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Das GC, Hollinger FB. GSK-3β as a Potential Coordinator of Anabolic and Catabolic Pathways in Hepatitis C Virus Insulin Resistance. Intervirology 2023; 67:6-18. [PMID: 38104537 PMCID: PMC10794973 DOI: 10.1159/000535787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 12/11/2023] [Indexed: 12/19/2023] Open
Abstract
INTRODUCTION Chronic hepatitis C infection can result in insulin resistance (IR). We have previously shown that it occurs through the interaction of pathways for glucose homeostasis, insulin signaling, and autophagy. But it is not known how soon the pathways are activated and how IR is related to the signals generated by catabolic and anabolic conditions occurring in infected cells. We have extended our studies to a cell culture system mimicking acute infection and to downstream pathways involving energy-sensor AMPK and nutrient-sensor mTOR that are active in catabolic and anabolic processes within the infected cells. METHODS Huh7 liver cells in culture were infected with hepatitis C virus (HCV). We performed proteomics analysis of key proteins in infected cells by Western blotting and IP experiments, with or without IFNα exposure as a component of conventional therapeutic strategy. RESULTS We present evidence that (a) IRS-1 Ser312, Beclin-1, protein conjugate Atg12-Atg5 or GS Ser641 are up-regulated early in infection presumably by activating the same pathways as utilized for persistent infection; (b) Bcl-XL, an inhibitor of both autophagy and apoptosis, is present in a core complex with IRS-1 Ser312 and Beclin-1 during progression of IR; (c) AMPK level remains about the same in infected cells where it is activated by phosphorylation at Thr172 concomitant with increased autophagy, a hallmark of catabolic conditions; (d) an mTOR level that promotes anabolism is increased rather than decreased under an expanded autophagy; (e) hypophosphorylation of translational repressor 4E-BP1 downstream of mTOR is suggestive of reduced protein synthesis; and (f) β-catenin, is up-regulated but not phosphorylated suggesting indirectly our previous contention that its kinase, GSK-3β, is mostly in an inactive state. CONCLUSION We report that in the development of IR following chronic infection, anabolic and catabolic pathways are activated early, and the metabolic interaction occurs possibly in a core complex with IRS-1 Ser312, Beclin-1, and autophagy inhibitor Bcl-XL. Induction of autophagy is usually controlled by a two-edged mechanism acting in opposition under anabolic and catabolic conditions by AMPK/mTOR/4E-BP1 pathway with GSK-3β-mediated feedback loops. However, we have observed an up-regulation of mTOR along with an up-regulation of AMPK caused by HCV infection is a deviation from the normal scenario described above which might be of therapeutic interest.
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Affiliation(s)
- Gokul C Das
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA
| | - F Blaine Hollinger
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA
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Comunale BA, Larson RJ, Jackson-Ward E, Singh A, Koback FL, Engineer LD. The Functional Implications of Broad Spectrum Bioactive Compounds Targeting RNA-Dependent RNA Polymerase (RdRp) in the Context of the COVID-19 Pandemic. Viruses 2023; 15:2316. [PMID: 38140557 PMCID: PMC10747147 DOI: 10.3390/v15122316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 11/20/2023] [Accepted: 11/21/2023] [Indexed: 12/24/2023] Open
Abstract
BACKGROUND As long as COVID-19 endures, viral surface proteins will keep changing and new viral strains will emerge, rendering prior vaccines and treatments decreasingly effective. To provide durable targets for preventive and therapeutic agents, there is increasing interest in slowly mutating viral proteins, including non-surface proteins like RdRp. METHODS A scoping review of studies was conducted describing RdRp in the context of COVID-19 through MEDLINE/PubMed and EMBASE. An iterative approach was used with input from content experts and three independent reviewers, focused on studies related to either RdRp activity inhibition or RdRp mechanisms against SARS-CoV-2. RESULTS Of the 205 records screened, 43 studies were included in the review. Twenty-five evaluated RdRp activity inhibition, and eighteen described RdRp mechanisms of existing drugs or compounds against SARS-CoV-2. In silico experiments suggested that RdRp inhibitors developed for other RNA viruses may be effective in disrupting SARS-CoV-2 replication, indicating a possible reduction of disease progression from current and future variants. In vitro, in vivo, and human clinical trial studies were largely consistent with these findings. CONCLUSIONS Future risk mitigation and treatment strategies against forthcoming SARS-CoV-2 variants should consider targeting RdRp proteins instead of surface proteins.
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Affiliation(s)
- Brittany A. Comunale
- Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Robin J. Larson
- Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA
- Department of Palliative Medicine, Dartmouth-Hitchcock Medical Center, Lebanon, NH 03756, USA
| | - Erin Jackson-Ward
- Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
- Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Aditi Singh
- Department of Biological Sciences, University of California San Diego, La Jolla, CA 92161, USA
| | | | - Lilly D. Engineer
- Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
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3
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Zhang Z, Ding C, Sun T, Wang L, Chen C. Tumor Therapy Strategies Based on Microenvironment-Specific Responsive Nanomaterials. Adv Healthc Mater 2023; 12:e2300153. [PMID: 36933000 DOI: 10.1002/adhm.202300153] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 03/10/2023] [Indexed: 03/19/2023]
Abstract
The tumor microenvironment (TME) is a complex and variable region characterized by hypoxia, low pH, high redox status, overexpression of enzymes, and high-adenosine triphosphate concentrations. In recent years, with the continuous in-depth study of nanomaterials, more and more TME-specific response nanomaterials are used for tumor treatment. However, the complexity of the TME causes different types of responses with various strategies and mechanisms of action. Aiming to systematically demonstrate the recent advances in research on TME-responsive nanomaterials, this work summarizes the characteristics of TME and outlines the strategies of different TME responses. Representative reaction types are illustrated and their merits and demerits are analyzed. Finally, forward-looking views on TME-response strategies for nanomaterials are presented. It is envisaged that such emerging strategies for the treatment of cancer are expected to exhibit dramatic trans-clinical capabilities, demonstrating the extensive potential for the diagnosis and therapy of cancer.
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Affiliation(s)
- Zhaocong Zhang
- Key Laboratory of Forest Plant Ecology, Ministry of Education, College of Chemistry, Chemical Engineering and Resource Utilization, Northeast Forestry University, Harbin, 150040, China
| | - Chengwen Ding
- Key Laboratory of Forest Plant Ecology, Ministry of Education, College of Chemistry, Chemical Engineering and Resource Utilization, Northeast Forestry University, Harbin, 150040, China
| | - Tiedong Sun
- Key Laboratory of Forest Plant Ecology, Ministry of Education, College of Chemistry, Chemical Engineering and Resource Utilization, Northeast Forestry University, Harbin, 150040, China
| | - Lei Wang
- School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, China
| | - Chunxia Chen
- Key Laboratory of Forest Plant Ecology, Ministry of Education, College of Chemistry, Chemical Engineering and Resource Utilization, Northeast Forestry University, Harbin, 150040, China
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4
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Basnet S, Mohanty C, Bochkov YA, Brockman-Schneider RA, Kendziorski C, Gern JE. Rhinovirus C causes heterogeneous infection and gene expression in airway epithelial cell subsets. Mucosal Immunol 2023; 16:386-398. [PMID: 36796588 PMCID: PMC10629931 DOI: 10.1016/j.mucimm.2023.01.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Accepted: 01/27/2023] [Indexed: 02/16/2023]
Abstract
Rhinoviruses infect ciliated airway epithelial cells, and rhinoviruses' nonstructural proteins quickly inhibit and divert cellular processes for viral replication. However, the epithelium can mount a robust innate antiviral immune response. Therefore, we hypothesized that uninfected cells contribute significantly to the antiviral immune response in the airway epithelium. Using single-cell RNA sequencing, we demonstrate that both infected and uninfected cells upregulate antiviral genes (e.g. MX1, IFIT2, IFIH1, and OAS3) with nearly identical kinetics, whereas uninfected non-ciliated cells are the primary source of proinflammatory chemokines. Furthermore, we identified a subset of highly infectable ciliated epithelial cells with minimal interferon responses and determined that interferon responses originate from distinct subsets of ciliated cells with moderate viral replication. These findings suggest that the composition of ciliated airway epithelial cells and coordinated responses of infected and uninfected cells could determine the risk of more severe viral respiratory illnesses in children with asthma, chronic obstructive pulmonary disease, and genetically susceptible individuals.
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Affiliation(s)
- Sarmila Basnet
- Department of Pediatrics, School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA.
| | - Chitrasen Mohanty
- Department of Biostatistics and Medical Informatics, University of Wisconsin, Madison, WI, USA
| | - Yury A Bochkov
- Department of Pediatrics, School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA
| | | | - Christina Kendziorski
- Department of Biostatistics and Medical Informatics, University of Wisconsin, Madison, WI, USA
| | - James E Gern
- Department of Pediatrics, School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA
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5
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Shi Z, Zhang Y, Wang X, Pang H, Jia L, Sun K, Zhang J, Du J, Feng H. Extracellular ATP sensing in living plant tissues with a genetically encoded, ratiometric fluorescent sensor. THE NEW PHYTOLOGIST 2023; 238:1343-1350. [PMID: 36891672 DOI: 10.1111/nph.18868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 03/01/2023] [Indexed: 06/18/2023]
Affiliation(s)
- Zhenzhen Shi
- College of Life Science, Northwest Normal University, Lanzhou, Gansu, 730070, China
| | - Yuejing Zhang
- College of Life Science, Northwest Normal University, Lanzhou, Gansu, 730070, China
| | - Xin Wang
- College of Life Science, Northwest Normal University, Lanzhou, Gansu, 730070, China
| | - Hailong Pang
- College of Life Science, Northwest Normal University, Lanzhou, Gansu, 730070, China
| | - Lingyun Jia
- College of Life Science, Northwest Normal University, Lanzhou, Gansu, 730070, China
| | - Kun Sun
- College of Life Science, Northwest Normal University, Lanzhou, Gansu, 730070, China
| | - Ji Zhang
- College of Life Science, Northwest Normal University, Lanzhou, Gansu, 730070, China
- New Rural Development Research Institute, Northwest Normal University, Lanzhou, Gansu, 730070, China
| | - Jie Du
- College of Life Science, Northwest Normal University, Lanzhou, Gansu, 730070, China
| | - Hanqing Feng
- College of Life Science, Northwest Normal University, Lanzhou, Gansu, 730070, China
- New Rural Development Research Institute, Northwest Normal University, Lanzhou, Gansu, 730070, China
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Metabolic Activation of PARP as a SARS-CoV-2 Therapeutic Target-Is It a Bait for the Virus or the Best Deal We Could Ever Make with the Virus? Is AMBICA the Potential Cure? Biomolecules 2023; 13:biom13020374. [PMID: 36830743 PMCID: PMC9953159 DOI: 10.3390/biom13020374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 02/10/2023] [Accepted: 02/11/2023] [Indexed: 02/18/2023] Open
Abstract
The COVID-19 pandemic has had a great impact on global health and is an economic burden. Even with vaccines and anti-viral medications we are still scrambling to get a balance. In this perspective, we have shed light upon an extremely feasible approach by which we can control the SARS-CoV-2 infection and the associated complications, bringing some solace to this ongoing turmoil. We are providing some insights regarding an ideal agent which could prevent SARS-CoV-2 multiplication. If we could identify an agent which is an activator of metabolism and is also bioactive, we could prevent corona activation (AMBICA). Some naturally occurring lipid molecules best fit this identity as an agent which has the capacity to replenish our host cells, specifically immune cells, with ATP. It could also act as a source for providing a substrate for host cell PARP family members for MARylation and PARylation processes, leading to manipulation of the viral macro domain function, resulting in curbing the virulence and propagation of SARS-CoV-2. Identification of the right lipid molecule or combination of lipid molecules will fulfill the criteria. This perspective has focused on a unique angle of host-pathogen interaction and will open up a new dimension in treating COVID-19 infection.
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Investigation of the Association between the Energy Metabolism of the Insect Vector Laodelphax striatellus and Rice Stripe Virus (RSV). Viruses 2022; 14:v14102298. [PMID: 36298853 PMCID: PMC9607531 DOI: 10.3390/v14102298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Revised: 10/14/2022] [Accepted: 10/18/2022] [Indexed: 11/25/2022] Open
Abstract
Viruses, as intracellular parasites, rely on the host organism to complete their life cycle. Although over 70% of plant viruses are transmitted by insect vectors, the role of vector energy metabolism on the infection process of insect-borne plant viruses is unclear. In this study, full-length cDNAs of three energy metabolism-related genes (LsATPase, LsMIT13 and LsNADP-ME) were obtained from the small brown planthopper (SBPH, Laodelphax striatellus), which transmits the Rice stripe virus (RSV). Expression levels of LsATPase, LsMIT13 and LsNADP-ME increased by 105%, 1120% and 259%, respectively, due to RSV infection. The repression of LsATPase, LsMIT13 or LsNADP-ME by RNAi had no effect on RSV nucleocapsid protein (NP) transcripts or protein levels. The repression of LsATPase caused a significant increase in LsMIT13 and LsNADP-ME transcript levels by 230% and 217%, respectively, and the repression of LsMIT13 caused a significant increase in LsNADP-ME mRNA levels. These results suggested that the silencing of LsATPase induced compensatory upregulation of LsMIT13 and LsNADP-ME, and silencing LsMIT13 induced compensatory upregulation of LsNADP-ME. Further study indicated that the co-silencing of LsATPase, LsMIT13 and LsNADP-ME in viruliferous SBPHs increased ATP production and RSV loads by 182% and 117%, respectively, as compared with nonviruliferous SBPHs. These findings indicate that SBPH energy metabolism is involved in RSV infection and provide insight into the association between plant viruses and energy metabolism in the insect vector.
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San Martín A, Arce-Molina R, Aburto C, Baeza-Lehnert F, Barros LF, Contreras-Baeza Y, Pinilla A, Ruminot I, Rauseo D, Sandoval PY. Visualizing physiological parameters in cells and tissues using genetically encoded indicators for metabolites. Free Radic Biol Med 2022; 182:34-58. [PMID: 35183660 DOI: 10.1016/j.freeradbiomed.2022.02.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 02/08/2022] [Accepted: 02/10/2022] [Indexed: 02/07/2023]
Abstract
The study of metabolism is undergoing a renaissance. Since the year 2002, over 50 genetically-encoded fluorescent indicators (GEFIs) have been introduced, capable of monitoring metabolites with high spatial/temporal resolution using fluorescence microscopy. Indicators are fusion proteins that change their fluorescence upon binding a specific metabolite. There are indicators for sugars, monocarboxylates, Krebs cycle intermediates, amino acids, cofactors, and energy nucleotides. They permit monitoring relative levels, concentrations, and fluxes in living systems. At a minimum they report relative levels and, in some cases, absolute concentrations may be obtained by performing ad hoc calibration protocols. Proper data collection, processing, and interpretation are critical to take full advantage of these new tools. This review offers a survey of the metabolic indicators that have been validated in mammalian systems. Minimally invasive, these indicators have been instrumental for the purposes of confirmation, rebuttal and discovery. We envision that this powerful technology will foster metabolic physiology.
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Affiliation(s)
- A San Martín
- Centro de Estudios Científicos (CECs), Valdivia, Chile.
| | - R Arce-Molina
- Centro de Estudios Científicos (CECs), Valdivia, Chile
| | - C Aburto
- Centro de Estudios Científicos (CECs), Valdivia, Chile; Universidad Austral de Chile, Valdivia, Chile
| | | | - L F Barros
- Centro de Estudios Científicos (CECs), Valdivia, Chile
| | - Y Contreras-Baeza
- Centro de Estudios Científicos (CECs), Valdivia, Chile; Universidad Austral de Chile, Valdivia, Chile
| | - A Pinilla
- Centro de Estudios Científicos (CECs), Valdivia, Chile; Universidad Austral de Chile, Valdivia, Chile
| | - I Ruminot
- Centro de Estudios Científicos (CECs), Valdivia, Chile
| | - D Rauseo
- Centro de Estudios Científicos (CECs), Valdivia, Chile; Universidad Austral de Chile, Valdivia, Chile
| | - P Y Sandoval
- Centro de Estudios Científicos (CECs), Valdivia, Chile
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Fawdry H, Gorrigan R, Ramachandran R, Drake WM. A novel variant of fructose‐1,6‐bisphosphatase gene identified in an adult with newly diagnosed hepatitis C. JIMD Rep 2022; 63:109-113. [PMID: 35281660 PMCID: PMC8898736 DOI: 10.1002/jmd2.12256] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 10/12/2021] [Accepted: 10/13/2021] [Indexed: 11/14/2022] Open
Abstract
Hepatic fructose‐1,6‐bisphosphatase (FBPase) deficiency commonly presents with acute crises during infancy when glycogen stores are depleted. In these patients, dependence on glycogenolysis means that the duration of normoglycaemia is related to liver glycogen stores. Clinical hallmarks of FBPase deficiency include hypoglycaemia and lactic acidosis with or without ketosis. Patients commonly present with hyperventilation, vomiting, tachycardia, reduced consciousness and glucagon‐resistant hypoglycaemia. Between crises, patients are usually well with normal growth and development; however significant ingestion of fructose, sucrose or glycerol during acute crises may be fatal, hence the importance of a prompt diagnosis. We present the case of a 30‐year‐old male who presented to our tertiary centre acutely unwell, shortly following a diagnosis of hepatitis C, which we speculate may have precipitated this severe presentation. He had similar, milder episodes throughout childhood. Furthermore, a pathological homozygous sequence variant in fructose‐1,6‐bisphosphatase (FBP1) gene, previously unreported, was identified. Diagnosis in adulthood is underreported in the literature, however, represents an important, albeit rare, cause of hypoglycaemia and lactic acidosis.
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10
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Molho M, Chuang C, Nagy PD. Co-opting of nonATP-generating glycolytic enzymes for TBSV replication. Virology 2021; 559:15-29. [PMID: 33799077 DOI: 10.1016/j.virol.2021.03.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 03/16/2021] [Accepted: 03/17/2021] [Indexed: 12/21/2022]
Abstract
Positive-strand RNA viruses build viral replication organelles (VROs) with the help of co-opted host factors. The energy requirement of intensive viral replication processes is less understood. Previous studies on tomato bushy stunt virus (TBSV) showed that tombusviruses hijack two ATP-producing glycolytic enzymes to produce ATP locally within VROs. In this work, we performed a cDNA library screen with Arabidopsis thaliana proteins and the TBSV p33 replication protein. The p33 - plant interactome contained highly conserved glycolytic proteins. We find that the glycolytic Hxk2 hexokinase, Eno2 phosphopyruvate hydratase and Fba1 fructose 1,6-bisphosphate aldolase are critical for TBSV replication in yeast or in a cell-free replicase reconstitution assay. The recruitment of Fba1 is important for the local production of ATP within VROs. Altogether, our data support the model that TBSV recruits and compartmentalizes possibly most members of the glycolytic pathway. This might allow TBSV to avoid competition with the host for ATP.
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Affiliation(s)
- Melissa Molho
- Department of Plant Pathology, University of Kentucky, Plant Science Building, Lexington, KY, USA
| | - Chingkai Chuang
- Department of Plant Pathology, University of Kentucky, Plant Science Building, Lexington, KY, USA
| | - Peter D Nagy
- Department of Plant Pathology, University of Kentucky, Plant Science Building, Lexington, KY, USA.
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Su JM, Wilson MZ, Samuel CE, Ma D. Formation and Function of Liquid-Like Viral Factories in Negative-Sense Single-Stranded RNA Virus Infections. Viruses 2021; 13:126. [PMID: 33477448 PMCID: PMC7835873 DOI: 10.3390/v13010126] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 01/14/2021] [Accepted: 01/15/2021] [Indexed: 12/11/2022] Open
Abstract
Liquid-liquid phase separation (LLPS) represents a major physiochemical principle to organize intracellular membrane-less structures. Studies with non-segmented negative-sense (NNS) RNA viruses have uncovered a key role of LLPS in the formation of viral inclusion bodies (IBs), sites of viral protein concentration in the cytoplasm of infected cells. These studies further reveal the structural and functional complexity of viral IB factories and provide a foundation for their future research. Herein, we review the literature leading to the discovery of LLPS-driven formation of IBs in NNS RNA virus-infected cells and the identification of viral scaffold components involved, and then outline important questions and challenges for IB assembly and disassembly. We discuss the functional implications of LLPS in the life cycle of NNS RNA viruses and host responses to infection. Finally, we speculate on the potential mechanisms underlying IB maturation, a phenomenon relevant to many human diseases.
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Affiliation(s)
| | | | | | - Dzwokai Ma
- Department of Molecular, Cellular and Developmental Biology & Neuroscience Research Institute, University of California, Santa Barbara, CA 93106, USA; (J.M.S.); (M.Z.W.); (C.E.S.)
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Aydin H, Engin A, Keleş S, Ertemur Z, Hekim N. Glutamine depletion in patients with Crimean-Congo hemorrhagic fever. J Med Virol 2020; 92:2983-2991. [PMID: 32281664 DOI: 10.1002/jmv.25872] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 04/08/2020] [Indexed: 12/17/2022]
Abstract
Crimean-Congo hemorrhagic fever (CCHF) is a viral disease. There is not enough knowledge about plasma amino acid levels in CCHF. Therefore, we investigated plasma amino acid levels in patients with CCHF and the association between the levels of these amino acids and disease severity. The plasma amino acid levels (including glutamate [Glu], aspartate [Asp], glutamine [Gln], asparagine [Asn] and gamma-aminobutyric acid [GABA]) in CCHF patients and controls were measured by using liquid chromatography-mass spectrometry. Plasma levels of Gln were lower while Asp, Glu, and GABA levels were higher in patients. In fatal CCHF patients, we found the plasma level of Asn was increased whereas the plasma level of GABA was decreased. This study is the first in the literature to evaluate the plasma Gln, Glu, Asn, Asp, and GABA levels in CCHF patients. We found that the plasma Gln levels were significantly lower in CCHF patients while Asp, Glu, and GABA levels were elevated. Considering that these amino acids are important for immune cells, the plasma amino acid levels of CCHF patients may contribute to the understanding of the pathophysiology of disease and it can be important for supportive treatment of CCHF.
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Affiliation(s)
- Hüseyin Aydin
- Department of Biochemistry, Sivas Cumhuriyet University School of Medicine, Sivas, Turkey
| | - Aynur Engin
- Department of Infectious Diseases and Clinical Microbiology, Sivas Cumhuriyet University School of Medicine, Sivas, Turkey
| | - Sami Keleş
- Ahenk Medical Diagnostic and Research Laboratory, Istanbul, Turkey
| | - Zeynep Ertemur
- Department of Biochemistry, Sivas Cumhuriyet University School of Medicine, Sivas, Turkey
| | - Nezih Hekim
- Department of Molecular Biology and Genetics, Biruni University, School of Medicine and Faculty of Engineering and Natural Sciences, Istanbul, Turkey
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Cambré A, Aertsen A. Bacterial Vivisection: How Fluorescence-Based Imaging Techniques Shed a Light on the Inner Workings of Bacteria. Microbiol Mol Biol Rev 2020; 84:e00008-20. [PMID: 33115939 PMCID: PMC7599038 DOI: 10.1128/mmbr.00008-20] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The rise in fluorescence-based imaging techniques over the past 3 decades has improved the ability of researchers to scrutinize live cell biology at increased spatial and temporal resolution. In microbiology, these real-time vivisections structurally changed the view on the bacterial cell away from the "watery bag of enzymes" paradigm toward the perspective that these organisms are as complex as their eukaryotic counterparts. Capitalizing on the enormous potential of (time-lapse) fluorescence microscopy and the ever-extending pallet of corresponding probes, initial breakthroughs were made in unraveling the localization of proteins and monitoring real-time gene expression. However, later it became clear that the potential of this technique extends much further, paving the way for a focus-shift from observing single events within bacterial cells or populations to obtaining a more global picture at the intra- and intercellular level. In this review, we outline the current state of the art in fluorescence-based vivisection of bacteria and provide an overview of important case studies to exemplify how to use or combine different strategies to gain detailed information on the cell's physiology. The manuscript therefore consists of two separate (but interconnected) parts that can be read and consulted individually. The first part focuses on the fluorescent probe pallet and provides a perspective on modern methodologies for microscopy using these tools. The second section of the review takes the reader on a tour through the bacterial cell from cytoplasm to outer shell, describing strategies and methods to highlight architectural features and overall dynamics within cells.
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Affiliation(s)
- Alexander Cambré
- KU Leuven, Department of Microbial and Molecular Systems, Faculty of Bioscience Engineering, Leuven, Belgium
| | - Abram Aertsen
- KU Leuven, Department of Microbial and Molecular Systems, Faculty of Bioscience Engineering, Leuven, Belgium
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Lee YM, Kim DY, Park KH, Lee MS, Kim YJ. Monitoring environmental contamination caused by SARS-CoV-2 in a healthcare facility by using adenosine triphosphate testing. Am J Infect Control 2020; 48:1280-1281. [PMID: 32652254 PMCID: PMC7342043 DOI: 10.1016/j.ajic.2020.06.207] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 06/24/2020] [Indexed: 01/22/2023]
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15
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Zhao RZ, Wang XB, Jiang S, Ru NY, Jiao B, Wang YY, Yu ZB. Elevated ROS depress mitochondrial oxygen utilization efficiency in cardiomyocytes during acute hypoxia. Pflugers Arch 2020; 472:1619-1630. [PMID: 32940783 DOI: 10.1007/s00424-020-02463-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 07/24/2020] [Accepted: 09/07/2020] [Indexed: 11/28/2022]
Abstract
Mitochondria are important sites for the production of ATP and the generation of ROS in cells. However, whether acute hypoxia increases ROS generation in cells or affects ATP production remains unclear, and therefore, monitoring the changes in ATP and ROS in living cells in real time is important. In this study, cardiomyocytes were transfected with RoGFP for ROS detection and MitGO-Ateam2 for ATP detection, whereby ROS and ATP production in cardiomyocytes were respectively monitored in real time. Furthermore, the oxygen consumption rate (OCR) of cardiomyocytes was measured. Similar results were produced for adult and neonatal rat cardiomyocytes. Hypoxia (1% O2) reduced the basal OCR, ATP-linked OCR, and maximal OCR in cardiomyocytes compared with these OCR levels in the cardiomyocytes in the normoxic group (21% O2). However, ATP-linked OCR, normalized to maximal OCR, was increased during hypoxia, indicating that the electron leakage of complex III exacerbated the increase of ATP-linked oxygen consumption during hypoxia and vice versa. Combined with the result that cardiomyocytes expressing MitGO-Ateam2 showed a significant decrease in ATP production during hypoxia compared with that of normoxic group, acute hypoxia might depress the mitochondrial oxygen utilization efficiency of the cardiomyocytes. Moreover, cardiomyocytes expressing Cyto-RoGFP or IMS-RoGFP showed an increase in ROS generation in the cytosol and the mitochondrial intermembrane space (IMS) during hypoxia. All of these results indicate that acute hypoxia generated more ROS in complex III and increased mitochondrial oxygen consumption, leading to less ATP production. In conclusion, acute hypoxia depresses the mitochondrial oxygen utilization efficiency by decreasing ATP production and increasing oxygen consumption as a result of the enhanced ROS generation at mitochondrial complex III.
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Affiliation(s)
- Ru-Zhou Zhao
- Department of Aerospace Physiology, Fourth Military Medical University, 169# Changle West Road, Xi'an, 710032, China
| | - Xiao-Bo Wang
- Department of Aerospace Physiology, Fourth Military Medical University, 169# Changle West Road, Xi'an, 710032, China
| | - Shuai Jiang
- Department of Aerospace Physiology, Fourth Military Medical University, 169# Changle West Road, Xi'an, 710032, China
| | - Ning-Yu Ru
- Department of Aerospace Physiology, Fourth Military Medical University, 169# Changle West Road, Xi'an, 710032, China
| | - Bo Jiao
- Department of Aerospace Physiology, Fourth Military Medical University, 169# Changle West Road, Xi'an, 710032, China
| | - Yun-Ying Wang
- Department of Aerospace Physiology, Fourth Military Medical University, 169# Changle West Road, Xi'an, 710032, China.
| | - Zhi-Bin Yu
- Department of Aerospace Physiology, Fourth Military Medical University, 169# Changle West Road, Xi'an, 710032, China.
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Experimental validation of influenza A virus matrix protein (M1) interaction with host cellular alpha enolase and pyruvate kinase. Virology 2020; 549:59-67. [PMID: 32841760 DOI: 10.1016/j.virol.2020.07.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 07/30/2020] [Accepted: 07/30/2020] [Indexed: 01/15/2023]
Abstract
Influenza A virus, a respiratory pathogen manipulates various host cellular processes to establish a successful infection in a host. We had reported earlier the interaction of influenza A virus nucleoprotein with host glycolytic enzymes; alpha enolase and pyruvate kinase in A549 cells. Matrix protein (M1), another multifunctional protein encoded by genome segment 7 forms the inner layer of the virion and interacts with the ribonucleoprotein complex. Nucleoprotein and matrix protein, major structural components of the virion together contribute to the stability of the capsid. Thus, we have investigated the interaction of viral matrix protein with host glycolytic enzymes; alpha enolase and pyruvate kinase. Results had demonstrated differential expression of these two glycolytic enzymes in response to matrix protein and their interaction with matrix protein by in vitro binding, co-immunoprecipitation and co-localization studies. Our results confirmed that viral matrix protein interacts with host glycolytic enzymes in association with viral nucleoprotein.
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Wang P, Jia J, Zhang D. Purinergic signalling in liver diseases: Pathological functions and therapeutic opportunities. JHEP Rep 2020; 2:100165. [PMID: 33103092 PMCID: PMC7575885 DOI: 10.1016/j.jhepr.2020.100165] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 06/24/2020] [Accepted: 07/22/2020] [Indexed: 12/12/2022] Open
Abstract
Extracellular nucleotides, including ATP, are essential regulators of liver function and serve as danger signals that trigger inflammation upon injury. Ectonucleotidases, which are expressed by liver-resident cells and recruited immune cells sequentially hydrolyse nucleotides to adenosine. The nucleotide/nucleoside balance orchestrates liver homeostasis, tissue repair, and functional restoration by regulating the crosstalk between liver-resident cells and recruited immune cells. In this review, we discuss our current knowledge on the role of purinergic signals in liver homeostasis, restriction of inflammation, stimulation of liver regeneration, modulation of fibrogenesis, and regulation of carcinogenesis. Moreover, we discuss potential targeted therapeutic strategies for liver diseases based on purinergic signals involving blockade of nucleotide receptors, enhancement of ectonucleoside triphosphate diphosphohydrolase activity, and activation of adenosine receptors.
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Key Words
- A1, adenosine receptor A1
- A2A, adenosine receptor A2A
- A2B, adenosine receptor A2B
- A3, adenosine receptor A3
- AIH, autoimmune hepatitis
- ALT, alanine aminotransferase
- APAP, acetaminophen
- APCP, α,β-methylene ADP
- Adenosine receptors
- BDL, bile duct ligation
- CCl4, carbon tetrachloride
- CD73, ecto-5ʹ-nucleotidase
- ConA, concanavalin A
- DCs, dendritic cells
- DMN, dimethylnitrosamine
- Ecto-5ʹ-nucleotidase
- Ectonucleoside triphosphate diphosphohydrolases 1
- HCC, hepatocellular carcinoma
- HFD, high-fat diet
- HGF, hepatocyte growth factor
- HSCs, hepatic stellate cells
- IFN, interferon
- IL-, interleukin-
- IPC, ischaemic preconditioning
- IR, ischaemia-reperfusion
- Liver
- MAPK, mitogen-activating protein kinase
- MCDD, methionine- and choline-deficient diet
- MHC, major histocompatibility complex
- NAFLD, non-alcoholic fatty liver disease
- NK, natural killer
- NKT, natural killer T
- NTPDases, ectonucleoside triphosphate diphosphohydrolases
- Nucleotide receptors
- P1, purinergic type 1
- P2, purinergic type 2
- PBC, primary biliary cholangitis
- PH, partial hepatectomy
- PKA, protein kinase A
- PPADS, pyridoxal-phosphate-6-azophenyl-2′,4′-disulphonate
- Purinergic signals
- ROS, reactive oxygen species
- TAA, thioacetamide
- TNF, tumour necrosis factor
- Tregs, regulatory T cells
- VEGF, vascular endothelial growth factor
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Affiliation(s)
- Ping Wang
- Liver Research Center, Beijing Friendship Hospital, Capital Medical University, Beijing Key Laboratory of Translational Medicine on Liver Cirrhosis & National Clinical Research Center for Digestive Diseases, Beijing 100050, China
| | - Jidong Jia
- Liver Research Center, Beijing Friendship Hospital, Capital Medical University, Beijing Key Laboratory of Translational Medicine on Liver Cirrhosis & National Clinical Research Center for Digestive Diseases, Beijing 100050, China
| | - Dong Zhang
- Experimental and Translational Research Center, Beijing Friendship Hospital, Capital Medical University, Beijing Key Laboratory of Tolerance Induction and Organ Protection in Transplantation & National Clinical Research Center for Digestive Diseases, Beijing 100050, China
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Doysabas KCC, Oba M, Ishibashi T, Shibata H, Takemae H, Shimoda H, Tarigan R, Mizutani T, Iida A, Hondo E. ATeam technology for detecting early signs of viral cytopathic effect. J Vet Med Sci 2020; 82:387-393. [PMID: 32051347 PMCID: PMC7118481 DOI: 10.1292/jvms.20-0021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Adenosine 5’-triphosphate (ATP), the major energy currency of the cell, is involved in many cellular processes, including the viral life cycle, and can be used as an indicator of early
signs of cytopathic effect (CPE). In this study, we demonstrated that CPE can be analyzed using an FRET-based ATP probe named ATP indicator based on Epsilon subunit for Analytical
Measurements (ATeam). The results revealed that as early as 3 hr, the virus infected cells showed a significantly different Venus/cyan fluorescent protein (CFP) ratio compared to the
mock-infected cells. The ATeam technology is therefore useful to determine the early signs of ATP-based CPE as early as 3 hr without morphology-based CPE by light microscopy, and enables
high throughput determination of the presence of microorganisms in neglected samples stored in laboratories.
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Affiliation(s)
- Karla Cristine C Doysabas
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan
| | - Mami Oba
- Laboratory of Veterinary Microbiology, Cooperative Department of Veterinary Medicine, Tokyo University of Agriculture and Technology, Sawai, Fuchu, Tokyo 183-8509, Japan
| | - Tomoki Ishibashi
- Laboratory of Insect Ecology, Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8224, Japan
| | - Hideki Shibata
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan
| | - Hitoshi Takemae
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan
| | - Hiroshi Shimoda
- Laboratory of Veterinary Microbiology, Joint Faculty of Veterinary Medicine, Yamaguchi University, 1677-1 Yoshida, Yamaguchi-shi, Yamaguchi 753-8511, Japan
| | - Ronald Tarigan
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan
| | - Tetsuya Mizutani
- Laboratory of Veterinary Microbiology, Cooperative Department of Veterinary Medicine, Tokyo University of Agriculture and Technology, Sawai, Fuchu, Tokyo 183-8509, Japan
| | - Atsuo Iida
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan
| | - Eiichi Hondo
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan
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Malabi R, Lebohang Manoto S, Ombinda-Lemboumba S, Maaza M, Mthunzi-Kufa P. Laser-enhanced drug delivery of antiretroviral drugs into human immunodeficiency virus-1 infected TZMbl cells. JOURNAL OF BIOPHOTONICS 2019; 12:e201800424. [PMID: 31140728 DOI: 10.1002/jbio.201800424] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 04/26/2019] [Accepted: 05/27/2019] [Indexed: 06/09/2023]
Abstract
The introduction of highly active antiretroviral therapy (HAART) has significantly increased life expectancy and improved management of the human immunodeficiency virus-1 (HIV-1) disease globally. This well-established treatment regime has shown to reduce viral capacity to undetectable limits when using traditional clinical assays. The establishment of viral reservoirs during the early stages of infection are the major contributors to failure of the current regimens to eradicate HIV-1 infection since the reservoirs are not affected by antiretroviral drugs (ARVs). Therefore, advanced modification of the present treatment and investigation of novel antiretroviral drug delivery system are needed. The aim of this study was to use femtosecond (fs) laser pulses to deliver ARVs into HIV-1 infected TZMbl cells. Different ARVs were translocated into TZMbl cells using fs pulsed laser (800 nm) with optimum power of 4 μW and 10 ms laser to cell exposure time. Changes in cellular processes were evaluated using cellular morphology, viability, cytotoxicity and luciferase activity assays. Cells treated with the laser in the presence of ARVs showed a significant reduction in viral infectivity, cell viability and an increase in cytotoxicity. This study demonstrated that fs laser pulses were highly effective in delivering ARVs into HIV-1 infected TZMbl cells, causing a significant reduction in HIV-1 infection.
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Affiliation(s)
- Rudzani Malabi
- Biophotonics, National Laser Centre, Council for Scientific and Industrial Research, Pretoria, South Africa
- College of Science, Engineering and Technology, Department of Physics, NB Pityana Building, University of South Africa, Florida, South Africa
| | - Sello Lebohang Manoto
- Biophotonics, National Laser Centre, Council for Scientific and Industrial Research, Pretoria, South Africa
| | - Saturnin Ombinda-Lemboumba
- Biophotonics, National Laser Centre, Council for Scientific and Industrial Research, Pretoria, South Africa
| | - Malik Maaza
- College of Science, Engineering and Technology, Department of Physics, NB Pityana Building, University of South Africa, Florida, South Africa
| | - Patience Mthunzi-Kufa
- Biophotonics, National Laser Centre, Council for Scientific and Industrial Research, Pretoria, South Africa
- College of Science, Engineering and Technology, Department of Physics, NB Pityana Building, University of South Africa, Florida, South Africa
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20
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Model System for the Formation of Tick-Borne Encephalitis Virus Replication Compartments without Viral RNA Replication. J Virol 2019; 93:JVI.00292-19. [PMID: 31243132 PMCID: PMC6714791 DOI: 10.1128/jvi.00292-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 06/17/2019] [Indexed: 01/01/2023] Open
Abstract
TBEV infection causes a broad spectrum of symptoms, ranging from mild fever to severe encephalitis. Similar to other flaviviruses, TBEV exploits intracellular membranes to build RCs for viral replication. The viral NS proteins have been suggested to be involved in this process; however, the mechanism of RC formation and the roles of individual NS proteins remain unclear. To study how TBEV induces membrane remodeling, we developed an inducible stable cell system expressing the TBEV NS polyprotein in the absence of viral RNA replication. Using this system, we were able to reproduce RC-like vesicles that resembled the RCs formed in flavivirus-infected cells, in terms of morphology and size. This cell system is a robust tool to facilitate studies of flavivirus RC formation and is an ideal model for the screening of antiviral agents at a lower biosafety level. Flavivirus is a positive-sense, single-stranded RNA viral genus, with members causing severe diseases in humans such as tick-borne encephalitis, yellow fever, and dengue fever. Flaviviruses are known to cause remodeling of intracellular membranes into small cavities, where replication of the viral RNA takes place. Nonstructural (NS) proteins are not part of the virus coat and are thought to participate in the formation of these viral replication compartments (RCs). Here, we used tick-borne encephalitis virus (TBEV) as a model for the flaviviruses and developed a stable human cell line in which the expression of NS proteins can be induced without viral RNA replication. The model system described provides a novel and benign tool for studies of the viral components under controlled expression levels. We show that the expression of six NS proteins is sufficient to induce infection-like dilation of the endoplasmic reticulum (ER) and the formation of RC-like membrane invaginations. The NS proteins form a membrane-associated complex in the ER, and electron tomography reveals that the dilated areas of the ER are closely associated with lipid droplets and mitochondria. We propose that the NS proteins drive the remodeling of ER membranes and that viral RNA, RNA replication, viral polymerase, and TBEV structural proteins are not required. IMPORTANCE TBEV infection causes a broad spectrum of symptoms, ranging from mild fever to severe encephalitis. Similar to other flaviviruses, TBEV exploits intracellular membranes to build RCs for viral replication. The viral NS proteins have been suggested to be involved in this process; however, the mechanism of RC formation and the roles of individual NS proteins remain unclear. To study how TBEV induces membrane remodeling, we developed an inducible stable cell system expressing the TBEV NS polyprotein in the absence of viral RNA replication. Using this system, we were able to reproduce RC-like vesicles that resembled the RCs formed in flavivirus-infected cells, in terms of morphology and size. This cell system is a robust tool to facilitate studies of flavivirus RC formation and is an ideal model for the screening of antiviral agents at a lower biosafety level.
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21
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Qu C, Zhang S, Li Y, Wang Y, Peppelenbosch MP, Pan Q. Mitochondria in the biology, pathogenesis, and treatment of hepatitis virus infections. Rev Med Virol 2019; 29:e2075. [PMID: 31322806 PMCID: PMC6771966 DOI: 10.1002/rmv.2075] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 06/18/2019] [Accepted: 06/19/2019] [Indexed: 12/19/2022]
Abstract
Hepatitis virus infections affect a large proportion of the global population. The host responds rapidly to viral infection by orchestrating a variety of cellular machineries, in particular, the mitochondrial compartment. Mitochondria actively regulate viral infections through modulation of the cellular innate immunity and reprogramming of metabolism. In turn, hepatitis viruses are able to modulate the morphodynamics and functions of mitochondria, but the mode of actions are distinct with respect to different types of hepatitis viruses. The resulting mutual interactions between viruses and mitochondria partially explain the clinical presentation of viral hepatitis, influence the response to antiviral treatment, and offer rational avenues for novel therapy. In this review, we aim to consider in depth the multifaceted interactions of mitochondria with hepatitis virus infections and emphasize the implications for understanding pathogenesis and advancing therapeutic development.
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Affiliation(s)
- Changbo Qu
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, China.,The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, China.,Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, The Netherlands
| | - Shaoshi Zhang
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, The Netherlands
| | - Yang Li
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, The Netherlands
| | - Yijin Wang
- Department of Pathology and Hepatology, Beijing 302 Hospital, Beijing, China
| | - Maikel P Peppelenbosch
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, The Netherlands
| | - Qiuwei Pan
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, The Netherlands
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22
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Westerlund E, Valfridsson C, Yi DX, Persson JJ. The Secreted Virulence Factor NADase of Group A Streptococcus Inhibits P2X7 Receptor-Mediated Release of IL-1β. Front Immunol 2019; 10:1385. [PMID: 31275321 PMCID: PMC6591467 DOI: 10.3389/fimmu.2019.01385] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 06/03/2019] [Indexed: 12/29/2022] Open
Abstract
The common human pathogen Group A Streptococcus (GAS) causes superficial as well as invasive, life-threatening diseases. An increase in the occurrence of invasive GAS infection by strains of the M1 and M89 serotypes has been correlated with increased expression of the genetically and functionally linked virulence factors streptolysin O (SLO) and β-NAD+-glycohydrolase (NADase). NADase affects host cells differently depending on its location: its SLO-dependent translocation into the cytosol can lead to cell death through β-NAD+ depletion, while extracellularly located NADase inhibits IL-1β release downstream of Nlrp3 inflammasome activation. In this study, we use a macrophage infection model to investigate the NADase-dependent inhibition of IL-1β release. We show that bacteria expressing a functional NADase evade P2X7 activation, while infection with a NADase-deficient GAS strain leads to a P2X7-mediated increase in IL-1β. Further, our data indicate that in the absence of NADase, IL-1β is released through both P2X7-dependent and -independent pathways, although the precise mechanisms of how this occur are still unclear. This study adds information about the mechanism by which NADase regulates inflammasome-dependent IL-1β release, which may in part explain why increased NADase expression correlates with bacterial virulence.
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Affiliation(s)
- Elsa Westerlund
- Immunology Section, Department of Experimental Medical Sciences, Lund University, Lund, Sweden
| | - Christine Valfridsson
- Immunology Section, Department of Experimental Medical Sciences, Lund University, Lund, Sweden
| | - Daisy X Yi
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, United States
| | - Jenny J Persson
- Immunology Section, Department of Experimental Medical Sciences, Lund University, Lund, Sweden
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23
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The kinetic characteristics of human and trypanosomatid phosphofructokinases for the reverse reaction. Biochem J 2019; 476:179-191. [PMID: 30404924 PMCID: PMC6340114 DOI: 10.1042/bcj20180635] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 11/02/2018] [Accepted: 11/06/2018] [Indexed: 02/06/2023]
Abstract
Eukaryotic ATP-dependent phosphofructokinases (PFKs) are often considered unidirectional enzymes catalysing the transfer of a phospho moiety from ATP to fructose 6-phosphate to produce ADP and fructose 1,6-bisphosphate. The reverse reaction is not generally considered to occur under normal conditions and has never been demonstrated for any eukaryotic ATP-dependent PFKs, though it does occur in inorganic pyrophosphate-dependent PFKs and has been experimentally shown for bacterial ATP-dependent PFKs. The evidence is provided via two orthogonal assays that all three human PFK isoforms can catalyse the reverse reaction in vitro, allowing determination of kinetic properties. Additionally, the reverse reaction was shown possible for PFKs from three clinically important trypanosomatids; these enzymes are contained within glycosomes in vivo. This compartmentalisation may facilitate reversal, given the potential for trypanosomatids to have an altered ATP/ADP ratio in glycosomes compared with the cytosol. The kinetic properties of each trypanosomatid PFK were determined, including the response to natural and artificial modulators of enzyme activity. The possible physiological relevance of the reverse reaction in trypanosomatid and human PFKs is discussed.
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24
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Seacrist CD, Blind RD. Crystallographic and kinetic analyses of human IPMK reveal disordered domains modulate ATP binding and kinase activity. Sci Rep 2018; 8:16672. [PMID: 30420721 PMCID: PMC6232094 DOI: 10.1038/s41598-018-34941-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 10/26/2018] [Indexed: 11/09/2022] Open
Abstract
Inositol polyphosphate multikinase (IPMK) is a member of the IPK-superfamily of kinases, catalyzing phosphorylation of several soluble inositols and the signaling phospholipid PI(4,5)P2 (PIP2). IPMK also has critical non-catalytic roles in p53, mTOR/Raptor, TRAF6 and AMPK signaling mediated partly by two disordered domains. Although IPMK non-catalytic functions are well established, it is less clear if the disordered domains are important for IPMK kinase activity or ATP binding. Here, kinetic and structural analyses of an engineered human IPMK lacking all disordered domains (ΔIPMK) are presented. Although the KM for PIP2 is identical between ΔIPMK and wild type, ΔIPMK has a 1.8-fold increase in kcat for PIP2, indicating the native IPMK disordered domains decrease IPMK activity in vitro. The 2.5 Å crystal structure of ΔIPMK is reported, confirming the conserved ATP-grasp fold. A comparison with other IPK-superfamily structures revealed a putative "ATP-clamp" in the disordered N-terminus, we predicted would stabilize ATP binding. Consistent with this observation, removal of the ATP clamp sequence increases the KM for ATP 4.9-fold, indicating the N-terminus enhances ATP binding to IPMK. Together, these structural and kinetic studies suggest in addition to mediating protein-protein interactions, the disordered domains of IPMK impart modulatory capacity to IPMK kinase activity through multiple kinetic mechanisms.
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Affiliation(s)
- Corey D Seacrist
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Raymond D Blind
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA.
- Departments of Pharmacology, Biochemistry and Medicine; Division of Diabetes, Endocrinology and Metabolism, Vanderbilt Diabetes Research and Training Center, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA.
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25
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Li X, Qian X, Jiang H, Xia Y, Zheng Y, Li J, Huang BJ, Fang J, Qian CN, Jiang T, Zeng YX, Lu Z. Nuclear PGK1 Alleviates ADP-Dependent Inhibition of CDC7 to Promote DNA Replication. Mol Cell 2018; 72:650-660.e8. [PMID: 30392930 DOI: 10.1016/j.molcel.2018.09.007] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 07/30/2018] [Accepted: 09/06/2018] [Indexed: 01/11/2023]
Abstract
DNA replication is initiated by assembly of the kinase cell division cycle 7 (CDC7) with its regulatory activation subunit, activator of S-phase kinase (ASK), to activate DNA helicase. However, the mechanism underlying regulation of CDC7-ASK complex is unclear. Here, we show that ADP generated from CDC7-mediated MCM phosphorylation binds to an allosteric region of CDC7, disrupts CDC7-ASK interaction, and inhibits CDC7-ASK activity in a feedback way. EGFR- and ERK-activated casein kinase 2α (CK2α) phosphorylates nuclear phosphoglycerate kinase (PGK) 1 at S256, resulting in interaction of PGK1 with CDC7. CDC7-bound PGK1 converts ADP to ATP, thereby abrogating the inhibitory effect of ADP on CDC7-ASK activity, promoting the recruitment of DNA helicase to replication origins, DNA replication, cell proliferation, and brain tumorigenesis. These findings reveal an instrumental self-regulatory mechanism of CDC7-ASK activity by its kinase reaction product ADP and a nonglycolytic role for PGK1 in abrogating this negative feedback in promoting tumor development.
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Affiliation(s)
- Xinjian Li
- Brain Tumor Center, Department of Neuro-Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA; CAS Key Laboratory of Infection and Immunity, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Xu Qian
- Brain Tumor Center, Department of Neuro-Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA; Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Cancer Personalized Medicine, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Hongfei Jiang
- Qingdao National Laboratory for Marine Science and Technology, Key Laboratory of Marine Drugs of Minister of Education of China, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Yan Xia
- Brain Tumor Center, Department of Neuro-Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Yanhua Zheng
- Brain Tumor Center, Department of Neuro-Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Jing Li
- Qingdao National Laboratory for Marine Science and Technology, Key Laboratory of Marine Drugs of Minister of Education of China, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Bi-Jun Huang
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou 510060, China
| | - Jing Fang
- Cancer Institute, The Affiliated Hospital of Qingdao University, Qingdao, Shandong 266061, China; Qingdao Cancer Institute, Qingdao, Shandong 266061, China
| | - Chao-Nan Qian
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou 510060, China
| | - Tao Jiang
- Qingdao National Laboratory for Marine Science and Technology, Key Laboratory of Marine Drugs of Minister of Education of China, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Yi-Xin Zeng
- CAS Key Laboratory of Infection and Immunity, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou 510060, China
| | - Zhimin Lu
- Brain Tumor Center, Department of Neuro-Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA; Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA; Cancer Biology Program, MD Anderson Cancer Center UT Health Graduate School of Biomedical Sciences, The University of TX, Houston, Texas 77030, USA.
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26
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Khalid M, Manzoor S, Ahmad H, Asif A, Bangash TA, Latif A, Jaleel S. Purinoceptor expression in hepatocellular virus (HCV)-induced and non-HCV hepatocellular carcinoma: an insight into the proviral role of the P2X4 receptor. Mol Biol Rep 2018; 45:2625-2630. [PMID: 30343397 DOI: 10.1007/s11033-018-4432-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 10/09/2018] [Indexed: 12/15/2022]
Abstract
The basic idea behind this study was to discover the association and prevalence of purinoceptors in hepatitis C virus (HCV) and non-HCV hepatocellular carcinoma (HCC). Immunohistochemistry was performed to study the expression of P2X4 and P2X7 receptors on ex-planted liver tissue samples that were collected from HCC patients. Antibodies specific for the P2X4 and P2X7 receptors were used to target the specific receptors and secondary antibody was used with 3,3'-diaminobenzidine (DAB) detection system to visualize the color change in case of any positive expression There was a substantial increase in P2X4 receptor expression in HCV induced HCC as compared to non-HCV HCC. Surprisingly, there was no increase in the P2X7 receptor expression in both HCV HCC and non-HCV HCC. We conclude that P2X4 receptor expression was significant in the presence of HCV HCC. This may confirms the potential role of P2X4 receptor in the presence of virus in liver pathology. However insignificant expression of P2X7 receptor may avert our attention towards understanding the role of this receptor in pro-inflammatory and immune responses.
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Affiliation(s)
- Madiha Khalid
- Atta-ur-Rahman School of Applied Bio-Sciences, Department of Healthcare Biotechnology, National University of Sciences and Technology, Islamabad, 44000, Pakistan
| | - Sobia Manzoor
- Atta-ur-Rahman School of Applied Bio-Sciences, Department of Healthcare Biotechnology, National University of Sciences and Technology, Islamabad, 44000, Pakistan.
| | - Hassam Ahmad
- HepatopancreatoBiliary Liver Transplant Unit, Shaikh Zayd Hospital, Lahore, 54000, Punjab, Pakistan
| | - Arun Asif
- Atta-ur-Rahman School of Applied Bio-Sciences, Department of Healthcare Biotechnology, National University of Sciences and Technology, Islamabad, 44000, Pakistan
| | - Tariq Ali Bangash
- HepatopancreatoBiliary Liver Transplant Unit, Shaikh Zayd Hospital, Lahore, 54000, Punjab, Pakistan
| | - Amer Latif
- HepatopancreatoBiliary Liver Transplant Unit, Shaikh Zayd Hospital, Lahore, 54000, Punjab, Pakistan
| | - Shahla Jaleel
- Department of Histopathology, Shaikh Zayd Hospital, Lahore, 54000, Punjab, Pakistan
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27
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Infection with flaviviruses requires BCLXL for cell survival. PLoS Pathog 2018; 14:e1007299. [PMID: 30261081 PMCID: PMC6177207 DOI: 10.1371/journal.ppat.1007299] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 10/09/2018] [Accepted: 08/27/2018] [Indexed: 12/12/2022] Open
Abstract
BCL2 family proteins including pro-survival proteins, BH3-only proteins and BAX/BAK proteins control mitochondria-mediated apoptosis to maintain cell homeostasis via the removal of damaged cells and pathogen-infected cells. In this study, we examined the roles of BCL2 proteins in the induction of apoptosis in cells upon infection with flaviviruses, such as Japanese encephalitis virus, Dengue virus and Zika virus. We showed that survival of the infected cells depends on BCLXL, a pro-survival BCL2 protein due to suppression of the expression of another pro-survival protein, MCL1. Treatment with BCLXL inhibitors, as well as deficient BCLXL gene expression, induced BAX/BAK-dependent apoptosis upon infection with flaviviruses. Flavivirus infection attenuates cellular protein synthesis, which confers reduction of short-half-life proteins like MCL1. Inhibition of BCLXL increased phagocytosis of virus-infected cells by macrophages, thereby suppressing viral dissemination and chemokine production. Furthermore, we examined the roles of BCLXL in the death of JEV-infected cells during in vivo infection. Haploinsufficiency of the BCLXL gene, as well as administration of BH3 mimetic compounds, increased survival rate after challenge of JEV infection and suppressed inflammation. These results suggest that BCLXL plays a crucial role in the survival of cells infected with flaviviruses, and that BCLXL may provide a novel antiviral target to suppress propagation of the family of Flaviviridae viruses. The genus Flavivirus including Japanese encephalitis virus, Dengue virus, and Zika virus all of which are mosquito-borne human pathogen and cause serious diseases in humans. Therefore, the development of effective vaccines and antivirals against several flaviviruses is still needed. BCL2 family proteins control mitochondria-mediated apoptosis to maintain cell homeostasis via the removal of damaged cells and pathogen-infected cells, deregulation of which leads to severe diseases including cancer and autoimmune diseases. Here, we showed that BCLXL is a critical cell survival factor during infection with flaviviruses, and that inhibition of BCLXL by treatment with BH3 mimetics restricts the production of infectious particles and the expression of chemokines in vitro and in vivo. Inhibition of BCLXL induces apoptosis in cells infected with flaviviruses and these cells are quickly removed by engulfment of phagocytes, which leads to inhibition of virus dissemination without any inflammatory reaction. Based on these data, BCLXL would appear to be a suitable target for the development of novel antivirals against a broad range of flavivirus infections.
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28
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Maruyama H, Kimura T, Liu H, Ohtsuki S, Miyake Y, Isogai M, Arai F, Honda A. Influenza virus replication raises the temperature of cells. Virus Res 2018; 257:94-101. [PMID: 30248374 DOI: 10.1016/j.virusres.2018.09.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 09/03/2018] [Accepted: 09/19/2018] [Indexed: 01/08/2023]
Abstract
Influenza virus invades the cell by binding sialic acid on the cell membrane through haemagglutinin (HA), and then genome replication and transcription are carried out in the nucleus to produce progeny virus. Multiplication of influenza virus requires metabolites, such as nucleotides and amino acids, as well as cellular machinery to synthesize its genome and proteins, thereby producing viral particles. Influenza virus infection forces the start of several metabolic systems in the cell, which consume or generate large amounts of energy. Thus, the viral multiplication processes involved in both genome replication and transcription are considered to require large numbers of nucleotides. The high-level consumption of nucleotides generates large amounts of energy, some of which is converted into heat, and this heat may increase the temperature of cells. To address this question, we prepared a tool based on rhodamine B fluorescence, which we used to measure the temperatures of influenza virus-infected and uninfected cells. The results indicated that influenza virus multiplication increased the temperature of cells by approximately 4 °C - 5 °C, ATP levels in the cells decreased at 3 h after infection, and mitochondrial membrane potential decreased with multiplication level. Thus, the increase in cellular temperature during influenza virus infection appears to be due to the massive consumption of ATP over a short period.
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Affiliation(s)
- Hisataka Maruyama
- Department of Micro-Nano Systems Engineering, Nagoya University, Nagoya, Aichi, 464-8603, Japan
| | - Takahiro Kimura
- Department of Frontier Bioscience, Hosei University, Koganei, Tokyo, 184-8584, Japan
| | - Hengiun Liu
- Department of Micro-Nano Systems Engineering, Nagoya University, Nagoya, Aichi, 464-8603, Japan
| | - Sumio Ohtsuki
- Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto 862-0973, Japan
| | - Yukari Miyake
- Department of Frontier Bioscience, Hosei University, Koganei, Tokyo, 184-8584, Japan
| | - Masashi Isogai
- Technical section, PerkinElmer Japan Co, LTD, Yokohama, Kanagawa, 240-0005, Japan
| | - Fumihito Arai
- Department of Micro-Nano Systems Engineering, Nagoya University, Nagoya, Aichi, 464-8603, Japan.
| | - Ayae Honda
- Department of Frontier Bioscience, Hosei University, Koganei, Tokyo, 184-8584, Japan; Research Center of Phamacy, Nihon University, Narashino-dai, Chiba, 274-0005, Japan.
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29
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Krah A, Bond PJ. Single mutations in the ε subunit from thermophilic Bacillus PS3 generate a high binding affinity site for ATP. PeerJ 2018; 6:e5505. [PMID: 30202650 PMCID: PMC6129141 DOI: 10.7717/peerj.5505] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 08/02/2018] [Indexed: 01/23/2023] Open
Abstract
The ε subunit from ATP synthases acts as an ATP sensor in the bacterial cell to prevent ATP hydrolysis and thus the waste of ATP under conditions of low ATP concentration. However, the ATP binding affinities from various bacterial organisms differ markedly, over several orders of magnitude. For example, the ATP synthases from thermophilic Bacillus PS3 and Escherichia coli exhibit affinities of 4 µM and 22 mM, respectively. The recently reported R103A/R115A double mutant of Bacillus PS3 ATP synthase demonstrated an increased binding affinity by two orders of magnitude with respect to the wild type. Here, we used atomic-resolution molecular dynamics simulations to determine the role of the R103A and R115A single mutations. These lead us to predict that both single mutations also cause an increased ATP binding affinity. Evolutionary analysis reveals R103 and R115 substitutions in the ε subunit from other bacillic organisms, leading us to predict they likely have a higher ATP binding affinity than previously expected.
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Affiliation(s)
- Alexander Krah
- School of Computational Sciences, Korea Institute for Advanced Study, Seoul, Republic of Korea.,Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Peter J Bond
- Bioinformatics Institute, Agency for Science, Technology and Research (ASTAR), Singapore, Singapore.,Department of Biological Sciences, National University of Singapore, Singapore, Singapore
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30
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Qu C, Zhang S, Wang W, Li M, Wang Y, van der Heijde-Mulder M, Shokrollahi E, Hakim MS, Raat NJH, Peppelenbosch MP, Pan Q. Mitochondrial electron transport chain complex III sustains hepatitis E virus replication and represents an antiviral target. FASEB J 2018; 33:1008-1019. [PMID: 30070932 DOI: 10.1096/fj.201800620r] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Hepatitis E virus (HEV) infection has emerged as a global health problem. However, no approved medication is available, and the infection biology remains largely elusive. Electron transport chain (ETC), a key component of the mitochondria, is the main site that produces ATP and reactive oxygen species (ROS). By profiling the role of the different complexes of the mitochondrial ETC, we found that pharmacological inhibition of complex III, a well-defined drug target for the treatment of malaria and Pneumocystis pneumonia, potently restricts HEV replication. This effect demonstrated in our HEV models is equivalent to the anti-HEV potency of ribavirin, a widely used off-label treatment for patients with chronic HEV. Mechanistically, we found that this effect is independent of ATP production, ROS level, and pyridine depletion. By using pharmacological inhibitors and genetic approaches, we found that mitochondrial permeability transition pore (MPTP), a newly identified component of ETC, provides basal defense against HEV infection. HEV interferes with the opening of the MPTP. Furthermore, inhibition of the MPTP attenuated the anti-HEV effect of complex III inhibitors, suggesting that the MPTP mediates the antiviral effects of these inhibitors. These findings reveal new insights on HEV-host interactions and provide viable anti-HEV targets for therapeutic development.-Qu, C., Zhang, S., Wang, W., Li, M., Wang, Y., van der Heijde-Mulder, M., Shokrollahi, E., Hakim, M. S., Raat, N. J. H., Peppelenbosch, M. P., Pan, Q. Mitochondrial electron transport chain complex III sustains hepatitis E virus replication and represents an antiviral target.
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Affiliation(s)
- Changbo Qu
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, The Netherlands
| | - Shaoshi Zhang
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, The Netherlands
| | - Wenshi Wang
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, The Netherlands
| | - Meng Li
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, The Netherlands
| | - Yijin Wang
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, The Netherlands.,Department of Pathology and Hepatology, Beijing 302 Hospital, Beijing, China
| | | | - Ehsan Shokrollahi
- Department of Anesthesiology, Laboratory of Experimental Anesthesiology, The Erasmus University Medical Center (Erasmus MC), Rotterdam, The Netherlands; and
| | - Mohamad S Hakim
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, The Netherlands.,Department of Microbiology, Faculty of Medicine, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Nicolaas J H Raat
- Department of Anesthesiology, Laboratory of Experimental Anesthesiology, The Erasmus University Medical Center (Erasmus MC), Rotterdam, The Netherlands; and
| | - Maikel P Peppelenbosch
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, The Netherlands
| | - Qiuwei Pan
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, The Netherlands
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31
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Zhang J, Lan Y, Sanyal S. Modulation of Lipid Droplet Metabolism-A Potential Target for Therapeutic Intervention in Flaviviridae Infections. Front Microbiol 2017; 8:2286. [PMID: 29234310 PMCID: PMC5712332 DOI: 10.3389/fmicb.2017.02286] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 11/06/2017] [Indexed: 12/21/2022] Open
Abstract
Lipid droplets (LDs) are endoplasmic reticulum (ER)-related dynamic organelles that store and regulate fatty acids and neutral lipids. They play a central role in cellular energy storage, lipid metabolism and cellular homeostasis. It has become evident that viruses have co-evolved in order to exploit host lipid metabolic pathways. This is especially characteristic of the Flaviviridae family, including hepatitis C virus (HCV) and several flaviviruses. Devoid of an appropriate lipid biosynthetic machinery of their own, these single-strand positive-sense RNA viruses can induce dramatic changes in host metabolic pathways to establish a favorable environment for viral multiplication and acquire essential components to facilitate their assembly and traffic. Here we have reviewed the current knowledge on the intracellular life cycle of those from the Flaviviridae family, with particular emphasis on HCV and dengue virus (DENV), and their association with the biosynthesis and metabolism of LDs, with the aim to identify potential antiviral targets for development of novel therapeutic interventions.
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Affiliation(s)
- Jingshu Zhang
- HKU-Pasteur Research Pole, School of Public Health, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong, China
| | - Yun Lan
- HKU-Pasteur Research Pole, School of Public Health, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong, China
| | - Sumana Sanyal
- HKU-Pasteur Research Pole, School of Public Health, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong, China.,School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong, China
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32
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A simple in vitro tumor chemosensitivity assay based on cell penetrating peptide tagged luciferase. PLoS One 2017; 12:e0186184. [PMID: 29125836 PMCID: PMC5681261 DOI: 10.1371/journal.pone.0186184] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 09/26/2017] [Indexed: 12/11/2022] Open
Abstract
The analysis of intracellular ATP can reveal the response of cells to different treatments and is important for individualized medicine. In the present study, we developed a cell penetrating peptides (CPPs) tagged luciferase (TAT-LUC) for tumor chemosensitivity assay. The activity of recombinant TAT-LUC was evaluated using ATP standard solution and tumor cells. This recombinant TAT-LUC was then used for the analysis of sensitivity index (SI) of four strains of tumor cells. The results showed that TAT-LUC could detect less than 10 nM extracellular ATP with a strong correlation between the luminescence intensity and the ATP content (R2 = 0.994). Without cell lysis, the detection limit for intracellular ATP analysis was 40 tumor cells. Furthermore, chemosensitivity of four strains of tumor cells (Skov-3/DDP, A549/DDP, MDA-MB-231, Huh-7) was determined by this assay successfully. The cell penetration ability of TAT-LUC enables the assay not only to reflect drug resistance of tumor cells real-timely but also to minimize the test time, which can be a valuable aid for personalized cancer chemotherapy.
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33
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Chuang C, Prasanth KR, Nagy PD. The Glycolytic Pyruvate Kinase Is Recruited Directly into the Viral Replicase Complex to Generate ATP for RNA Synthesis. Cell Host Microbe 2017; 22:639-652.e7. [PMID: 29107644 DOI: 10.1016/j.chom.2017.10.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 07/24/2017] [Accepted: 10/03/2017] [Indexed: 01/17/2023]
Abstract
Viruses accomplish their replication by exploiting many cellular resources, including metabolites and energy. Similarly to other (+)RNA viruses, tomato bushy stunt virus (TBSV) induces major changes in infected cells. However, the source of energy required to fuel TBSV replication is unknown. We find that TBSV co-opts the cellular glycolytic ATP-generating pyruvate kinase (PK) directly into the viral replicase complex to boost progeny RNA synthesis. The co-opted PK generates high levels of ATP within the viral replication compartment at the expense of a reduction in cytosolic ATP pools. The ATP generated by the co-opted PK is used to promote the helicase activity of recruited cellular DEAD-box helicases, which are involved in the production of excess viral (+)RNA progeny. Altogether, recruitment of PK and local production of ATP within the replication compartment allow the virus replication machinery an access to plentiful ATP, facilitating robust virus replication.
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Affiliation(s)
- Chingkai Chuang
- Department of Plant Pathology, University of Kentucky, Plant Science Building, Lexington, KY 40546, USA
| | - K Reddisiva Prasanth
- Department of Plant Pathology, University of Kentucky, Plant Science Building, Lexington, KY 40546, USA
| | - Peter D Nagy
- Department of Plant Pathology, University of Kentucky, Plant Science Building, Lexington, KY 40546, USA.
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34
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You DG, Lee HR, Kim WK, Kim HJ, Lee GY, Yoo YD. Hepatitis C virus p7 induces mitochondrial depolarization of isolated liver mitochondria. Mol Med Rep 2017; 16:9533-9538. [PMID: 29039530 DOI: 10.3892/mmr.2017.7809] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 03/20/2017] [Indexed: 11/06/2022] Open
Abstract
Hepatitis C virus (HCV)‑encoded protein p7 is a viroporin that acts as an ion channel and is indispensable for HCV particle production. Although the main target of HCV p7 is the endoplasmic reticulum, it also targets mitochondria. HCV‑infected cells show mitochondrial depolarization and ATP depletion; however, the function of HCV p7 in mitochondria is not fully understood. The present study demonstrated that treatment of isolated mouse liver mitochondria with the synthesized HCV p7 protein induced mitochondrial dysfunction. It also demonstrated that HCV p7 targeted isolated mouse liver mitochondria and induced mitochondrial depolarization. In addition, HCV p7 triggered matrix acidification and, ultimately, a decrease in ATP synthesis in isolated mitochondria. These findings indicate that targeting of mitochondria by HCV p7 in infected cells causes mitochondrial dysfunction to support HCV particle production. The present study provided evidence for the role of HCV p7 in mitochondria, and may lead to the development of novel strategies for HCV therapy.
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Affiliation(s)
- Deok-Gyun You
- Laboratory of Molecular Cell Biology, Graduate School of Medicine, College of Medicine, Korea University, Seoul 02841, Republic of Korea
| | - Hye-Ra Lee
- Laboratory of Molecular Cell Biology, Graduate School of Medicine, College of Medicine, Korea University, Seoul 02841, Republic of Korea
| | - Won-Ki Kim
- Department of Neuroscience, College of Medicine, Korea University, Seoul 02841, Republic of Korea
| | - Hyung Jung Kim
- Department of Internal Medicine, Yonsei University College of Medicine, Yonsei University Health System, Seoul 03722, Republic of Korea
| | - Gi Young Lee
- Laboratory of Molecular Cell Biology, Graduate School of Medicine, College of Medicine, Korea University, Seoul 02841, Republic of Korea
| | - Young Do Yoo
- Laboratory of Molecular Cell Biology, Graduate School of Medicine, College of Medicine, Korea University, Seoul 02841, Republic of Korea
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35
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Prasanth KR, Chuang C, Nagy PD. Co-opting ATP-generating glycolytic enzyme PGK1 phosphoglycerate kinase facilitates the assembly of viral replicase complexes. PLoS Pathog 2017; 13:e1006689. [PMID: 29059239 PMCID: PMC5695612 DOI: 10.1371/journal.ppat.1006689] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 11/02/2017] [Accepted: 10/10/2017] [Indexed: 11/19/2022] Open
Abstract
The intricate interactions between viruses and hosts include exploitation of host cells for viral replication by using many cellular resources, metabolites and energy. Tomato bushy stunt virus (TBSV), similar to other (+)RNA viruses, induces major changes in infected cells that lead to the formation of large replication compartments consisting of aggregated peroxisomal and ER membranes. Yet, it is not known how TBSV obtains the energy to fuel these energy-consuming processes. In the current work, the authors discovered that TBSV co-opts the glycolytic ATP-generating Pgk1 phosphoglycerate kinase to facilitate the assembly of new viral replicase complexes. The recruitment of Pgk1 into the viral replication compartment is through direct interaction with the viral replication proteins. Altogether, we provide evidence that the ATP generated locally within the replication compartment by the co-opted Pgk1 is used to fuel the ATP-requirement of the co-opted heat shock protein 70 (Hsp70) chaperone, which is essential for the assembly of new viral replicase complexes and the activation of functional viral RNA-dependent RNA polymerase. The advantage of direct recruitment of Pgk1 into the virus replication compartment could be that the virus replicase assembly does not need to intensively compete with cellular processes for access to ATP. In addition, local production of ATP within the replication compartment could greatly facilitate the efficiency of Hsp70-driven replicase assembly by providing high ATP concentration within the replication compartment.
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Affiliation(s)
- K. Reddisiva Prasanth
- Department of Plant Pathology, University of Kentucky, Plant Science Building, Lexington, KY, United States of America
| | - Chingkai Chuang
- Department of Plant Pathology, University of Kentucky, Plant Science Building, Lexington, KY, United States of America
| | - Peter D. Nagy
- Department of Plant Pathology, University of Kentucky, Plant Science Building, Lexington, KY, United States of America
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36
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De Col V, Fuchs P, Nietzel T, Elsässer M, Voon CP, Candeo A, Seeliger I, Fricker MD, Grefen C, Møller IM, Bassi A, Lim BL, Zancani M, Meyer AJ, Costa A, Wagner S, Schwarzländer M. ATP sensing in living plant cells reveals tissue gradients and stress dynamics of energy physiology. eLife 2017; 6. [PMID: 28716182 PMCID: PMC5515573 DOI: 10.7554/elife.26770] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 06/28/2017] [Indexed: 12/13/2022] Open
Abstract
Growth and development of plants is ultimately driven by light energy captured through photosynthesis. ATP acts as universal cellular energy cofactor fuelling all life processes, including gene expression, metabolism, and transport. Despite a mechanistic understanding of ATP biochemistry, ATP dynamics in the living plant have been largely elusive. Here, we establish MgATP2- measurement in living plants using the fluorescent protein biosensor ATeam1.03-nD/nA. We generate Arabidopsis sensor lines and investigate the sensor in vitro under conditions appropriate for the plant cytosol. We establish an assay for ATP fluxes in isolated mitochondria, and demonstrate that the sensor responds rapidly and reliably to MgATP2- changes in planta. A MgATP2- map of the Arabidopsis seedling highlights different MgATP2- concentrations between tissues and within individual cell types, such as root hairs. Progression of hypoxia reveals substantial plasticity of ATP homeostasis in seedlings, demonstrating that ATP dynamics can be monitored in the living plant.
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Affiliation(s)
- Valentina De Col
- Institute of Crop Science and Resource Conservation, University of Bonn, Bonn, Germany.,Department of Agricultural, Food, Environmental and Animal Sciences, University of Udine, Udine, Italy
| | - Philippe Fuchs
- Institute of Crop Science and Resource Conservation, University of Bonn, Bonn, Germany
| | - Thomas Nietzel
- Institute of Crop Science and Resource Conservation, University of Bonn, Bonn, Germany
| | - Marlene Elsässer
- Institute of Crop Science and Resource Conservation, University of Bonn, Bonn, Germany
| | - Chia Pao Voon
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - Alessia Candeo
- Dipartimento di Fisica, Politecnico di Milano, Milano, Italy
| | - Ingo Seeliger
- Institute of Crop Science and Resource Conservation, University of Bonn, Bonn, Germany
| | - Mark D Fricker
- Department of Plant Sciences, University of Oxford, Oxford, United Kingdom
| | - Christopher Grefen
- Centre for Plant Molecular Biology, Developmental Genetics, University of Tübingen, Tübingen, Germany
| | - Ian Max Møller
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Andrea Bassi
- Dipartimento di Fisica, Politecnico di Milano, Milano, Italy
| | - Boon Leong Lim
- School of Biological Sciences, University of Hong Kong, Hong Kong, China.,State Key Laboratory of Agrobiotechnology, Chinese University of Hong Kong, Hong Kong, China
| | - Marco Zancani
- Department of Agricultural, Food, Environmental and Animal Sciences, University of Udine, Udine, Italy
| | - Andreas J Meyer
- Institute of Crop Science and Resource Conservation, University of Bonn, Bonn, Germany.,Bioeconomy Science Center, Forschungszentrum Jülich, Jülich, Germany
| | - Alex Costa
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milano, Italy
| | - Stephan Wagner
- Institute of Crop Science and Resource Conservation, University of Bonn, Bonn, Germany
| | - Markus Schwarzländer
- Institute of Crop Science and Resource Conservation, University of Bonn, Bonn, Germany.,Bioeconomy Science Center, Forschungszentrum Jülich, Jülich, Germany
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37
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Abstract
ATP, the energy exchange factor that connects anabolism and catabolism, is required for major reactions and processes that occur in living cells, such as muscle contraction, phosphorylation and active transport. ATP is also the key molecule in extracellular purinergic signaling mechanisms, with an established crucial role in inflammation and several additional disease conditions. Here, we describe detailed protocols to measure the ATP concentration in isolated living cells and animals using luminescence techniques based on targeted luciferase probes. In the presence of magnesium, oxygen and ATP, the protein luciferase catalyzes oxidation of the substrate luciferin, which is associated with light emission. Recombinantly expressed wild-type luciferase is exclusively cytosolic; however, adding specific targeting sequences can modify its cellular localization. Using this strategy, we have constructed luciferase chimeras targeted to the mitochondrial matrix and the outer surface of the plasma membrane. Here, we describe optimized protocols for monitoring ATP concentrations in the cytosol, mitochondrial matrix and pericellular space in living cells via an overall procedure that requires an average of 3 d. In addition, we present a detailed protocol for the in vivo detection of extracellular ATP in mice using luciferase-transfected reporter cells. This latter procedure may require up to 25 d to complete.
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38
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A Molecular Model for Lithium's Bioactive Form. Biophys J 2017; 111:294-300. [PMID: 27463132 DOI: 10.1016/j.bpj.2016.06.015] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 05/13/2016] [Accepted: 06/10/2016] [Indexed: 01/05/2023] Open
Abstract
Lithium carbonate, a drug for the treatment of bipolar disorder, provides mood stability to mitigate recurrent episodes of mania and/or depression. Despite its long-term and widespread use, the mechanism by which lithium acts to elicit these psychological changes has remained unknown. Using nuclear magnetic resonance (NMR) methods, in this study we characterized the association of lithium with adenosine triphosphate (ATP) and identified a bimetallic (Mg·Li) ATP complex. Lithium's affinity to form this complex was found to be relatively high (Kd ∼1.6 mM) compared with other monovalent cations and relevant, considering lithium dosing and physiological concentrations of Mg(2+) and ATP. The ATP·Mg·Li complex reveals, for the first time, to the best of our knowledge, that lithium can associate with magnesium-bound phosphate sites and then act to modulate purine receptor activity in neuronal cells, suggesting a molecular mode for in vivo lithium action.
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Pelosse M, Cottet-Rousselle C, Grichine A, Berger I, Schlattner U. Genetically Encoded Fluorescent Biosensors to Explore AMPK Signaling and Energy Metabolism. ACTA ACUST UNITED AC 2017; 107:491-523. [PMID: 27812993 DOI: 10.1007/978-3-319-43589-3_20] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Maintenance of energy homeostasis is a basic requirement for cell survival. Different mechanisms have evolved to cope with spatial and temporal mismatch between energy-providing and -consuming processes. Among these, signaling by AMP-activated protein kinase (AMPK) is one of the key players, regulated by and itself regulating cellular adenylate levels. Further understanding its complex cellular function requires deeper insight into its activation patterns in space and time at a single cell level. This may become possible with an increasing number of genetically encoded fluorescent biosensors, mostly based on fluorescence resonance energy transfer, which have been engineered to monitor metabolic parameters and kinase activities. Here, we review basic principles of biosensor design and function and the advantages and limitations of their use and provide an overview on existing FRET biosensors to monitor AMPK activation, ATP concentration, and ATP/ADP ratios, together with other key metabolites and parameters of energy metabolism.
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Affiliation(s)
- Martin Pelosse
- Laboratory of Fundamental and Applied Bioenergetics (LBFA) and SFR Environmental and Systems Biology (BEeSy), University Grenoble Alpes, Grenoble, France.,Inserm, U1055 and U1209, Grenoble, France
| | - Cécile Cottet-Rousselle
- Laboratory of Fundamental and Applied Bioenergetics (LBFA) and SFR Environmental and Systems Biology (BEeSy), University Grenoble Alpes, Grenoble, France.,Inserm, U1055 and U1209, Grenoble, France
| | - Alexei Grichine
- Inserm, U1055 and U1209, Grenoble, France.,Institute for Advanced Biosciences, University Grenoble Alpes, Grenoble, France
| | | | - Uwe Schlattner
- Laboratory of Fundamental and Applied Bioenergetics (LBFA) and SFR Environmental and Systems Biology (BEeSy), University Grenoble Alpes, Grenoble, France. .,Inserm, U1055 and U1209, Grenoble, France.
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Krah A, Kato-Yamada Y, Takada S. The structural basis of a high affinity ATP binding ε subunit from a bacterial ATP synthase. PLoS One 2017; 12:e0177907. [PMID: 28542497 PMCID: PMC5436830 DOI: 10.1371/journal.pone.0177907] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 05/04/2017] [Indexed: 01/09/2023] Open
Abstract
The ε subunit from bacterial ATP synthases functions as an ATP sensor, preventing ATPase activity when the ATP concentration in bacterial cells crosses a certain threshold. The R103A/R115A double mutant of the ε subunit from thermophilic Bacillus PS3 has been shown to bind ATP two orders of magnitude stronger than the wild type protein. We use molecular dynamics simulations and free energy calculations to derive the structural basis of the high affinity ATP binding to the R103A/R115A double mutant. Our results suggest that the double mutant is stabilized by an enhanced hydrogen-bond network and fewer repulsive contacts in the ligand binding site. The inferred structural basis of the high affinity mutant may help to design novel nucleotide sensors based on the ε subunit from bacterial ATP synthases.
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Affiliation(s)
- Alexander Krah
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto, Japan
- School of Computational Sciences, Korea Institute for Advanced Study, Dongdaemun-gu, Seoul, Republic of Korea
- * E-mail:
| | - Yasuyuki Kato-Yamada
- Department of Life Science, College of Science, Rikkyo University, Nishi-Ikebukuro, Toshima-ku, Tokyo, Japan
| | - Shoji Takada
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto, Japan
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41
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Gu C, Nguyen HN, Hofer A, Jessen HJ, Dai X, Wang H, Shears SB. The Significance of the Bifunctional Kinase/Phosphatase Activities of Diphosphoinositol Pentakisphosphate Kinases (PPIP5Ks) for Coupling Inositol Pyrophosphate Cell Signaling to Cellular Phosphate Homeostasis. J Biol Chem 2017; 292:4544-4555. [PMID: 28126903 PMCID: PMC5377771 DOI: 10.1074/jbc.m116.765743] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 01/25/2017] [Indexed: 12/31/2022] Open
Abstract
Proteins responsible for Pi homeostasis are critical for all life. In Saccharomyces cerevisiae, extracellular [Pi] is "sensed" by the inositol-hexakisphosphate kinase (IP6K) that synthesizes the intracellular inositol pyrophosphate 5-diphosphoinositol 1,2,3,4,6-pentakisphosphate (5-InsP7) as follows: during a period of Pi starvation, there is a decline in cellular [ATP]; the unusually low affinity of IP6Ks for ATP compels 5-InsP7 levels to fall in parallel (Azevedo, C., and Saiardi, A. (2017) Trends. Biochem. Sci. 42, 219-231. Hitherto, such Pi sensing has not been documented in metazoans. Here, using a human intestinal epithelial cell line (HCT116), we show that levels of both 5-InsP7 and ATP decrease upon [Pi] starvation and subsequently recover during Pi replenishment. However, a separate inositol pyrophosphate, 1,5-bisdiphosphoinositol 2,3,4,6-tetrakisphosphate (InsP8), reacts more dramatically (i.e. with a wider dynamic range and greater sensitivity). To understand this novel InsP8 response, we characterized kinetic properties of the bifunctional 5-InsP7 kinase/InsP8 phosphatase activities of full-length diphosphoinositol pentakisphosphate kinases (PPIP5Ks). These data fulfil previously published criteria for any bifunctional kinase/phosphatase to exhibit concentration robustness, permitting levels of the kinase product (InsP8 in this case) to fluctuate independently of varying precursor (i.e. 5-InsP7) pool size. Moreover, we report that InsP8 phosphatase activities of PPIP5Ks are strongly inhibited by Pi (40-90% within the 0-1 mm range). For PPIP5K2, Pi sensing by InsP8 is amplified by a 2-fold activation of 5-InsP7 kinase activity by Pi within the 0-5 mm range. Overall, our data reveal mechanisms that can contribute to specificity in inositol pyrophosphate signaling, regulating InsP8 turnover independently of 5-InsP7, in response to fluctuations in extracellular supply of a key nutrient.
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Affiliation(s)
- Chunfang Gu
- From the Laboratory of Signal Transduction, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina, 27709
| | - Hoai-Nghia Nguyen
- From the Laboratory of Signal Transduction, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina, 27709
| | - Alexandre Hofer
- Department of Chemistry, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
| | - Henning J Jessen
- Institute of Organic Chemistry, Albert Ludwigs University, Albertstrasse 21, 79104 Freiburg, Germany, and
| | - Xuming Dai
- Division of Cardiology, McAllister Heart Institute, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Huanchen Wang
- From the Laboratory of Signal Transduction, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina, 27709
| | - Stephen B Shears
- From the Laboratory of Signal Transduction, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina, 27709,
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Abstract
Viruses use synthetic mechanism and organelles of the host cells to facilitate their replication and make new viruses. Host's ATP provides necessary energy. Hepatitis C virus (HCV) is a major cause of liver disease. Like other positive-strand RNA viruses, the HCV genome is thought to be synthesized by the replication complex, which consists of viral- and host cell-derived factors, in tight association with structurally rearranged vesicle-like cytoplasmic membranes. The virus-induced remodeling of subcellular membranes, which protect the viral RNA from nucleases in the cytoplasm, promotes efficient replication of HCV genome. The assembly of HCV particle involves interactions between viral structural and nonstructural proteins and pathways related to lipid metabolisms in a concerted fashion. Association of viral core protein, which forms the capsid, with lipid droplets appears to be a prerequisite for early steps of the assembly, which are closely linked with the viral genome replication. This review presents the recent progress in understanding the mechanisms for replication and assembly of HCV through its interactions with organelles or distinct organelle-like structures.
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Affiliation(s)
- Tetsuro Suzuki
- Department of Virology and Parasitology, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, 431-3192, Japan.
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43
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Erdmann T, Bartelheimer K, Schwarz US. Sensitivity of small myosin II ensembles from different isoforms to mechanical load and ATP concentration. Phys Rev E 2016; 94:052403. [PMID: 27967122 DOI: 10.1103/physreve.94.052403] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2015] [Indexed: 02/02/2023]
Abstract
Based on a detailed crossbridge model for individual myosin II motors, we systematically study the influence of mechanical load and adenosine triphosphate (ATP) concentration on small myosin II ensembles made from different isoforms. For skeletal and smooth muscle myosin II, which are often used in actomyosin gels that reconstitute cell contractility, fast forward movement is restricted to a small region of phase space with low mechanical load and high ATP concentration, which is also characterized by frequent ensemble detachment. At high load, these ensembles are stalled or move backwards, but forward motion can be restored by decreasing ATP concentration. In contrast, small ensembles of nonmuscle myosin II isoforms, which are found in the cytoskeleton of nonmuscle cells, are hardly affected by ATP concentration due to the slow kinetics of the bound states. For all isoforms, the thermodynamic efficiency of ensemble movement increases with decreasing ATP concentration, but this effect is weaker for the nonmuscle myosin II isoforms.
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Affiliation(s)
- Thorsten Erdmann
- Institute for Theoretical Physics and BioQuant, Heidelberg University, Heidelberg, Germany
| | - Kathrin Bartelheimer
- Institute for Theoretical Physics and BioQuant, Heidelberg University, Heidelberg, Germany
| | - Ulrich S Schwarz
- Institute for Theoretical Physics and BioQuant, Heidelberg University, Heidelberg, Germany
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Abstract
Replication of positive-strand RNA viruses occurs in tight association with reorganized host cell membranes. In a concerted fashion, viral and cellular factors generate distinct organelle-like structures, designated viral replication factories. These virus-induced compartments promote highly efficient genome replication, allow spatiotemporal coordination of the different steps of the viral replication cycle, and protect viral RNA from the hostile cytoplasmic environment. The combined use of ultrastructural and functional studies has greatly increased our understanding of the architecture and biogenesis of viral replication factories. Here, we review common concepts and distinct differences in replication organelle morphology and biogenesis within the Flaviviridae family, exemplified by dengue virus and hepatitis C virus. We discuss recent progress made in our understanding of the complex interplay between viral determinants and subverted cellular membrane homeostasis in biogenesis and maintenance of replication factories of this virus family.
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Affiliation(s)
- David Paul
- Department of Infectious Diseases, Molecular Virology, University of Heidelberg, 69120 Heidelberg, Germany; ,
| | - Ralf Bartenschlager
- Department of Infectious Diseases, Molecular Virology, University of Heidelberg, 69120 Heidelberg, Germany; , .,Division of Virus-Associated Carcinogenesis, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
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45
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Meireles P, Sales-Dias J, Andrade CM, Mello-Vieira J, Mancio-Silva L, Simas JP, Staines HM, Prudêncio M. GLUT1-mediated glucose uptake plays a crucial role during Plasmodium hepatic infection. Cell Microbiol 2016; 19. [PMID: 27404888 PMCID: PMC5297879 DOI: 10.1111/cmi.12646] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Revised: 06/20/2016] [Accepted: 07/06/2016] [Indexed: 02/06/2023]
Abstract
Intracellular pathogens have evolved mechanisms to ensure their survival and development inside their host cells. Here, we show that glucose is a pivotal modulator of hepatic infection by the rodent malaria parasite Plasmodium berghei and that glucose uptake via the GLUT1 transporter is specifically enhanced in P. berghei‐infected cells. We further show that ATP levels of cells containing developing parasites are decreased, which is known to enhance membrane GLUT1 activity. In addition, GLUT1 molecules are translocated to the membrane of the hepatic cell, increasing glucose uptake at later stages of infection. Chemical inhibition of GLUT1 activity leads to a decrease in glucose uptake and the consequent impairment of hepatic infection, both in vitro and in vivo. Our results reveal that changes in GLUT1 conformation and cellular localization seem to be part of an adaptive host response to maintain adequate cellular nutrition and energy levels, ensuring host cell survival and supporting P. berghei hepatic development.
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Affiliation(s)
- Patrícia Meireles
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Joana Sales-Dias
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Carolina M Andrade
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - João Mello-Vieira
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Liliana Mancio-Silva
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - J Pedro Simas
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Henry M Staines
- Institute for Infection & Immunity, St. George's, University of London, Cranmer Terrace, London, UK
| | - Miguel Prudêncio
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
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Wang H, Tai AW. Mechanisms of Cellular Membrane Reorganization to Support Hepatitis C Virus Replication. Viruses 2016; 8:v8050142. [PMID: 27213428 PMCID: PMC4885097 DOI: 10.3390/v8050142] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 04/20/2016] [Accepted: 05/15/2016] [Indexed: 12/13/2022] Open
Abstract
Like all positive-sense RNA viruses, hepatitis C virus (HCV) induces host membrane alterations for its replication termed the membranous web (MW). Assembling replication factors at a membranous structure might facilitate the processes necessary for genome replication and packaging and shield viral components from host innate immune defenses. The biogenesis of the HCV MW is a complex process involving a concerted effort of HCV nonstructural proteins with a growing list of host factors. Although a comprehensive understanding of MW formation is still missing, a number of important viral and host determinants have been identified. This review will summarize the recent studies that have led to our current knowledge of the role of viral and host factors in the biogenesis of the MWs and discuss how HCV uses this specialized membrane structure for its replication.
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Affiliation(s)
- Hongliang Wang
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
| | - Andrew W Tai
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
- Medicine Service, Ann Arbor Veterans Administration Health System, Ann Arbor, MI 48105, USA.
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47
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On the ATP binding site of the ε subunit from bacterial F-type ATP synthases. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:332-40. [PMID: 26780667 DOI: 10.1016/j.bbabio.2016.01.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Revised: 12/11/2015] [Accepted: 01/14/2016] [Indexed: 11/20/2022]
Abstract
F-type ATP synthases are reversible machinery that not only synthesize adenosine triphosphate (ATP) using an electrochemical gradient across the membrane, but also can hydrolyze ATP to pump ions under certain conditions. To prevent wasteful ATP hydrolysis, subunit ε in bacterial ATP synthases changes its conformation from the non-inhibitory down- to the inhibitory up-state at a low cellular ATP concentration. Recently, a crystal structure of the ε subunit in complex with ATP was solved in a non-biologically relevant dimeric form. Here, to derive the functional ATP binding site motif, we carried out molecular dynamics simulations and free energy calculations. Our results suggest that the ATP binding site markedly differs from the experimental resolved one; we observe a reorientation of several residues, which bind to ATP in the crystal structure. In addition we find that an Mg(2+) ion is coordinated by ATP, replacing interactions of the second chain in the crystal structure. Thus we demonstrate more generally the influence of crystallization effects on ligand binding sites and their respective binding modes. Furthermore, we propose a role for two highly conserved residues to control the ATP binding/unbinding event, which have not been considered before. Additionally our results provide the basis for the rational development of new biosensors based on subunit ε, as shown previously for novel sensors measuring the ATP concentration in cells.
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48
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Prolactin Regulatory Element Binding Protein Is Involved in Hepatitis C Virus Replication by Interaction with NS4B. J Virol 2016; 90:3093-111. [PMID: 26739056 DOI: 10.1128/jvi.01540-15] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 12/30/2015] [Indexed: 12/12/2022] Open
Abstract
UNLABELLED It has been proposed that the hepatitis C virus (HCV) NS4B protein triggers the membranous HCV replication compartment, but the underlying molecular mechanism is not fully understood. Here, we screened for NS4B-associated membrane proteins by tandem affinity purification and proteome analysis and identified 202 host proteins. Subsequent screening of replicon cells with small interfering RNA identified prolactin regulatory element binding (PREB) to be a novel HCV host cofactor. The interaction between PREB and NS4B was confirmed by immunoprecipitation, immunofluorescence, and proximity ligation assays. PREB colocalized with double-stranded RNA and the newly synthesized HCV RNA labeled with bromouridine triphosphate in HCV replicon cells. Furthermore, PREB shifted to detergent-resistant membranes (DRMs), where HCV replication complexes reside, in the presence of NS4B expression in Huh7 cells. However, a PREB mutant lacking the NS4B-binding region (PREBd3) could not colocalize with double-stranded RNA and did not shift to the DRM in the presence of NS4B. These results indicate that PREB locates at the HCV replication complex by interacting with NS4B. PREB silencing inhibited the formation of the membranous HCV replication compartment and increased the protease and nuclease sensitivity of HCV replicase proteins and RNA in DRMs, respectively. Collectively, these data indicate that PREB promotes HCV RNA replication by participating in the formation of the membranous replication compartment and by maintaining its proper structure by interacting with NS4B. Furthermore, PREB was induced by HCV infection in vitro and in vivo. Our findings provide new insights into HCV host cofactors. IMPORTANCE The hepatitis C virus (HCV) protein NS4B can induce alteration of the endoplasmic reticulum and the formation of a membranous web structure, which provides a platform for the HCV replication complex. The molecular mechanism by which NS4B induces the membranous HCV replication compartment is not understood. We screened for NS4B-associated membrane proteins by tandem affinity purification and proteome analysis, followed by screening with small interfering RNA. We identified prolactin regulatory element binding (PREB) to be a novel HCV host cofactor. PREB is induced by HCV infection and recruited into the replication complex by interaction with NS4B. Recruited PREB promotes HCV RNA replication by participating in the formation of the membranous HCV replication compartment. To our knowledge, the effect of NS4B-binding protein on the formation of the membranous HCV replication compartment is newly described in this report. Our findings are expected to provide new insights into HCV host cofactors.
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Nomura J, So A, Tamura M, Busso N. Intracellular ATP Decrease Mediates NLRP3 Inflammasome Activation upon Nigericin and Crystal Stimulation. THE JOURNAL OF IMMUNOLOGY 2015; 195:5718-24. [PMID: 26546608 DOI: 10.4049/jimmunol.1402512] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 10/09/2015] [Indexed: 12/20/2022]
Abstract
Activation of the nucleotide-binding oligomerization domain-like receptor family, pyrin domain-containing 3 (NLRP3) inflammasome initiates an inflammatory response, which is associated with host defense against pathogens and the progression of chronic inflammatory diseases such as gout and atherosclerosis. The NLRP3 inflammasome mediates caspase-1 activation and subsequent IL-1β processing in response to various stimuli, including extracellular ATP, although the roles of intracellular ATP (iATP) in NLRP3 activation remain unclear. In this study, we found that in activated macrophages artificial reduction of iATP by 2-deoxyglucose, a glycolysis inhibitor, caused mitochondrial membrane depolarization, leading to IL-1β secretion via NLRP3 and caspase-1 activation. Additionally, the NLRP3 activators nigericin and monosodium urate crystals lowered iATP through K(+)- and Ca(2+)-mediated mitochondrial dysfunction, suggesting a feedback loop between iATP loss and lowering of mitochondrial membrane potential. These results demonstrate the fundamental roles of iATP in the maintenance of mitochondrial function and regulation of IL-1β secretion, and they suggest that maintenance of the intracellular ATP pools could be a strategy for countering NLRP3-mediated inflammation.
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Affiliation(s)
- Johji Nomura
- Pharmaceutical Development Research Laboratories, Teijin Institute for Bio-Medical Research, Teijin Pharma Ltd., Hino, Tokyo 191-8512, Japan; and Service de Rhumatologie, Département de l'Appareil Locomoteur, Centre Hospitalier Universitaire Vaudois, Université de Lausanne, 1011 Lausanne, Switzerland
| | - Alexander So
- Service de Rhumatologie, Département de l'Appareil Locomoteur, Centre Hospitalier Universitaire Vaudois, Université de Lausanne, 1011 Lausanne, Switzerland
| | - Mizuho Tamura
- Pharmaceutical Development Research Laboratories, Teijin Institute for Bio-Medical Research, Teijin Pharma Ltd., Hino, Tokyo 191-8512, Japan; and
| | - Nathalie Busso
- Service de Rhumatologie, Département de l'Appareil Locomoteur, Centre Hospitalier Universitaire Vaudois, Université de Lausanne, 1011 Lausanne, Switzerland
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50
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Sulfatide-Hsp70 interaction promotes Hsp70 clustering and stabilizes binding to unfolded protein. Biomolecules 2015; 5:958-73. [PMID: 25989600 PMCID: PMC4496704 DOI: 10.3390/biom5020958] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Revised: 04/24/2015] [Accepted: 05/07/2015] [Indexed: 01/01/2023] Open
Abstract
The 70-kDa heat shock protein (Hsp70), one of the major stress-inducible molecular chaperones, is localized not only in the cytosol, but also in extracellular milieu in mammals. Hsp70 interacts with various cell surface glycolipids including sulfatide (3'-sulfogalactosphingolipid). However, the molecular mechanism, as well as the biological relevance, underlying the glycolipid-Hsp70 interaction is unknown. Here we report that sulfatide promotes Hsp70 oligomerization through the N-terminal ATPase domain, which stabilizes the binding of Hsp70 to unfolded protein in vitro. We find that the Hsp70 oligomer has apparent molecular masses ranging from 440 kDa to greater than 669 kDa. The C-terminal peptide-binding domain is dispensable for the sulfatide-induced oligomer formation. The oligomer formation is impaired in the presence of ATP, while the Hsp70 oligomer, once formed, is unable to bind to ATP. These results suggest that sulfatide locks Hsp70 in a high-affinity state to unfolded proteins by clustering the peptide-binding domain and blocking the binding to ATP that induces the dissociation of Hsp70 from protein substrates.
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