151
|
Sudhakaran IP, Ramaswami M. Long-term memory consolidation: The role of RNA-binding proteins with prion-like domains. RNA Biol 2017; 14:568-586. [PMID: 27726526 PMCID: PMC5449092 DOI: 10.1080/15476286.2016.1244588] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 09/07/2016] [Accepted: 09/29/2016] [Indexed: 12/23/2022] Open
Abstract
Long-term and short-term memories differ primarily in the duration of their retention. At a molecular level, long-term memory (LTM) is distinguished from short-term memory (STM) by its requirement for new gene expression. In addition to transcription (nuclear gene expression) the translation of stored mRNAs is necessary for LTM formation. The mechanisms and functions for temporal and spatial regulation of mRNAs required for LTM is a major contemporary problem, of interest from molecular, cell biological, neurobiological and clinical perspectives. This review discusses primary evidence in support for translational regulatory events involved in LTM and a model in which different phases of translation underlie distinct phases of consolidation of memories. However, it focuses largely on mechanisms of memory persistence and the role of prion-like domains in this defining aspect of long-term memory. We consider primary evidence for the concept that Cytoplasmic Polyadenylation Element Binding (CPEB) protein enables the persistence of formed memories by transforming in prion-like manner from a soluble monomeric state to a self-perpetuating and persistent polymeric translationally active state required for maintaining persistent synaptic plasticity. We further discuss prion-like domains prevalent on several other RNA-binding proteins involved in neuronal translational control underlying LTM. Growing evidence indicates that such RNA regulatory proteins are components of mRNP (RiboNucleoProtein) granules. In these proteins, prion-like domains, being intrinsically disordered, could mediate weak transient interactions that allow the assembly of RNP granules, a source of silenced mRNAs whose translation is necessary for LTM. We consider the structural bases for RNA granules formation as well as functions of disordered domains and discuss how these complicate the interpretation of existing experimental data relevant to general mechanisms by which prion-domain containing RBPs function in synapse specific plasticity underlying LTM.
Collapse
Affiliation(s)
- Indulekha P. Sudhakaran
- National Center for Biological Sciences, TIFR, Bangalore, India
- Manipal University, Manipal, India
| | - Mani Ramaswami
- National Center for Biological Sciences, TIFR, Bangalore, India
- School of Genetics and Microbiology and School of Natural Sciences, Smurfit Institute of Genetics and Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland
| |
Collapse
|
152
|
Mishra S, Nyomba BG. Prohibitin - At the crossroads of obesity-linked diabetes and cancer. Exp Biol Med (Maywood) 2017; 242:1170-1177. [PMID: 28399645 DOI: 10.1177/1535370217703976] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The promoter of a gene that is selectively expressed in just a few cell types provides unique opportunities to study: (1) the pleiotropic function of a protein in two different cell types including the cell compartment specific function, and (2) the crosstalk between two cell/tissue types at the systemic level. This is not possible with a ubiquitous or a highly specific gene promoter. The adipocyte protein-2 ( aP2) is one such gene. It is primarily expressed in adipocytes, but also selectively in monocytic macrophages and dendritic cells, among various immune cell types. Thus, the adipocyte protein-2 gene promoter provides an opportunity to simultaneously manipulate adipose and immune functions in a transgenic animal. Prohibitin (PHB) is a pleiotropic protein that has roles in both adipocytes and immune cells. Adipocyte specific functions of prohibitin are mediated through its mitochondrial function, whereas its immune functions are mediated in a phosphorylation-dependent manner. We capitalized on this attribute of prohibitin to explore the crosstalk between adipose and immune functions, and to discern mitochondrial and plasma membrane-associated cell signaling functions of prohibitin, by expressing wild type prohibitin (Mito-Ob) and a phospho-mutant form of prohibitin (m-Mito-Ob) from the protein-2 gene promoter, individually. Both transgenic mice develop obesity in a sex-neutral manner, but develop obesity-related metabolic dysregulation in a male sex-specific manner. Subsequently, the male Mito-Ob mice spontaneously developed type 2 diabetes and liver cancer, whereas the male m-Mito-Ob mice developed lymph node tumors or autoimmune diabetes in a context-dependent manner. This review provides a point of view on the role of prohibitin in mediating sex differences in adipose and immune functions at the systemic level. We discuss the unique attributes of prohibitin and provide a new paradigm in adipose-immune crosstalk mediated through a pleiotropic protein. Impact statement Prohibitin (PHB) is ubiquitously expressed and plays a role in adipocyte-immune cell cross-talk. Both male and female transgenic mice expressing wild-type PHB in adipose tissue and in macrophages are obese, but only males develop diabetes and liver cancer. When the mice express PHB mutated on tyrosine-114 in adipocytes and macrophages, both males and females are still obese, but none develops liver cancer; instead, males develop lymph node tumors. Adipocyte specific functions of PHB are mediated through its mitochondrial function, whereas its immune functions are mediated in a phosphorylation-dependent manner. Thus, PHB appears to be an important molecule linking obesity, diabetes, and cancer. In addition, this link appears to be affected by sex steroids. Therefore, targeting PHB may lead to a better understanding of the pathogenesis of obesity, diabetes and cancer.
Collapse
Affiliation(s)
- Suresh Mishra
- 1 Department of Internal Medicine, University of Manitoba, Winnipeg R3E3P4, Canada.,2 Department of Physiology & Pathophysiology, University of Manitoba, Winnipeg R3E3P4, Canada
| | - Bl Grégoire Nyomba
- 1 Department of Internal Medicine, University of Manitoba, Winnipeg R3E3P4, Canada
| |
Collapse
|
153
|
Alberti S, Mateju D, Mediani L, Carra S. Granulostasis: Protein Quality Control of RNP Granules. Front Mol Neurosci 2017; 10:84. [PMID: 28396624 PMCID: PMC5367262 DOI: 10.3389/fnmol.2017.00084] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 03/10/2017] [Indexed: 12/14/2022] Open
Abstract
Ribonucleoprotein (RNP) granules transport, store, or degrade messenger RNAs, thereby indirectly regulating protein synthesis. Normally, RNP granules are highly dynamic compartments. However, because of aging or severe environmental stress, RNP granules, in particular stress granules (SGs), convert into solid, aggregate-like inclusions. There is increasing evidence that such RNA-protein inclusions are associated with several age-related neurodegenerative diseases, such as amyotrophic lateral sclerosis (ALS), fronto-temporal dementia (FTD) and Alzheimer's disease (AD). Thus, understanding what triggers the conversion of RNP granules into aggregates and identifying the cellular players that control RNP granules will be critical to develop treatments for these diseases. In this review article, we discuss recent insight into RNP and SG formation. More specifically, we examine the evidence for liquid-liquid phase separation (LLPS) as an organizing principle of RNP granules and the role of aggregation-prone RNA-binding proteins (RBPs) in this process. We further discuss recent findings that liquid-like SGs can sequester misfolded proteins, which promote an aberrant conversion of liquid SGs into solid aggregates. Importantly, very recent studies show that a specific protein quality control (PQC) process prevents the accumulation of misfolding-prone proteins in SGs and, by doing so, maintains the dynamic state of SGs. This quality control process has been referred to as granulostasis and it relies on the specific action of the HSPB8-BAG3-HSP70 complex. Additional players such as p97/valosin containing protein (VCP) and other molecular chaperones (e.g., HSPB1) participate, directly or indirectly, in granulostasis, and ensure the timely elimination of defective ribosomal products and other misfolded proteins from SGs. Finally, we discuss recent findings that, in the stress recovery phase, SGs are preferentially disassembled with the assistance of chaperones, and we discuss evidence for a back-up system that targets aberrant SGs to the aggresome for autophagy-mediated clearance. Altogether the findings discussed here provide evidence for an intricate network of interactions between RNP granules and various components of the PQC machinery. Molecular chaperones in particular are emerging as key players that control the composition and dynamics of RNP granules, which may be important to protect against age-related diseases.
Collapse
Affiliation(s)
- Simon Alberti
- Alberti Lab, Max Planck Institute of Molecular Cell Biology and Genetics Dresden, Germany
| | - Daniel Mateju
- Alberti Lab, Max Planck Institute of Molecular Cell Biology and Genetics Dresden, Germany
| | - Laura Mediani
- Department of Biomedical, Metabolic and Neural Sciences, Center for Neuroscience and Nanotechnology, University of Modena and Reggio Emilia Modena, Italy
| | - Serena Carra
- Department of Biomedical, Metabolic and Neural Sciences, Center for Neuroscience and Nanotechnology, University of Modena and Reggio Emilia Modena, Italy
| |
Collapse
|
154
|
Rabouille C, Alberti S. Cell adaptation upon stress: the emerging role of membrane-less compartments. Curr Opin Cell Biol 2017; 47:34-42. [PMID: 28342303 DOI: 10.1016/j.ceb.2017.02.006] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 02/06/2017] [Accepted: 02/09/2017] [Indexed: 11/26/2022]
Abstract
Cells under stress transition from a growth to a quiescent state. The conventional thinking is that this is achieved through transcriptional programs, translational regulation, protein degradation, and post-translational modifications. However, there is an increasing realization that stress adaptation also goes along with dramatic changes in the architecture and organization of cells. In particular, it seems to involve the formation of membrane-less compartments and macromolecular assemblies. We propose that cells make widespread use of this ability to change macromolecular organization to adapt to stress conditions and protect themselves. Here, we address what triggers the formation of these assemblies under stress conditions. We present examples illustrating that in some cases, sophisticated signaling pathways transmit environmental fluctuations from the outside to the inside and in others, that external fluctuations directly affect the internal conditions in cells. We further argue that changes in the organization of the cytoplasm and the formation of membrane-less compartments have many advantages over other ways of altering protein function, such as protein degradation, translation or transcription. Furthermore, membrane-less compartments may act as protective devices for key cellular components.
Collapse
Affiliation(s)
- Catherine Rabouille
- Hubrecht Institute of the KNAW & UMC Utrecht, 3584 CT Utrecht, The Netherlands; Department of Cell Biology, UMC Groningen, The Netherlands.
| | - Simon Alberti
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany.
| |
Collapse
|
155
|
Dissecting the molecular mechanisms that impair stress granule formation in aging cells. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017; 1864:475-486. [DOI: 10.1016/j.bbamcr.2016.12.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 11/21/2016] [Accepted: 12/09/2016] [Indexed: 01/20/2023]
|
156
|
Lysine acetyltransferase NuA4 and acetyl-CoA regulate glucose-deprived stress granule formation in Saccharomyces cerevisiae. PLoS Genet 2017; 13:e1006626. [PMID: 28231279 PMCID: PMC5344529 DOI: 10.1371/journal.pgen.1006626] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 03/09/2017] [Accepted: 02/09/2017] [Indexed: 01/09/2023] Open
Abstract
Eukaryotic cells form stress granules under a variety of stresses, however the signaling pathways regulating their formation remain largely unknown. We have determined that the Saccharomyces cerevisiae lysine acetyltransferase complex NuA4 is required for stress granule formation upon glucose deprivation but not heat stress. Further, the Tip60 complex, the human homolog of the NuA4 complex, is required for stress granule formation in cancer cell lines. Surprisingly, the impact of NuA4 on glucose-deprived stress granule formation is partially mediated through regulation of acetyl-CoA levels, which are elevated in NuA4 mutants. While elevated acetyl-CoA levels suppress the formation of glucose-deprived stress granules, decreased acetyl-CoA levels enhance stress granule formation upon glucose deprivation. Further our work suggests that NuA4 regulates acetyl-CoA levels through the Acetyl-CoA carboxylase Acc1. Altogether this work establishes both NuA4 and the metabolite acetyl-CoA as critical signaling pathways regulating the formation of glucose-deprived stress granules.
Collapse
|
157
|
Malek R, Wang H, Taparra K, Tran PT. Therapeutic Targeting of Epithelial Plasticity Programs: Focus on the Epithelial-Mesenchymal Transition. Cells Tissues Organs 2017; 203:114-127. [PMID: 28214899 DOI: 10.1159/000447238] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/27/2016] [Indexed: 12/14/2022] Open
Abstract
Mounting data points to epithelial plasticity programs such as the epithelial-mesenchymal transition (EMT) as clinically relevant therapeutic targets for the treatment of malignant tumors. In addition to the widely realized role of EMT in increasing cancer cell invasiveness during cancer metastasis, the EMT has also been implicated in allowing cancer cells to avoid tumor suppressor pathways during early tumorigenesis. In addition, data linking EMT to innate and acquired treatment resistance further points towards the desire to develop pharmacological therapies to target epithelial plasticity in cancer. In this review we organized our discussion on pathways and agents that can be used to target the EMT in cancer into 3 groups: (1) extracellular inducers of EMT, (2) the transcription factors that orchestrate the EMT transcriptome, and (3) the downstream effectors of EMT. We highlight only briefly specific canonical pathways known to be involved in EMT, such as the signal transduction pathways TGFβ, EFGR, and Axl-Gas6. We emphasize in more detail pathways that we believe are emerging novel pathways and therapeutic targets such as epigenetic therapies, glycosylation pathways, and immunotherapy. The heterogeneity of tumors and the dynamic nature of epithelial plasticity in cancer cells make it likely that targeting only 1 EMT-related process will be unsuccessful or only transiently successful. We suggest that with greater understanding of epithelial plasticity regulation, such as with the EMT, a more systematic targeting of multiple EMT regulatory networks will be the best path forward to improve cancer outcomes.
Collapse
Affiliation(s)
- Reem Malek
- Department of Radiation Oncology and Molecular Radiation Sciences, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | | | | | | |
Collapse
|
158
|
Disruption of Stress Granule Formation by the Multifunctional Cricket Paralysis Virus 1A Protein. J Virol 2017; 91:JVI.01779-16. [PMID: 28003491 DOI: 10.1128/jvi.01779-16] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Accepted: 12/15/2016] [Indexed: 12/26/2022] Open
Abstract
Stress granules (SGs) are cytosolic ribonucleoprotein aggregates that are induced during cellular stress. Several viruses modulate SG formation, suggesting that SGs have an impact on virus infection. However, the mechanisms and impact of modulating SG assembly in infected cells are not completely understood. In this study, we identify the dicistrovirus cricket paralysis virus 1A (CrPV-1A) protein that functions to inhibit SG assembly during infection. Moreover, besides inhibiting RNA interference, CrPV-1A also inhibits host transcription, which indirectly modulates SG assembly. Thus, CrPV-1A is a multifunctional protein. We identify a key R146A residue that is responsible for these effects, and mutant CrPV(R146A) virus infection is attenuated in Drosophila melanogaster S2 cells and adult fruit flies and results in increased SG formation. Treatment of CrPV(R146A)-infected cells with actinomycin D, which represses transcription, restores SG assembly suppression and viral yield. In summary, CrPV-1A modulates several cellular processes to generate a cellular environment that promotes viral translation and replication.IMPORTANCE RNA viruses encode a limited set of viral proteins to modulate an array of cellular processes in order to facilitate viral replication and inhibit antiviral defenses. In this study, we identified a viral protein, called CrPV-1A, within the dicistrovirus cricket paralysis virus that can inhibit host transcription, modulate viral translation, and block a cellular process called stress granule assembly. We also identified a specific amino acid within CrPV-1A that is important for these cellular processes and that mutant viruses containing mutations of CrPV-1A attenuate virus infection. We also demonstrate that the CrPV-1A protein can also modulate cellular processes in human cells, suggesting that the mode of action of CrPV-1A is conserved. We propose that CrPV-1A is a multifunctional, versatile protein that creates a cellular environment in virus-infected cells that permits productive virus infection.
Collapse
|
159
|
Kim EJ, Bond MR, Nam G, Hanover JA. Evaluation of the Chemical Reporter Analog PNP-6AzGlcNAc as an O-GlcNAcase Substrate. B KOREAN CHEM SOC 2017. [DOI: 10.1002/bkcs.11076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Eun J. Kim
- Department of Science Education-Chemistry Major; Daegu University; GyeongBuk 712-714 S. Korea
| | - Michelle R. Bond
- Laboratory of Cell Biochemistry and Biology; NIDDK, National Institute of Health; Bethesda MD 20892 USA
| | - Ghilsoo Nam
- Center for Neuro-Medicine, Brain Science Institute, Korea Institute of Science and Technology; Seoul 136-791 S. Korea
| | - John A. Hanover
- Laboratory of Cell Biochemistry and Biology; NIDDK, National Institute of Health; Bethesda MD 20892 USA
| |
Collapse
|
160
|
Kim JA, Jayabalan AK, Kothandan VK, Mariappan R, Kee Y, Ohn T. Identification of Neuregulin-2 as a novel stress granule component. BMB Rep 2017; 49:449-54. [PMID: 27345716 PMCID: PMC5070733 DOI: 10.5483/bmbrep.2016.49.8.090] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Indexed: 01/09/2023] Open
Abstract
Stress Granules (SGs) are microscopically visible, phase dense aggregates of translationally stalled messenger ribonucleoprotein (mRNP) complexes formed in response to distinct stress conditions. It is generally considered that SG formation is induced to protect cells from conditions of stress. The precise constituents of SGs and the mechanism through which SGs are dynamically regulated in response to stress are not completely understood. Hence, it is important to identify proteins which regulate SG assembly and disassembly. In the present study, we report Neuregulin-2 (NRG2) as a novel component of SGs; furthermore, depletion of NRG2 potently inhibits SG formation. We also demonstrate that NRG2 specifically localizes to SGs under various stress conditions. Knockdown of NRG2 has no effect on stress-induced polysome disassembly, suggesting that the component does not influence early step of SG formation. It was also observed that reduced expression of NRG2 led to marginal increase in cell survival under arsenite-induced stress. [BMB Reports 2016; 49(8): 449-454]
Collapse
Affiliation(s)
- Jin Ah Kim
- Department of Cellular & Molecular Medicine, College of Medicine, Chosun University, Gwangju 61452, Korea
| | - Aravinth Kumar Jayabalan
- Department of Cellular & Molecular Medicine, College of Medicine, Chosun University, Gwangju 61452, Korea
| | - Vinoth Kumar Kothandan
- Department of Cellular & Molecular Medicine, College of Medicine, Chosun University, Gwangju 61452, Korea
| | - Ramesh Mariappan
- Department of Cellular & Molecular Medicine, College of Medicine, Chosun University, Gwangju 61452, Korea
| | - Younghoon Kee
- Department of Cell Biology, Microbiology, and Molecular Biology, College of Arts and Sciences, University of South Florida, Tampa, Florida 33620, USA
| | - Takbum Ohn
- Department of Cellular & Molecular Medicine, College of Medicine, Chosun University, Gwangju 61452, Korea
| |
Collapse
|
161
|
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: 187] [Impact Index Per Article: 26.7] [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.
Collapse
Affiliation(s)
- Hicham Mahboubi
- Department of Physiology, McGill University, Montreal, Canada
| | - Ursula Stochaj
- Department of Physiology, McGill University, Montreal, Canada.
| |
Collapse
|
162
|
Le Sage V, Cinti A, McCarthy S, Amorim R, Rao S, Daino GL, Tramontano E, Branch DR, Mouland AJ. Ebola virus VP35 blocks stress granule assembly. Virology 2016; 502:73-83. [PMID: 28013103 DOI: 10.1016/j.virol.2016.12.012] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 12/08/2016] [Accepted: 12/12/2016] [Indexed: 10/20/2022]
Abstract
Stress granules (SGs) are dynamic cytoplasmic aggregates of translationally silenced mRNAs that assemble in response to environmental stress. SGs appear to play an important role in antiviral innate immunity and many viruses have evolved to block or subvert SGs components for their own benefit. Here, we demonstrate that intracellular Ebola virus (EBOV) replication and transcription-competent virus like particles (trVLP) infection does not lead to SG assembly but leads to a blockade to Arsenite-induced SG assembly. Moreover we show that EBOV VP35 represses the assembly of canonical and non-canonical SGs induced by a variety of pharmacological stresses. This SG blockade requires, at least in part, the C-terminal domain of VP35. Furthermore, results from our co-immunoprecipitation studies indicate that VP35 interacts with multiple SG components, including G3BP1, eIF3 and eEF2 through a stress- and RNA-independent mechanism. These data suggest a novel function for EBOV VP35 in the repression of SG assembly.
Collapse
Affiliation(s)
- Valerie Le Sage
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute at the Jewish General Hospital, Montréal, Québec, Canada H3T 1E2
| | - Alessandro Cinti
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute at the Jewish General Hospital, Montréal, Québec, Canada H3T 1E2; Department of Medicine, McGill University, Montréal, Québec, Canada H3A 0G4
| | - Stephen McCarthy
- Centre for Innovation, Canadian Blood Services, Toronto, Ontario, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Ontario, Toronto, Canada
| | - Raquel Amorim
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute at the Jewish General Hospital, Montréal, Québec, Canada H3T 1E2; Department of Medicine, McGill University, Montréal, Québec, Canada H3A 0G4
| | - Shringar Rao
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute at the Jewish General Hospital, Montréal, Québec, Canada H3T 1E2; Department of Microbiology and Immunology, McGill University, Montréal, Québec, Canada H3A 0G4
| | - Gian Luca Daino
- Department of Life and Environmental Sciences, University of Cagliari, Cittadella Universitaria di Monserrato, SS 554, 09042 Monserrato, Cagliari, Italy
| | - Enzo Tramontano
- Department of Life and Environmental Sciences, University of Cagliari, Cittadella Universitaria di Monserrato, SS 554, 09042 Monserrato, Cagliari, Italy
| | - Donald R Branch
- Centre for Innovation, Canadian Blood Services, Toronto, Ontario, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Ontario, Toronto, Canada
| | - Andrew J Mouland
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute at the Jewish General Hospital, Montréal, Québec, Canada H3T 1E2; Department of Medicine, McGill University, Montréal, Québec, Canada H3A 0G4; Department of Microbiology and Immunology, McGill University, Montréal, Québec, Canada H3A 0G4.
| |
Collapse
|
163
|
Loss of O-GlcNAc glycosylation in forebrain excitatory neurons induces neurodegeneration. Proc Natl Acad Sci U S A 2016; 113:15120-15125. [PMID: 27956640 DOI: 10.1073/pnas.1606899113] [Citation(s) in RCA: 142] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
O-GlcNAc glycosylation (or O-GlcNAcylation) is a dynamic, inducible posttranslational modification found on proteins associated with neurodegenerative diseases such as α-synuclein, amyloid precursor protein, and tau. Deletion of the O-GlcNAc transferase (ogt) gene responsible for the modification causes early postnatal lethality in mice, complicating efforts to study O-GlcNAcylation in mature neurons and to understand its roles in disease. Here, we report that forebrain-specific loss of OGT in adult mice leads to progressive neurodegeneration, including widespread neuronal cell death, neuroinflammation, increased production of hyperphosphorylated tau and amyloidogenic Aβ-peptides, and memory deficits. Furthermore, we show that human cortical brain tissue from Alzheimer's disease patients has significantly reduced levels of OGT protein expression compared with cortical tissue from control individuals. Together, these studies indicate that O-GlcNAcylation regulates pathways critical for the maintenance of neuronal health and suggest that dysfunctional O-GlcNAc signaling may be an important contributor to neurodegenerative diseases.
Collapse
|
164
|
Lee A, Miller D, Henry R, Paruchuri VDP, O'Meally RN, Boronina T, Cole RN, Zachara NE. Combined Antibody/Lectin Enrichment Identifies Extensive Changes in the O-GlcNAc Sub-proteome upon Oxidative Stress. J Proteome Res 2016; 15:4318-4336. [PMID: 27669760 DOI: 10.1021/acs.jproteome.6b00369] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
O-Linked N-acetyl-β-d-glucosamine (O-GlcNAc) is a dynamic post-translational modification that modifies and regulates over 3000 nuclear, cytoplasmic, and mitochondrial proteins. Upon exposure to stress and injury, cells and tissues increase the O-GlcNAc modification, or O-GlcNAcylation, of numerous proteins promoting the cellular stress response and thus survival. The aim of this study was to identify proteins that are differentially O-GlcNAcylated upon acute oxidative stress (H2O2) to provide insight into the mechanisms by which O-GlcNAc promotes survival. We achieved this goal by employing Stable Isotope Labeling of Amino Acids in Cell Culture (SILAC) and a novel "G5-lectibody" immunoprecipitation strategy that combines four O-GlcNAc-specific antibodies (CTD110.6, RL2, HGAC39, and HGAC85) and the lectin WGA. Using the G5-lectibody column in combination with basic reversed phase chromatography and C18 RPLC-MS/MS, 990 proteins were identified and quantified. Hundreds of proteins that were identified demonstrated increased (>250) or decreased (>110) association with the G5-lectibody column upon oxidative stress, of which we validated the O-GlcNAcylation status of 24 proteins. Analysis of proteins with altered glycosylation suggests that stress-induced changes in O-GlcNAcylation cluster into pathways known to regulate the cell's response to injury and include protein folding, transcriptional regulation, epigenetics, and proteins involved in RNA biogenesis. Together, these data suggest that stress-induced O-GlcNAcylation regulates numerous and diverse cellular pathways to promote cell and tissue survival.
Collapse
Affiliation(s)
- Albert Lee
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine , 725 North Wolfe Street, Baltimore, Maryland 21205-2185, United States
| | - Devin Miller
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine , 725 North Wolfe Street, Baltimore, Maryland 21205-2185, United States
| | - Roger Henry
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine , 725 North Wolfe Street, Baltimore, Maryland 21205-2185, United States
| | - Venkata D P Paruchuri
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine , 725 North Wolfe Street, Baltimore, Maryland 21205-2185, United States
| | - Robert N O'Meally
- Mass Spectrometry and Proteomics Facility, The Johns Hopkins University School of Medicine , 733 North Broadway Street, Baltimore, Maryland 21205-2185, United States
| | - Tatiana Boronina
- Mass Spectrometry and Proteomics Facility, The Johns Hopkins University School of Medicine , 733 North Broadway Street, Baltimore, Maryland 21205-2185, United States
| | - Robert N Cole
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine , 725 North Wolfe Street, Baltimore, Maryland 21205-2185, United States.,Mass Spectrometry and Proteomics Facility, The Johns Hopkins University School of Medicine , 733 North Broadway Street, Baltimore, Maryland 21205-2185, United States
| | - Natasha E Zachara
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine , 725 North Wolfe Street, Baltimore, Maryland 21205-2185, United States
| |
Collapse
|
165
|
Adjibade P, St-Sauveur VG, Quevillon Huberdeau M, Fournier MJ, Savard A, Coudert L, Khandjian EW, Mazroui R. Sorafenib, a multikinase inhibitor, induces formation of stress granules in hepatocarcinoma cells. Oncotarget 2016; 6:43927-43. [PMID: 26556863 PMCID: PMC4791277 DOI: 10.18632/oncotarget.5980] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 10/04/2015] [Indexed: 01/14/2023] Open
Abstract
Stress granules (SGs) are cytoplasmic RNA multimeric bodies that form under stress conditions known to inhibit translation initiation. In most reported stress cases, the formation of SGs was associated with the cell recovery from stress and survival. In cells derived from cancer, SGs formation was shown to promote resistance to either proteasome inhibitors or 5-Fluorouracil used as chemotherapeutic agents. Despite these studies, the induction of SGs by chemotherapeutic drugs contributing to cancer cells resistance is still understudied. Here we identified sorafenib, a tyrosine kinase inhibitor used to treat hepatocarcinoma, as a potent chemotherapeutic inducer of SGs. The formation of SGs in sorafenib-treated hepatocarcionoma cells correlates with inhibition of translation initiation; both events requiring the phosphorylation of the translation initiation factor eIF2α. Further characterisation of the mechanism of sorafenib-induced SGs revealed PERK as the main eIF2α kinase responsible for SGs formation. Depletion experiments support the implication of PERK-eIF2α-SGs pathway in hepatocarcinoma cells resistance to sorafenib. This study also suggests the existence of an unexpected complex regulatory balance between SGs and phospho-eIF2α where SGs dampen the activation of the phospho-eIF2α-downstream ATF4 cell death pathway.
Collapse
Affiliation(s)
- Pauline Adjibade
- Centre de Recherche du toCHU de Québec, Université Laval, Québec, PQ, Canada.,Département de Biologie Moléculaire, Biochimie Médicale et Pathologie, Faculté de Médecine, Université Laval, Québec, PQ, Canada.,Centre de Recherche en Cancérologie de l'Université Laval, Université Laval, Québec, PQ, Canada
| | - Valérie Grenier St-Sauveur
- Centre de Recherche du toCHU de Québec, Université Laval, Québec, PQ, Canada.,Département de Biologie Moléculaire, Biochimie Médicale et Pathologie, Faculté de Médecine, Université Laval, Québec, PQ, Canada.,Centre de Recherche en Cancérologie de l'Université Laval, Université Laval, Québec, PQ, Canada
| | - Miguel Quevillon Huberdeau
- Centre de Recherche du toCHU de Québec, Université Laval, Québec, PQ, Canada.,Département de Biologie Moléculaire, Biochimie Médicale et Pathologie, Faculté de Médecine, Université Laval, Québec, PQ, Canada.,Centre de Recherche en Cancérologie de l'Université Laval, Université Laval, Québec, PQ, Canada
| | - Marie-Josée Fournier
- Centre de Recherche du toCHU de Québec, Université Laval, Québec, PQ, Canada.,Département de Biologie Moléculaire, Biochimie Médicale et Pathologie, Faculté de Médecine, Université Laval, Québec, PQ, Canada.,Centre de Recherche en Cancérologie de l'Université Laval, Université Laval, Québec, PQ, Canada
| | - Andreanne Savard
- Centre de Recherche du toCHU de Québec, Université Laval, Québec, PQ, Canada.,Département de Biologie Moléculaire, Biochimie Médicale et Pathologie, Faculté de Médecine, Université Laval, Québec, PQ, Canada.,Centre de Recherche en Cancérologie de l'Université Laval, Université Laval, Québec, PQ, Canada
| | - Laetitia Coudert
- Centre de Recherche du toCHU de Québec, Université Laval, Québec, PQ, Canada.,Département de Biologie Moléculaire, Biochimie Médicale et Pathologie, Faculté de Médecine, Université Laval, Québec, PQ, Canada.,Centre de Recherche en Cancérologie de l'Université Laval, Université Laval, Québec, PQ, Canada
| | - Edouard W Khandjian
- Centre de Recherche, Institut Universitaire en Santé Mentale de Québec, Université Laval, Québec, PQ, Canada.,Département de Psychiatrie et de Neurosciences, Faculté de Médecine, Université Laval, Québec, PQ, Canada
| | - Rachid Mazroui
- Centre de Recherche du toCHU de Québec, Université Laval, Québec, PQ, Canada.,Département de Biologie Moléculaire, Biochimie Médicale et Pathologie, Faculté de Médecine, Université Laval, Québec, PQ, Canada.,Centre de Recherche en Cancérologie de l'Université Laval, Université Laval, Québec, PQ, Canada
| |
Collapse
|
166
|
Abstract
RNA-binding proteins are often multifunctional, interact with a variety of protein partners and display complex localizations within cells. Mammalian cytoplasmic poly(A)-binding proteins (PABPs) are multifunctional RNA-binding proteins that regulate multiple aspects of mRNA translation and stability. Although predominantly diffusely cytoplasmic at steady state, they shuttle through the nucleus and can be localized to a variety of cytoplasmic foci, including those associated with mRNA storage and localized translation. Intriguingly, PABP sub-cellular distribution can alter dramatically in response to cellular stress or viral infection, becoming predominantly nuclear and/or being enriched in induced cytoplasmic foci. However, relatively little is known about the mechanisms that govern this distribution/relocalization and in many cases PABP functions within specific sites remain unclear. Here we discuss the emerging evidence with respect to these questions in mammals.
Collapse
|
167
|
Wheeler JR, Matheny T, Jain S, Abrisch R, Parker R. Distinct stages in stress granule assembly and disassembly. eLife 2016; 5:e18413. [PMID: 27602576 DOI: 10.7554/elife.18413.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 08/15/2016] [Indexed: 05/23/2023] Open
Abstract
Stress granules are non-membrane bound RNA-protein (RNP) assemblies that form when translation initiation is limited and contain a biphasic structure with stable core structures surrounded by a less concentrated shell. The order of assembly and disassembly of these two structures remains unknown. Time course analysis of granule assembly suggests that core formation is an early event in granule assembly. Stress granule disassembly is also a stepwise process with shell dissipation followed by core clearance. Perturbations that alter liquid-liquid phase separations (LLPS) driven by intrinsically disordered protein regions (IDR) of RNA binding proteins in vitro have the opposite effect on stress granule assembly in vivo. Taken together, these observations argue that stress granules assemble through a multistep process initiated by stable assembly of untranslated mRNPs into core structures, which could provide sufficient high local concentrations to allow for a localized LLPS driven by IDRs on RNA binding proteins.
Collapse
Affiliation(s)
- Joshua R Wheeler
- Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, United States
| | - Tyler Matheny
- Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, United States
| | - Saumya Jain
- Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, United States
| | - Robert Abrisch
- Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, United States
| | - Roy Parker
- Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, United States
- Howard Hughes Medical Institute, University of Colorado, Boulder, United States
| |
Collapse
|
168
|
Wheeler JR, Matheny T, Jain S, Abrisch R, Parker R. Distinct stages in stress granule assembly and disassembly. eLife 2016; 5. [PMID: 27602576 PMCID: PMC5014549 DOI: 10.7554/elife.18413] [Citation(s) in RCA: 495] [Impact Index Per Article: 61.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 08/15/2016] [Indexed: 12/31/2022] Open
Abstract
Stress granules are non-membrane bound RNA-protein (RNP) assemblies that form when translation initiation is limited and contain a biphasic structure with stable core structures surrounded by a less concentrated shell. The order of assembly and disassembly of these two structures remains unknown. Time course analysis of granule assembly suggests that core formation is an early event in granule assembly. Stress granule disassembly is also a stepwise process with shell dissipation followed by core clearance. Perturbations that alter liquid-liquid phase separations (LLPS) driven by intrinsically disordered protein regions (IDR) of RNA binding proteins in vitro have the opposite effect on stress granule assembly in vivo. Taken together, these observations argue that stress granules assemble through a multistep process initiated by stable assembly of untranslated mRNPs into core structures, which could provide sufficient high local concentrations to allow for a localized LLPS driven by IDRs on RNA binding proteins. DOI:http://dx.doi.org/10.7554/eLife.18413.001
Collapse
Affiliation(s)
- Joshua R Wheeler
- Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, United States
| | - Tyler Matheny
- Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, United States
| | - Saumya Jain
- Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, United States
| | - Robert Abrisch
- Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, United States
| | - Roy Parker
- Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, United States.,Howard Hughes Medical Institute, University of Colorado, Boulder, United States
| |
Collapse
|
169
|
Tsai WC, Gayatri S, Reineke LC, Sbardella G, Bedford MT, Lloyd RE. Arginine Demethylation of G3BP1 Promotes Stress Granule Assembly. J Biol Chem 2016; 291:22671-22685. [PMID: 27601476 DOI: 10.1074/jbc.m116.739573] [Citation(s) in RCA: 133] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 08/15/2016] [Indexed: 12/22/2022] Open
Abstract
Stress granules (SGs) are cytoplasmic condensates of stalled messenger ribonucleoprotein complexes (mRNPs) that form when eukaryotic cells encounter environmental stress. RNA-binding proteins are enriched for arginine methylation and facilitate SG assembly through interactions involving regions of low amino acid complexity. How methylation of specific RNA-binding proteins regulates RNA granule assembly has not been characterized. Here, we examined the potent SG-nucleating protein Ras-GAP SH3-binding protein 1 (G3BP1), and found that G3BP1 is differentially methylated on specific arginine residues by protein arginine methyltransferase (PRMT) 1 and PRMT5 in its RGG domain. Several genetic and biochemical interventions that increased methylation repressed SG assembly, whereas interventions that decreased methylation promoted SG assembly. Arsenite stress quickly and reversibly decreased asymmetric arginine methylation on G3BP1. These data indicate that arginine methylation in the RGG domain prevents large SG assembly and rapid demethylation is a novel signal that regulates SG formation.
Collapse
Affiliation(s)
- Wei-Chih Tsai
- From the Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas 77030
| | - Sitaram Gayatri
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas M. D. Anderson Cancer Center, Science Park, Smithville, Texas 78957, and
| | - Lucas C Reineke
- From the Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas 77030
| | - Gianluca Sbardella
- Epigenetic Med Chem Lab, Dipartimento di Farmacia, Università degli Studi di Salerno, Via Giovanni Paolo II 132, I-84084 Fisciano, Salerno, Italy
| | - Mark T Bedford
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas M. D. Anderson Cancer Center, Science Park, Smithville, Texas 78957, and
| | - Richard E Lloyd
- From the Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas 77030,
| |
Collapse
|
170
|
Kedersha N, Panas MD, Achorn CA, Lyons S, Tisdale S, Hickman T, Thomas M, Lieberman J, McInerney GM, Ivanov P, Anderson P. G3BP-Caprin1-USP10 complexes mediate stress granule condensation and associate with 40S subunits. J Cell Biol 2016; 212:845-60. [PMID: 27022092 PMCID: PMC4810302 DOI: 10.1083/jcb.201508028] [Citation(s) in RCA: 399] [Impact Index Per Article: 49.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 02/17/2016] [Indexed: 12/11/2022] Open
Abstract
Stress granule condensation (SGC) of translationally arrested mRNAs requires G3BP, and G3BP-mediated SGC is inhibited by serine 149 phosphorylation, regulated by mutually exclusive binding of Caprin1 and USP10, and requires its RGG region for SGC and for interactions with 40S ribosomal subunits. Mammalian stress granules (SGs) contain stalled translation preinitiation complexes that are assembled into discrete granules by specific RNA-binding proteins such as G3BP. We now show that cells lacking both G3BP1 and G3BP2 cannot form SGs in response to eukaryotic initiation factor 2α phosphorylation or eIF4A inhibition, but are still SG-competent when challenged with severe heat or osmotic stress. Rescue experiments using G3BP1 mutants show that phosphomimetic G3BP1-S149E fails to rescue SG formation, whereas G3BP1-F33W, a mutant unable to bind G3BP partner proteins Caprin1 or USP10, rescues SG formation. Caprin1/USP10 binding to G3BP is mutually exclusive: Caprin binding promotes, but USP10 binding inhibits, SG formation. G3BP interacts with 40S ribosomal subunits through its RGG motif, which is also required for G3BP-mediated SG formation. We propose that G3BP mediates the condensation of SGs by shifting between two different states that are controlled by the phosphorylation of S149 and by binding to Caprin1 or USP10.
Collapse
Affiliation(s)
- Nancy Kedersha
- Division of Rheumatology, Immunology and Allergy, Harvard Medical School and Brigham and Women's Hospital, Boston, MA 02115
| | - Marc D Panas
- Division of Rheumatology, Immunology and Allergy, Harvard Medical School and Brigham and Women's Hospital, Boston, MA 02115
| | - Christopher A Achorn
- Division of Rheumatology, Immunology and Allergy, Harvard Medical School and Brigham and Women's Hospital, Boston, MA 02115
| | - Shawn Lyons
- Division of Rheumatology, Immunology and Allergy, Harvard Medical School and Brigham and Women's Hospital, Boston, MA 02115
| | - Sarah Tisdale
- Division of Rheumatology, Immunology and Allergy, Harvard Medical School and Brigham and Women's Hospital, Boston, MA 02115
| | - Tyler Hickman
- Division of Rheumatology, Immunology and Allergy, Harvard Medical School and Brigham and Women's Hospital, Boston, MA 02115
| | - Marshall Thomas
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115
| | - Judy Lieberman
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115
| | - Gerald M McInerney
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm SE-171 77, Sweden
| | - Pavel Ivanov
- Division of Rheumatology, Immunology and Allergy, Harvard Medical School and Brigham and Women's Hospital, Boston, MA 02115 The Broad Institute of Harvard and MIT, Cambridge, MA 02142
| | - Paul Anderson
- Division of Rheumatology, Immunology and Allergy, Harvard Medical School and Brigham and Women's Hospital, Boston, MA 02115
| |
Collapse
|
171
|
Herpes Simplex Virus 2 Virion Host Shutoff Endoribonuclease Activity Is Required To Disrupt Stress Granule Formation. J Virol 2016; 90:7943-55. [PMID: 27334584 DOI: 10.1128/jvi.00947-16] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 06/20/2016] [Indexed: 12/15/2022] Open
Abstract
UNLABELLED We previously established that cells infected with herpes simplex virus 2 (HSV-2) are disrupted in their ability to form stress granules (SGs) in response to oxidative stress and that this disruption is mediated by virion host shutoff protein (vhs), a virion-associated endoribonuclease. Here, we test the requirement for vhs endoribonuclease activity in disruption of SG formation. We analyzed the ability of HSV-2 vhs carrying the point mutation D215N, which ablates its endoribonuclease activity, to disrupt SG formation in both transfected and infected cells. We present evidence that ablation of vhs endoribonuclease activity results in defects in vhs-mediated disruption of SG formation. Furthermore, we demonstrate that preformed SGs can be disassembled by HSV-2 infection in a manner that requires vhs endoribonuclease activity and that, befitting this ability to promote SG disassembly, vhs is able to localize to SGs. Together these data indicate that endoribonuclease activity must be maintained in order for vhs to disrupt SG formation. We propose a model whereby vhs-mediated destruction of SG mRNA promotes SG disassembly and may also prevent SG assembly. IMPORTANCE Stress granules (SGs) are transient cytoplasmic structures that form when a cell is exposed to stress. SGs are emerging as potential barriers to viral infection, necessitating a more thorough understanding of their basic biology. We identified virion host shutoff protein (vhs) as a herpes simplex virus 2 (HSV-2) protein capable of disrupting SG formation. As mRNA is a central component of SGs and the best-characterized activity of vhs is as an endoribonuclease specific for mRNA in vivo, we investigated the requirement for vhs endoribonuclease activity in disruption of SG formation. Our studies demonstrate that endoribonuclease activity is required for vhs to disrupt SG formation and, more specifically, that SG disassembly can be driven by vhs endoribonuclease activity. Notably, during the course of these studies we discovered that there is an ordered departure of SG components during their disassembly and, furthermore, that vhs itself has the capacity to localize to SGs.
Collapse
|
172
|
Jayabalan AK, Sanchez A, Park RY, Yoon SP, Kang GY, Baek JH, Anderson P, Kee Y, Ohn T. NEDDylation promotes stress granule assembly. Nat Commun 2016; 7:12125. [PMID: 27381497 PMCID: PMC4935812 DOI: 10.1038/ncomms12125] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 06/02/2016] [Indexed: 12/21/2022] Open
Abstract
Stress granules (SGs) harbour translationally stalled messenger ribonucleoproteins and play important roles in regulating gene expression and cell fate. Here we show that neddylation promotes SG assembly in response to arsenite-induced oxidative stress. Inhibition or depletion of key components of the neddylation machinery concomitantly inhibits stress-induced polysome disassembly and SG assembly. Affinity purification and subsequent mass-spectrometric analysis of Nedd8-conjugated proteins from translationally stalled ribosomal fractions identified ribosomal proteins, translation factors and RNA-binding proteins (RBPs), including SRSF3, a previously known SG regulator. We show that SRSF3 is selectively neddylated at Lys85 in response to arsenite. A non-neddylatable SRSF3 (K85R) mutant do not prevent arsenite-induced polysome disassembly, but fails to support the SG assembly, suggesting that the neddylation pathway plays an important role in SG assembly.
Collapse
Affiliation(s)
- Aravinth Kumar Jayabalan
- Department of Cellular &Molecular Medicine, College of Medicine, Chosun University, Gwangju 61452, Republic of Korea
| | - Anthony Sanchez
- Department of Cell Biology, Microbiology, and Molecular Biology, College of Arts and Sciences, University of South Florida, Tampa, Florida 33620, USA
| | - Ra Young Park
- Department of Cellular &Molecular Medicine, College of Medicine, Chosun University, Gwangju 61452, Republic of Korea
| | - Sang Pil Yoon
- Department of Anatomy, School of Medicine, Jeju National University, Jeju-Do 690-756, Republic of Korea
| | - Gum-Yong Kang
- Diatech Korea Co, Ltd, Saemal-ro 5-gil, Songpa-gu, Seoul 05807, Republic of Korea
| | - Je-Hyun Baek
- Diatech Korea Co, Ltd, Saemal-ro 5-gil, Songpa-gu, Seoul 05807, Republic of Korea
| | - Paul Anderson
- Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital, Smith652, One Jimmy Fund Way, Boston, Massachusetts 02115, USA
| | - Younghoon Kee
- Department of Cell Biology, Microbiology, and Molecular Biology, College of Arts and Sciences, University of South Florida, Tampa, Florida 33620, USA
| | - Takbum Ohn
- Department of Cellular &Molecular Medicine, College of Medicine, Chosun University, Gwangju 61452, Republic of Korea
| |
Collapse
|
173
|
Heaven MR, Flint D, Randall SM, Sosunov AA, Wilson L, Barnes S, Goldman JE, Muddiman DC, Brenner M. Composition of Rosenthal Fibers, the Protein Aggregate Hallmark of Alexander Disease. J Proteome Res 2016; 15:2265-82. [PMID: 27193225 PMCID: PMC5036859 DOI: 10.1021/acs.jproteome.6b00316] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Alexander disease (AxD) is a neurodegenerative disorder characterized by astrocytic protein aggregates called Rosenthal fibers (RFs). We used mouse models of AxD to determine the protein composition of RFs to obtain information about disease mechanisms including the hypothesis that sequestration of proteins in RFs contributes to disease. A method was developed for RF enrichment, and analysis of the resulting fraction using isobaric tags for relative and absolute quantitation mass spectrometry identified 77 proteins not previously associated with RFs. Three of five proteins selected for follow-up were confirmed enriched in the RF fraction by immunobloting of both the AxD mouse models and human patients: receptor for activated protein C kinase 1 (RACK1), G1/S-specific cyclin D2, and ATP-dependent RNA helicase DDX3X. Immunohistochemistry validated cyclin D2 as a new RF component, but results for RACK1 and DDX3X were equivocal. None of these was decreased in the non-RF fractions compared to controls. A similar result was obtained for the previously known RF component, alphaB-crystallin, which had been a candidate for sequestration. Thus, no support was obtained for the sequestration hypothesis for AxD. Providing possible insight into disease progression, the association of several of the RF proteins with stress granules suggests a role for stress granules in the origin of RFs.
Collapse
Affiliation(s)
- Michael R. Heaven
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Alabama 35294
| | - Daniel Flint
- Department of Neurobiology and the Civitan International Research Center, Center for Glial Biology in Medicine, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Shan M. Randall
- Keck Fourier Transform Mass Spectrometry Laboratory, Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695
| | | | - Landon Wilson
- Department of Pharmacology and Toxicology, Targeted Metabolomics and Proteomics Laboratory, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Stephen Barnes
- Department of Pharmacology and Toxicology, Targeted Metabolomics and Proteomics Laboratory, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - James E. Goldman
- Department of Pathology & Cell Biology, Columbia University, New York, New York, 10032
| | - David C. Muddiman
- Keck Fourier Transform Mass Spectrometry Laboratory, Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695
| | - Michael Brenner
- Department of Neurobiology and the Civitan International Research Center, Center for Glial Biology in Medicine, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, Alabama 35294
| |
Collapse
|
174
|
Poblete-Durán N, Prades-Pérez Y, Vera-Otarola J, Soto-Rifo R, Valiente-Echeverría F. Who Regulates Whom? An Overview of RNA Granules and Viral Infections. Viruses 2016; 8:v8070180. [PMID: 27367717 PMCID: PMC4974515 DOI: 10.3390/v8070180] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 06/10/2016] [Accepted: 06/21/2016] [Indexed: 12/22/2022] Open
Abstract
After viral infection, host cells respond by mounting an anti-viral stress response in order to create a hostile atmosphere for viral replication, leading to the shut-off of mRNA translation (protein synthesis) and the assembly of RNA granules. Two of these RNA granules have been well characterized in yeast and mammalian cells, stress granules (SGs), which are translationally silent sites of RNA triage and processing bodies (PBs), which are involved in mRNA degradation. This review discusses the role of these RNA granules in the evasion of anti-viral stress responses through virus-induced remodeling of cellular ribonucleoproteins (RNPs).
Collapse
Affiliation(s)
- Natalia Poblete-Durán
- Molecular and Cellular Virology Laboratory, Virology Program, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Independencia 1027, Santiago, 8389100, Chile.
| | - Yara Prades-Pérez
- Molecular and Cellular Virology Laboratory, Virology Program, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Independencia 1027, Santiago, 8389100, Chile.
| | - Jorge Vera-Otarola
- Laboratorio de Virología Molecular, Instituto Milenio de Inmunología e Inmunoterapia, Centro de Investigaciones Médicas, Departamento de Enfermedades Infecciosas e Inmunología Pediátrica, Escuela de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago 8330024, Chile.
| | - Ricardo Soto-Rifo
- Molecular and Cellular Virology Laboratory, Virology Program, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Independencia 1027, Santiago, 8389100, Chile.
| | - Fernando Valiente-Echeverría
- Molecular and Cellular Virology Laboratory, Virology Program, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Independencia 1027, Santiago, 8389100, Chile.
| |
Collapse
|
175
|
Protter DSW, Parker R. Principles and Properties of Stress Granules. Trends Cell Biol 2016; 26:668-679. [PMID: 27289443 DOI: 10.1016/j.tcb.2016.05.004] [Citation(s) in RCA: 1026] [Impact Index Per Article: 128.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 05/02/2016] [Accepted: 05/10/2016] [Indexed: 12/27/2022]
Abstract
Stress granules are assemblies of untranslating messenger ribonucleoproteins (mRNPs) that form from mRNAs stalled in translation initiation. Stress granules form through interactions between mRNA-binding proteins that link together populations of mRNPs. Interactions promoting stress granule formation include conventional protein-protein interactions as well as interactions involving intrinsically disordered regions (IDRs) of proteins. Assembly and disassembly of stress granules are modulated by various post-translational modifications as well as numerous ATP-dependent RNP or protein remodeling complexes, illustrating that stress granules represent an active liquid wherein energy input maintains their dynamic state. Stress granule formation modulates the stress response, viral infection, and signaling pathways. Persistent or aberrant stress granule formation contributes to neurodegenerative disease and some cancers.
Collapse
Affiliation(s)
- David S W Protter
- Department of Chemistry and Biochemistry, Howard Hughes Medical Institute, University of Colorado, Boulder, CO 80309, USA
| | - Roy Parker
- Department of Chemistry and Biochemistry, Howard Hughes Medical Institute, University of Colorado, Boulder, CO 80309, USA.
| |
Collapse
|
176
|
Cervantes-Ortiz SL, Zamorano Cuervo N, Grandvaux N. Respiratory Syncytial Virus and Cellular Stress Responses: Impact on Replication and Physiopathology. Viruses 2016; 8:v8050124. [PMID: 27187445 PMCID: PMC4885079 DOI: 10.3390/v8050124] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 04/14/2016] [Accepted: 04/21/2016] [Indexed: 02/08/2023] Open
Abstract
Human respiratory syncytial virus (RSV), a member of the Paramyxoviridae family, is a major cause of severe acute lower respiratory tract infection in infants, elderly and immunocompromised adults. Despite decades of research, a complete integrated picture of RSV-host interaction is still missing. Several cellular responses to stress are involved in the host-response to many virus infections. The endoplasmic reticulum stress induced by altered endoplasmic reticulum (ER) function leads to activation of the unfolded-protein response (UPR) to restore homeostasis. Formation of cytoplasmic stress granules containing translationally stalled mRNAs is a means to control protein translation. Production of reactive oxygen species is balanced by an antioxidant response to prevent oxidative stress and the resulting damages. In recent years, ongoing research has started to unveil specific regulatory interactions of RSV with these host cellular stress responses. Here, we discuss the latest findings regarding the mechanisms evolved by RSV to induce, subvert or manipulate the ER stress, the stress granule and oxidative stress responses. We summarize the evidence linking these stress responses with the regulation of RSV replication and the associated pathogenesis.
Collapse
Affiliation(s)
- Sandra L Cervantes-Ortiz
- CRCHUM-Centre Hospitalier de l'Université de Montréal, Montréal, QC H2X 0A9, Canada.
- Faculty of Medicine, Université de Montréal, Montréal, QC H3C 3J7, Canada.
- Department of Microbiology, Infectiology and Immunology, Université de Montréal, Montréal, QC H3C 3J7, Canada.
| | - Natalia Zamorano Cuervo
- CRCHUM-Centre Hospitalier de l'Université de Montréal, Montréal, QC H2X 0A9, Canada.
- Faculty of Medicine, Université de Montréal, Montréal, QC H3C 3J7, Canada.
| | - Nathalie Grandvaux
- CRCHUM-Centre Hospitalier de l'Université de Montréal, Montréal, QC H2X 0A9, Canada.
- Faculty of Medicine, Université de Montréal, Montréal, QC H3C 3J7, Canada.
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, QC H3C 3J7, Canada.
| |
Collapse
|
177
|
Bellato HM, Hajj GNM. Translational control by eIF2α in neurons: Beyond the stress response. Cytoskeleton (Hoboken) 2016; 73:551-565. [PMID: 26994324 DOI: 10.1002/cm.21294] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 03/14/2016] [Accepted: 03/14/2016] [Indexed: 12/21/2022]
Abstract
The translation of mRNAs is a tightly controlled process that responds to multiple signaling pathways. In neurons, this control is also exerted locally due to the differential necessity of proteins in axons and dendrites. The phosphorylation of the alpha subunit of the translation initiation factor 2 (eIF2α) is one of the mechanisms of translational control. The phosphorylation of eIF2α has classically been viewed as a stress response, halting translation initiation. However, in the nervous system this type of regulation has been related to other mechanisms besides stress response, such as behavior, memory consolidation and nervous system development. Additionally, neurodegenerative diseases have a major stress component, thus eIF2α phosphorylation plays a preeminent role and its modulation is currently viewed as a new opportunity for therapeutic interventions. This review consolidates current information regarding eIF2α phosphorylation in neurons and its impact in neurodegenerative diseases. © 2016 Wiley Periodicals, Inc.
Collapse
|
178
|
Huelgas-Morales G, Silva-García CG, Salinas LS, Greenstein D, Navarro RE. The Stress Granule RNA-Binding Protein TIAR-1 Protects Female Germ Cells from Heat Shock in Caenorhabditis elegans. G3 (BETHESDA, MD.) 2016; 6:1031-47. [PMID: 26865701 PMCID: PMC4825639 DOI: 10.1534/g3.115.026815] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Accepted: 02/07/2016] [Indexed: 01/25/2023]
Abstract
In response to stressful conditions, eukaryotic cells launch an arsenal of regulatory programs to protect the proteome. One major protective response involves the arrest of protein translation and the formation of stress granules, cytoplasmic ribonucleoprotein complexes containing the conserved RNA-binding proteins TIA-1 and TIAR. The stress granule response is thought to preserve mRNA for translation when conditions improve. For cells of the germline-the immortal cell lineage required for sexual reproduction-protection from stress is critically important for perpetuation of the species, yet how stress granule regulatory mechanisms are deployed in animal reproduction is incompletely understood. Here, we show that the stress granule protein TIAR-1 protects the Caenorhabditis elegans germline from the adverse effects of heat shock. Animals containing strong loss-of-function mutations in tiar-1 exhibit significantly reduced fertility compared to the wild type following heat shock. Analysis of a heat-shock protein promoter indicates that tiar-1 mutants display an impaired heat-shock response. We observed that TIAR-1 was associated with granules in the gonad core and oocytes during several stressful conditions. Both gonad core and oocyte granules are dynamic structures that depend on translation; protein synthesis inhibitors altered their formation. Nonetheless, tiar-1 was required for the formation of gonad core granules only. Interestingly, the gonad core granules did not seem to be needed for the germ cells to develop viable embryos after heat shock. This suggests that TIAR-1 is able to protect the germline from heat stress independently of these structures.
Collapse
Affiliation(s)
- Gabriela Huelgas-Morales
- Departamento de Biología Celular y Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
| | - Carlos Giovanni Silva-García
- Departamento de Biología Celular y Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
| | - Laura S Salinas
- Departamento de Biología Celular y Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
| | - David Greenstein
- Department of Genetics, Cell Biology and Development, University of Minnesota Minneapolis, 55455 Minnesota
| | - Rosa E Navarro
- Departamento de Biología Celular y Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico.
| |
Collapse
|
179
|
Lloyd RE. Enterovirus Control of Translation and RNA Granule Stress Responses. Viruses 2016; 8:93. [PMID: 27043612 PMCID: PMC4848588 DOI: 10.3390/v8040093] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 03/26/2016] [Accepted: 03/29/2016] [Indexed: 12/24/2022] Open
Abstract
Enteroviruses such as poliovirus (PV) and coxsackievirus B3 (CVB3) have evolved several parallel strategies to regulate cellular gene expression and stress responses to ensure efficient expression of the viral genome. Enteroviruses utilize their encoded proteinases to take over the cellular translation apparatus and direct ribosomes to viral mRNAs. In addition, viral proteinases are used to control and repress the two main types of cytoplasmic RNA granules, stress granules (SGs) and processing bodies (P-bodies, PBs), which are stress-responsive dynamic structures involved in repression of gene expression. This review discusses these processes and the current understanding of the underlying mechanisms with respect to enterovirus infections. In addition, the review discusses accumulating data suggesting linkage exists between RNA granule formation and innate immune sensing and activation.
Collapse
Affiliation(s)
- Richard E Lloyd
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA.
| |
Collapse
|
180
|
Abstract
Stress granules (SGs) are dynamic accumulations of stalled preinitiation complexes and translational machinery that assemble under stressful conditions. Sodium selenite (Se) induces the assembly of noncanonical type II SGs that differ in morphology, composition, and mechanism of assembly from canonical SGs. Se inhibits translation initiation by altering the cap-binding activity of eukaryotic translation initiation factor 4E (eIF4E)-binding protein 1 (4EBP1). In this work, we show that human immunodeficiency virus type 1 (HIV-1) Gag is able to block the assembly of type II noncanonical SGs to facilitate continued Gag protein synthesis. We demonstrate that expression of Gag reduces the amount of hypophosphorylated 4EBP1 associated with the 5′ cap potentially through an interaction with its target, eIF4E. These results suggest that the assembly of SGs is an important host antiviral defense that HIV-1 has evolved for inhibition through several distinct mechanisms. The antiviral stress response is an important host defense that many viruses, including HIV-1, have evolved to evade. Selenite induces a block in translation and leads to stress granule assembly through the sequestration of eIF4E by binding hypophosphorylated 4EBP1. In this work, we demonstrate that in the face of selenite-induced stress, HIV-1 is able to maintain Gag mRNA translation and to elicit a blockade to selenite-induced stress granule assembly by altering the amount of hypophosphorylated 4EBP1 on the 5′ cap.
Collapse
|
181
|
Finnen RL, Banfield BW. Alphaherpesvirus Subversion of Stress-Induced Translational Arrest. Viruses 2016; 8:81. [PMID: 26999187 PMCID: PMC4810271 DOI: 10.3390/v8030081] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Revised: 03/01/2016] [Accepted: 03/02/2016] [Indexed: 12/14/2022] Open
Abstract
In this article, we provide an overview of translational arrest in eukaryotic cells in response to stress and the tactics used specifically by alphaherpesviruses to overcome translational arrest. One consequence of translational arrest is the formation of cytoplasmic compartments called stress granules (SGs). Many viruses target SGs for disruption and/or modification, including the alphaherpesvirus herpes simplex virus type 2 (HSV-2). Recently, it was discovered that HSV-2 disrupts SG formation early after infection via virion host shutoff protein (vhs), an endoribonuclease that is packaged within the HSV-2 virion. We review this discovery and discuss the insights it has provided into SG biology as well as its potential significance in HSV-2 infection. A model for vhs-mediated disruption of SG formation is presented.
Collapse
Affiliation(s)
- Renée L Finnen
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON K7L 3N6, Canada.
| | - Bruce W Banfield
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON K7L 3N6, Canada.
| |
Collapse
|
182
|
Abstract
RNA granules are dynamic cellular structures essential for proper gene expression and homeostasis. The two principal types of cytoplasmic RNA granules are stress granules, which contain stalled translation initiation complexes, and processing bodies (P bodies), which concentrate factors involved in mRNA degradation. RNA granules are associated with gene silencing of transcripts; thus, viruses repress RNA granule functions to favor replication. This article discusses the breadth of viral interactions with cytoplasmic RNA granules, focusing on mechanisms that modulate the functions of RNA granules and that typically promote viral replication. Currently, mechanisms for virus manipulation of RNA granules can be loosely grouped into three nonexclusive categories: (a) cleavage of key RNA granule factors, (b) regulation of PKR activation, and (c) co-opting of RNA granule factors for new roles in viral replication. Viral modulation of RNA granules supports productive infection by inhibiting their gene-silencing functions and counteracting their role in linking stress sensing with innate immune activation.
Collapse
Affiliation(s)
- Wei-Chih Tsai
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas 77030;
| | - Richard E Lloyd
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas 77030;
| |
Collapse
|
183
|
Yan B, Wang X, Wang Z, Chen N, Mu C, Mao K, Han L, Zhang W, Liu H. Identification of potential cargo proteins of transportin protein AtTRN1 in Arabidopsis thaliana. PLANT CELL REPORTS 2016; 35:629-640. [PMID: 26650834 DOI: 10.1007/s00299-015-1908-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Revised: 10/26/2015] [Accepted: 11/17/2015] [Indexed: 06/05/2023]
Abstract
We identified 23 novel proteins that can interact with At TRN1. These proteins are potential candidates of At TRN1 cargo proteins, which will facilitate our comprehending of At TRN1 functions in Arabidopsis. Tranportin 1 (TRN1) carries out the nucleo-cytoplasmic transport of many proteins, thereby ensuring that each of them is delivered to the right compartment for its proper function. These cargo proteins involved in lots of important processes, such as alternative pre-mRNA splicing, transcriptional regulation, and protein translation. Current understanding of cargo proteins transported by Arabidopsis thaliana transportin 1 (AtTRN1) is limited. Here, first we employed the yeast two-hybrid (Y2H) screening to identify proteins that can interact with AtTRN1 in Arabidopsis, and 12 novel proteins were found. Searching for PY-NLS motif in these 12 proteins suggested that no typical PY-NLS motif was present. We next investigated the specific motifs that will mediate the interactions in these sequences, and found that thirteen truncated fragments interacted with AtTRN1, containing 8 acidic and 5 basic fragments, respectively. We also searched the Arabidopsis proteome for homologs of cargo proteins of yeast Kapl04p and mammalian Kapβ2, and PY-NLS motif-containing proteins. Among these proteins, 11 were identified to interact with AtTRN1. The interactions between all the 23 proteins and AtTRN1 were confirmed by both Y2H and bimolecular fluorescence complementation (BiFC) assays. Our results show that AtTRN1 recognizes a broad spectrum of proteins having diverse functions, which will potentially be the cargoes of AtTRN1. Taken together, these results demonstrate the feasibility and potential power of these methods to identify cargo proteins of AtTRN1, and represent a primary and significant step in interpretation of AtTRN1 functionalities.
Collapse
Affiliation(s)
- Bo Yan
- Ministry Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China
| | - Xiaoning Wang
- Ministry Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China
| | - Zhenyu Wang
- Ministry Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China
| | - Ni Chen
- Ministry Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China
| | - Changjun Mu
- Ministry Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China
| | - Kaili Mao
- Ministry Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China
| | - Lirong Han
- Ministry Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China
| | - Wei Zhang
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, Shanghai, 200444, People's Republic of China
| | - Heng Liu
- Ministry Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China.
| |
Collapse
|
184
|
Vonaesch P, Campbell-Valois FX, Dufour A, Sansonetti PJ, Schnupf P. Shigella flexneri modulates stress granule composition and inhibits stress granule aggregation. Cell Microbiol 2016; 18:982-97. [PMID: 27282465 DOI: 10.1111/cmi.12561] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2015] [Revised: 12/07/2015] [Accepted: 12/09/2015] [Indexed: 02/07/2023]
Abstract
Invasion and multiplication of the facultative, cytosolic, enteropathogen Shigella flexneri within the colonic epithelial lining leads to an acute inflammatory response, fever and diarrhea. During the inflammatory process, infected cells are subjected to numerous stresses including heat, oxidative stress and genotoxic stress. The evolutionarily conserved pathway of cellular stress management is the formation of stress granules that store translationally inactive cellular mRNAs and interfere with cellular signalling pathways by sequestering signalling components. In this study, we investigated the ability of S. flexneri-infected cells to form stress granules in response to exogenous stresses. We found that S. flexneri infection inhibits movement of the stress granule markers eIF3 and eIF4B into stress granules and prevents the aggregation of G3BP1 and eIF4G-containing stress granules. This inhibition occurred only with invasive, but not with non-invasive bacteria and occurred in response to stresses that induce translational arrest through the phosphorylation of eIF2α and by treating cells with pateamine A, a drug that induces stress granules by inhibiting the eIF4A helicase. The S. flexneri-mediated stress granule inhibition could be largely phenocopied by the microtubule-destabilizing drug nocodazole and while S. flexneri infection did not lead to microtubule depolymerization, infection greatly enhanced acetylation of alpha-tubulin. Our data suggest that qualitative differences in the microtubule network or subversion of the microtubule-transport machinery by S. flexneri may be involved in preventing the full execution of this cellular stress response.
Collapse
Affiliation(s)
- Pascale Vonaesch
- Unité de Pathogénie Microbienne Moléculaire (INSERM U786), France
| | | | - Alexandre Dufour
- Unité d'Analyse d'Images Biologiques, CNRS UMR 3691, Institut Pasteur, 25-28 Rue du Dr Roux, 75724, Paris Cedex 15, France
| | - Philippe J Sansonetti
- Unité de Pathogénie Microbienne Moléculaire (INSERM U786), France.,Microbiologie et Maladies Infectieuses, Collège de France, 11 Place Marcelin Berthelot, 75005, Paris, France
| | - Pamela Schnupf
- Unité de Pathogénie Microbienne Moléculaire (INSERM U786), France
| |
Collapse
|
185
|
ATPase-Modulated Stress Granules Contain a Diverse Proteome and Substructure. Cell 2016; 164:487-98. [PMID: 26777405 DOI: 10.1016/j.cell.2015.12.038] [Citation(s) in RCA: 1015] [Impact Index Per Article: 126.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Revised: 09/29/2015] [Accepted: 12/15/2015] [Indexed: 12/13/2022]
Abstract
Stress granules are mRNA-protein granules that form when translation initiation is limited, and they are related to pathological granules in various neurodegenerative diseases. Super-resolution microscopy reveals stable substructures, referred to as cores, within stress granules that can be purified. Proteomic analysis of stress granule cores reveals a dense network of protein-protein interactions and links between stress granules and human diseases and identifies ATP-dependent helicases and protein remodelers as conserved stress granule components. ATP is required for stress granule assembly and dynamics. Moreover, multiple ATP-driven machines affect stress granules differently, with the CCT complex inhibiting stress granule assembly, while the MCM and RVB complexes promote stress granule persistence. Our observations suggest that stress granules contain a stable core structure surrounded by a dynamic shell with assembly, disassembly, and transitions between the core and shell modulated by numerous protein and RNA remodeling complexes.
Collapse
|
186
|
Fu X, Gao X, Ge L, Cui X, Su C, Yang W, Sun X, Zhang W, Yao Z, Yang X, Yang J. Malonate induces the assembly of cytoplasmic stress granules. FEBS Lett 2016; 590:22-33. [PMID: 26787461 DOI: 10.1002/1873-3468.12049] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 11/21/2015] [Accepted: 12/15/2015] [Indexed: 01/01/2023]
Abstract
Malonate, a classic inhibitor of respiratory electron transport chain, induces mitochondrial stress. Stress granules (SGs) are a kind of dynamic foci structure during stress. The study on the connection of mitochondrial stress and SG assembly is still limited. Here, we demonstrated that malonate treatment leads to SG formation and translation inhibition, apart from mitochondrial stress, including enhanced ROS formation, reduced mitochondrial Δψm and ATP level. The phosphorylation levels of eIF2α and 4EBP1 protein were affected upon mitochondrial dysfunction. However, knockdown of 4EBP1 affected SG formation, rather than eIF2α. In addition, an increase of ATP level under mitochondrial stress enhanced malonate-induced SG aggregation. Overall, malonate stimulation triggers mitochondrial stress and induces the assembly of non-canonical cellular SGs via 4EBP1 pathway.
Collapse
Affiliation(s)
- Xue Fu
- Department of Biochemistry and Molecular Biology, Department of Immunology, School of Basic Medical Sciences, Tianjin Medical University, China.,Laboratory of Molecular Immunology, Research Center of Basic Medical Science, Tianjin Medical University, China.,Tianjin Key Laboratory of Cellular and Molecular Immunology, Tianjin Medical University, China.,Key Laboratory of Educational Ministry of China, Tianjin Medical University, China
| | - Xingjie Gao
- Department of Biochemistry and Molecular Biology, Department of Immunology, School of Basic Medical Sciences, Tianjin Medical University, China.,Laboratory of Molecular Immunology, Research Center of Basic Medical Science, Tianjin Medical University, China.,Tianjin Key Laboratory of Cellular and Molecular Immunology, Tianjin Medical University, China.,Key Laboratory of Educational Ministry of China, Tianjin Medical University, China
| | - Lin Ge
- Department of Biochemistry and Molecular Biology, Department of Immunology, School of Basic Medical Sciences, Tianjin Medical University, China.,Laboratory of Molecular Immunology, Research Center of Basic Medical Science, Tianjin Medical University, China.,Tianjin Key Laboratory of Cellular and Molecular Immunology, Tianjin Medical University, China.,Key Laboratory of Educational Ministry of China, Tianjin Medical University, China
| | - Xiaoteng Cui
- Department of Biochemistry and Molecular Biology, Department of Immunology, School of Basic Medical Sciences, Tianjin Medical University, China.,Laboratory of Molecular Immunology, Research Center of Basic Medical Science, Tianjin Medical University, China.,Tianjin Key Laboratory of Cellular and Molecular Immunology, Tianjin Medical University, China.,Key Laboratory of Educational Ministry of China, Tianjin Medical University, China
| | - Chao Su
- Department of Biochemistry and Molecular Biology, Department of Immunology, School of Basic Medical Sciences, Tianjin Medical University, China.,Laboratory of Molecular Immunology, Research Center of Basic Medical Science, Tianjin Medical University, China.,Tianjin Key Laboratory of Cellular and Molecular Immunology, Tianjin Medical University, China.,Key Laboratory of Educational Ministry of China, Tianjin Medical University, China
| | - Wendong Yang
- Department of Biochemistry and Molecular Biology, Department of Immunology, School of Basic Medical Sciences, Tianjin Medical University, China.,Laboratory of Molecular Immunology, Research Center of Basic Medical Science, Tianjin Medical University, China.,Tianjin Key Laboratory of Cellular and Molecular Immunology, Tianjin Medical University, China.,Key Laboratory of Educational Ministry of China, Tianjin Medical University, China
| | - Xiaoming Sun
- Department of Biochemistry and Molecular Biology, Department of Immunology, School of Basic Medical Sciences, Tianjin Medical University, China.,Laboratory of Molecular Immunology, Research Center of Basic Medical Science, Tianjin Medical University, China.,Tianjin Key Laboratory of Cellular and Molecular Immunology, Tianjin Medical University, China.,Key Laboratory of Educational Ministry of China, Tianjin Medical University, China
| | - Wei Zhang
- Department of Biochemistry and Molecular Biology, Department of Immunology, School of Basic Medical Sciences, Tianjin Medical University, China.,Laboratory of Molecular Immunology, Research Center of Basic Medical Science, Tianjin Medical University, China.,Tianjin Key Laboratory of Cellular and Molecular Immunology, Tianjin Medical University, China.,Key Laboratory of Educational Ministry of China, Tianjin Medical University, China
| | - Zhi Yao
- Department of Biochemistry and Molecular Biology, Department of Immunology, School of Basic Medical Sciences, Tianjin Medical University, China.,Laboratory of Molecular Immunology, Research Center of Basic Medical Science, Tianjin Medical University, China.,Tianjin Key Laboratory of Cellular and Molecular Immunology, Tianjin Medical University, China.,Key Laboratory of Educational Ministry of China, Tianjin Medical University, China
| | - Xi Yang
- Department of Immunology, University of Manitoba, Winnipeg, Canada
| | - Jie Yang
- Department of Biochemistry and Molecular Biology, Department of Immunology, School of Basic Medical Sciences, Tianjin Medical University, China.,Laboratory of Molecular Immunology, Research Center of Basic Medical Science, Tianjin Medical University, China.,Tianjin Key Laboratory of Cellular and Molecular Immunology, Tianjin Medical University, China.,Key Laboratory of Educational Ministry of China, Tianjin Medical University, China.,Department of Immunology, University of Manitoba, Winnipeg, Canada
| |
Collapse
|
187
|
Sedwick C. How stressed cells triage mRNAs. ACTA ACUST UNITED AC 2015; 211:940. [PMID: 26644510 PMCID: PMC4674285 DOI: 10.1083/jcb.2115fta] [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] [Indexed: 11/25/2022]
Abstract
In 2005, Kedersha et al. demonstrated the dynamic interactions between cytoplasmic RNA granules.
Collapse
|
188
|
|
189
|
Durning SP, Flanagan-Steet H, Prasad N, Wells L. O-Linked β-N-acetylglucosamine (O-GlcNAc) Acts as a Glucose Sensor to Epigenetically Regulate the Insulin Gene in Pancreatic Beta Cells. J Biol Chem 2015; 291:2107-18. [PMID: 26598517 DOI: 10.1074/jbc.m115.693580] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Indexed: 11/06/2022] Open
Abstract
The post-translational protein modification O-linked β-N-acetylglucosamine (O-GlcNAc) is a proposed nutrient sensor that has been shown to regulate multiple biological pathways. This dynamic and inducible enzymatic modification to intracellular proteins utilizes the end product of the nutrient sensing hexosamine biosynthetic pathway, UDP-GlcNAc, as its substrate donor. Type II diabetic patients have elevated O-GlcNAc-modified proteins within pancreatic beta cells due to chronic hyperglycemia-induced glucose overload, but a molecular role for O-GlcNAc within beta cells remains unclear. Using directed pharmacological approaches in the mouse insulinoma-6 (Min6) cell line, we demonstrate that elevating nuclear O-GlcNAc increases intracellular insulin levels and preserves glucose-stimulated insulin secretion during chronic hyperglycemia. The molecular mechanism for these observed changes appears to be, at least in part, due to elevated O-GlcNAc-dependent increases in Ins1 and Ins2 mRNA levels via elevations in histone H3 transcriptional activation marks. Furthermore, RNA deep sequencing reveals that this mechanism of altered gene transcription is restricted and that the majority of genes regulated by elevated O-GlcNAc levels are similarly regulated by a shift from euglycemic to hyperglycemic conditions. These findings implicate the O-GlcNAc modification as a potential mechanism for hyperglycemic-regulated gene expression in the beta cell.
Collapse
Affiliation(s)
- Sean P Durning
- From the Complex Carbohydrate Research Center, Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602-1516 and
| | - Heather Flanagan-Steet
- From the Complex Carbohydrate Research Center, Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602-1516 and
| | - Nripesh Prasad
- HudsonAlpha Institute of Biotechnology, Genomic Services Laboratory, Huntsville, Alabama 35806
| | - Lance Wells
- From the Complex Carbohydrate Research Center, Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602-1516 and
| |
Collapse
|
190
|
Aulas A, Vande Velde C. Alterations in stress granule dynamics driven by TDP-43 and FUS: a link to pathological inclusions in ALS? Front Cell Neurosci 2015; 9:423. [PMID: 26557057 PMCID: PMC4615823 DOI: 10.3389/fncel.2015.00423] [Citation(s) in RCA: 160] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 10/06/2015] [Indexed: 12/12/2022] Open
Abstract
Stress granules (SGs) are RNA-containing cytoplasmic foci formed in response to stress exposure. Since their discovery in 1999, over 120 proteins have been described to be localized to these structures (in 154 publications). Most of these components are RNA binding proteins (RBPs) or are involved in RNA metabolism and translation. SGs have been linked to several pathologies including inflammatory diseases, cancer, viral infection, and neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). In ALS and FTD, the majority of cases have no known etiology and exposure to external stress is frequently proposed as a contributor to either disease initiation or the rate of disease progression. Of note, both ALS and FTD are characterized by pathological inclusions, where some well-known SG markers localize with the ALS related proteins TDP-43 and FUS. We propose that TDP-43 and FUS serve as an interface between genetic susceptibility and environmental stress exposure in disease pathogenesis. Here, we will discuss the role of TDP-43 and FUS in SG dynamics and how disease-linked mutations affect this process.
Collapse
Affiliation(s)
- Anaïs Aulas
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal Montréal, QC, Canada ; Department of Biochemistry, Université de Montréal Montréal, QC, Canada
| | - Christine Vande Velde
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal Montréal, QC, Canada ; Department of Neurosciences, Université de Montréal Montréal, QC, Canada
| |
Collapse
|
191
|
Cytoplasmic mRNA turnover and ageing. Mech Ageing Dev 2015; 152:32-42. [PMID: 26432921 PMCID: PMC4710634 DOI: 10.1016/j.mad.2015.09.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Revised: 09/17/2015] [Accepted: 09/27/2015] [Indexed: 12/12/2022]
Abstract
We address the cytoplasmic mRNA decay processes that determine the mRNAs half-life. We briefly describe the major, evolutionary conserved, ageing pathways and mechanisms. We summarize critical findings that link mRNA turnover and ageing modulators.
Messenger RNA (mRNA) turnover that determines the lifetime of cytoplasmic mRNAs is a means to control gene expression under both normal and stress conditions, whereas its impact on ageing and age-related disorders has just become evident. Gene expression control is achieved at the level of the mRNA clearance as well as mRNA stability and accessibility to other molecules. All these processes are regulated by cis-acting motifs and trans-acting factors that determine the rates of translation and degradation of transcripts. Specific messenger RNA granules that harbor the mRNA decay machinery or various factors, involved in translational repression and transient storage of mRNAs, are also part of the mRNA fate regulation. Their assembly and function can be modulated to promote stress resistance to adverse conditions and over time affect the ageing process and the lifespan of the organism. Here, we provide insights into the complex relationships of ageing modulators and mRNA turnover mechanisms.
Collapse
|
192
|
Bilanchone V, Clemens K, Kaake R, Dawson AR, Matheos D, Nagashima K, Sitlani P, Patterson K, Chang I, Huang L, Sandmeyer S. Ty3 Retrotransposon Hijacks Mating Yeast RNA Processing Bodies to Infect New Genomes. PLoS Genet 2015; 11:e1005528. [PMID: 26421679 PMCID: PMC4589538 DOI: 10.1371/journal.pgen.1005528] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 08/24/2015] [Indexed: 01/15/2023] Open
Abstract
Retrotransposition of the budding yeast long terminal repeat retrotransposon Ty3 is activated during mating. In this study, proteins that associate with Ty3 Gag3 capsid protein during virus-like particle (VLP) assembly were identified by mass spectrometry and screened for roles in mating-stimulated retrotransposition. Components of RNA processing bodies including DEAD box helicases Dhh1/DDX6 and Ded1/DDX3, Sm-like protein Lsm1, decapping protein Dcp2, and 5' to 3' exonuclease Xrn1 were among the proteins identified. These proteins associated with Ty3 proteins and RNA, and were required for formation of Ty3 VLP retrosome assembly factories and for retrotransposition. Specifically, Dhh1/DDX6 was required for normal levels of Ty3 genomic RNA, and Lsm1 and Xrn1 were required for association of Ty3 protein and RNA into retrosomes. This role for components of RNA processing bodies in promoting VLP assembly and retrotransposition during mating in a yeast that lacks RNA interference, contrasts with roles proposed for orthologous components in animal germ cell ribonucleoprotein granules in turnover and epigenetic suppression of retrotransposon RNAs.
Collapse
Affiliation(s)
- Virginia Bilanchone
- Department of Biological Chemistry, University of California, Irvine, Irvine, California, United States of America
| | - Kristina Clemens
- Department of Biological Chemistry, University of California, Irvine, Irvine, California, United States of America
| | - Robyn Kaake
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, California, United States of America
| | - Anthony R. Dawson
- Department of Biological Chemistry, University of California, Irvine, Irvine, California, United States of America
| | - Dina Matheos
- Department of Biological Chemistry, University of California, Irvine, Irvine, California, United States of America
| | - Kunio Nagashima
- Electron Microscope Laboratory, NCI-Frederick, SAIC-Frederick, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland, United States of America
| | - Parth Sitlani
- Department of Biological Chemistry, University of California, Irvine, Irvine, California, United States of America
| | - Kurt Patterson
- Department of Biological Chemistry, University of California, Irvine, Irvine, California, United States of America
| | - Ivan Chang
- Department of Biological Chemistry, University of California, Irvine, Irvine, California, United States of America
| | - Lan Huang
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, California, United States of America
| | - Suzanne Sandmeyer
- Department of Biological Chemistry, University of California, Irvine, Irvine, California, United States of America
- Institute for Genomics and Bioinformatics, University of California, Irvine, Irvine, California, United States of America
- * E-mail:
| |
Collapse
|
193
|
Aronov S, Dover-Biterman S, Suss-Toby E, Shmoish M, Duek L, Choder M. Pheromone-encoding mRNA is transported to the yeast mating projection by specific RNP granules. J Cell Biol 2015; 209:829-42. [PMID: 26101218 PMCID: PMC4477862 DOI: 10.1083/jcb.201408045] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
In response to mating pheromone, the yeast MFA2 mRNA is transported to the tip of the mating projection as an RNP granule and translated; integrity of the granules is required for normal mRNA transport and for the mating process. Association of messenger RNAs with large complexes such as processing bodies (PBs) plays a pivotal role in regulating their translation and decay. Little is known about other possible functions of these assemblies. Exposure of haploid yeast cells, carrying mating type “a,” to “α pheromone” stimulates polarized growth resulting in a “shmoo” projection; it also induces synthesis of “a pheromone,” encoded by MFA2. In this paper, we show that, in response to α pheromone, MFA2 mRNA is assembled with two types of granules; both contain some canonical PB proteins, yet they differ in size, localization, motility, and sensitivity to cycloheximide. Remarkably, one type is involved in mRNA transport to the tip of the shmoo, whereas the other—in local translation in the shmoo. Normal assembly of these granules is critical for their movement, localization, and for mating. Thus, MFA2 mRNAs are transported to the shmoo tip, in complex with PB-like particles, where they are locally translated.
Collapse
Affiliation(s)
- Stella Aronov
- Department of Molecular Microbiology, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel Department of Molecular Biology, Ariel University, Ariel 40700, Israel
| | - Saray Dover-Biterman
- Department of Molecular Microbiology, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel
| | - Edith Suss-Toby
- Multidisciplinary Laboratory, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel
| | - Michael Shmoish
- Multidisciplinary Laboratory, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel Bioinformatics Knowledge Unit, The Lorry I. Lokey Interdisciplinary Center for Life Sciences and Engineering, Technion-Israel Institute of Technology, Haifa 31096, Israel
| | - Lea Duek
- Department of Molecular Microbiology, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel
| | - Mordechai Choder
- Department of Molecular Microbiology, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel
| |
Collapse
|
194
|
Abstract
Messenger ribonucleoprotein (mRNP) granules are dynamic, self-assembling structures that harbor non-translating mRNAs bound by various proteins that regulate mRNA translation, localization, and turnover. Their importance in gene expression regulation is far reaching, ranging from precise spatial-temporal control of mRNAs that drive developmental programs in oocytes and embryos, to similarly exquisite control of mRNAs in neurons that underpin synaptic plasticity, and thus, memory formation. Analysis of mRNP granules in their various contexts has revealed common themes of assembly, disassembly, and modes of mRNA regulation, yet new studies continue to reveal unexpected and important findings, such as links between aberrant mRNP granule assembly and neurodegenerative disease. Continued study of these enigmatic structures thus promises fascinating new insights into cellular function, and may also suggest novel therapeutic strategies in various disease states.
Collapse
Affiliation(s)
- J Ross Buchan
- a Department of Molecular and Cellular Biology ; University of Arizona ; Tucson , AZ USA
| |
Collapse
|
195
|
Ohshima D, Arimoto-Matsuzaki K, Tomida T, Takekawa M, Ichikawa K. Spatio-temporal Dynamics and Mechanisms of Stress Granule Assembly. PLoS Comput Biol 2015; 11:e1004326. [PMID: 26115353 PMCID: PMC4482703 DOI: 10.1371/journal.pcbi.1004326] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 04/07/2015] [Indexed: 12/31/2022] Open
Abstract
Stress granules (SGs) are non-membranous cytoplasmic aggregates of mRNAs and related proteins, assembled in response to environmental stresses such as heat shock, hypoxia, endoplasmic reticulum (ER) stress, chemicals (e.g. arsenite), and viral infections. SGs are hypothesized as a loci of mRNA triage and/or maintenance of proper translation capacity ratio to the pool of mRNAs. In brain ischemia, hippocampal CA3 neurons, which are resilient to ischemia, assemble SGs. In contrast, CA1 neurons, which are vulnerable to ischemia, do not assemble SGs. These results suggest a critical role SG plays in regards to cell fate decisions. Thus SG assembly along with its dynamics should determine the cell fate. However, the process that exactly determines the SG assembly dynamics is largely unknown. In this paper, analyses of experimental data and computer simulations were used to approach this problem. SGs were assembled as a result of applying arsenite to HeLa cells. The number of SGs increased after a short latent period, reached a maximum, then decreased during the application of arsenite. At the same time, the size of SGs grew larger and became localized at the perinuclear region. A minimal mathematical model was constructed, and stochastic simulations were run to test the modeling. Since SGs are discrete entities as there are only several tens of them in a cell, commonly used deterministic simulations could not be employed. The stochastic simulations replicated observed dynamics of SG assembly. In addition, these stochastic simulations predicted a gamma distribution relative to the size of SGs. This same distribution was also found in our experimental data suggesting the existence of multiple fusion steps in the SG assembly. Furthermore, we found that the initial steps in the SG assembly process and microtubules were critical to the dynamics. Thus our experiments and stochastic simulations presented a possible mechanism regulating SG assembly. Cells suffer from various environmental stresses such as heat shock and viral infection. In response to a stress, small non-membranous cytoplasmic aggregates, stress granules (SGs), are assembled. SGs contain mRNAs and related proteins. Hippocampal CA1 neurons located in the brain, which are vulnerable to ischemia, do not assemble SGs, while CA3 neurons, which are resilient to ischemia, assemble SGs. The dysfunction of SGs has been reported in human diseases including pathogenic viral infection. These observations led to a hypothesis that SGs play an important role in cell fate decisions, and the dynamics of SG assembly would regulate cell fate. However, the conditions that determine the number and distribution of SGs in a cell in response to a stress are largely unknown. We approached this problem by experiments and simulations. Our stochastic simulations replicated the observations. Furthermore, we found that initial steps in the SG assembly process were important to the dynamics of SG assembly, and that SG size resembled the gamma distribution both in simulations and experiments, suggesting the existence of multiple steps in the SG assembly process. To the best of our knowledge, this work was the first to show SG assembly in a whole cell by stochastic simulations.
Collapse
Affiliation(s)
- Daisuke Ohshima
- Division of Mathematical Oncology, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - Kyoko Arimoto-Matsuzaki
- Division of Molecular Cell Signaling, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - Taichiro Tomida
- Division of Molecular Cell Signaling, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - Mutsuhiro Takekawa
- Division of Cell Signaling and Molecular Medicine, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - Kazuhisa Ichikawa
- Division of Mathematical Oncology, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
- * E-mail:
| |
Collapse
|
196
|
Kim EJ. The Utilities of Chemical Reactions and Molecular Tools for O-GlcNAc Proteomic Studies. Chembiochem 2015; 16:1397-409. [PMID: 26096757 DOI: 10.1002/cbic.201500183] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Indexed: 11/05/2022]
Abstract
The post-translational modification of nuclear and cytoplasmic proteins with O-linked β-N-acetylglucosamine (O-GlcNAc) is involved in a wide variety of cellular processes and is associated with the pathological progression of chronic diseases. Considering its emerging biological significance, systematic identification, site mapping, and quantification of O-GlcNAc proteins are essential and have led to the development of several approaches for O-GlcNAc protein profiling. This minireview mainly focuses on the various useful chemical reactions and molecular tools with detailed reaction mechanisms widely adopted for O-GlcNAc protein/peptide enrichment and its quantification for comprehensive O-GlcNAc protein profiling.
Collapse
Affiliation(s)
- Eun Ju Kim
- Department of Science Education-Chemistry Major, Daegu University, Gyeongsan-si, GyeongBuk 712-714 (Republic of Korea). ,
| |
Collapse
|
197
|
Jevtov I, Zacharogianni M, van Oorschot MM, van Zadelhoff G, Aguilera-Gomez A, Vuillez I, Braakman I, Hafen E, Stocker H, Rabouille C. TORC2 mediates the heat stress response in Drosophila by promoting the formation of stress granules. J Cell Sci 2015; 128:2497-508. [PMID: 26054799 PMCID: PMC4510851 DOI: 10.1242/jcs.168724] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 06/03/2015] [Indexed: 12/29/2022] Open
Abstract
The kinase TOR is found in two complexes, TORC1, which is involved in growth control, and TORC2, whose roles are less well defined. Here, we asked whether TORC2 has a role in sustaining cellular stress. We show that TORC2 inhibition in Drosophila melanogaster leads to a reduced tolerance to heat stress, whereas sensitivity to other stresses is not affected. Accordingly, we show that upon heat stress, both in the animal and Drosophila cultured S2 cells, TORC2 is activated and is required for maintaining the level of its known target, Akt1 (also known as PKB). We show that the phosphorylation of the stress-activated protein kinases is not modulated by TORC2 nor is the heat-induced upregulation of heat-shock proteins. Instead, we show, both in vivo and in cultured cells, that TORC2 is required for the assembly of heat-induced cytoprotective ribonucleoprotein particles, the pro-survival stress granules. These granules are formed in response to protein translation inhibition imposed by heat stress that appears to be less efficient in the absence of TORC2 function. We propose that TORC2 mediates heat resistance in Drosophila by promoting the cell autonomous formation of stress granules.
Collapse
Affiliation(s)
- Irena Jevtov
- Institute of Molecular Systems Biology, ETH Zurich, Zurich 8093, Switzerland
| | | | - Marinke M van Oorschot
- Hubrecht Institute of the KNAW and UMC Utrecht, Uppsalalaan 8, Utrecht 3584 CT, Netherlands
| | - Guus van Zadelhoff
- Cellular Protein Chemistry, Utrecht University, Padualaan 8, Utrecht 3584 CH, The Netherlands
| | | | - Igor Vuillez
- Institute of Molecular Systems Biology, ETH Zurich, Zurich 8093, Switzerland
| | - Ineke Braakman
- Cellular Protein Chemistry, Utrecht University, Padualaan 8, Utrecht 3584 CH, The Netherlands
| | - Ernst Hafen
- Institute of Molecular Systems Biology, ETH Zurich, Zurich 8093, Switzerland
| | - Hugo Stocker
- Institute of Molecular Systems Biology, ETH Zurich, Zurich 8093, Switzerland
| | - Catherine Rabouille
- Hubrecht Institute of the KNAW and UMC Utrecht, Uppsalalaan 8, Utrecht 3584 CT, Netherlands Department of Cell Biology, UMC Utrecht, Heidelberglaan 100, Utrecht 3584 CX, The Netherlands
| |
Collapse
|
198
|
Heck MV, Azizov M, Stehning T, Walter M, Kedersha N, Auburger G. Dysregulated expression of lipid storage and membrane dynamics factors in Tia1 knockout mouse nervous tissue. Neurogenetics 2015; 15:135-44. [PMID: 24659297 PMCID: PMC3994287 DOI: 10.1007/s10048-014-0397-x] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Accepted: 03/03/2014] [Indexed: 12/13/2022]
Abstract
During cell stress, the transcription and translation of immediate early genes are prioritized, while most other messenger RNAs (mRNAs) are stored away in stress granules or degraded in processing bodies (P-bodies). TIA-1 is an mRNA-binding protein that needs to translocate from the nucleus to seed the formation of stress granules in the cytoplasm. Because other stress granule components such as TDP-43, FUS, ATXN2, SMN, MAPT, HNRNPA2B1, and HNRNPA1 are crucial for the motor neuron diseases amyotrophic lateral sclerosis (ALS)/spinal muscular atrophy (SMA) and for the frontotemporal dementia (FTD), here we studied mouse nervous tissue to identify mRNAs with selective dependence on Tia1 deletion. Transcriptome profiling with oligonucleotide microarrays in comparison of spinal cord and cerebellum, together with independent validation in quantitative reverse transcriptase PCR and immunoblots demonstrated several strong and consistent dysregulations. In agreement with previously reported TIA1 knock down effects, cell cycle and apoptosis regulators were affected markedly with expression changes up to +2-fold, exhibiting increased levels for Cdkn1a, Ccnf, and Tprkb vs. decreased levels for Bid and Inca1 transcripts. Novel and surprisingly strong expression alterations were detected for fat storage and membrane trafficking factors, with prominent +3-fold upregulations of Plin4, Wdfy1, Tbc1d24, and Pnpla2 vs. a −2.4-fold downregulation of Cntn4 transcript, encoding an axonal membrane adhesion factor with established haploinsufficiency. In comparison, subtle effects on the RNA processing machinery included up to 1.2-fold upregulations of Dcp1b and Tial1. The effect on lipid dynamics factors is noteworthy, since also the gene deletion of Tardbp (encoding TDP-43) and Atxn2 led to fat metabolism phenotypes in mouse. In conclusion, genetic ablation of the stress granule nucleator TIA-1 has a novel major effect on mRNAs encoding lipid homeostasis factors in the brain, similar to the fasting effect.
Collapse
Affiliation(s)
- Melanie Vanessa Heck
- Experimental Neurology, Department of Neurology, Goethe University Medical School, Building 89, 3rd floor, Theodor Stern Kai 7, 60590 Frankfurt am Main, Germany
| | - Mekhman Azizov
- Experimental Neurology, Department of Neurology, Goethe University Medical School, Building 89, 3rd floor, Theodor Stern Kai 7, 60590 Frankfurt am Main, Germany
| | - Tanja Stehning
- Experimental Neurology, Department of Neurology, Goethe University Medical School, Building 89, 3rd floor, Theodor Stern Kai 7, 60590 Frankfurt am Main, Germany
| | - Michael Walter
- Institute for Medical Genetics, Eberhard-Karls-University of Tuebingen, 72076 Tübingen, Germany
| | - Nancy Kedersha
- Division of Rheumatology, Immunology and Allergy, Brigham and Women’s Hospital, Smith 652, One Jimmy Fund Way, Boston, MA 02115 USA
| | - Georg Auburger
- Experimental Neurology, Department of Neurology, Goethe University Medical School, Building 89, 3rd floor, Theodor Stern Kai 7, 60590 Frankfurt am Main, Germany
| |
Collapse
|
199
|
Zhu Y, Liu TW, Cecioni S, Eskandari R, Zandberg WF, Vocadlo DJ. O-GlcNAc occurs cotranslationally to stabilize nascent polypeptide chains. Nat Chem Biol 2015; 11:319-25. [PMID: 25774941 DOI: 10.1038/nchembio.1774] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2014] [Accepted: 02/13/2015] [Indexed: 12/20/2022]
Abstract
Nucleocytoplasmic glycosylation of proteins with O-linked N-acetylglucosamine residues (O-GlcNAc) is recognized as a conserved post-translational modification found in all metazoans. O-GlcNAc has been proposed to regulate diverse cellular processes. Impaired cellular O-GlcNAcylation has been found to lead to decreases in the levels of various proteins, which is one mechanism by which O-GlcNAc seems to exert its varied physiological effects. Here we show that O-GlcNAcylation also occurs cotranslationally. This process protects nascent polypeptide chains from premature degradation by decreasing cotranslational ubiquitylation. Given that hundreds of proteins are O-GlcNAcylated within cells, our findings suggest that cotranslational O-GlcNAcylation may be a phenomenon regulating proteostasis of an array of nucleocytoplasmic proteins. These findings set the stage to assess whether O-GlcNAcylation has a role in protein quality control in a manner that bears similarity with the role played by N-glycosylation within the secretory pathway.
Collapse
Affiliation(s)
- Yanping Zhu
- 1] Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada. [2] Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Ta-Wei Liu
- 1] Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada. [2] Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Samy Cecioni
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Razieh Eskandari
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Wesley F Zandberg
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada
| | - David J Vocadlo
- 1] Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada. [2] Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada
| |
Collapse
|
200
|
Panas MD, Kedersha N, McInerney GM. Methods for the characterization of stress granules in virus infected cells. Methods 2015; 90:57-64. [PMID: 25896634 PMCID: PMC7128402 DOI: 10.1016/j.ymeth.2015.04.009] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Revised: 04/08/2015] [Accepted: 04/09/2015] [Indexed: 12/25/2022] Open
Abstract
Stress granules are induced as a cellular defence against virus infection. We discuss methods for the detection of viral and cellular proteins and RNA in SGs. In addition, we describe a surrogate in vitro assay for SG formation.
Stress granules are induced in many different viral infections, and in turn are inhibited by the expression of viral proteins or RNAs. It is therefore evident that these bodies are not compatible with efficient viral replication, but the mechanism by which they act to restrict viral gene expression or genome replication is not yet understood. This article discusses a number of methods that can be employed to gain a more complete understanding of the relationship between cellular SGs and viral RNA and protein synthesis in cells infected with diverse viruses.
Collapse
Affiliation(s)
- Marc D Panas
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Nancy Kedersha
- Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital, Boston, MA, USA
| | - Gerald M McInerney
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden.
| |
Collapse
|