteostasis failure and applications of the yeast proteostasis network to understand AD pathology and its potential to guide interventions against AD.
Collapse
Affiliation(s)
| | - Ian Macreadie
- School of Science, RMIT University, Bundoora, Victoria 3083, Australia;
| |
Collapse
|
296
|
Jing H, Chang H, Lin Y, Bai Q, Liang D. Protocells with hierarchical structures as regulated by liquid-liquid and liquid-solid phase separations. Chem Commun (Camb) 2020; 56:12041-12044. [PMID: 32902524 DOI: 10.1039/d0cc04432f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The construction of a protocell with dynamic hierarchical structures via spontaneous phase separation sheds light on the mechanisms of life processes. Taking advantage of the transition from the liquid to solid phase, we built composite droplets with PLL/oligo/oligocomp solid particles randomly distributed inside a PLL/oligo liquid coacervate. The circulation and vacuolization under an electric field drive the particles into a fibrous structure and even clusters. A PLL/oligo/oligocomp solid phase can also form on the interface of the PLL/oligo coacervate, turning the droplet into a vesicular structure.
Collapse
Affiliation(s)
- Hairong Jing
- Beijing National Laboratory for Molecular Sciences, MOE Key Laboratory of Polymer Chemistry and Physics, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China.
| | | | | | | | | |
Collapse
|
297
|
Aceituno-Valenzuela U, Micol-Ponce R, Ponce MR. Genome-wide analysis of CCHC-type zinc finger (ZCCHC) proteins in yeast, Arabidopsis, and humans. Cell Mol Life Sci 2020; 77:3991-4014. [PMID: 32303790 PMCID: PMC11105112 DOI: 10.1007/s00018-020-03518-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 03/06/2020] [Accepted: 03/30/2020] [Indexed: 12/22/2022]
Abstract
The diverse eukaryotic proteins that contain zinc fingers participate in many aspects of nucleic acid metabolism, from DNA transcription to RNA degradation, post-transcriptional gene silencing, and small RNA biogenesis. These proteins can be classified into at least 30 types based on structure. In this review, we focus on the CCHC-type zinc fingers (ZCCHC), which contain an 18-residue domain with the CX2CX4HX4C sequence, where C is cysteine, H is histidine, and X is any amino acid. This motif, also named the "zinc knuckle", is characteristic of the retroviral Group Antigen protein and occurs alone or with other motifs. Many proteins containing zinc knuckles have been identified in eukaryotes, but only a few have been studied. Here, we review the available information on ZCCHC-containing factors from three evolutionarily distant eukaryotes-Saccharomyces cerevisiae, Arabidopsis thaliana, and Homo sapiens-representing fungi, plants, and metazoans, respectively. We performed systematic searches for proteins containing the CX2CX4HX4C sequence in organism-specific and generalist databases. Next, we analyzed the structural and functional information for all such proteins stored in UniProtKB. Excluding retrotransposon-encoded proteins and proteins harboring uncertain ZCCHC motifs, we found seven ZCCHC-containing proteins in yeast, 69 in Arabidopsis, and 34 in humans. ZCCHC-containing proteins mainly localize to the nucleus, but some are nuclear and cytoplasmic, or exclusively cytoplasmic, and one localizes to the chloroplast. Most of these factors participate in RNA metabolism, including transcriptional elongation, polyadenylation, translation, pre-messenger RNA splicing, RNA export, RNA degradation, microRNA and ribosomal RNA biogenesis, and post-transcriptional gene silencing. Several human ZCCHC-containing factors are derived from neofunctionalized retrotransposons and act as proto-oncogenes in diverse neoplastic processes. The conservation of ZCCHCs in orthologs of these three phylogenetically distant eukaryotes suggests that these domains have biologically relevant functions that are not well known at present.
Collapse
Affiliation(s)
- Uri Aceituno-Valenzuela
- Instituto de Bioingeniería, Universidad Miguel Hernández, Campus de Elche, 03202, Elche, Spain
| | - Rosa Micol-Ponce
- Instituto de Bioingeniería, Universidad Miguel Hernández, Campus de Elche, 03202, Elche, Spain
| | - María Rosa Ponce
- Instituto de Bioingeniería, Universidad Miguel Hernández, Campus de Elche, 03202, Elche, Spain.
| |
Collapse
|
298
|
G3BP1 interacts with YWHAZ to regulate chemoresistance and predict adjuvant chemotherapy benefit in gastric cancer. Br J Cancer 2020; 124:425-436. [PMID: 32989225 PMCID: PMC7852868 DOI: 10.1038/s41416-020-01067-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 08/06/2020] [Accepted: 08/26/2020] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND A large proportion of gastric cancer patients are susceptible to chemoresistance, while the underlying mechanism remains obscure. Stress granules (SGs) play a self-defence role for tumour cells in inhibiting chemotherapy-induced apoptosis. As an SG assembly effector, G3BP1 (Ras-GTPase-activating protein SH3 domain-binding protein) has been reported to be overexpressed in gastric cancer; thus, here we aim to explore its potent roles in gastric cancer chemoresistance. METHODS Kaplan–Meier analysis was used to compare survival rates in gastric cancer patients with different G3BP1 expression. The influence of G3BP1 on gastric cancer cell chemoresistance and apoptosis were evaluated by in vitro and in vivo approaches. The interaction between G3BP1 and YWHAZ was assessed by immunohistochemistry, immunoprecipitation and immunofluorescence. RESULTS G3BP1 was associated with the poor outcome of gastric cancer patients who received adjuvant chemotherapy. G3BP1 knockdown significantly increased the sensitivity of gastric cancer cells to chemotherapy drugs. Mechanically, cell apoptosis and pro-apoptotic-associated molecules were significantly elevated upon G3BP1 depletion. Gene co-expression network analyses identified YWHAZ as the critical interlayer of G3BP1; as a result, G3BP1 interacted with YWHAZ to sequester Bax into the cytoplasm. Clinically, G3BP1highYWHAZhigh gastric cancer patients displayed the worst outcome compared with other patients after chemotherapy. CONCLUSIONS The expression of G3BP1 and YWHAZ could predict the adjuvant chemotherapy benefit in gastric cancer patients.
Collapse
|
299
|
Hofmann S, Kedersha N, Anderson P, Ivanov P. Molecular mechanisms of stress granule assembly and disassembly. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1868:118876. [PMID: 33007331 DOI: 10.1016/j.bbamcr.2020.118876] [Citation(s) in RCA: 162] [Impact Index Per Article: 40.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 09/18/2020] [Accepted: 09/19/2020] [Indexed: 12/11/2022]
Abstract
Stress granules (SGs) are membrane-less ribonucleoprotein (RNP)-based cellular compartments that form in the cytoplasm of a cell upon exposure to various environmental stressors. SGs contain a large set of proteins, as well as mRNAs that have been stalled in translation as a result of stress-induced polysome disassembly. Despite the fact that SGs have been extensively studied for many years, their function is still not clear. They presumably help the cell to cope with the encountered stress, and facilitate the recovery process after stress removal upon which SGs disassemble. Aberrant formation of SGs and impaired SG disassembly majorly contribute to various pathological phenomena in cancer, viral infections, and neurodegeneration. The assembly of SGs is largely driven by liquid-liquid phase separation (LLPS), however, the molecular mechanisms behind that are not fully understood. Recent studies have proposed a novel mechanism for SG formation that involves the interplay of a large interaction network of mRNAs and proteins. Here, we review this novel concept of SG assembly, and discuss the current insights into SG disassembly.
Collapse
Affiliation(s)
- Sarah Hofmann
- Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Nancy Kedersha
- Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Paul Anderson
- Brigham and Women's Hospital, Harvard Medical School, Harvard Initiative for RNA Medicine, Boston, MA 02115, USA
| | - Pavel Ivanov
- Brigham and Women's Hospital, Harvard Medical School, Harvard Initiative for RNA Medicine, Boston, MA 02115, USA.
| |
Collapse
|
300
|
Fernandes N, Nero L, Lyons SM, Ivanov P, Mittelmeier TM, Bolger TA, Buchan JR. Stress Granule Assembly Can Facilitate but Is Not Required for TDP-43 Cytoplasmic Aggregation. Biomolecules 2020; 10:biom10101367. [PMID: 32992901 PMCID: PMC7650667 DOI: 10.3390/biom10101367] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 09/21/2020] [Indexed: 01/08/2023] Open
Abstract
Stress granules (SGs) are hypothesized to facilitate TAR DNA-binding protein 43 (TDP-43) cytoplasmic mislocalization and aggregation, which may underly amyotrophic lateral sclerosis pathology. However, much data for this hypothesis is indirect. Additionally, whether P-bodies (PBs; related mRNA-protein granules) affect TDP-43 phenotypes is unclear. Here, we determine that induction of TDP-43 expression in yeast results in the accumulation of SG-like foci that in >90% of cases become the sites where TDP-43 cytoplasmic foci first appear. Later, TDP-43 foci associate less with SGs and more with PBs, though independent TDP-43 foci also accumulate. However, depleting or over-expressing yeast SG and PB proteins reveals no consistent trend between SG or PB assembly and TDP-43 foci formation, toxicity or protein abundance. In human cells, immunostaining endogenous TDP-43 with different TDP-43 antibodies reveals distinct localization and aggregation behaviors. Following acute arsenite stress, all phospho-TDP-43 foci colocalize with SGs. Interestingly, in SG assembly mutant cells (G3BP1/2ΔΔ), TDP-43 is enriched in nucleoli. Finally, formation of TDP-43 cytoplasmic foci following low-dose chronic arsenite stress is impaired, but not completely blocked, in G3BP1/2ΔΔ cells. Collectively, our data suggest that SG and PB assembly may facilitate TDP-43 cytoplasmic localization and aggregation but are likely not essential for these events.
Collapse
Affiliation(s)
- Nikita Fernandes
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ 85721, USA; (N.F.); (L.N.); (T.M.M.); (T.A.B.)
| | - Luke Nero
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ 85721, USA; (N.F.); (L.N.); (T.M.M.); (T.A.B.)
| | - Shawn M. Lyons
- Department of Medicine, Harvard Medical School, Boston, MA 02115, USA; (S.M.L.); (P.I.)
- Division of Rheumatology, Immunity and Inflammation, Brigham and Women’s Hospital, Boston, MA 02115, USA
| | - Pavel Ivanov
- Department of Medicine, Harvard Medical School, Boston, MA 02115, USA; (S.M.L.); (P.I.)
- Division of Rheumatology, Immunity and Inflammation, Brigham and Women’s Hospital, Boston, MA 02115, USA
| | - Telsa M. Mittelmeier
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ 85721, USA; (N.F.); (L.N.); (T.M.M.); (T.A.B.)
| | - Timothy A. Bolger
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ 85721, USA; (N.F.); (L.N.); (T.M.M.); (T.A.B.)
| | - J. Ross Buchan
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ 85721, USA; (N.F.); (L.N.); (T.M.M.); (T.A.B.)
- Correspondence: ; Tel.: +1-520-626-1881
| |
Collapse
|