1
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Kharel P, Ivanov P. RNA G-quadruplexes and stress: emerging mechanisms and functions. Trends Cell Biol 2024:S0962-8924(24)00005-9. [PMID: 38341346 DOI: 10.1016/j.tcb.2024.01.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 12/27/2023] [Accepted: 01/12/2024] [Indexed: 02/12/2024]
Abstract
RNA G-quadruplexes (rG4s) are noncanonical secondary structures formed by guanine-rich sequences that are found in different regions of RNA molecules. These structures have been implicated in diverse biological processes, including translation, splicing, and RNA stability. Recent studies have suggested that rG4s play a role in the cellular response to stress. This review summarizes the current knowledge on rG4s under stress, focusing on their formation, regulation, and potential functions in stress response pathways. We discuss the molecular mechanisms that regulate the formation of rG4 under different stress conditions and the impact of these structures on RNA metabolism, gene expression, and cell survival. Finally, we highlight the potential therapeutic implications of targeting rG4s for the treatment of stress-related diseases through modulating cell survival.
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Affiliation(s)
- Prakash Kharel
- Division of Rheumatology, Inflammation, and Immunity, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
| | - Pavel Ivanov
- Division of Rheumatology, Inflammation, and Immunity, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA; HMS Initiative for RNA Medicine, Boston, MA 02115, USA.
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2
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Hu S, Zhang Y, Yi Q, Yang C, Liu Y, Bai Y. Time-resolved proteomic profiling reveals compositional and functional transitions across the stress granule life cycle. Nat Commun 2023; 14:7782. [PMID: 38012130 PMCID: PMC10682001 DOI: 10.1038/s41467-023-43470-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 11/09/2023] [Indexed: 11/29/2023] Open
Abstract
Stress granules (SGs) are dynamic, membrane-less organelles. With their formation and disassembly processes characterized, it remains elusive how compositional transitions are coordinated during prolonged stress to meet changing functional needs. Here, using time-resolved proteomic profiling of the acute to prolonged heat-shock SG life cycle, we identify dynamic SG proteins, further segregated into early and late proteins. Comparison of different groups of SG proteins suggests that their biochemical properties help coordinate SG compositional and functional transitions. In particular, early proteins, with high phase-separation-propensity, drive the rapid formation of the initial SG platform, while late proteins are subsequently recruited as discrete modules to further functionalize SGs. This model, supported by immunoblotting and immunofluorescence imaging, provides a conceptual framework for the compositional transitions throughout the acute to prolonged SG life cycle. Additionally, an early SG constituent, non-muscle myosin II, is shown to promote SG formation by increasing SG fusion, underscoring the strength of this dataset in revealing the complexity of SG regulation.
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Affiliation(s)
- Shuyao Hu
- School of Life Science and Technology, ShanghaiTech University, 201210, Shanghai, China.
| | - Yufeng Zhang
- School of Life Science and Technology, ShanghaiTech University, 201210, Shanghai, China
| | - Qianqian Yi
- School of Life Science and Technology, ShanghaiTech University, 201210, Shanghai, China
| | - Cuiwei Yang
- School of Life Science and Technology, ShanghaiTech University, 201210, Shanghai, China
| | - Yanfen Liu
- School of Life Science and Technology, ShanghaiTech University, 201210, Shanghai, China.
| | - Yun Bai
- School of Life Science and Technology, ShanghaiTech University, 201210, Shanghai, China.
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3
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Jung DM, Kwon E, Choi S, Kim KK. 1,2,4-trihydroxybenzene induces stress granule formation and causes DNA damage in human keratinocytes. Toxicol In Vitro 2023; 92:105638. [PMID: 37406782 DOI: 10.1016/j.tiv.2023.105638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 04/26/2023] [Accepted: 06/29/2023] [Indexed: 07/07/2023]
Abstract
Household chemical products are typically evaluated for toxicity through ingestion and inhalation, with limited information on skin absorption. Furthermore, current research focuses on the long-term toxic effects of harmful substances contained in these household chemical products, however not much is known about their acute toxic effects. In this study, the effects of 1,2,4-trihydroxybenzene (THB) in human keratinocytes by examining its effects on stress granule (SG) formation, a marker of acute stress response, and DNA double strand breaks caused by repeated exposure. THB effectively induced SG formation via endoplasmic reticulum stress-mediated eIF2α phosphorylation in keratinocytes. Furthermore, repeated exposure to THB causes apoptotic cell death due to DNA double strand breaks. Collectively, THB exposure leads to skin toxicity, suggesting precautions for the use of THB-containing household chemical products.
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Affiliation(s)
- Da-Min Jung
- Department of Biochemistry, College of Natural Sciences, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Eunhye Kwon
- Department of Biochemistry, College of Natural Sciences, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Sunkyung Choi
- Department of Biochemistry, College of Natural Sciences, Chungnam National University, Daejeon 34134, Republic of Korea.
| | - Kee K Kim
- Department of Biochemistry, College of Natural Sciences, Chungnam National University, Daejeon 34134, Republic of Korea.
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4
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Magg V, Klein P, Ruggieri A. Monitoring Virus-Induced Stress Granule Dynamics Using Long-Term Live-Cell Imaging. Methods Mol Biol 2022; 2428:325-348. [PMID: 35171489 DOI: 10.1007/978-1-0716-1975-9_20] [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] [Indexed: 06/14/2023]
Abstract
The integrated stress response is a highly regulated signaling cascade that allows cells to react to a variety of external and internal stimuli. Activation of different stress-responsive kinases leads to the phosphorylation of their common downstream target, the eukaryotic translation initiation factor 2 alpha (eIF2α), which is a critical component of functional translation preinitiation complexes. As a consequence, stalled ribonucleoprotein complexes accumulate in the cytoplasm and condense into microscopically visible cytoplasmic stress granules (SGs). Over the past years, numerous microscopy approaches have been developed to study the spatiotemporal control of SG formation in response to a variety of stressors. Here, we apply long-term live-cell microscopy to monitor the dynamic cellular stress response triggered by infection with chronic hepatitis C virus (HCV) at single-cell level and study the behavior of infected cells that repeatedly switch between a stressed and unstressed state. We describe in detail the engineering of fluorescent SG-reporter cells expressing enhanced yellow fluorescent protein (YFP)-tagged T cell internal antigen 1 (TIA-1) using lentiviral delivery, as well as the production of mCherry-tagged HCV trans-complemented particles, which allow live tracking of SG assembly and disassembly, SG number and size in single infected cells over time.
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Affiliation(s)
- Vera Magg
- Department of Infectious Diseases, Molecular Virology, Center for Integrative Infectious Disease Research (CIID), Heidelberg University, Heidelberg, Germany
| | - Philipp Klein
- Department of Infectious Diseases, Molecular Virology, Center for Integrative Infectious Disease Research (CIID), Heidelberg University, Heidelberg, Germany
| | - Alessia Ruggieri
- Department of Infectious Diseases, Molecular Virology, Center for Integrative Infectious Disease Research (CIID), Heidelberg University, Heidelberg, Germany.
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5
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Fuller GG, Han T, Freeberg MA, Moresco JJ, Ghanbari Niaki A, Roach NP, Yates JR, Myong S, Kim JK. RNA promotes phase separation of glycolysis enzymes into yeast G bodies in hypoxia. eLife 2020; 9:e48480. [PMID: 32298230 PMCID: PMC7162659 DOI: 10.7554/elife.48480] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 03/31/2020] [Indexed: 12/20/2022] Open
Abstract
In hypoxic stress conditions, glycolysis enzymes assemble into singular cytoplasmic granules called glycolytic (G) bodies. G body formation in yeast correlates with increased glucose consumption and cell survival. However, the physical properties and organizing principles that define G body formation are unclear. We demonstrate that glycolysis enzymes are non-canonical RNA binding proteins, sharing many common mRNA substrates that are also integral constituents of G bodies. Targeting nonspecific endoribonucleases to G bodies reveals that RNA nucleates G body formation and maintains its structural integrity. Consistent with a phase separation mechanism of biogenesis, recruitment of glycolysis enzymes to G bodies relies on multivalent homotypic and heterotypic interactions. Furthermore, G bodies fuse in vivo and are largely insensitive to 1,6-hexanediol, consistent with a hydrogel-like composition. Taken together, our results elucidate the biophysical nature of G bodies and demonstrate that RNA nucleates phase separation of the glycolysis machinery in response to hypoxic stress.
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Affiliation(s)
- Gregory G Fuller
- Department of Biology, Johns Hopkins UniversityBaltimoreUnited States
| | - Ting Han
- National Institute of Biological SciencesBeijingChina
| | | | - James J Moresco
- Department of Chemical Physiology, The Scripps Research InstituteLa JollaUnited States
| | | | - Nathan P Roach
- Department of Biology, Johns Hopkins UniversityBaltimoreUnited States
| | - John R Yates
- Department of Chemical Physiology, The Scripps Research InstituteLa JollaUnited States
| | - Sua Myong
- Department of Biophysics, Johns Hopkins UniversityBaltimoreUnited States
| | - John K Kim
- Department of Biology, Johns Hopkins UniversityBaltimoreUnited States
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6
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Puumala and Andes Orthohantaviruses Cause Transient Protein Kinase R-Dependent Formation of Stress Granules. J Virol 2020; 94:JVI.01168-19. [PMID: 31723021 DOI: 10.1128/jvi.01168-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 11/06/2019] [Indexed: 02/06/2023] Open
Abstract
Virus infection frequently triggers host cell stress signaling resulting in translational arrest; as a consequence, many viruses employ means to modulate the host stress response. Hantaviruses are negative-sense, single-stranded RNA viruses known to inhibit host innate immune responses and apoptosis, but their impact on host cell stress signaling remains largely unknown. In this study, we investigated activation of host cell stress responses during hantavirus infection. We show that hantavirus infection causes transient formation of stress granules (SGs) but does so in only a limited proportion of infected cells. Our data indicate some cell type-specific and hantavirus species-specific variability in SG prevalence and show SG formation to be dependent on the activation of protein kinase R (PKR). Hantavirus infection inhibited PKR-dependent SG formation, which could account for the transient nature and low prevalence of SG formation observed during hantavirus infection. In addition, we report only limited colocalization of hantaviral proteins or RNA with SGs and show evidence indicating hantavirus-mediated inhibition of PKR-like endoplasmic reticulum (ER) kinase (PERK).IMPORTANCE Our work presents the first report on stress granule formation during hantavirus infection. We show that hantavirus infection actively inhibits stress granule formation, thereby escaping the detrimental effects on global translation imposed by host stress signaling. Our results highlight a previously uncharacterized aspect of hantavirus-host interactions with possible implications for how hantaviruses are able to cause persistent infection in natural hosts and for pathogenesis.
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7
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Götte B, Panas MD, Hellström K, Liu L, Samreen B, Larsson O, Ahola T, McInerney GM. Separate domains of G3BP promote efficient clustering of alphavirus replication complexes and recruitment of the translation initiation machinery. PLoS Pathog 2019; 15:e1007842. [PMID: 31199850 PMCID: PMC6594655 DOI: 10.1371/journal.ppat.1007842] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Revised: 06/26/2019] [Accepted: 05/15/2019] [Indexed: 12/15/2022] Open
Abstract
G3BP-1 and -2 (hereafter referred to as G3BP) are multifunctional RNA-binding proteins involved in stress granule (SG) assembly. Viruses from diverse families target G3BP for recruitment to replication or transcription complexes in order to block SG assembly but also to acquire pro-viral effects via other unknown functions of G3BP. The Old World alphaviruses, including Semliki Forest virus (SFV) and chikungunya virus (CHIKV) recruit G3BP into viral replication complexes, via an interaction between FGDF motifs in the C-terminus of the viral non-structural protein 3 (nsP3) and the NTF2-like domain of G3BP. To study potential proviral roles of G3BP, we used human osteosarcoma (U2OS) cell lines lacking endogenous G3BP generated using CRISPR-Cas9 and reconstituted with a panel of G3BP1 mutants and truncation variants. While SFV replicated with varying efficiency in all cell lines, CHIKV could only replicate in cells expressing G3BP1 variants containing both the NTF2-like and the RGG domains. The ability of SFV to replicate in the absence of G3BP allowed us to study effects of different domains of the protein. We used immunoprecipitation to demonstrate that that both NTF2-like and RGG domains are necessary for the formation a complex between nsP3, G3BP1 and the 40S ribosomal subunit. Electron microscopy of SFV-infected cells revealed that formation of nsP3:G3BP1 complexes via the NTF2-like domain was necessary for clustering of cytopathic vacuoles (CPVs) and that the presence of the RGG domain was necessary for accumulation of electron dense material containing G3BP1 and nsP3 surrounding the CPV clusters. Clustered CPVs also exhibited localised high levels of translation of viral mRNAs as detected by ribopuromycylation staining. These data confirm that G3BP is a ribosomal binding protein and reveal that alphaviral nsP3 uses G3BP to concentrate viral replication complexes and to recruit the translation initiation machinery, promoting the efficient translation of viral mRNAs. In order to repel viral infections, cells activate stress responses. One such response involves inhibition of translation and restricted availability of the translation machinery via the formation of stress granules. However, the host translation machinery is absolutely essential for synthesis of viral proteins and consequently viruses have developed a broad spectrum of strategies to circumvent this restriction. Old World alphaviruses, such as Semliki Forest virus (SFV) and chikungunya virus (CHIKV), interfere with stress granule formation by sequestration of G3BP, a stress granule nucleating protein, mediated by the viral non-structural protein 3 (nsP3). Here we show that nsP3:G3BP complexes engage factors of the host translation machinery, which during the course of infection accumulate in the vicinity of viral replication complexes. Accordingly, we demonstrate that the nsP3:G3BP interaction is required for high localized translational activity around viral replication complexes. We find the RGG domain of G3BP to be essential for the recruitment of the host translation machinery. In cells expressing mutant G3BP lacking the RGG domain, SFV replication was attenuated, but detectable, while CHIKV was essentially non-viable. Our data demonstrate a novel mechanism by which viruses can recruit factors of the translation machinery in a G3BP-dependent manner.
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MESH Headings
- Adaptor Proteins, Signal Transducing
- Animals
- Carrier Proteins/genetics
- Carrier Proteins/metabolism
- Cell Line, Tumor
- Chikungunya Fever/genetics
- Chikungunya Fever/metabolism
- Chikungunya Fever/pathology
- Chikungunya virus/physiology
- Cricetinae
- DNA Helicases/genetics
- DNA Helicases/metabolism
- Humans
- Peptide Chain Initiation, Translational
- Poly-ADP-Ribose Binding Proteins/genetics
- Poly-ADP-Ribose Binding Proteins/metabolism
- Protein Domains
- RNA Helicases/genetics
- RNA Helicases/metabolism
- RNA Recognition Motif Proteins/genetics
- RNA Recognition Motif Proteins/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Viral/genetics
- RNA, Viral/metabolism
- RNA-Binding Proteins
- Ribosome Subunits, Small, Eukaryotic/genetics
- Ribosome Subunits, Small, Eukaryotic/metabolism
- Semliki forest virus/physiology
- Virus Replication
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Affiliation(s)
- Benjamin Götte
- Department of Microbiology, Tumor and Cell Biology, Biomedicum, Karolinska Institutet, Stockholm, Sweden
| | - Marc D. Panas
- Department of Microbiology, Tumor and Cell Biology, Biomedicum, Karolinska Institutet, Stockholm, Sweden
| | - Kirsi Hellström
- University of Helsinki, Department of Microbiology, Faculty of Agriculture and Forestry, Helsinki, Finland
| | - Lifeng Liu
- Department of Microbiology, Tumor and Cell Biology, Biomedicum, Karolinska Institutet, Stockholm, Sweden
| | - Baila Samreen
- Department of Oncology-Pathology, Science for Life Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Ola Larsson
- Department of Oncology-Pathology, Science for Life Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Tero Ahola
- University of Helsinki, Department of Microbiology, Faculty of Agriculture and Forestry, Helsinki, Finland
- * E-mail: (GMM); (TA)
| | - Gerald M. McInerney
- Department of Microbiology, Tumor and Cell Biology, Biomedicum, Karolinska Institutet, Stockholm, Sweden
- * E-mail: (GMM); (TA)
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8
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Rayman JB, Karl KA, Kandel ER. TIA-1 Self-Multimerization, Phase Separation, and Recruitment into Stress Granules Are Dynamically Regulated by Zn 2. Cell Rep 2019; 22:59-71. [PMID: 29298433 DOI: 10.1016/j.celrep.2017.12.036] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 11/08/2017] [Accepted: 12/11/2017] [Indexed: 01/09/2023] Open
Abstract
Stress granules are non-membranous structures that transiently form in the cytoplasm during cellular stress, where they promote translational repression of non-essential RNAs and modulate cell signaling by sequestering key signal transduction proteins. These and other functions of stress granules facilitate an adaptive cellular response to environmental adversity. A key component of stress granules is the prion-related RNA-binding protein, T cell intracellular antigen-1 (TIA-1). Here, we report that recombinant TIA-1 undergoes rapid multimerization and phase separation in the presence of divalent zinc, which can be reversed by the zinc chelator, TPEN. Similarly, the formation and maintenance of TIA-1-positive stress granules in arsenite-treated cells are inhibited by TPEN. In addition, Zn2+ is released in cells treated with arsenite, before stress granule formation. These findings suggest that Zn2+ is a physiological ligand of TIA-1, acting as a stress-inducible second messenger to promote multimerization of TIA-1 and subsequent localization into stress granules.
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Affiliation(s)
- Joseph B Rayman
- Department of Neuroscience, College of Physicians and Surgeons of Columbia University, New York, NY 10032, USA; Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10032, USA
| | - Kevin A Karl
- Department of Neuroscience, College of Physicians and Surgeons of Columbia University, New York, NY 10032, USA; Howard Hughes Medical Institute at Columbia University, New York, NY 10032, USA; Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10032, USA
| | - Eric R Kandel
- Department of Neuroscience, College of Physicians and Surgeons of Columbia University, New York, NY 10032, USA; Department of Psychiatry, College of Physicians and Surgeons of Columbia University, New York, NY 10032, USA; Howard Hughes Medical Institute at Columbia University, New York, NY 10032, USA; Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10032, USA; Kavli Institute for Brain Science, Columbia University, New York, NY 10032, USA.
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9
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Wilbertz JH, Voigt F, Horvathova I, Roth G, Zhan Y, Chao JA. Single-Molecule Imaging of mRNA Localization and Regulation during the Integrated Stress Response. Mol Cell 2019; 73:946-958.e7. [PMID: 30661979 DOI: 10.1016/j.molcel.2018.12.006] [Citation(s) in RCA: 102] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 10/24/2018] [Accepted: 12/11/2018] [Indexed: 12/31/2022]
Abstract
Biological phase transitions form membrane-less organelles that generate distinct cellular environments. How molecules are partitioned between these compartments and the surrounding cellular space and the functional consequence of this localization is not well understood. Here, we report the localization of mRNA to stress granules (SGs) and processing bodies (PBs) and its effect on translation and degradation during the integrated stress response. Using single mRNA imaging in living human cells, we find that the interactions of mRNAs with SGs and PBs have different dynamics, very few mRNAs directly move between SGs and PBs, and that specific RNA-binding proteins can anchor mRNAs within these compartments. During recovery from stress, we show that mRNAs that were within SGs and PBs are translated and degraded at similar rates as their cytosolic counterparts. Our work provides a framework for using single-molecule measurements to directly investigate the molecular mechanisms of phase-separated compartments within their cellular environment.
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Affiliation(s)
- Johannes H Wilbertz
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland; University of Basel, 4003 Basel, Switzerland
| | - Franka Voigt
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland
| | - Ivana Horvathova
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland; University of Basel, 4003 Basel, Switzerland
| | - Gregory Roth
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland
| | - Yinxiu Zhan
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland; University of Basel, 4003 Basel, Switzerland
| | - Jeffrey A Chao
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland.
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10
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Moon SL, Morisaki T, Khong A, Lyon K, Parker R, Stasevich TJ. Multicolour single-molecule tracking of mRNA interactions with RNP granules. Nat Cell Biol 2019; 21:162-168. [PMID: 30664789 PMCID: PMC6375083 DOI: 10.1038/s41556-018-0263-4] [Citation(s) in RCA: 129] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 12/10/2018] [Indexed: 12/11/2022]
Abstract
Ribonucleoprotein (RNP) granules are non-membrane-bound organelles that have critical roles in the stress response1,2, maternal messenger RNA storage3, synaptic plasticity4, tumour progression5,6 and neurodegeneration7-9. However, the dynamics of their mRNA components within and near the granule surface remain poorly characterized, particularly in the context and timing of mRNAs exiting translation. Herein, we used multicolour single-molecule tracking to quantify the precise timing and kinetics of single mRNAs as they exit translation and enter RNP granules during stress. We observed single mRNAs interacting with stress granules and P-bodies, with mRNAs moving bidirectionally between them. Although translating mRNAs only interact with RNP granules dynamically, non-translating mRNAs can form stable, and sometimes rigid, associations with RNP granules with stability increasing with both mRNA length and granule size. Live and fixed cell imaging demonstrated that mRNAs can extend beyond the protein surface of a stress granule, which may facilitate interactions between RNP granules. Thus, the recruitment of mRNPs to RNP granules involves dynamic, stable and extended interactions affected by translation status, mRNA length and granule size that collectively regulate RNP granule dynamics.
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Affiliation(s)
- Stephanie L Moon
- Department of Biochemistry, University of Colorado, Boulder, CO, USA
- Howard Hughes Medical Institute, University of Colorado, Boulder, CO, USA
| | - Tatsuya Morisaki
- Department of Biochemistry, Colorado State University, Fort Collins, CO, USA
| | - Anthony Khong
- Department of Biochemistry, University of Colorado, Boulder, CO, USA
- Howard Hughes Medical Institute, University of Colorado, Boulder, CO, USA
| | - Kenneth Lyon
- Department of Biochemistry, Colorado State University, Fort Collins, CO, USA
| | - Roy Parker
- Department of Biochemistry, University of Colorado, Boulder, CO, USA.
- Howard Hughes Medical Institute, University of Colorado, Boulder, CO, USA.
| | - Timothy J Stasevich
- Department of Biochemistry, Colorado State University, Fort Collins, CO, USA.
- World Research Hub Initiative, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan.
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11
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Kardyńska M, Paszek A, Śmieja J, Spiller D, Widłak W, White MRH, Paszek P, Kimmel M. Quantitative analysis reveals crosstalk mechanisms of heat shock-induced attenuation of NF-κB signaling at the single cell level. PLoS Comput Biol 2018; 14:e1006130. [PMID: 29708974 PMCID: PMC5945226 DOI: 10.1371/journal.pcbi.1006130] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 05/10/2018] [Accepted: 04/10/2018] [Indexed: 11/22/2022] Open
Abstract
Elevated temperature induces the heat shock (HS) response, which modulates cell proliferation, apoptosis, the immune and inflammatory responses. However, specific mechanisms linking the HS response pathways to major cellular signaling systems are not fully understood. Here we used integrated computational and experimental approaches to quantitatively analyze the crosstalk mechanisms between the HS-response and a master regulator of inflammation, cell proliferation, and apoptosis the Nuclear Factor κB (NF-κB) system. We found that populations of human osteosarcoma cells, exposed to a clinically relevant 43°C HS had an attenuated NF-κB p65 response to Tumor Necrosis Factor α (TNFα) treatment. The degree of inhibition of the NF-κB response depended on the HS exposure time. Mathematical modeling of single cells indicated that individual crosstalk mechanisms differentially encode HS-mediated NF-κB responses while being consistent with the observed population-level responses. In particular "all-or-nothing" encoding mechanisms were involved in the HS-dependent regulation of the IKK activity and IκBα phosphorylation, while others involving transport were "analogue". In order to discriminate between these mechanisms, we used live-cell imaging of nuclear translocations of the NF-κB p65 subunit. The single cell responses exhibited "all-or-nothing" encoding. While most cells did not respond to TNFα stimulation after a 60 min HS, 27% showed responses similar to those not receiving HS. We further demonstrated experimentally and theoretically that the predicted inhibition of IKK activity was consistent with the observed HS-dependent depletion of the IKKα and IKKβ subunits in whole cell lysates. However, a combination of "all-or-nothing" crosstalk mechanisms was required to completely recapitulate the single cell data. We postulate therefore that the heterogeneity of the single cell responses might be explained by the cell-intrinsic variability of HS-modulated IKK signaling. In summary, we show that high temperature modulates NF-κB responses in single cells in a complex and unintuitive manner, which needs to be considered in hyperthermia-based treatment strategies.
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Affiliation(s)
| | - Anna Paszek
- Systems Engineering Group, Silesian University of Technology, Gliwice, Poland
- System Microscopy Centre, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, United Kingdom
- Maria Skłodowska-Curie Institute–Oncology Center, Gliwice Branch, Gliwice, Poland
| | - Jarosław Śmieja
- Systems Engineering Group, Silesian University of Technology, Gliwice, Poland
| | - David Spiller
- System Microscopy Centre, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, United Kingdom
| | - Wiesława Widłak
- Maria Skłodowska-Curie Institute–Oncology Center, Gliwice Branch, Gliwice, Poland
| | - Michael R. H. White
- System Microscopy Centre, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, United Kingdom
| | - Pawel Paszek
- System Microscopy Centre, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, United Kingdom
| | - Marek Kimmel
- Systems Engineering Group, Silesian University of Technology, Gliwice, Poland
- Departments of Statistics and Bioengineering, Rice University, Houston, TX, United States of America
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12
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Mahboubi H, Stochaj U. Cytoplasmic stress granules: Dynamic modulators of cell signaling and disease. Biochim Biophys Acta Mol Basis Dis 2017; 1863:884-895. [PMID: 28095315 DOI: 10.1016/j.bbadis.2016.12.022] [Citation(s) in RCA: 185] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 12/15/2016] [Accepted: 12/26/2016] [Indexed: 12/14/2022]
Abstract
Stress granule (SG) assembly is a conserved cellular strategy to minimize stress-related damage and promote cell survival. Beyond their fundamental role in the stress response, SGs have emerged as key players for human health. As such, SG assembly is associated with cancer, neurodegenerative disorders, ischemia, and virus infections. SGs and granule-related signaling circuits are therefore promising targets to improve therapeutic intervention for several diseases. This is clinically relevant, because pharmacological drugs can affect treatment outcome by modulating SG formation. As membraneless and highly dynamic compartments, SGs regulate translation, ribostasis and proteostasis. Moreover, they serve as signaling hubs that determine cell viability and stress recovery. Various compounds can modulate SG formation and dynamics. Rewiring cell signaling through SG manipulation thus represents a new strategy to control cell fate under various physiological and pathological conditions.
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Affiliation(s)
- Hicham Mahboubi
- Department of Physiology, McGill University, Montreal, Canada
| | - Ursula Stochaj
- Department of Physiology, McGill University, Montreal, Canada.
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Gnazzo MM, Uhlemann EME, Villarreal AR, Shirayama M, Dominguez EG, Skop AR. The RNA-binding protein ATX-2 regulates cytokinesis through PAR-5 and ZEN-4. Mol Biol Cell 2016; 27:3052-3064. [PMID: 27559134 PMCID: PMC5063614 DOI: 10.1091/mbc.e16-04-0219] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 08/17/2016] [Indexed: 12/15/2022] Open
Abstract
The mechanisms that mediate the temporal and spatial recruitment of cell division factors to the spindle midzone and midbody remain unclear. Cell division is regulated by the conserved RNA-binding protein, ATX-2/Ataxin-2, which facilitates the targeting of ZEN-4 to the spindle midzone by mediating PAR-5. The spindle midzone harbors both microtubules and proteins necessary for furrow formation and the completion of cytokinesis. However, the mechanisms that mediate the temporal and spatial recruitment of cell division factors to the spindle midzone and midbody remain unclear. Here we describe a mechanism governed by the conserved RNA-binding protein ATX-2/Ataxin-2, which targets and maintains ZEN-4 at the spindle midzone. ATX-2 does this by regulating the amount of PAR-5 at mitotic structures, particularly the spindle, centrosomes, and midbody. Preventing ATX-2 function leads to elevated levels of PAR-5, enhanced chromatin and centrosome localization of PAR-5–GFP, and ultimately a reduction of ZEN-4–GFP at the spindle midzone. Codepletion of ATX-2 and PAR-5 rescued the localization of ZEN-4 at the spindle midzone, indicating that ATX-2 mediates the localization of ZEN-4 upstream of PAR-5. We provide the first direct evidence that ATX-2 is necessary for cytokinesis and suggest a model in which ATX-2 facilitates the targeting of ZEN-4 to the spindle midzone by mediating the posttranscriptional regulation of PAR-5.
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Affiliation(s)
- Megan M Gnazzo
- Laboratory of Genetics and Medical Genetics, University of Wisconsin-Madison, Madison, WI 53706
| | - Eva-Maria E Uhlemann
- Laboratory of Genetics and Medical Genetics, University of Wisconsin-Madison, Madison, WI 53706
| | - Alex R Villarreal
- Laboratory of Genetics and Medical Genetics, University of Wisconsin-Madison, Madison, WI 53706
| | - Masaki Shirayama
- Program in Molecular Medicine, RNA Therapeutics Institute, and Howard Hughes Medical Institute, University of Massachusetts Medical School, Worcester, MA 01605
| | - Eddie G Dominguez
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705
| | - Ahna R Skop
- Laboratory of Genetics and Medical Genetics, University of Wisconsin-Madison, Madison, WI 53706
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