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Garcia BCB, Mukai Y, Tomonaga K, Horie M. The hidden diversity of ancient bornaviral sequences from X and P genes in vertebrate genomes. Virus Evol 2023; 9:vead038. [PMID: 37360682 PMCID: PMC10288550 DOI: 10.1093/ve/vead038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 01/10/2023] [Accepted: 05/31/2023] [Indexed: 06/28/2023] Open
Abstract
Endogenous bornavirus-like elements (EBLs) are heritable sequences derived from bornaviruses in vertebrate genomes that originate from transcripts of ancient bornaviruses. EBLs have been detected using sequence similarity searches such as tBLASTn, whose technical limitations may hinder the detection of EBLs derived from small and/or rapidly evolving viral X and P genes. Indeed, no EBLs derived from the X and P genes of orthobornaviruses have been detected to date in vertebrate genomes. Here, we aimed to develop a novel strategy to detect such 'hidden' EBLs. To this aim, we focused on the 1.9-kb read-through transcript of orthobornaviruses, which encodes a well-conserved N gene and small and rapidly evolving X and P genes. We show a series of evidence supporting the existence of EBLs derived from orthobornaviral X and P genes (EBLX/Ps) in mammalian genomes. Furthermore, we found that an EBLX/P is expressed as a fusion transcript with the cellular gene, ZNF451, which potentially encodes the ZNF451/EBLP fusion protein in miniopterid bat cells. This study contributes to a deeper understanding of ancient bornaviruses and co-evolution between bornaviruses and their hosts. Furthermore, our data suggest that endogenous viral elements are more abundant than those previously appreciated using BLAST searches alone, and further studies are required to understand ancient viruses more accurately.
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Affiliation(s)
- Bea Clarise B Garcia
- Laboratory of Veterinary Microbiology, Graduate School of Veterinary Science, Osaka Metropolitan University, 1-58 Rinku Orai-kita, Izumisano, Osaka 598-8531, Japan
| | - Yahiro Mukai
- Laboratory of RNA Viruses, Institute for Frontier Life and Medical Sciences, Kyoto University, 53 Kawahara-cho, Shogo-in, Sakyo, Kyoto 606-8507, Japan
- Laboratory of RNA Viruses, Department of Mammalian Regulatory Network, Graduate School of Biostudies, Kyoto University, 53 Kawahara-cho, Shogo-in, Sakyo, Kyoto 606-8507, Japan
| | - Keizo Tomonaga
- Laboratory of RNA Viruses, Institute for Frontier Life and Medical Sciences, Kyoto University, 53 Kawahara-cho, Shogo-in, Sakyo, Kyoto 606-8507, Japan
- Laboratory of RNA Viruses, Department of Mammalian Regulatory Network, Graduate School of Biostudies, Kyoto University, 53 Kawahara-cho, Shogo-in, Sakyo, Kyoto 606-8507, Japan
- Department of Molecular Virology, Graduate School of Medicine, Kyoto University, 53 Kawahara-cho, Shogo-in, Sakyo, Kyoto 606-8507, Japan
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2
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Zhang Y, Alwin Prem Anand A, Bode L, Ludwig H, Emrich HM, Dietrich DE. Word recognition memory and serum levels of Borna disease virus specific circulating immune complexes in obsessive-compulsive disorder. BMC Psychiatry 2022; 22:597. [PMID: 36076225 PMCID: PMC9454108 DOI: 10.1186/s12888-022-04208-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 08/09/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Borna disease virus 1 (BoDV-1) is a non-segmented, negative-strand RNA virus that persistently infects mammals including humans. BoDV-1 worldwide occurring strains display highly conserved genomes with overlapping genetic signatures between those of either human or animal origin. BoDV-1 infection may cause behavioral and cognitive disturbances in animals but has also been found in human major depression and obsessive-compulsive disorder (OCD). However, the impact of BoDV-1 on memory functions in OCD is unknown. METHOD To evaluate the cognitive impact of BoDV-1 in OCD, event-related brain potentials (ERPs) were recorded in a continuous word recognition paradigm in OCD patients (n = 16) and in healthy controls (n = 12). According to the presence of BoDV-1-specific circulating immune complexes (CIC), they were divided into two groups, namely group H (high) and L (low), n = 8 each. Typically, ERPs to repeated items are characterized by more positive waveforms beginning approximately 250 ms post-stimulus. This "old/new effect" has been shown to be relevant for memory processing. The early old/new effect (ca. 300-500 ms) with a frontal distribution is proposed to be a neural correlate of familiarity-based recognition. The late old/new effect (post-500 ms) is supposed to reflect memory recollection processes. RESULTS OCD patients were reported to show a normal early old/new effect and a reduced late old/new effect compared to normal controls. In our study, OCD patients with a high virus load (group H) displayed exactly these effects, while patients with a low virus load (group L) did not differ from healthy controls. CONCLUSION These results confirmed that OCD patients had impaired memory recollection processes compared to the normal controls which may to some extent be related to their BoDV-1 infection.
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Affiliation(s)
- Yuanyuan Zhang
- Clinic of Psychiatry, Social Psychiatry and Psychotherapy, Hannover Medical School, 30625 Hanover, Germany. .,Present Address: Social Psychiatry Counseling Center, Region Hannover, Podbielskistr. 157, 30177, Hanover, Germany.
| | - A Alwin Prem Anand
- grid.10423.340000 0000 9529 9877Clinic of Psychiatry, Social Psychiatry and Psychotherapy, Hannover Medical School, 30625 Hanover, Germany
| | - Liv Bode
- Freelance Bornavirus Workgroup, Beerenstr. 41, 14163 Berlin, Germany
| | - Hanns Ludwig
- Freelance Bornavirus Workgroup, Beerenstr. 41, 14163 Berlin, Germany
| | - Hinderk M. Emrich
- grid.10423.340000 0000 9529 9877Clinic of Psychiatry, Social Psychiatry and Psychotherapy, Hannover Medical School, 30625 Hanover, Germany
| | - Detlef E. Dietrich
- grid.10423.340000 0000 9529 9877Clinic of Psychiatry, Social Psychiatry and Psychotherapy, Hannover Medical School, 30625 Hanover, Germany ,AMEOS Klinikum Hildesheim, Goslarsche Landstr. 60, 31135 Hildesheim, Germany ,grid.412970.90000 0001 0126 6191Center for Systems Neuroscience Hannover, Hanover, Germany
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3
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Sabariegos R, Albentosa-González L, Palmero B, Clemente-Casares P, Ramírez E, García-Crespo C, Gallego I, de Ávila AI, Perales C, Domingo E, Mas A. Akt Phosphorylation of Hepatitis C Virus NS5B Regulates Polymerase Activity and Hepatitis C Virus Infection. Front Microbiol 2021; 12:754664. [PMID: 34745059 PMCID: PMC8570118 DOI: 10.3389/fmicb.2021.754664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 09/20/2021] [Indexed: 11/13/2022] Open
Abstract
Hepatitis C virus (HCV) is a single-stranded RNA virus of positive polarity [ssRNA(+)] that replicates its genome through the activity of one of its proteins, called NS5B. This viral protein is responsible for copying the positive-polarity RNA genome into a negative-polarity RNA strand, which will be the template for new positive-polarity RNA genomes. The NS5B protein is phosphorylated by cellular kinases, including Akt. In this work, we have identified several amino acids of NS5B that are phosphorylated by Akt, with positions S27, T53, T267, and S282 giving the most robust results. Site-directed mutagenesis of these residues to mimic (Glu mutants) or prevent (Ala mutants) their phosphorylation resulted in a reduced NS5B in vitro RNA polymerase activity, except for the T267E mutant, the only non-conserved position of all those that are phosphorylated. In addition, in vitro transcribed RNAs derived from HCV complete infectious clones carrying mutations T53E/A and S282E/A were transfected in Huh-7.5 permissive cells, and supernatant viral titers were measured at 6 and 15 days post-transfection. No virus was rescued from the mutants except for T53A at 15 days post-transfection whose viral titer was statistically lower as compared to the wild type. Therefore, phosphorylation of NS5B by cellular kinases is a mechanism of viral polymerase inactivation. Whether this inactivation is a consequence of interaction with cellular kinases or a way to generate inactive NS5B that may have other functions are questions that need further experimental work.
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Affiliation(s)
- Rosario Sabariegos
- Centro Regional de Investigaciones Biomédicas, Universidad de Castilla-La Mancha, Albacete, Spain.,Facultad de Medicina, Universidad de Castilla-La Mancha, Albacete, Spain.,Unidad de Biomedicina UCLM-CSIC, Madrid, Spain
| | - Laura Albentosa-González
- Centro Regional de Investigaciones Biomédicas, Universidad de Castilla-La Mancha, Albacete, Spain
| | - Blanca Palmero
- Centro Regional de Investigaciones Biomédicas, Universidad de Castilla-La Mancha, Albacete, Spain
| | - Pilar Clemente-Casares
- Centro Regional de Investigaciones Biomédicas, Universidad de Castilla-La Mancha, Albacete, Spain.,Unidad de Biomedicina UCLM-CSIC, Madrid, Spain.,Facultad de Farmacia, Universidad de Castilla-La Mancha, Albacete, Spain
| | - Eugenio Ramírez
- Centro Regional de Investigaciones Biomédicas, Universidad de Castilla-La Mancha, Albacete, Spain
| | - Carlos García-Crespo
- Centro de Biología Molecular "Severo Ochoa" (CBMSO) (CSIC-UAM), Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd) del Instituto de Salud Carlos III, Madrid, Spain
| | - Isabel Gallego
- Centro de Biología Molecular "Severo Ochoa" (CBMSO) (CSIC-UAM), Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd) del Instituto de Salud Carlos III, Madrid, Spain
| | - Ana Isabel de Ávila
- Centro de Biología Molecular "Severo Ochoa" (CBMSO) (CSIC-UAM), Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd) del Instituto de Salud Carlos III, Madrid, Spain
| | - Celia Perales
- Centro de Biología Molecular "Severo Ochoa" (CBMSO) (CSIC-UAM), Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd) del Instituto de Salud Carlos III, Madrid, Spain.,Department of Clinical Microbiology, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
| | - Esteban Domingo
- Unidad de Biomedicina UCLM-CSIC, Madrid, Spain.,Centro de Biología Molecular "Severo Ochoa" (CBMSO) (CSIC-UAM), Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd) del Instituto de Salud Carlos III, Madrid, Spain
| | - Antonio Mas
- Centro Regional de Investigaciones Biomédicas, Universidad de Castilla-La Mancha, Albacete, Spain.,Unidad de Biomedicina UCLM-CSIC, Madrid, Spain.,Facultad de Farmacia, Universidad de Castilla-La Mancha, Albacete, Spain
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4
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Yanai M, Sakai M, Makino A, Tomonaga K. Dual function of the nuclear export signal of the Borna disease virus nucleoprotein in nuclear export activity and binding to viral phosphoprotein. Virol J 2017; 14:126. [PMID: 28693611 PMCID: PMC5504739 DOI: 10.1186/s12985-017-0793-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 07/03/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Borna disease virus (BoDV), which has a negative-sense, single-stranded RNA genome, causes persistent infection in the cell nucleus. The nuclear export signal (NES) of the viral nucleoprotein (N) consisting of leucine at positions 128 and 131 and isoleucine at positions 133 and 136 overlaps with one of two predicted binding sites for the viral phosphoprotein (P). A previous study demonstrated that higher expression of BoDV-P inhibits nuclear export of N; however, the function of N NES in the interaction with P remains unclear. We examined the subcellular localization, viral polymerase activity, and P-binding ability of BoDV-N NES mutants. We also characterized a recombinant BoDV (rBoDV) harboring an NES mutation of N. RESULTS BoDV-N with four alanine-substitutions in the leucine and isoleucine residues of the NES impaired its cytoplasmic localization and abolished polymerase activity and P-binding ability. Although an alanine-substitution at position 131 markedly enhanced viral polymerase activity as determined by a minigenome assay, rBoDV harboring this mutation showed expression of viral RNAs and proteins relative to that of wild-type rBoDV. CONCLUSIONS Our results demonstrate that BoDV-N NES has a dual function in BoDV replication, i.e., nuclear export of N and an interaction with P, affecting viral polymerase activity in the nucleus.
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Affiliation(s)
- Mako Yanai
- Laboratory of RNA virus, Institute for Frontier Life and Medical Sciences, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan.,Department of Mammalian Regulatory Network, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Madoka Sakai
- Laboratory of RNA virus, Institute for Frontier Life and Medical Sciences, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan.,Department of Mammalian Regulatory Network, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Akiko Makino
- Laboratory of RNA virus, Institute for Frontier Life and Medical Sciences, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan.
| | - Keizo Tomonaga
- Laboratory of RNA virus, Institute for Frontier Life and Medical Sciences, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan.,Department of Mammalian Regulatory Network, Graduate School of Biostudies, Kyoto University, Kyoto, Japan.,Department of Molecular Viruses, Graduate School of Medicine, Kyoto University, Kyoto, Japan
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Komorizono R, Makino A, Horie M, Honda T, Tomonaga K. Sequence determination of a new parrot bornavirus-5 strain in Japan: implications of clade-specific sequence diversity in the regions interacting with host factors. Microbiol Immunol 2016; 60:437-41. [DOI: 10.1111/1348-0421.12385] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 04/12/2016] [Accepted: 05/05/2016] [Indexed: 11/30/2022]
Affiliation(s)
- Ryo Komorizono
- Department of Viral Oncology; Institute for Virus Research
- Department of Mammalian Regulatory Network; Graduate School of Biostudies
| | - Akiko Makino
- Department of Viral Oncology; Institute for Virus Research
- Center for Emerging Virus Research; Institute for Virus Research; Kyoto University
| | - Masayuki Horie
- Transboundary Animal Diseases Research Center; Joint Faculty of Veterinary Medicine; Kagoshima University
- United Graduate School of Veterinary Science; Yamaguchi University; Yamaguchi
| | - Tomoyuki Honda
- Department of Viral Oncology; Institute for Virus Research
- Department of Mammalian Regulatory Network; Graduate School of Biostudies
| | - Keizo Tomonaga
- Department of Viral Oncology; Institute for Virus Research
- Department of Mammalian Regulatory Network; Graduate School of Biostudies
- Department of Tumor Viruses; Graduate School of Medicine; Kyoto University; Kyoto Japan
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6
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Scordel C, Huttin A, Cochet-Bernoin M, Szelechowski M, Poulet A, Richardson J, Benchoua A, Gonzalez-Dunia D, Eloit M, Coulpier M. Borna disease virus phosphoprotein impairs the developmental program controlling neurogenesis and reduces human GABAergic neurogenesis. PLoS Pathog 2015; 11:e1004859. [PMID: 25923687 PMCID: PMC4414417 DOI: 10.1371/journal.ppat.1004859] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2014] [Accepted: 04/07/2015] [Indexed: 12/31/2022] Open
Abstract
It is well established that persistent viral infection may impair cellular function of specialized cells without overt damage. This concept, when applied to neurotropic viruses, may help to understand certain neurologic and neuropsychiatric diseases. Borna disease virus (BDV) is an excellent example of a persistent virus that targets the brain, impairs neural functions without cell lysis, and ultimately results in neurobehavioral disturbances. Recently, we have shown that BDV infects human neural progenitor cells (hNPCs) and impairs neurogenesis, revealing a new mechanism by which BDV may interfere with brain function. Here, we sought to identify the viral proteins and molecular pathways that are involved. Using lentiviral vectors for expression of the bdv-p and bdv-x viral genes, we demonstrate that the phosphoprotein P, but not the X protein, diminishes human neurogenesis and, more particularly, GABAergic neurogenesis. We further reveal a decrease in pro-neuronal factors known to be involved in neuronal differentiation (ApoE, Noggin, TH and Scg10/Stathmin2), demonstrating that cellular dysfunction is associated with impairment of specific components of the molecular program that controls neurogenesis. Our findings thus provide the first evidence that a viral protein impairs GABAergic human neurogenesis, a process that is dysregulated in several neuropsychiatric disorders. They improve our understanding of the mechanisms by which a persistent virus may interfere with brain development and function in the adult. When a virus enters the brain, it most often induces inflammation, fever, and brain injury, all signs that are indicative of acute encephalitis. Under certain conditions, however, some neurotropic viruses may cause disease in a subtler manner. The Borna disease virus (BDV) is an excellent example of this second class of viruses, as it impairs neural function without cell lysis and induces neurobehavioral disturbances. Recently, we have shown that BDV infects human neural progenitor cells (hNPCs) and impairs neurogenesis, revealing a new mechanism by which BDV may interfere with brain function. In the present study, we identify that a singled-out BDV protein called P causes similar impairment of human neurogenesis, and further show that it leads to diminution in the genesis of a particular neuronal subtype, the GABAergic neurons. We have also found that the expression of several genes involved in the generation and the maturation of neurons is dysregulated by this viral protein, which strongly suggests their implication in P-induced impairment of GABAergic neurogenesis. This study is the first to demonstrate that a viral protein interferes with human GABAergic neurogenesis, a process that is frequently impaired in neuropsychiatric disorders. It may thus contribute to elucidating the molecular bases of psychiatric disorders.
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Affiliation(s)
- Chloé Scordel
- INRA, UMR 1161, Maisons-Alfort, France
- ANSES, UMR Virologie, Maisons-Alfort, France
- Université Paris-Est, Ecole Nationale Vétérinaire d’Alfort, UMR Virologie, Maisons-Alfort, France
| | - Alexandra Huttin
- INRA, UMR 1161, Maisons-Alfort, France
- ANSES, UMR Virologie, Maisons-Alfort, France
- Université Paris-Est, Ecole Nationale Vétérinaire d’Alfort, UMR Virologie, Maisons-Alfort, France
| | - Marielle Cochet-Bernoin
- INRA, UMR 1161, Maisons-Alfort, France
- ANSES, UMR Virologie, Maisons-Alfort, France
- Université Paris-Est, Ecole Nationale Vétérinaire d’Alfort, UMR Virologie, Maisons-Alfort, France
| | - Marion Szelechowski
- Institut National de la Santé et de la Recherche Médicale, UMR 1043, Toulouse, France
- Centre National de la Recherche Scientifique, UMR 5282, Toulouse, France
- Université Paul Sabatier, Toulouse 3, Toulouse, France
| | | | - Jennifer Richardson
- INRA, UMR 1161, Maisons-Alfort, France
- ANSES, UMR Virologie, Maisons-Alfort, France
- Université Paris-Est, Ecole Nationale Vétérinaire d’Alfort, UMR Virologie, Maisons-Alfort, France
| | | | - Daniel Gonzalez-Dunia
- Institut National de la Santé et de la Recherche Médicale, UMR 1043, Toulouse, France
- Centre National de la Recherche Scientifique, UMR 5282, Toulouse, France
- Université Paul Sabatier, Toulouse 3, Toulouse, France
| | - Marc Eloit
- Université Paris-Est, Ecole Nationale Vétérinaire d’Alfort, UMR Virologie, Maisons-Alfort, France
- Pasteur Institute, Pathogen Discovery Laboratory, Biology of Infection Unit, INSERM U1117, Paris, France
| | - Muriel Coulpier
- INRA, UMR 1161, Maisons-Alfort, France
- ANSES, UMR Virologie, Maisons-Alfort, France
- Université Paris-Est, Ecole Nationale Vétérinaire d’Alfort, UMR Virologie, Maisons-Alfort, France
- * E-mail:
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Borna disease virus phosphoprotein modulates epigenetic signaling in neurons to control viral replication. J Virol 2015; 89:5996-6008. [PMID: 25810554 DOI: 10.1128/jvi.00454-15] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 03/17/2015] [Indexed: 01/08/2023] Open
Abstract
UNLABELLED Understanding the modalities of interaction of neurotropic viruses with their target cells represents a major challenge that may improve our knowledge of many human neurological disorders for which viral origin is suspected. Borna disease virus (BDV) represents an ideal model to analyze the molecular mechanisms of viral persistence in neurons and its consequences for neuronal homeostasis. It is now established that BDV ensures its long-term maintenance in infected cells through a stable interaction of viral components with the host cell chromatin, in particular, with core histones. This has led to our hypothesis that such an interaction may trigger epigenetic changes in the host cell. Here, we focused on histone acetylation, which plays key roles in epigenetic regulation of gene expression, notably for neurons. We performed a comparative analysis of histone acetylation patterns of neurons infected or not infected by BDV, which revealed that infection decreases histone acetylation on selected lysine residues. We showed that the BDV phosphoprotein (P) is responsible for these perturbations, even when it is expressed alone independently of the viral context, and that this action depends on its phosphorylation by protein kinase C. We also demonstrated that BDV P inhibits cellular histone acetyltransferase activities. Finally, by pharmacologically manipulating cellular acetylation levels, we observed that inhibiting cellular acetyl transferases reduces viral replication in cell culture. Our findings reveal that manipulation of cellular epigenetics by BDV could be a means to modulate viral replication and thus illustrate a fascinating example of virus-host cell interaction. IMPORTANCE Persistent DNA viruses often subvert the mechanisms that regulate cellular chromatin dynamics, thereby benefitting from the resulting epigenetic changes to create a favorable milieu for their latent and persistent states. Here, we reasoned that Borna disease virus (BDV), the only RNA virus known to durably persist in the nucleus of infected cells, notably neurons, might employ a similar mechanism. In this study, we uncovered a novel modality of virus-cell interaction in which BDV phosphoprotein inhibits cellular histone acetylation by interfering with histone acetyltransferase activities. Manipulation of cellular histone acetylation is accompanied by a modulation of viral replication, revealing a perfect adaptation of this "ancient" virus to its host that may favor neuronal persistence and limit cellular damage.
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Phosphorylation of highly conserved serine residues in the influenza A virus nuclear export protein NEP plays a minor role in viral growth in human cells and mice. J Virol 2014; 88:7668-73. [PMID: 24741082 DOI: 10.1128/jvi.00854-14] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Phosphorylation at the highly conserved serine residues S23 to S25 in the nuclear export protein (NEP) of influenza A viruses was suspected to regulate its nuclear export activity or polymerase activity-enhancing function. Mutation of these phosphoacceptor sites to either alanine or aspartic acid showed only a minor effect on both activities but revealed the presence of other phosphoacceptor sites that might be involved in regulating NEP activity.
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Lin CC, Wu YJ, Heimrich B, Schwemmle M. Absence of a robust innate immune response in rat neurons facilitates persistent infection of Borna disease virus in neuronal tissue. Cell Mol Life Sci 2013; 70:4399-410. [PMID: 23793543 PMCID: PMC11113786 DOI: 10.1007/s00018-013-1402-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Revised: 05/17/2013] [Accepted: 06/06/2013] [Indexed: 10/26/2022]
Abstract
Borna disease virus (BDV) persistently infects neurons of the central nervous system of various hosts, including rats. Since type I IFN-mediated antiviral response efficiently blocks BDV replication in primary rat embryo fibroblasts, it has been speculated that BDV is not effectively sensed by the host innate immune system in the nervous system. To test this assumption, organotypical rat hippocampal slice cultures were infected with BDV for up to 4 weeks. This resulted in the secretion of IFN and the up-regulation of IFN-stimulated genes. Using the rat Mx protein as a specific marker for IFN-induced gene expression, astrocytes and microglial cells were found to be Mx positive, whereas neurons, the major cell type in which BDV is replicating, lacked detectable levels of Mx protein. In uninfected cultures, neurons also remained Mx negative even after treatment with high concentrations of IFN-α. This non-responsiveness correlated with a lack of detectable nuclear translocation of both pSTAT1 and pSTAT2 in these cells. Consistently, neuronal dissemination of BDV was not prevented by treatment with IFN-α. These data suggest that the poor innate immune response in rat neurons renders this cell type highly susceptible to BDV infection even in the presence of exogenous IFN-α. Intriguingly, in contrast to rat neurons, IFN-α treatment of mouse neurons resulted in the up-regulation of Mx proteins and block of BDV replication, indicating species-specific differences in the type I IFN response of neurons between mice and rats.
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Affiliation(s)
- Chia-Ching Lin
- Department of Virology, University of Freiburg, Hermann-Herder-Strasse 11, 79104 Freiburg, Germany
- Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, 79104 Freiburg, Germany
- Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Yuan-Ju Wu
- Department of Virology, University of Freiburg, Hermann-Herder-Strasse 11, 79104 Freiburg, Germany
- Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, 79104 Freiburg, Germany
- Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Bernd Heimrich
- Institute of Anatomy and Cell Biology, University of Freiburg, Albertstrasse 23, 79104 Freiburg, Germany
| | - Martin Schwemmle
- Department of Virology, University of Freiburg, Hermann-Herder-Strasse 11, 79104 Freiburg, Germany
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10
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Adaptive mutations in the nuclear export protein of human-derived H5N1 strains facilitate a polymerase activity-enhancing conformation. J Virol 2013; 88:263-71. [PMID: 24155389 DOI: 10.1128/jvi.01495-13] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The nuclear export protein (NEP) (NS2) of the highly pathogenic human-derived H5N1 strain A/Thailand/1(KAN-1)/2004 with the adaptive mutation M16I greatly enhances the polymerase activity in human cells in a concentration-dependent manner. While low NEP levels enhance the polymerase activity, high levels are inhibitory. To gain insights into the underlying mechanism, we analyzed the effect of NEP deletion mutants on polymerase activity after reconstitution in human cells. This revealed that the polymerase-enhancing function of NEP resides in the C-terminal moiety and that removal of the last three amino acids completely abrogates this activity. Moreover, compared to full-length NEP, the C-terminal moiety alone exhibited significantly higher activity and seemed to be deregulated, since even the highest concentration did not result in an inhibition of polymerase activity. To determine transient interactions between the N- and C-terminal domains in cis, we fused both ends of NEP to a split click beetle luciferase and performed fragment complementation assays. With decreasing temperature, increased luciferase activity was observed, suggesting that intramolecular binding between the C- and N-terminal domains is preferentially stabilized at low temperatures. This stabilizing effect was significantly reduced with the adaptive mutation M16I or a combination of adaptive mutations (M16I, Y41C, and E75G), which further increased polymerase activity also at 34°C. We therefore propose a model in which the N-terminal moiety of NEP exerts an inhibitory function by back-folding to the C-terminal domain. In this model, adaptive mutations in NEP decrease binding between the C- and N-terminal domains, thereby allowing the protein to "open up" and become active already at a low temperature.
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Song W, Kao W, Zhai A, Qian J, Li Y, Zhang Q, Zhao H, Hu Y, Li H, Zhang F. Borna disease virus nucleoprotein inhibits type I interferon induction through the interferon regulatory factor 7 pathway. Biochem Biophys Res Commun 2013; 438:619-23. [DOI: 10.1016/j.bbrc.2013.08.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 08/02/2013] [Indexed: 12/01/2022]
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12
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Horie M, Kobayashi Y, Suzuki Y, Tomonaga K. Comprehensive analysis of endogenous bornavirus-like elements in eukaryote genomes. Philos Trans R Soc Lond B Biol Sci 2013; 368:20120499. [PMID: 23938751 DOI: 10.1098/rstb.2012.0499] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Bornaviruses are the only animal RNA viruses that establish a persistent infection in their host cell nucleus. Studies of bornaviruses have provided unique information about viral replication strategies and virus-host interactions. Although bornaviruses do not integrate into the host genome during their replication cycle, we and others have recently reported that there are DNA sequences derived from the mRNAs of ancient bornaviruses in the genomes of vertebrates, including humans, and these have been designated endogenous borna-like (EBL) elements. Therefore, bornaviruses have been interacting with their hosts as driving forces in the evolution of host genomes in a previously unexpected way. Studies of EBL elements have provided new models for virology, evolutionary biology and general cell biology. In this review, we summarize the data on EBL elements including what we have newly identified in eukaryotes genomes, and discuss the biological significance of EBL elements, with a focus on EBL nucleoprotein elements in mammalian genomes. Surprisingly, EBL elements were detected in the genomes of invertebrates, suggesting that the host range of bornaviruses may be much wider than previously thought. We also review our new data on non-retroviral integration of Borna disease virus.
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Affiliation(s)
- Masayuki Horie
- Department of Virology, Institute for Medical Microbiology and Hygiene, University of Freiburg, , 79104 Freiburg, Germany
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13
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Nucleocytoplasmic shuttling of viral proteins in borna disease virus infection. Viruses 2013; 5:1978-90. [PMID: 23965528 PMCID: PMC3761237 DOI: 10.3390/v5081978] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Revised: 08/02/2013] [Accepted: 08/05/2013] [Indexed: 12/20/2022] Open
Abstract
Nuclear import and export of viral RNA and proteins are critical to the replication cycle of viruses that replicate in the nucleus. Borna disease virus (BDV) is a nonsegmented, negative-strand RNA virus that belongs to the order Mononegavirales. BDV has several distinguishing features, one of the most striking being the site of its replication. BDV RNA is transcribed and replicated in the nucleus, while most other negative-strand RNA viruses replicate in the cytoplasm. Therefore, the nucleocytoplasmic trafficking of BDV macromolecules plays a key role in virus replication. Growing evidence indicates that several BDV proteins, including the nucleoprotein, phosphoprotein, protein X and large protein, contribute to the nucleocytoplasmic trafficking of BDV ribonucleoprotein (RNP). The directional control of BDV RNP trafficking is likely determined by the ratios of and interactions between the nuclear localization signals and nuclear export signals in the RNP. In this review, we present a comprehensive view of several unique mechanisms that BDV has developed to control its RNP trafficking and discuss the significance of BDV RNP trafficking in the replication cycle of BDV.
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14
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Sugai A, Sato H, Yoneda M, Kai C. Phosphorylation of measles virus phosphoprotein at S86 and/or S151 downregulates viral transcriptional activity. FEBS Lett 2012; 586:3900-7. [PMID: 23022562 DOI: 10.1016/j.febslet.2012.09.021] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Revised: 09/10/2012] [Accepted: 09/15/2012] [Indexed: 01/14/2023]
Abstract
Measles virus phosphoprotein (P protein) is a cofactor of the viral RNA polymerase (L protein) that associates with the nucleoprotein-RNA complex to support viral transcription and replication. Here, we report a significant inverse correlation between the phosphorylation level of MV-P protein and viral transcriptional activity. Upregulation of P protein phosphorylation resulted in reduction of viral transcription. Additionally, we found that strong phosphorylation at S86 and S151 of P protein, which may be generally prevented by association with nucleoprotein, downregulates the viral transcriptional activity. These findings suggest that P protein is involved in regulation of viral transcription through changes in its phosphorylation status.
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Affiliation(s)
- Akihiro Sugai
- International Research Center for Infectious Diseases, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, Japan
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15
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Modulation of miR-122 on persistently Borna disease virus infected human oligodendroglial cells. Antiviral Res 2010; 87:249-56. [PMID: 20561966 DOI: 10.1016/j.antiviral.2010.05.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2010] [Revised: 05/16/2010] [Accepted: 05/25/2010] [Indexed: 11/20/2022]
Abstract
Using RNAhybrid software we found the predicted binding of complementary sequences between miR-122 and viral mRNAs, may be important for the antiviral effect of miR-122 on Borna disease virus (BDV). A moderate expression of miR-122 was identified in human oligodendroglial cells (OL), but with a much lower level of miR-122 in BDV persistent infection (OL/BDV) and cells transfected with BDV gene expression vectors. Over-expression of miR-122 and specific blocking experiments demonstrated that miR-122 was able to specifically inhibit BDV protein synthesis, viral gene replication and transcription, and induce the secretion/synthesis of interferon (IFN) in OL and OL/BDV cells. The abolishment of miR-122 by AMO-122 inhibited endogenous IFN induction by IFN-beta. These results indicate that miR-122 can exert direct antiviral function by inhibiting BDV translation and replication on one hand, while acting indirectly through IFN to increase the host innate immunity to modulate the virus-host interactions on the other hand.
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16
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Protein kinase C-dependent phosphorylation of Borna disease virus P protein is required for efficient viral spread. Arch Virol 2010; 155:789-93. [DOI: 10.1007/s00705-010-0645-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2009] [Accepted: 01/15/2010] [Indexed: 10/19/2022]
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17
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Hock M, Kraus I, Schoehn G, Jamin M, Andrei-Selmer C, Garten W, Weissenhorn W. RNA induced polymerization of the Borna disease virus nucleoprotein. Virology 2010; 397:64-72. [DOI: 10.1016/j.virol.2009.11.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2009] [Revised: 10/29/2009] [Accepted: 11/10/2009] [Indexed: 10/20/2022]
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18
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Watanabe Y, Ohtaki N, Hayashi Y, Ikuta K, Tomonaga K. Autogenous translational regulation of the Borna disease virus negative control factor X from polycistronic mRNA using host RNA helicases. PLoS Pathog 2009; 5:e1000654. [PMID: 19893625 PMCID: PMC2766071 DOI: 10.1371/journal.ppat.1000654] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2009] [Accepted: 10/13/2009] [Indexed: 11/24/2022] Open
Abstract
Borna disease virus (BDV) is a nonsegmented, negative-strand RNA virus that employs several unique strategies for gene expression. The shortest transcript of BDV, X/P mRNA, encodes at least three open reading frames (ORFs): upstream ORF (uORF), X, and P in the 5′ to 3′ direction. The X is a negative regulator of viral polymerase activity, while the P phosphoprotein is a necessary cofactor of the polymerase complex, suggesting that the translation of X is controlled rigorously, depending on viral replication. However, the translation mechanism used by the X/P polycistronic mRNA has not been determined in detail. Here we demonstrate that the X/P mRNA autogenously regulates the translation of X via interaction with host factors. Transient transfection of cDNA clones corresponding to the X/P mRNA revealed that the X ORF is translated predominantly by uORF-termination-coupled reinitiation, the efficiency of which is upregulated by expression of P. We found that P may enhance ribosomal reinitiation at the X ORF by inhibition of the interaction of the DEAD-box RNA helicase DDX21 with the 5′ untranslated region of X/P mRNA, via interference with its phosphorylation. Our results not only demonstrate a unique translational control of viral regulatory protein, but also elucidate a previously unknown mechanism of regulation of polycistronic mRNA translation using RNA helicases. All viruses rely on host cell factors to complete their life cycles. Therefore, the replication strategies of viruses may provide not only the understanding of virus pathogenesis but also useful models to disentangle the complex machinery of host cells. Translation regulation of viral mRNA is a good example of this. Borna disease virus (BDV) is a highly neurotropic RNA virus which is characterized by persistent infection. BDV expresses mRNAs as polycistronic coding transcripts. Among them, the 0.8 kb X/P mRNA encodes at least three open reading frames (ORFs), upstream ORF, X, and P. Although BDV X and P have opposing effects in terms of viral polymerase activity, the translational regulation of X/P polycistronic mRNA has not been elucidated. In this study, we show an ingenious strategy of translational control of viral regulatory protein using host factors. We demonstrate that host RNA helicases, mainly DDX21, can affect ribosomal reinitiation of X via interaction with the 5′ untranslated region (UTR) of X/P mRNA and that the downstream P protein autogenously controls the translation of X by interfering with the binding of DDX21 to the 5′ UTR. Our findings uncover not only a unique translational control of viral regulatory protein but also a previously unknown mechanism of translational regulation of polycistronic mRNA using RNA helicases.
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Affiliation(s)
- Yohei Watanabe
- Department of Virology, Research Institute for Microbial Diseases (BIKEN), Osaka University, Suita, Osaka, Japan
| | - Naohiro Ohtaki
- Department of Virology, Research Institute for Microbial Diseases (BIKEN), Osaka University, Suita, Osaka, Japan
| | - Yohei Hayashi
- Department of Virology, Research Institute for Microbial Diseases (BIKEN), Osaka University, Suita, Osaka, Japan
| | - Kazuyoshi Ikuta
- Department of Virology, Research Institute for Microbial Diseases (BIKEN), Osaka University, Suita, Osaka, Japan
- Section of Viral Infections, Thailand–Japan Research Collaboration Center on Emerging and Re-emerging Infections (RCC-ERI), Nonthaburi, Thailand
| | - Keizo Tomonaga
- Department of Virology, Research Institute for Microbial Diseases (BIKEN), Osaka University, Suita, Osaka, Japan
- PRESTO, Japan Science and Technology Agency (JST), Chiyoda-ku, Tokyo, Japan
- * E-mail:
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Thakur R, Sarma S, Sharma B. Role of Borna disease virus in neuropsychiatric illnesses: are we inching closer? Indian J Med Microbiol 2009; 27:191-201. [PMID: 19584498 DOI: 10.4103/0255-0857.53200] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
The biological cause of psychiatric illnesses continues to be under intense scrutiny. Among the various neurotropic viruses, Borna disease virus (BDV) is another virus that preferentially targets the neurons of the limbic system and has been shown to be associated with behavioural abnormalities. Presence of various BDV markers, including viral RNA, in patients with affective and mood disorders have triggered ongoing debate worldwide regarding its aetiopathogenic relationship. This article analyses its current state of knowledge and recent advances in diagnosis in order to prove or refute the association of BDV in causation of human neuropsychiatric disorders. This emerging viral causative association of behavioural disorders, which seems to be inching closer, has implication not only for a paradigm shift in the treatment and management of neuropsychiatric illnesses but also has an important impact on the public health systems.
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Affiliation(s)
- R Thakur
- Department of Microbiology, IHBAS, Dilshad Garden, Delhi, India.
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Prat CMA, Schmid S, Farrugia F, Cenac N, Le Masson G, Schwemmle M, Gonzalez-Dunia D. Mutation of the protein kinase C site in borna disease virus phosphoprotein abrogates viral interference with neuronal signaling and restores normal synaptic activity. PLoS Pathog 2009; 5:e1000425. [PMID: 19424436 PMCID: PMC2673689 DOI: 10.1371/journal.ppat.1000425] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2008] [Accepted: 04/13/2009] [Indexed: 01/17/2023] Open
Abstract
Understanding the pathogenesis of infection by neurotropic viruses represents a major challenge and may improve our knowledge of many human neurological diseases for which viruses are thought to play a role. Borna disease virus (BDV) represents an attractive model system to analyze the molecular mechanisms whereby a virus can persist in the central nervous system (CNS) and lead to altered brain function, in the absence of overt cytolysis or inflammation. Recently, we showed that BDV selectively impairs neuronal plasticity through interfering with protein kinase C (PKC)-dependent signaling in neurons. Here, we tested the hypothesis that BDV phosphoprotein (P) may serve as a PKC decoy substrate when expressed in neurons, resulting in an interference with PKC-dependent signaling and impaired neuronal activity. By using a recombinant BDV with mutated PKC phosphorylation site on P, we demonstrate the central role of this protein in BDV pathogenesis. We first showed that the kinetics of dissemination of this recombinant virus was strongly delayed, suggesting that phosphorylation of P by PKC is required for optimal viral spread in neurons. Moreover, neurons infected with this mutant virus exhibited a normal pattern of phosphorylation of the PKC endogenous substrates MARCKS and SNAP-25. Finally, activity-dependent modulation of synaptic activity was restored, as assessed by measuring calcium dynamics in response to depolarization and the electrical properties of neuronal networks grown on microelectrode arrays. Therefore, preventing P phosphorylation by PKC abolishes viral interference with neuronal activity in response to stimulation. Our findings illustrate a novel example of viral interference with a differentiated neuronal function, mainly through competition with the PKC signaling pathway. In addition, we provide the first evidence that a viral protein can specifically interfere with stimulus-induced synaptic plasticity in neurons.
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Affiliation(s)
- Christine M. A. Prat
- INSERM, U563, Centre de Physiopathologie de Toulouse Purpan and Université Paul-Sabatier, Toulouse, France
| | - Sonja Schmid
- Department of Virology, University of Freiburg, Freiburg, Germany
| | | | - Nicolas Cenac
- Avenir Team, INSERM U563, Centre de Physiopathologie de Toulouse Purpan and Université Paul-Sabatier, Toulouse, France
| | | | - Martin Schwemmle
- Department of Virology, University of Freiburg, Freiburg, Germany
| | - Daniel Gonzalez-Dunia
- INSERM, U563, Centre de Physiopathologie de Toulouse Purpan and Université Paul-Sabatier, Toulouse, France
- * E-mail:
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Planz O, Pleschka S, Wolff T. Borna disease virus: a unique pathogen and its interaction with intracellular signalling pathways. Cell Microbiol 2009; 11:872-9. [PMID: 19290912 DOI: 10.1111/j.1462-5822.2009.01310.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Borna disease virus (BDV) is a neurotropic RNA virus that establishes non-cytolytic persistent infection in the central nervous system of warm-blooded animals. Depending on the host species and the route of infection, BDV persistence can modulate neuronal plasticity and animal behaviour and/or may provoke a T cell-mediated immunopathological reaction with high mortality. Therefore, BDV functions as a model pathogen to study persistent virus infection in the central nervous system. Here, we review recent evidence showing that BDV interferes with a spectrum of intracellular signalling pathways, which may be involved in viral spread, maintenance of persistence and modulation of neurotransmitter pathways.
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Affiliation(s)
- Oliver Planz
- Friedrich-Loeffler-Institute (FLI), 72076 Tübingen, Germany
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Abstract
Studies on the molecular biology of rotavirus, the major etiologic agent of gastroenteritis in infants and young children worldwide, have so far led to a large but not exhaustive knowledge of the mechanisms by which rotavirus replicates in the host cell. While the role of rotavirus structural proteins in the replication cycle is well defined, the functions of nonstructural proteins remain poorly understood. Recent experiments of RNA interference have clearly indicated the phases of the replication cycle for which the nonstructural proteins are essentially required. In addition, biochemical studies of their interactions with other viral proteins, together with immunofluorescence experiments on cells expressing recombinant proteins in different combinations, are providing new indications of their functions. This article contains a critical collection of the most recent achievements and the current hypotheses about the roles of nonstructural proteins in virus replication.
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Affiliation(s)
- Francesca Arnoldi
- International Centre for Genetic Engineering & Biotechnology (ICGEB), Padriciano 99, 34012 Trieste, Italy
| | - Oscar R Burrone
- International Centre for Genetic Engineering & Biotechnology (ICGEB), Padriciano 99, 34012 Trieste, Italy
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Prat C, Schmid S, Schwemmle M, Gonzalez-Dunia D. Borna disease virus phosphoprotein interferes with neuronal function and contributes to neurobehavioral disorders. BMC Proc 2008. [DOI: 10.1186/1753-6561-2-s1-p56] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Borna disease virus P protein affects neural transmission through interactions with gamma-aminobutyric acid receptor-associated protein. J Virol 2008; 82:12487-97. [PMID: 18815298 DOI: 10.1128/jvi.00877-08] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Borna disease virus (BDV) is one of the infectious agents that causes diseases of the central nervous system in a wide range of vertebrate species and, perhaps, in humans. The phosphoprotein (P) of BDV, an essential cofactor of virus RNA-dependent RNA polymerase, is required for virus replication. In this study, we identified the gamma-aminobutyric acid receptor-associated protein (GABARAP) with functions in neurobiology as one of the viral P protein-interacting cellular factors by using an approach of phage display-based protein-protein interaction analysis. Direct binding between GABARAP and P protein was confirmed by coimmunoprecipitation, protein pull-down, and mammalian two-hybrid analyses. GABARAP originally was identified as a linker between the gamma-aminobutyric acid receptor (GABAR) and the microtubule to regulate receptor trafficking and plays important roles in the regulation of the inhibitory neural transmitter gamma-aminobutyric acid (GABA). We showed that GABARAP colocalizes with P protein in the cells infected with BDV or transfected with the P gene, which resulted in shifting the localization of GABARAP from the cytosol to the nucleus. We further demonstrated that P protein blocks the trafficking of GABAR, a principal GABA-gated ion channel that plays important roles in neural transmission, to the surface of cells infected with BDV or transfected with the P gene. We proposed that during BDV infection, P protein binds to GABARAP, shifts the distribution of GABARAP from the cytoplasm to the nucleus, and disrupts the trafficking of GABARs to the cell membranes, which may result in the inhibition of GABA-induced currents and in the enhancement of hyperactivity and anxiety.
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25
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