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De Sota RE, Quake SR, Sninsky JJ, Toden S. Decoding bioactive signals of the RNA secretome: the cell-free messenger RNA catalogue. Expert Rev Mol Med 2024; 26:e12. [PMID: 38682644 PMCID: PMC11140549 DOI: 10.1017/erm.2024.12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 01/18/2024] [Accepted: 03/18/2024] [Indexed: 05/01/2024]
Abstract
Despite gene-expression profiling being one of the most common methods to evaluate molecular dysregulation in tissues, the utilization of cell-free messenger RNA (cf-mRNA) as a blood-based non-invasive biomarker analyte has been limited compared to other RNA classes. Recent advancements in low-input RNA-sequencing and normalization techniques, however, have enabled characterization as well as accurate quantification of cf-mRNAs allowing direct pathological insights. The molecular profile of the cell-free transcriptome in multiple diseases has subsequently been characterized including, prenatal diseases, neurological disorders, liver diseases and cancers suggesting this biological compartment may serve as a disease agnostic platform. With mRNAs packaged in a myriad of extracellular vesicles and particles, these signals may be used to develop clinically actionable, non-invasive disease biomarkers. Here, we summarize the recent scientific developments of extracellular mRNA, biology of extracellular mRNA carriers, clinical utility of cf-mRNA as disease biomarkers, as well as proposed functions in cell and tissue pathophysiology.
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Affiliation(s)
- Rhys E. De Sota
- Superfluid Dx., 259 E Grand Avenue, South San Francisco, CA 94080, USA
| | - Stephen R. Quake
- Department of Bioengineering and Department of Applied Physics, Stanford University, Stanford, CA, USA
- Chan Zuckerberg Biohub, San Francisco, CA, USA
| | - John J. Sninsky
- Superfluid Dx., 259 E Grand Avenue, South San Francisco, CA 94080, USA
| | - Shusuke Toden
- Superfluid Dx., 259 E Grand Avenue, South San Francisco, CA 94080, USA
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2
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Vural A, Lanier SM. Properties of biomolecular condensates defined by Activator of G-protein Signaling 3. J Cell Sci 2024; 137:jcs261326. [PMID: 38264908 PMCID: PMC10911133 DOI: 10.1242/jcs.261326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 01/11/2024] [Indexed: 01/25/2024] Open
Abstract
Activator of G-protein signaling 3 (AGS3; also known as GPSM1), a receptor-independent activator of G-protein signaling, oscillates among defined subcellular compartments and biomolecular condensates (BMCs) in a regulated manner that is likely related to the functional diversity of the protein. We determined the influence of cell stress on the cellular distribution of AGS3 and core material properties of AGS3 BMCs. Cellular stress (oxidative, pHi and thermal) induced the formation of AGS3 BMCs in HeLa and COS-7 cells, as determined by fluorescent microscopy. Oxidative stress-induced AGS3 BMCs were distinct from G3BP1 stress granules and from RNA processing BMCs defined by the P-body protein Dcp1a. Immunoblots indicated that cellular stress shifted AGS3, but not the stress granule protein G3BP1 to a membrane pellet fraction following cell lysis. The stress-induced generation of AGS3 BMCs was reduced by co-expression of the signaling protein Gαi3, but not the AGS3-binding partner DVL2. Fluorescent recovery following photobleaching of individual AGS3 BMCs indicated that there are distinct diffusion kinetics and restricted fluidity for AGS3 BMCs. These data suggest that AGS3 BMCs represent a distinct class of stress granules that serve as a previously unrecognized signal processing node.
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Affiliation(s)
- Ali Vural
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Stephen M. Lanier
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, MI 48201, USA
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3
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Mokin YI, Ilyinsky NS, Nesterov SV, Smirnov EY, Sergeeva OS, Romanovich AE, Kuznetsova IM, Turoverov KK, Uversky VN, Fonin AV. Stress-granules, P-bodies, and cell aging: A bioinformatics study. Biochem Biophys Res Commun 2024; 694:149404. [PMID: 38147698 DOI: 10.1016/j.bbrc.2023.149404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 12/18/2023] [Indexed: 12/28/2023]
Abstract
At the molecular level, aging is often accompanied by dysfunction of stress-induced membrane-less organelles (MLOs) and changes in their physical state (or material properties). In this work, we analyzed the proteins included in the proteome of stress granules (SGs) and P-bodies for their tendency to transform the physical state of these MLOs. Particular attention was paid to the proteins whose gene expression changes during replicative aging. It was shown that the proteome of the studied MLOs consists of intrinsically disordered proteins, 30-40% of which are potentially capable of liquid-liquid phase separation (LLPS). Proteins whose gene expression changes during the transition of human cells to a senescent state make up about 20% of the studied proteomes. There is a statistically significant increase in the number of positively charged proteins in both datasets studied compared to the complete proteomes of these organelles. An increase in the relative content of DNA-, but not RNA-binding proteins, was also found in the SG dataset with senescence-related processes. Among SGs proteins potentially involved in senescent processes, there is an increase in the abundance of potentially amyloidogenic proteins compared to the whole proteome. Proteins common to SGs and P-bodies, potentially involved in processes associated with senescence, form clusters of interacting proteins. The largest cluster is represented by RNA-binding proteins involved in RNA processing and translation regulation. These data indicate that SG proteins, but not proteins of P-bodies, are more likely to transform the physical state of MLOs. Furthermore, these MLOs can participate in processes associated with aging in a coordinated manner.
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Affiliation(s)
- Yakov I Mokin
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky Ave., 194064, St. Petersburg, Russia.
| | - Nikolay S Ilyinsky
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Institutskiy Pereulok, 9, Dolgoprudny, 141700, Russia.
| | - Semen V Nesterov
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Institutskiy Pereulok, 9, Dolgoprudny, 141700, Russia.
| | - Eugene Y Smirnov
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky Ave., 194064, St. Petersburg, Russia.
| | - Olga S Sergeeva
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky Ave., 194064, St. Petersburg, Russia.
| | - Anna E Romanovich
- Resource Center of Molecular and Cell Technologies, St-Petersburg State University Research Park, Universitetskaya Emb. 7-9, 199034, St. Petersburg, Russia.
| | - Irina M Kuznetsova
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky Ave., 194064, St. Petersburg, Russia.
| | - Konstantin K Turoverov
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky Ave., 194064, St. Petersburg, Russia.
| | - Vladimir N Uversky
- Department of Molecular Medicine and USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, 12901 Bruce B. Downs Blvd., MDC07, Tampa, FL, 33612, USA.
| | - Alexander V Fonin
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky Ave., 194064, St. Petersburg, Russia.
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4
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Gao G, Sumrall ES, Pitchiaya S, Bitzer M, Alberti S, Walter NG. Biomolecular condensates in kidney physiology and disease. Nat Rev Nephrol 2023; 19:756-770. [PMID: 37752323 DOI: 10.1038/s41581-023-00767-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/27/2023] [Indexed: 09/28/2023]
Abstract
The regulation and preservation of distinct intracellular and extracellular solute microenvironments is crucial for the maintenance of cellular homeostasis. In mammals, the kidneys control bodily salt and water homeostasis. Specifically, the urine-concentrating mechanism within the renal medulla causes fluctuations in extracellular osmolarity, which enables cells of the kidney to either conserve or eliminate water and electrolytes, depending on the balance between intake and loss. However, relatively little is known about the subcellular and molecular changes caused by such osmotic stresses. Advances have shown that many cells, including those of the kidney, rapidly (within seconds) and reversibly (within minutes) assemble membraneless, nano-to-microscale subcellular assemblies termed biomolecular condensates via the biophysical process of hyperosmotic phase separation (HOPS). Mechanistically, osmotic cell compression mediates changes in intracellular hydration, concentration and molecular crowding, rendering HOPS one of many related phase-separation phenomena. Osmotic stress causes numerous homo-multimeric proteins to condense, thereby affecting gene expression and cell survival. HOPS rapidly regulates specific cellular biochemical processes before appropriate protective or corrective action by broader stress response mechanisms can be initiated. Here, we broadly survey emerging evidence for, and the impact of, biomolecular condensates in nephrology, where initial concentration buffering by HOPS and its subsequent cellular escalation mechanisms are expected to have important implications for kidney physiology and disease.
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Affiliation(s)
- Guoming Gao
- Biophysics Graduate Program, University of Michigan, Ann Arbor, MI, USA
- Department of Chemistry and Center for RNA Biomedicine, University of Michigan, Ann Arbor, MI, USA
| | - Emily S Sumrall
- Biophysics Graduate Program, University of Michigan, Ann Arbor, MI, USA
- Department of Chemistry and Center for RNA Biomedicine, University of Michigan, Ann Arbor, MI, USA
| | | | - Markus Bitzer
- Department of Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Simon Alberti
- Technische Universität Dresden, Biotechnology Center (BIOTEC) and Center for Molecular and Cellular Engineering (CMCB), Dresden, Germany
| | - Nils G Walter
- Department of Chemistry and Center for RNA Biomedicine, University of Michigan, Ann Arbor, MI, USA.
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5
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Manyilov VD, Ilyinsky NS, Nesterov SV, Saqr BMGA, Dayhoff GW, Zinovev EV, Matrenok SS, Fonin AV, Kuznetsova IM, Turoverov KK, Ivanovich V, Uversky VN. Chaotic aging: intrinsically disordered proteins in aging-related processes. Cell Mol Life Sci 2023; 80:269. [PMID: 37634152 PMCID: PMC11073068 DOI: 10.1007/s00018-023-04897-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Revised: 07/03/2023] [Accepted: 07/24/2023] [Indexed: 08/29/2023]
Abstract
The development of aging is associated with the disruption of key cellular processes manifested as well-established hallmarks of aging. Intrinsically disordered proteins (IDPs) and intrinsically disordered regions (IDRs) have no stable tertiary structure that provide them a power to be configurable hubs in signaling cascades and regulate many processes, potentially including those related to aging. There is a need to clarify the roles of IDPs/IDRs in aging. The dataset of 1702 aging-related proteins was collected from established aging databases and experimental studies. There is a noticeable presence of IDPs/IDRs, accounting for about 36% of the aging-related dataset, which is however less than the disorder content of the whole human proteome (about 40%). A Gene Ontology analysis of the used here aging proteome reveals an abundance of IDPs/IDRs in one-third of aging-associated processes, especially in genome regulation. Signaling pathways associated with aging also contain IDPs/IDRs on different hierarchical levels, revealing the importance of "structure-function continuum" in aging. Protein-protein interaction network analysis showed that IDPs present in different clusters associated with different aging hallmarks. Protein cluster with IDPs enrichment has simultaneously high liquid-liquid phase separation (LLPS) probability, "nuclear" localization and DNA-associated functions, related to aging hallmarks: genomic instability, telomere attrition, epigenetic alterations, and stem cells exhaustion. Intrinsic disorder, LLPS, and aggregation propensity should be considered as features that could be markers of pathogenic proteins. Overall, our analyses indicate that IDPs/IDRs play significant roles in aging-associated processes, particularly in the regulation of DNA functioning. IDP aggregation, which can lead to loss of function and toxicity, could be critically harmful to the cell. A structure-based analysis of aging and the identification of proteins that are particularly susceptible to disturbances can enhance our understanding of the molecular mechanisms of aging and open up new avenues for slowing it down.
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Affiliation(s)
- Vladimir D Manyilov
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Institutskiy Pereulok, 9, Dolgoprudny, 141700, Russia
| | - Nikolay S Ilyinsky
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Institutskiy Pereulok, 9, Dolgoprudny, 141700, Russia.
| | - Semen V Nesterov
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Institutskiy Pereulok, 9, Dolgoprudny, 141700, Russia
- Institute of Cytology, Russian Academy of Sciences, Saint Petersburg, 194064, Russia
| | - Baraa M G A Saqr
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Institutskiy Pereulok, 9, Dolgoprudny, 141700, Russia
| | - Guy W Dayhoff
- Department of Chemistry, University of South Florida, Tampa, FL, USA
| | - Egor V Zinovev
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Institutskiy Pereulok, 9, Dolgoprudny, 141700, Russia
| | - Simon S Matrenok
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Institutskiy Pereulok, 9, Dolgoprudny, 141700, Russia
| | - Alexander V Fonin
- Institute of Cytology, Russian Academy of Sciences, Saint Petersburg, 194064, Russia
| | - Irina M Kuznetsova
- Institute of Cytology, Russian Academy of Sciences, Saint Petersburg, 194064, Russia
| | | | - Valentin Ivanovich
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Institutskiy Pereulok, 9, Dolgoprudny, 141700, Russia
| | - Vladimir N Uversky
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Institutskiy Pereulok, 9, Dolgoprudny, 141700, Russia.
- Department of Molecular Medicine and USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, 12901 Bruce B. Downs Blvd., MDC07, Tampa, FL, 33612, USA.
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6
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Horio T, Ishikura Y, Ohashi R, Shiina N. Regulation of RNG105/caprin1 dynamics by pathogenic cytoplasmic FUS and TDP-43 in neuronal RNA granules modulates synaptic loss. Heliyon 2023; 9:e17065. [PMID: 37484309 PMCID: PMC10361247 DOI: 10.1016/j.heliyon.2023.e17065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 05/25/2023] [Accepted: 06/06/2023] [Indexed: 07/25/2023] Open
Abstract
In neurodegenerative diseases, the condensation of FUS and TDP-43 with RNA granules in neurons is linked to pathology, including synaptic disorders. However, the effects of FUS and TDP-43 on RNA granule factors remain unclear. Here, using primary cultured neurons from the mouse cerebral cortex, we show that excess cytoplasmic FUS and TDP-43 accumulated in dendritic RNA granules, where they increased the dynamics of a scaffold protein RNG105/caprin1 and dissociated it from the granules. This coincided with reduced levels of mRNA and translation around the granules and synaptic loss in dendrites. These defects were suppressed by non-dissociable RNG105, suggesting that RNG105 dissociation mediated the defects. In contrast to the model where FUS and TDP-43 co-aggregate with RNA granule factors to repress their activity, our findings provide a novel pathogenic mechanism whereby FUS and TDP-43 dissociate RNA scaffold proteins from RNA granules which are required for local translation that regulates synapse formation.
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Affiliation(s)
- Tomoyo Horio
- Laboratory of Neuronal Cell Biology, National Institute for Basic Biology, Okazaki, Aichi 444-8585, Japan
- Department of Basic Biology, Graduate University for Advanced Studies (SOKENDAI), Okazaki, Aichi 444-8585, Japan
| | - Yui Ishikura
- Laboratory of Neuronal Cell Biology, National Institute for Basic Biology, Okazaki, Aichi 444-8585, Japan
- Department of Basic Biology, Graduate University for Advanced Studies (SOKENDAI), Okazaki, Aichi 444-8585, Japan
| | - Rie Ohashi
- Laboratory of Neuronal Cell Biology, National Institute for Basic Biology, Okazaki, Aichi 444-8585, Japan
- Department of Basic Biology, Graduate University for Advanced Studies (SOKENDAI), Okazaki, Aichi 444-8585, Japan
- Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Okazaki, Aichi 444-8585, Japan
- Life Science Research Center, University of Toyama, Toyama, Toyama 930-0194, Japan
| | - Nobuyuki Shiina
- Laboratory of Neuronal Cell Biology, National Institute for Basic Biology, Okazaki, Aichi 444-8585, Japan
- Department of Basic Biology, Graduate University for Advanced Studies (SOKENDAI), Okazaki, Aichi 444-8585, Japan
- Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Okazaki, Aichi 444-8585, Japan
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7
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Kipper K, Mansour A, Pulk A. Neuronal RNA granules are ribosome complexes stalled at the pre-translocation state. J Mol Biol 2022; 434:167801. [PMID: 36038000 DOI: 10.1016/j.jmb.2022.167801] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 06/20/2022] [Accepted: 08/22/2022] [Indexed: 11/30/2022]
Abstract
The polarized cell morphology of neurons dictates many neuronal processes, including the axodendridic transport of specific mRNAs and subsequent translation. mRNAs together with ribosomes and RNA-binding proteins form RNA granules that are targeted to axodendrites for localized translation in neurons. It has been established that localized protein synthesis in neurons is essential for long-term memory formation, synaptic plasticity, and neurodegeneration. We have used proteomics and electron microscopy to characterize neuronal RNA granules (nRNAg) isolated from rat brain tissues or human neuroblastoma. We show that ribosome containing RNA granules are morula-like structures when visualized by electron microscopy. Crosslinking-coupled mass-spectrometry identified potential G3BP2 binding site on the ribosome near the eIF3d-binding site on the 40S ribosomal subunit. We used cryo-EM to resolve the structure of the ribosome-component of nRNAg. The cryo-EM reveals that predominant particles in nRNAg are 80S ribosomes, resembling the pre-translocation state where tRNA's are in the hybrid A/P and P/E site. We also describe a new kind of principal motion of the ribosome, which we call the rocking motion.
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Affiliation(s)
- Kalle Kipper
- Structural Biology Unit, Institute of Technology, University of Tartu, Tartu 50411, Estonia
| | - Abbas Mansour
- Structural Biology Unit, Institute of Technology, University of Tartu, Tartu 50411, Estonia
| | - Arto Pulk
- Structural Biology Unit, Institute of Technology, University of Tartu, Tartu 50411, Estonia.
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8
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Niss F, Piñero-Paez L, Zaidi W, Hallberg E, Ström AL. Key Modulators of the Stress Granule Response TIA1, TDP-43, and G3BP1 Are Altered by Polyglutamine-Expanded ATXN7. Mol Neurobiol 2022; 59:5236-5251. [PMID: 35689166 PMCID: PMC9363381 DOI: 10.1007/s12035-022-02888-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 05/17/2022] [Indexed: 11/26/2022]
Abstract
Spinocerebellar ataxia type 7 (SCA7) and other polyglutamine (polyQ) diseases are caused by expansions of polyQ repeats in disease-specific proteins. Aggregation of the polyQ proteins resulting in various forms of cellular stress, that could induce the stress granule (SG) response, is believed to be a common pathological mechanism in these disorders. SGs can contribute to cell survival but have also been suggested to exacerbate disease pathology by seeding protein aggregation. In this study, we show that two SG-related proteins, TDP-43 and TIA1, are sequestered into the aggregates formed by polyQ-expanded ATXN7 in SCA7 cells. Interestingly, mutant ATXN7 also localises to induced SGs, and this association altered the shape of the SGs. In spite of this, neither the ability to induce nor to disassemble SGs, in response to arsenite stress induction or relief, was affected in SCA7 cells. Moreover, we could not observe any change in the number of ATXN7 aggregates per cell following SG induction, although a small, non-significant, increase in total aggregated ATXN7 material could be detected using filter trap. However, mutant ATXN7 expression in itself increased the speckling of the SG-nucleating protein G3BP1 and the SG response. Taken together, our results indicate that the SG response is induced, and although some key modulators of SGs show altered behaviour, the dynamics of SGs appear normal in the presence of mutant ATXN7.
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Affiliation(s)
- Frida Niss
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Laura Piñero-Paez
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
- Science for Life Laboratory, Department of Women's and Children's Health, Karolinska Institutet, Solna, Sweden
| | - Wajiha Zaidi
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
- Department of Biomedical and Clinical Sciences, Division of Neurobiology, Linköping University, Linköping, Sweden
| | - Einar Hallberg
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Anna-Lena Ström
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden.
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9
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Glauninger H, Wong Hickernell CJ, Bard JAM, Drummond DA. Stressful steps: Progress and challenges in understanding stress-induced mRNA condensation and accumulation in stress granules. Mol Cell 2022; 82:2544-2556. [PMID: 35662398 PMCID: PMC9308734 DOI: 10.1016/j.molcel.2022.05.014] [Citation(s) in RCA: 41] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Revised: 03/14/2022] [Accepted: 05/11/2022] [Indexed: 01/11/2023]
Abstract
Stress-induced condensation of mRNA and protein into massive cytosolic clusters is conserved across eukaryotes. Known as stress granules when visible by imaging, these structures remarkably have no broadly accepted biological function, mechanism of formation or dispersal, or even molecular composition. As part of a larger surge of interest in biomolecular condensation, studies of stress granules and related RNA/protein condensates have increasingly probed the biochemical underpinnings of condensation. Here, we review open questions and recent advances, including the stages from initial condensate formation to accumulation in mature stress granules, mechanisms by which stress-induced condensates form and dissolve, and surprising twists in understanding the RNA components of stress granules and their role in condensation. We outline grand challenges in understanding stress-induced RNA condensation, centering on the unique and substantial barriers in the molecular study of cellular structures, such as stress granules, for which no biological function has been firmly established.
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Affiliation(s)
- Hendrik Glauninger
- Department of Biochemistry & Molecular Biology, University of Chicago, Chicago, IL 60673, USA
| | | | - Jared A M Bard
- Department of Biochemistry & Molecular Biology, University of Chicago, Chicago, IL 60673, USA
| | - D Allan Drummond
- Department of Biochemistry & Molecular Biology, University of Chicago, Chicago, IL 60673, USA.
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10
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Sato K, Sakai M, Ishii A, Maehata K, Takada Y, Yasuda K, Kotani T. Identification of embryonic RNA granules that act as sites of mRNA translation after changing their physical properties. iScience 2022; 25:104344. [PMID: 35620421 PMCID: PMC9127168 DOI: 10.1016/j.isci.2022.104344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 03/16/2022] [Accepted: 04/27/2022] [Indexed: 11/08/2022] Open
Abstract
Fertilized eggs begin to translate mRNAs at appropriate times and placements to control development, but how the translation is regulated remains unclear. Here, we found that pou5f3 mRNA encoding a transcriptional factor essential for development formed granules in a dormant state in zebrafish oocytes. Although the number of pou5f3 granules remained constant, Pou5f3 protein accumulated after fertilization. Intriguingly, signals of newly synthesized peptides and a ribosomal protein became colocalized with pou5f3 granules after fertilization and, moreover, nascent Pou5f3 was shown to be synthesized in the granules. This functional change was accompanied by changes in the state and internal structure of granules. Dissolution of the granules reduced the rate of protein synthesis. Similarly, nanog and sox19b mRNAs in zebrafish and Pou5f1/Oct4 mRNA in mouse assembled into granules. Our results reveal that subcellular compartments, termed embryonic RNA granules, function as activation sites of translation after changing physical properties for directing vertebrate development.
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Affiliation(s)
- Keisuke Sato
- Biosystems Science Course, Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Moeko Sakai
- Biosystems Science Course, Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Anna Ishii
- Biosystems Science Course, Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Kaori Maehata
- Biosystems Science Course, Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Yuki Takada
- Biosystems Science Course, Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Kyota Yasuda
- Department of Mathematical and Life Sciences, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima 739-8526, Japan
- Research Center for the Mathematics on Chromatin Live Dynamics, Hiroshima University, Hiroshima 739-8526, Japan
| | - Tomoya Kotani
- Biosystems Science Course, Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan
- Department of Biological Sciences, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
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11
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Stress-Induced Membraneless Organelles in Eukaryotes and Prokaryotes: Bird’s-Eye View. Int J Mol Sci 2022; 23:ijms23095010. [PMID: 35563401 PMCID: PMC9105482 DOI: 10.3390/ijms23095010] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 04/25/2022] [Accepted: 04/26/2022] [Indexed: 02/06/2023] Open
Abstract
Stress is an inevitable part of life. An organism is exposed to multiple stresses and overcomes their negative consequences throughout its entire existence. A correlation was established between life expectancy and resistance to stress, suggesting a relationship between aging and the ability to respond to external adverse effects as well as quickly restore the normal regulation of biological processes. To combat stress, cells developed multiple pro-survival mechanisms, one of them is the assembly of special stress-induced membraneless organelles (MLOs). MLOs are formations that do not possess a lipid membrane but rather form as a result of the “liquid–liquid” phase separation (LLPS) of biopolymers. Stress-responsive MLOs were found in eukaryotes and prokaryotes, they form as a reaction to the acute environmental conditions and are dismantled after its termination. These compartments function to prevent damage to the genetic and protein material of the cell during stress. In this review, we discuss the characteristics of stress-induced MLO-like structures in eukaryotic and prokaryotic cells.
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12
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Yasuda K, Watanabe TM, Kang MG, Seo JK, Rhee HW, Tate SI. Valosin-containing protein (VCP) regulates the stability of fused in sarcoma (FUS) granules in cells by changing ATP concentrations. FEBS Lett 2022; 596:1412-1423. [PMID: 35445401 DOI: 10.1002/1873-3468.14353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 03/28/2022] [Accepted: 04/02/2022] [Indexed: 11/08/2022]
Abstract
Fused in sarcoma (FUS), a DNA/RNA-binding protein, undergoes liquid-liquid phase separation to form granules in cells. Aberrant FUS granulation is associated with neurodegenerative diseases, including amyotrophic lateral sclerosis and frontotemporal lobar degeneration. We found that FUS granules contain a multifunctional AAA ATPase, valosin-containing protein (VCP), which is known as a key regulator of protein degradation. FUS granule stability depends on ATP concentrations in cells. VCP ATPase changes the FUS granule stability time-dependently by consuming ATP to reduce its concentrations in the granules: VCPs in de novo FUS granules stabilize the granules, while long-lasting VCP colocalization destabilizes the granules. The proteolysis-promoting function of VCP may subsequently dissolve the unstabilized granules. We propose that VCP colocalized to the FUS granules acts as a timer to limit the residence time of the granules in cells.
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Affiliation(s)
- Kyota Yasuda
- Department of Mathematical and Life Sciences, Graduate School of Integrated Sciences for Life, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima, 739-8526, Japan.,Research Center for the Mathematics on Chromatin Live Dynamics (RcMcD), Hiroshima University, 1-3-1, Kagamiyama, Higashi-Hiroshima, Hiroshima, 739-8526, Japan
| | - Tomonobu M Watanabe
- Laboratory for Comprehensive Bioimaging, RIKEN Center for Biosystems Dynamics Research (BDR), Minatomachi-Minami 2-2-3, Chuo-ku, Kobe, Hyogo, 650-0047, Japan.,Department of Stem Cell Biology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Kasumi 1-2-3, Minami-Ku, Hiroshima, 734-8553, Japan
| | - Myeong-Gyun Kang
- Department of Chemistry, School of Biological Sciences, Seoul National University, Seoul, 08826, Korea
| | - Jeong Kon Seo
- UNIST Central Research Facilities (UCRF), Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Korea
| | - Hyun-Woo Rhee
- Department of Chemistry, School of Biological Sciences, Seoul National University, Seoul, 08826, Korea
| | - Shin-Ichi Tate
- Department of Mathematical and Life Sciences, Graduate School of Integrated Sciences for Life, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima, 739-8526, Japan.,Research Center for the Mathematics on Chromatin Live Dynamics (RcMcD), Hiroshima University, 1-3-1, Kagamiyama, Higashi-Hiroshima, Hiroshima, 739-8526, Japan
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13
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Antifeeva IA, Fonin AV, Fefilova AS, Stepanenko OV, Povarova OI, Silonov SA, Kuznetsova IM, Uversky VN, Turoverov KK. Liquid-liquid phase separation as an organizing principle of intracellular space: overview of the evolution of the cell compartmentalization concept. Cell Mol Life Sci 2022; 79:251. [PMID: 35445278 PMCID: PMC11073196 DOI: 10.1007/s00018-022-04276-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 03/24/2022] [Accepted: 03/27/2022] [Indexed: 12/14/2022]
Abstract
At the turn of the twenty-first century, fundamental changes took place in the understanding of the structure and function of proteins and then in the appreciation of the intracellular space organization. A rather mechanistic model of the organization of living matter, where the function of proteins is determined by their rigid globular structure, and the intracellular processes occur in rigidly determined compartments, was replaced by an idea that highly dynamic and multifunctional "soft matter" lies at the heart of all living things. According this "new view", the most important role in the spatio-temporal organization of the intracellular space is played by liquid-liquid phase transitions of biopolymers. These self-organizing cellular compartments are open dynamic systems existing at the edge of chaos. They are characterized by the exceptional structural and compositional dynamics, and their multicomponent nature and polyfunctionality provide means for the finely tuned regulation of various intracellular processes. Changes in the external conditions can cause a disruption of the biogenesis of these cellular bodies leading to the irreversible aggregation of their constituent proteins, followed by the transition to a gel-like state and the emergence of amyloid fibrils. This work represents a historical overview of changes in our understanding of the intracellular space compartmentalization. It also reflects methodological breakthroughs that led to a change in paradigms in this area of science and discusses modern ideas about the organization of the intracellular space. It is emphasized here that the membrane-less organelles have to combine a certain resistance to the changes in their environment and, at the same time, show high sensitivity to the external signals, which ensures the normal functioning of the cell.
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Affiliation(s)
- Iuliia A Antifeeva
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Av., 4, St. Petersburg, 194064, Russia
| | - Alexander V Fonin
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Av., 4, St. Petersburg, 194064, Russia
| | - Anna S Fefilova
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Av., 4, St. Petersburg, 194064, Russia
| | - Olesya V Stepanenko
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Av., 4, St. Petersburg, 194064, Russia
| | - Olga I Povarova
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Av., 4, St. Petersburg, 194064, Russia
| | - Sergey A Silonov
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Av., 4, St. Petersburg, 194064, Russia
| | - Irina M Kuznetsova
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Av., 4, St. Petersburg, 194064, Russia
| | - Vladimir N Uversky
- Department of Molecular Medicine and USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, 12901 Bruce B. Downs Blvd. MDC07, Tampa, FL, 33612, USA.
| | - Konstantin K Turoverov
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Av., 4, St. Petersburg, 194064, Russia.
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14
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Liu J, Zhorabek F, Chau Y. Nucleic Acids Modulate Liquidity and Dynamics of Artificial Membraneless Organelles. ACS Macro Lett 2022; 11:562-567. [PMID: 35575335 DOI: 10.1021/acsmacrolett.2c00167] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Liquid-liquid phase separation (LLPS) emerges as a fundamental underlying mechanism for the biological organization, especially the formation of membraneless organelles (MLOs) hosting intrinsically disordered proteins (IDPs) as scaffolds. Nucleic acids are compositional biomacromolecules of MLOs with wide implications in normal cell functions as well as in pathophysiology caused by aberrant phase behavior. Exploiting a minimalist artificial membraneless organelles (AMLO) from LLPS of IDP-mimicking polymer-oligopeptide hybrid (IPH), we investigated the effect of nucleic acids with different lengths and sequence variations on AMLO. The behavior of this AMLO in the presence of DNAs and RNAs resembled natural MLOs in multiple aspects, namely, modulated propensity of formation, morphology, liquidity, and dynamics. Both DNA and RNA could enhance the LLPS of AMLO, while compared with RNA, DNA had a higher tendency to solidify and diminish dynamics thereof. These findings suggest its potential as a concise model system for the understanding of the interaction between nucleic acids and natural MLOs and for studying the molecular mechanism of diseases involving MLOs.
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Affiliation(s)
- Jianhui Liu
- Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR 999077, China
| | - Fariza Zhorabek
- Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR 999077, China
| | - Ying Chau
- Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR 999077, China
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15
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Deater M, Tamhankar M, Lloyd RE. TDRD3 is an antiviral restriction factor that promotes IFN signaling with G3BP1. PLoS Pathog 2022; 18:e1010249. [PMID: 35085371 PMCID: PMC8824378 DOI: 10.1371/journal.ppat.1010249] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 02/08/2022] [Accepted: 01/05/2022] [Indexed: 12/19/2022] Open
Abstract
Stress granules (SGs) are highly dynamic cytoplasmic foci that form in response to activation of the integrated stress response (ISR) that results in eIF2α phosphorylation and global translation shutdown. Stress granules, which are largely nucleated by G3BP1, serve as hubs for mRNA triage, but there is mounting evidence that they also perform cell signaling functions that are vital to cell survival, particularly during viral infection. We previously showed that SG formation leads to NFκB activation and JNK signaling and that this association may be due in part to G3BP1-dependent recruitment of PKR to SGs. Others have reported close associations between G3BP1 and various innate immune PRRs of the type 1 interferon signaling system, including RIG-I. We also reported SG assembly dynamics is dependent on the arginine-methylation status of G3BP1. Another protein that rapidly localizes to SGs, TDRD3, is a methyl reader protein that performs transcriptional activation and adaptor functions within the nucleus, but neither the mechanism nor its function in SGs is clear. Here, we present evidence that TDRD3 localizes to SGs partly based upon methylation potential of G3BP1. We also characterize granules that TDRD3 forms during overexpression and show that these granules can form in the absence of G3BP but also contain translation components found in canonical SGs. We also show for the first time that SGs recruit additional interferon effectors IRF3, IRF7, TBK1, and Sting, and provide evidence that TDRD3 may play a role in recruitment of these factors. We also present evidence that TDRD3 is a novel antiviral protein that is cleaved by enteroviral 2A proteinase. G3BP1 and TDRD3 knockdown in cells results in altered transcriptional regulation of numerous IFN effectors in complex modulatory patterns that are distinctive for G3BP1 and TDRD3. Overall, we describe a novel role of TDRD3 in innate immunity in which G3BP1 and TDRD3 may coordinate to play important roles in regulation of innate antiviral defenses. When cells are exposed to environmental stresses, such as oxidative stress and viral infection, it induces a cellular response leading to the formation of Stress Granules (SGs) composed of stalled translation initiation complexes (RNA-binding proteins and mRNA) and many other cellular proteins. SGs are also considered to be antiviral structures when they form during viral infection, but viruses can block SG formation to facilitate their survival, often by targeting the essential SG protein G3BP1. Here, we show that a methyl reader protein, TDRD3, localizes to SGs partly based on the methylation potential of G3BP1, and may play a role in the recruitment of innate immune factors to SGs. Further, when overexpressed, TDRD3 can also form SG-like structures independently of G3BP1. We also present evidence that TDRD3 is a novel antiviral protein. Virus replication is enhanced in the absence of both TDRD3 and G3BP1, and virus infection leads to cleavage of TDRD3 by the enterovirus proteinase 2A. Finally, we also show that depletion of TDRD3 and G3BP1 together in cells leads to restriction of transcriptional activation of numerous IFN effectors in response to dsRNA. The patterns of transcriptional activation are distinctive for G3BP1 and TDRD3. We conclude that TDRD3 may play a novel and important role in the regulation of the host antiviral response.
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Affiliation(s)
- Matthew Deater
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Manasi Tamhankar
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Richard E. Lloyd
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, United States of America
- * E-mail:
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16
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Aprile FA, Temussi PA, Pastore A. Man does not live by intrinsically unstructured proteins alone: The role of structured regions in aggregation. Bioessays 2021; 43:e2100178. [PMID: 34674273 DOI: 10.1002/bies.202100178] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 09/11/2021] [Accepted: 09/13/2021] [Indexed: 12/30/2022]
Abstract
Protein misfolding is a topic that is of primary interest both in biology and medicine because of its impact on fundamental processes and disease. In this review, we revisit the concept of protein misfolding and discuss how the field has evolved from the study of globular folded proteins to focusing mainly on intrinsically unstructured and often disordered regions. We argue that this shift of paradigm reflects the more recent realisation that misfolding may not only be an adverse event, as originally considered, but also may fulfil a basic biological need to compartmentalise the cell with transient reversible granules. We nevertheless provide examples in which structure is an important component of a much more complex aggregation behaviour that involves both structured and unstructured regions of a protein. We thus suggest that a more comprehensive evaluation of the mechanisms that lead to aggregation might be necessary.
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Affiliation(s)
- Francesco A Aprile
- Department of Chemistry, Imperial College London, White City Campus, 82 Wood Lane, London, W12 0BZ, UK
| | - Piero Andrea Temussi
- UK Dementia Research Institute at the Maurice Wohl Institute of King's College London, London, UK
| | - Annalisa Pastore
- UK Dementia Research Institute at the Maurice Wohl Institute of King's College London, London, UK
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17
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Iglesias V, Santos J, Santos-Suárez J, Pintado-Grima C, Ventura S. SGnn: A Web Server for the Prediction of Prion-Like Domains Recruitment to Stress Granules Upon Heat Stress. Front Mol Biosci 2021; 8:718301. [PMID: 34490351 PMCID: PMC8416484 DOI: 10.3389/fmolb.2021.718301] [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: 05/31/2021] [Accepted: 08/09/2021] [Indexed: 11/15/2022] Open
Abstract
Proteins bearing prion-like domains (PrLDs) are essential players in stress granules (SG) assembly. Analysis of data on heat stress-induced recruitment of yeast PrLDs to SG suggests that this propensity might be connected with three defined protein biophysical features: aggregation propensity, net charge, and the presence of free cysteines. These three properties can be read directly in the PrLDs sequences, and their combination allows to predict protein recruitment to SG under heat stress. On this basis, we implemented SGnn, an online predictor of SG recruitment that exploits a feed-forward neural network for high accuracy classification of the assembly behavior of PrLDs. The simplicity and precision of our strategy should allow its implementation to identify heat stress-induced SG-forming proteins in complete proteomes.
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Affiliation(s)
- Valentín Iglesias
- Institut de Biotecnologia i Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
| | - Jaime Santos
- Institut de Biotecnologia i Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
| | - Juan Santos-Suárez
- Institut de Biotecnologia i Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
| | - Carlos Pintado-Grima
- Institut de Biotecnologia i Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
| | - Salvador Ventura
- Institut de Biotecnologia i Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
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18
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Metastable biomolecular condensates of interferon-inducible antiviral Mx-family GTPases: A paradigm shift in the last three years. J Biosci 2021. [PMID: 34323222 PMCID: PMC8319588 DOI: 10.1007/s12038-021-00187-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Membraneless organelles (MLOs) in the cytoplasm and nucleus in the form of phase-separated biomolecular condensates are increasingly viewed as critical in regulating diverse cellular functions. We summarize a paradigm shift over the last 3 years in the field of interferon (IFN)-inducible antiviral Mx-family GTPases. Expression of the ‘myxovirus resistance proteins’ MxA in human cells and its ortholog Mx1 in murine cells is increased 50- to 100-fold by Type I (IFN-α and -β) and III IFNs (IFN-λ). Human MxA forms cytoplasmic structures, while murine Mx1 forms nuclear bodies. Since 2002, it has been widely thought that human (Hu) MxA is associated with the membraneous smooth endoplasmic reticulum (ER). In a paradigm shift, our recent data showed that HuMxA formed membraneless phase-separated biomolecular condensates in the cytoplasm. Some of the HuMxA condensates adhered to intermediate filaments generating a reticular pattern. Murine (Mu) Mx1, which was predominantly nuclear, was also confirmed to be in phase-separated nuclear biomolecular condensates. A subset of Huh7 cells showed association of GFP-MuMx1 with intermediate filaments in the cytoplasm. While cells with cytoplasmic GFP-HuMxA condensates and cytoplasmic GFP-MuMx1 filaments showed an antiviral phenotype towards vesicular stomatitis virus (VSV), those with only nuclear GFP-MuMx1 bodies did not. The new data bring forward the paradigm that both human MxA and murine Mx1 give rise to phase-separated biomolecular condensates, albeit in different subcellular compartments, and that differences in the subcellular localization of condensates of different Mx proteins determines the spectrum of their antiviral activity.
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19
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Lo LHY, Dong R, Lyu Q, Lai KO. The Protein Arginine Methyltransferase PRMT8 and Substrate G3BP1 Control Rac1-PAK1 Signaling and Actin Cytoskeleton for Dendritic Spine Maturation. Cell Rep 2021; 31:107744. [PMID: 32521269 DOI: 10.1016/j.celrep.2020.107744] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 04/01/2020] [Accepted: 05/18/2020] [Indexed: 01/25/2023] Open
Abstract
Excitatory synapses of neurons are located on dendritic spines. Spine maturation is essential for the stability of synapses and memory consolidation, and overproduction of the immature filopodia is associated with brain disorders. The structure and function of synapses can be modulated by protein post-translational modification (PTM). Arginine methylation is a major PTM that regulates chromatin structure, transcription, and splicing within the nucleus. Here we find that the protein arginine methyltransferase PRMT8 is present at neuronal synapses and its expression is upregulated in the hippocampus when dendritic spine maturation occurs. Depletion of PRMT8 leads to overabundance of filopodia and mis-localization of excitatory synapses. Mechanistically, PRMT8 promotes dendritic spine morphology through methylation of the dendritic RNA-binding protein G3BP1 and suppression of the Rac1-PAK1 signaling pathway to control synaptic actin dynamics. Our findings unravel arginine methylation as a crucial regulatory mechanism for actin cytoskeleton during synapse development.
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Affiliation(s)
- Louisa Hoi-Ying Lo
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Rui Dong
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Quanwei Lyu
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Kwok-On Lai
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China; State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China.
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20
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Broix L, Turchetto S, Nguyen L. Coordination between Transport and Local Translation in Neurons. Trends Cell Biol 2021; 31:372-386. [PMID: 33526339 DOI: 10.1016/j.tcb.2021.01.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 12/31/2020] [Accepted: 01/04/2021] [Indexed: 11/15/2022]
Abstract
The axonal microtubules (MTs) support long-distance transport of cargoes that are dispatched to distinct cellular subcompartments. Among them, mRNAs are directly transported in membraneless ribonucleoprotein (RNP) granules that, together with ribosomes, can also hitchhike on fast-moving membrane-bound organelles for accurate transport along MTs. These organelles serve as platforms for mRNA translation, thus generating axonal foci of newly synthesized proteins. Local translation along axons not only supports MT network integrity but also modulates the processivity and function of molecular motors to allow proper trafficking of cargoes along MTs. Thus, identifying the mechanisms that coordinate axonal transport with local protein synthesis will shed new light on the processes underlying axon development and maintenance, whose deregulation often contribute to neurological disorders.
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Affiliation(s)
- Loïc Broix
- GIGA Stem Cells, GIGA-Neurosciences, University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium
| | - Silvia Turchetto
- GIGA Stem Cells, GIGA-Neurosciences, University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium
| | - Laurent Nguyen
- GIGA Stem Cells, GIGA-Neurosciences, University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium.
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21
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Nosella ML, Forman-Kay JD. Phosphorylation-dependent regulation of messenger RNA transcription, processing and translation within biomolecular condensates. Curr Opin Cell Biol 2021; 69:30-40. [PMID: 33450720 DOI: 10.1016/j.ceb.2020.12.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 12/09/2020] [Accepted: 12/13/2020] [Indexed: 12/29/2022]
Abstract
Regulation of messenger RNA (mRNA) transcription, processing and translation occurs in the context of biomolecular condensates. How the physical properties of condensates connect with their biological regulatory functions is an ongoing area of interest, particularly for RNA metabolic pathways. Phosphorylation has emerged as an important mechanism for regulating protein phase separation propensities and localization patterns into different condensates, affecting compositions and dynamics. Key factors in transcription, mRNA processing and translation exhibit such phosphorylation-dependent changes in their roles within condensates, including their catalytic activities. Phosphorylation is increasingly understood to regulate the exchange of proteins through functionally linked condensates to fulfil their mRNA metabolic functions.
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Affiliation(s)
- Michael L Nosella
- Molecular Medicine Program, The Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada; Department of Biochemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Julie D Forman-Kay
- Molecular Medicine Program, The Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada; Department of Biochemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada.
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22
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Takei N, Takada Y, Kawamura S, Sato K, Saitoh A, Bormann J, Yuen WS, Carroll J, Kotani T. Changes in subcellular structures and states of pumilio 1 regulate the translation of target Mad2 and cyclin B1 mRNAs. J Cell Sci 2020; 133:jcs249128. [PMID: 33148609 DOI: 10.1242/jcs.249128] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 10/22/2020] [Indexed: 12/12/2022] Open
Abstract
Temporal and spatial control of mRNA translation has emerged as a major mechanism for promoting diverse biological processes. However, the molecular nature of temporal and spatial control of translation remains unclear. In oocytes, many mRNAs are deposited as a translationally repressed form and are translated at appropriate times to promote the progression of meiosis and development. Here, we show that changes in subcellular structures and states of the RNA-binding protein pumilio 1 (Pum1) regulate the translation of target mRNAs and progression of oocyte maturation. Pum1 was shown to bind to Mad2 (also known as Mad2l1) and cyclin B1 mRNAs, assemble highly clustered aggregates, and surround Mad2 and cyclin B1 RNA granules in mouse oocytes. These Pum1 aggregates were dissolved prior to the translational activation of target mRNAs, possibly through phosphorylation. Stabilization of Pum1 aggregates prevented the translational activation of target mRNAs and progression of oocyte maturation. Together, our results provide an aggregation-dissolution model for the temporal and spatial control of translation.
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Affiliation(s)
- Natsumi Takei
- Biosystems Science Course, Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Yuki Takada
- Biosystems Science Course, Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Shohei Kawamura
- Biosystems Science Course, Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Keisuke Sato
- Biosystems Science Course, Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Atsushi Saitoh
- Biosystems Science Course, Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Jenny Bormann
- Development and Stem Cells Program and Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria 3800, Australia
| | - Wai Shan Yuen
- Development and Stem Cells Program and Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria 3800, Australia
| | - John Carroll
- Development and Stem Cells Program and Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria 3800, Australia
| | - Tomoya Kotani
- Biosystems Science Course, Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan
- Department of Biological Sciences, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
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23
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Rhine K, Makurath MA, Liu J, Skanchy S, Lopez C, Catalan KF, Ma Y, Fare CM, Shorter J, Ha T, Chemla YR, Myong S. ALS/FTLD-Linked Mutations in FUS Glycine Residues Cause Accelerated Gelation and Reduced Interactions with Wild-Type FUS. Mol Cell 2020; 80:666-681.e8. [PMID: 33159856 PMCID: PMC7688085 DOI: 10.1016/j.molcel.2020.10.014] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 08/06/2020] [Accepted: 10/09/2020] [Indexed: 12/12/2022]
Abstract
The RNA-binding protein fused in sarcoma (FUS) can form pathogenic inclusions in neurodegenerative diseases like amyotrophic lateral sclerosis (ALS) and frontotemporal lobar dementia (FTLD). Over 70 mutations in Fus are linked to ALS/FTLD. In patients, all Fus mutations are heterozygous, indicating that the mutant drives disease progression despite the presence of wild-type (WT) FUS. Here, we demonstrate that ALS/FTLD-linked FUS mutations in glycine (G) strikingly drive formation of droplets that do not readily interact with WT FUS, whereas arginine (R) mutants form mixed condensates with WT FUS. Remarkably, interactions between WT and G mutants are disfavored at the earliest stages of FUS nucleation. In contrast, R mutants physically interact with the WT FUS such that WT FUS recovers the mutant defects by reducing droplet size and increasing dynamic interactions with RNA. This result suggests disparate molecular mechanisms underlying ALS/FTLD pathogenesis and differing recovery potential depending on the type of mutation.
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Affiliation(s)
- Kevin Rhine
- Program in Cell, Molecular, Developmental Biology, and Biophysics, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA; Department of Biology, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA
| | - Monika A Makurath
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Department of Physics, Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - James Liu
- Department of Biology, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA; Medical Genetics and Ophthalmic Genomics Unit, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sophie Skanchy
- Department of Biophysics, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA
| | - Christian Lopez
- Department of Biology, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA
| | - Kevin F Catalan
- Program in Cell, Molecular, Developmental Biology, and Biophysics, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA; Department of Biology, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA
| | - Ye Ma
- Department of Biomedical Engineering, Johns Hopkins Medical Institute, 615 N Wolfe St, Baltimore, MD 21231, USA
| | - Charlotte M Fare
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - James Shorter
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Taekjip Ha
- Program in Cell, Molecular, Developmental Biology, and Biophysics, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA; Department of Physics, Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Department of Biophysics, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA; Department of Biomedical Engineering, Johns Hopkins Medical Institute, 615 N Wolfe St, Baltimore, MD 21231, USA; Howard Hughes Medical Institute, Baltimore, MD 21218, USA
| | - Yann R Chemla
- Department of Physics, Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Sua Myong
- Program in Cell, Molecular, Developmental Biology, and Biophysics, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA; Department of Physics, Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Department of Biophysics, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA.
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24
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Abstract
Proteinaceous liquid-liquid phase separation (LLPS) occurs when a polypeptide coalesces into a dense phase to form a liquid droplet (i.e., condensate) in aqueous solution. In vivo, functional protein-based condensates are often referred to as membraneless organelles (MLOs), which have roles in cellular processes ranging from stress responses to regulation of gene expression. Late embryogenesis abundant (LEA) proteins containing seed maturation protein domains (SMP; PF04927) have been linked to storage tolerance of orthodox seeds. The mechanism by which anhydrobiotic longevity is improved is unknown. Interestingly, the brine shrimp Artemia franciscana is the only animal known to express such a protein (AfrLEA6) in its anhydrobiotic embryos. Ectopic expression of AfrLEA6 (AWM11684) in insect cells improves their desiccation tolerance and a fraction of the protein is sequestered into MLOs, while aqueous AfrLEA6 raises the viscosity of the cytoplasm. LLPS of AfrLEA6 is driven by the SMP domain, while the size of formed MLOs is regulated by a domain predicted to engage in protein binding. AfrLEA6 condensates formed in vitro selectively incorporate target proteins based on their surface charge, while cytoplasmic MLOs formed in AfrLEA6-transfected insect cells behave like stress granules. We suggest that AfrLEA6 promotes desiccation tolerance by engaging in two distinct molecular mechanisms: by raising cytoplasmic viscosity at even modest levels of water loss to promote cell integrity during drying and by forming condensates that may act as protective compartments for desiccation-sensitive proteins. Identifying and understanding the molecular mechanisms that govern anhydrobiosis will lead to significant advancements in preserving biological samples.
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25
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Tauber D, Tauber G, Parker R. Mechanisms and Regulation of RNA Condensation in RNP Granule Formation. Trends Biochem Sci 2020; 45:764-778. [PMID: 32475683 PMCID: PMC7211619 DOI: 10.1016/j.tibs.2020.05.002] [Citation(s) in RCA: 102] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 04/20/2020] [Accepted: 05/05/2020] [Indexed: 01/01/2023]
Abstract
Ribonucleoprotein (RNP) granules are RNA-protein assemblies that are involved in multiple aspects of RNA metabolism and are linked to memory, development, and disease. Some RNP granules form, in part, through the formation of intermolecular RNA-RNA interactions. In vitro, such trans RNA condensation occurs readily, suggesting that cells require mechanisms to modulate RNA-based condensation. We assess the mechanisms of RNA condensation and how cells modulate this phenomenon. We propose that cells control RNA condensation through ATP-dependent processes, static RNA buffering, and dynamic post-translational mechanisms. Moreover, perturbations in these mechanisms can be involved in disease. This reveals multiple cellular mechanisms of kinetic and thermodynamic control that maintain the proper distribution of RNA molecules between dispersed and condensed forms.
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Affiliation(s)
- Devin Tauber
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO 80308, USA
| | - Gabriel Tauber
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Roy Parker
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO 80308, USA; Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, CO 80308, USA.
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26
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Nakazawa K, Shichino Y, Iwasaki S, Shiina N. Implications of RNG140 (caprin2)-mediated translational regulation in eye lens differentiation. J Biol Chem 2020; 295:15029-15044. [PMID: 32839273 DOI: 10.1074/jbc.ra120.012715] [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: 01/18/2020] [Revised: 08/07/2020] [Indexed: 01/02/2023] Open
Abstract
Regulation of gene expression at the translational level is key to determining cell fate and function. An RNA-binding protein, RNG140 (caprin2), plays a role in eye lens differentiation and has been reported to function in translational regulation. However, the mechanism and its role in eyes has remained unclear. Here, we show that RNG140 binds to the translation initiation factor eukaryotic initiation factor 3 (eIF3) and suppresses translation through mechanisms involving suppression of eIF3-dependent translation initiation. Comprehensive ribosome profiling revealed that overexpression of RNG140 in cultured Chinese hamster ovary cells reduces translation of long mRNAs, including those associated with cell proliferation. RNG140-mediated translational regulation also operates in the mouse eye, where RNG140 knockout increased the translation of long mRNAs. mRNAs involved in lens differentiation, such as crystallin mRNAs, are short and can escape translational inhibition by RNG140 and be translated in differentiating lenses. Thus, this study provides insights into the mechanistic basis of lens cell transition from proliferation to differentiation via RNG140-mediated translational regulation.
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Affiliation(s)
- Kaori Nakazawa
- Laboratory of Neuronal Cell Biology, National Institute for Basic Biology, Okazaki, Aichi, Japan; Department of Basic Biology, SOKENDAI (Graduate University for Advanced Studies), Okazaki, Aichi, Japan
| | - Yuichi Shichino
- RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering Research, Saitama, Japan
| | - Shintaro Iwasaki
- RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering Research, Saitama, Japan; Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, University of Tokyo, Chiba, Japan
| | - Nobuyuki Shiina
- Laboratory of Neuronal Cell Biology, National Institute for Basic Biology, Okazaki, Aichi, Japan; Department of Basic Biology, SOKENDAI (Graduate University for Advanced Studies), Okazaki, Aichi, Japan; Exploratory Research Center on Life and Living Systems (ExCELLS), Okazaki, Aichi, Japan.
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27
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Sehgal PB, Westley J, Lerea KM, DiSenso-Browne S, Etlinger JD. Biomolecular condensates in cell biology and virology: Phase-separated membraneless organelles (MLOs). Anal Biochem 2020; 597:113691. [PMID: 32194074 DOI: 10.1016/j.ab.2020.113691] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 03/06/2020] [Accepted: 03/13/2020] [Indexed: 12/12/2022]
Abstract
Membraneless organelles (MLOs) in the cytoplasm and nucleus in the form of 2D and 3D phase-separated biomolecular condensates are increasingly viewed as critical in regulating diverse cellular functions. These functions include cell signaling, immune synapse function, nuclear transcription, RNA splicing and processing, mRNA storage and translation, virus replication and maturation, antiviral mechanisms, DNA sensing, synaptic transmission, protein turnover and mitosis. Components comprising MLOs often associate with low affinity; thus cell integrity can be critical to the maintenance of the full complement of respective MLO components. Phase-separated condensates are typically metastable (shape-changing) and can undergo dramatic, rapid and reversible assembly and disassembly in response to cell signaling events, cell stress, during mitosis, and after changes in cytoplasmic "crowding" (as observed with condensates of the human myxovirus resistance protein MxA). Increasing evidence suggests that neuron-specific aberrations in phase-separation properties of RNA-binding proteins (e.g. FUS and TDP-43) and others (such as the microtubule-binding protein tau) contribute to the development of degenerative neurological diseases (e.g. amyotrophic lateral sclerosis, frontotemporal lobar degeneration, and Alzheimer's disease). Thus, studies of liquid-like phase separation (LLPS) and the formation, structure and function of MLOs are of considerable importance in understanding basic cell biology and the pathogenesis of human diseases.
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Affiliation(s)
- Pravin B Sehgal
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, 10595, USA; Department of Medicine, New York Medical College, Valhalla, NY, 10595, USA.
| | - Jenna Westley
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, 10595, USA
| | - Kenneth M Lerea
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, 10595, USA
| | - Susan DiSenso-Browne
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, 10595, USA; Department of Dental Medicine, Touro College of Dental Medicine, Hawthorne, NY, 10532, USA
| | - Joseph D Etlinger
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, 10595, USA
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28
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Abstract
Liquid-liquid phase separation is emerging as the universal mechanism by which membraneless cellular granules form. Despite many previous studies on condensation of intrinsically disordered proteins and low complexity domains, we lack understanding about the role of RNA, which is the essential component of all ribonucleoprotein (RNP) granules. RNA, as an anionic polymer, is inherently an excellent platform for achieving multivalency and can accommodate many RNA binding proteins. Recent findings have highlighted the diverse function of RNA in tuning phase-separation propensity up or down, altering viscoelastic properties and thereby driving immiscibility between different condensates. In addition to contributing to the biophysical properties of droplets, RNA is a functionally critical constituent that defines the identity of cellular condensates and controls the temporal and spatial distribution of specific RNP granules. In this review, we summarize what we have learned so far about such roles of RNA in the context of in vitro and in vivo studies.
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Affiliation(s)
- Kevin Rhine
- Department of Biology, Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - Velinda Vidaurre
- Department of Biology, Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - Sua Myong
- Department of Biophysics, Johns Hopkins University, Baltimore, Maryland 21218, USA; .,Physics Frontier Center (Center for the Physics of Living Cells), University of Illinois, Urbana, Illinois 61801, USA
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29
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Cataloguing and Selection of mRNAs Localized to Dendrites in Neurons and Regulated by RNA-Binding Proteins in RNA Granules. Biomolecules 2020; 10:biom10020167. [PMID: 31978946 PMCID: PMC7072219 DOI: 10.3390/biom10020167] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 01/18/2020] [Accepted: 01/20/2020] [Indexed: 12/15/2022] Open
Abstract
Spatiotemporal translational regulation plays a key role in determining cell fate and function. Specifically, in neurons, local translation in dendrites is essential for synaptic plasticity and long-term memory formation. To achieve local translation, RNA-binding proteins in RNA granules regulate target mRNA stability, localization, and translation. To date, mRNAs localized to dendrites have been identified by comprehensive analyses. In addition, mRNAs associated with and regulated by RNA-binding proteins have been identified using various methods in many studies. However, the results obtained from these numerous studies have not been compiled together. In this review, we have catalogued mRNAs that are localized to dendrites and are associated with and regulated by the RNA-binding proteins fragile X mental retardation protein (FMRP), RNA granule protein 105 (RNG105, also known as Caprin1), Ras-GAP SH3 domain binding protein (G3BP), cytoplasmic polyadenylation element binding protein 1 (CPEB1), and staufen double-stranded RNA binding proteins 1 and 2 (Stau1 and Stau2) in RNA granules. This review provides comprehensive information on dendritic mRNAs, the neuronal functions of mRNA-encoded proteins, the association of dendritic mRNAs with RNA-binding proteins in RNA granules, and the effects of RNA-binding proteins on mRNA regulation. These findings provide insights into the mechanistic basis of protein-synthesis-dependent synaptic plasticity and memory formation and contribute to future efforts to understand the physiological implications of local regulation of dendritic mRNAs in neurons.
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30
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Wong LE, Kim TH, Muhandiram DR, Forman-Kay JD, Kay LE. NMR Experiments for Studies of Dilute and Condensed Protein Phases: Application to the Phase-Separating Protein CAPRIN1. J Am Chem Soc 2020; 142:2471-2489. [DOI: 10.1021/jacs.9b12208] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Leo E. Wong
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Tae Hun Kim
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
- Hospital for Sick Children, Program in Molecular Medicine, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada
| | - D. Ranjith Muhandiram
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Julie D. Forman-Kay
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
- Hospital for Sick Children, Program in Molecular Medicine, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada
| | - Lewis E. Kay
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
- Hospital for Sick Children, Program in Molecular Medicine, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada
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31
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Roy R, Shiina N, Wang DO. More dynamic, more quantitative, unexpectedly intricate: Advanced understanding on synaptic RNA localization in learning and memory. Neurobiol Learn Mem 2019; 168:107149. [PMID: 31881355 DOI: 10.1016/j.nlm.2019.107149] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 10/25/2019] [Accepted: 12/23/2019] [Indexed: 01/13/2023]
Abstract
Synaptic signaling exhibits great diversity, complexity, and plasticity which necessitates maintenance and rapid modification of a local proteome. One solution neurons actively exploit to meet such demands is the strategic deposition of mRNAs encoding proteins for both basal and experience-driven activities into ribonucleoprotein complexes at the synapse. Transcripts localized in this manner can be rapidly accessed for translation in response to a diverse range of stimuli in a temporal- and spatially-restricted manner. Here we review recent findings on localized RNAs and RNA binding proteins in the context of learning and memory, as revealed by cutting-edge in-vitro and in-vivo technologies capable of yielding quantitative and dynamic information. The new technologies include proteomic and transcriptomic analyses, high-resolution multiplexed RNA imaging, single-molecule RNA tracking in living neurons, animal models and human neuron cell models. Among many recent advances in the field, RNA chemical modification has emerged as one of the new regulatory layers of gene expression at synapse that is complex and yet largely unexplored. These exciting new discoveries have enhanced our understanding of the modulation mechanisms of synaptic gene expression and their roles in cognition.
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Affiliation(s)
- Rohini Roy
- Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University, Kyoto, Japan; Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Nobuyuki Shiina
- Laboratory of Neuronal Cell Biology, National Institute for Basic Biology, Okazaki, Japan; Department of Basic Biology, SOKENDAI, Okazaki, Japan; Exploratory Research Center on Life and Living Systems, Okazaki, Japan.
| | - Dan Ohtan Wang
- Wuya College of Innovation, Shenyang Pharmaceutical University, Liaoning, China; Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University, Kyoto, Japan; The Keihanshin Consortium for Fostering the Next Generation of Global Leaders in Research (K-CONNEX), Kyoto University, Kyoto, Japan.
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32
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Human Antiviral Protein MxA Forms Novel Metastable Membraneless Cytoplasmic Condensates Exhibiting Rapid Reversible Tonicity-Driven Phase Transitions. J Virol 2019; 93:JVI.01014-19. [PMID: 31484749 DOI: 10.1128/jvi.01014-19] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 08/28/2019] [Indexed: 12/13/2022] Open
Abstract
Phase-separated biomolecular condensates of proteins and nucleic acids form functional membrane-less organelles (e.g., stress granules and P-bodies) in the mammalian cell cytoplasm and nucleus. In contrast to the long-standing belief that interferon (IFN)-inducible human myxovirus resistance protein A (MxA) associated with the endoplasmic reticulum (ER) and Golgi apparatus, we report that MxA formed membraneless metastable (shape-changing) condensates in the cytoplasm. In our studies, we used the same cell lines and methods as those used by previous investigators but concluded that wild-type MxA formed variably sized spherical or irregular bodies, filaments, and even a reticulum distinct from that of ER/Golgi membranes. Moreover, in Huh7 cells, MxA structures associated with a novel cytoplasmic reticular meshwork of intermediate filaments. In live-cell assays, 1,6-hexanediol treatment led to rapid disassembly of green fluorescent protein (GFP)-MxA structures; FRAP revealed a relative stiffness with a mobile fraction of 0.24 ± 0.02 within condensates, consistent with a higher-order MxA network structure. Remarkably, in intact cells, GFP-MxA condensates reversibly disassembled/reassembled within minutes of sequential decrease/increase, respectively, in tonicity of extracellular medium, even in low-salt buffers adjusted only with sucrose. Condensates formed from IFN-α-induced endogenous MxA also displayed tonicity-driven disassembly/reassembly. In vesicular stomatitis virus (VSV)-infected Huh7 cells, the nucleocapsid (N) protein, which participates in forming phase-separated viral structures, associated with spherical GFP-MxA condensates in cells showing an antiviral effect. These observations prompt comparisons with the extensive literature on interactions between viruses and stress granules/P-bodies. Overall, the new data correct a long-standing misinterpretation in the MxA literature and provide evidence for membraneless MxA biomolecular condensates in the uninfected cell cytoplasm.IMPORTANCE There is a long-standing belief that interferon (IFN)-inducible human myxovirus resistance protein A (MxA), which displays antiviral activity against several RNA and DNA viruses, associates with the endoplasmic reticulum (ER) and Golgi apparatus. We provide data to correct this misinterpretation and further report that MxA forms membraneless metastable (shape-changing) condensates in the cytoplasm consisting of variably sized spherical or irregular bodies, filaments, and even a reticulum. Remarkably, MxA condensates showed the unique property of rapid (within 1 to 3 min) reversible disassembly and reassembly in intact cells exposed sequentially to hypotonic and isotonic conditions. Moreover, GFP-MxA condensates included the VSV nucleocapsid (N) protein, a protein previously shown to form liquid-like condensates. Since intracellular edema and ionic changes are hallmarks of cytopathic effects of a viral infection, the tonicity-driven regulation of MxA condensates may reflect a mechanism for modulation of MxA function during viral infection.
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33
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Oroz J, Laurents DV. RNA binding proteins: Diversity from microsurgeons to cowboys. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2019; 1862:194398. [PMID: 31271896 DOI: 10.1016/j.bbagrm.2019.06.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 06/03/2019] [Accepted: 06/13/2019] [Indexed: 01/21/2023]
Abstract
The conformation and mechanism of proteins that degrade and bind RNA, which has provided key insights into post-transcriptional gene regulation, is explored here. During the twentieth century's last decades, the characterization of ribonucleases and RNA binding domains revealed the diversity of their reaction mechanisms and modes of RNA recognition, and the bases of protein folding, substrate specificity and binding affinity. More recent research showed how these domains combine through oligomerization or genetic recombination to create larger proteins with highly specific and readily programmable ribonucleolytic activity. In the last 15 years, the study of the capacity of proteins, usually disordered, to pool RNAs into discrete, non-aqueous microdroplets to facilitate their transport, modification and degradation - analogous to cowboys herding cattle - has advanced our comprehension of gene expression. Finally, the current uses of RNA binding proteins and the future applications of protein/RNA microdroplets are highlighted.
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Affiliation(s)
- Javier Oroz
- "Rocasolano" Institute of Physical Chemistry, Spanish National Research Council, Serrano 119, Madrid 28006, Spain
| | - Douglas V Laurents
- "Rocasolano" Institute of Physical Chemistry, Spanish National Research Council, Serrano 119, Madrid 28006, Spain.
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