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Rocchi A, Sariyer IK, Berger JR. Revisiting JC virus and progressive multifocal leukoencephalopathy. J Neurovirol 2023; 29:524-537. [PMID: 37659983 DOI: 10.1007/s13365-023-01164-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 07/10/2023] [Accepted: 07/27/2023] [Indexed: 09/04/2023]
Abstract
Since its definition 65 years ago, progressive multifocal leukoencephalopathy (PML) has continued to devastate a growing population of immunosuppressed patients despite major advances in our understanding of the causative JC virus (JCV). Unless contained by the immune system, JCV lyses host oligodendrocytes collateral to its life cycle, leading to demyelination, neurodegeneration, and death. Novel treatments have stagnated in the absence of an animal model while current antiviral agents fail to address the now ubiquitous polyomavirus. In this review, we highlight the established pathogenesis by which JCV infection progresses to PML, highlighting major challenges that must be overcome to eliminate the underlying virus and, therefore, the debilitating disease.
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Affiliation(s)
- Angela Rocchi
- Department of Microbiology, Immunology and Inflammation, Center for Neurovirology and Gene Editing, Temple University Lewis Katz School of Medicine, Philadelphia, PA, 19140, USA
| | - Ilker K Sariyer
- Department of Microbiology, Immunology and Inflammation, Center for Neurovirology and Gene Editing, Temple University Lewis Katz School of Medicine, Philadelphia, PA, 19140, USA.
| | - Joseph R Berger
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, 3400 Convention Avenue, Philadelphia, PA, 19104, USA.
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2
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Liu X, Zhao X, He J, Wang S, Shen X, Liu Q, Wang S. Advances in the Structure of GGGGCC Repeat RNA Sequence and Its Interaction with Small Molecules and Protein Partners. Molecules 2023; 28:5801. [PMID: 37570771 PMCID: PMC10420822 DOI: 10.3390/molecules28155801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 07/21/2023] [Accepted: 07/21/2023] [Indexed: 08/13/2023] Open
Abstract
The aberrant expansion of GGGGCC hexanucleotide repeats within the first intron of the C9orf72 gene represent the predominant genetic etiology underlying amyotrophic lateral sclerosis (ALS) and frontal temporal dementia (FTD). The transcribed r(GGGGCC)n RNA repeats form RNA foci, which recruit RNA binding proteins and impede their normal cellular functions, ultimately resulting in fatal neurodegenerative disorders. Furthermore, the non-canonical translation of the r(GGGGCC)n sequence can generate dipeptide repeats, which have been postulated as pathological causes. Comprehensive structural analyses of r(GGGGCC)n have unveiled its polymorphic nature, exhibiting the propensity to adopt dimeric, hairpin, or G-quadruplex conformations, all of which possess the capacity to interact with RNA binding proteins. Small molecules capable of binding to r(GGGGCC)n have been discovered and proposed as potential lead compounds for the treatment of ALS and FTD. Some of these molecules function in preventing RNA-protein interactions or impeding the phase transition of r(GGGGCC)n. In this review, we present a comprehensive summary of the recent advancements in the structural characterization of r(GGGGCC)n, its propensity to form RNA foci, and its interactions with small molecules and proteins. Specifically, we emphasize the structural diversity of r(GGGGCC)n and its influence on partner binding. Given the crucial role of r(GGGGCC)n in the pathogenesis of ALS and FTD, the primary objective of this review is to facilitate the development of therapeutic interventions targeting r(GGGGCC)n RNA.
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Affiliation(s)
- Xiaole Liu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China; (X.L.); (X.Z.); (J.H.); (S.W.); (X.S.); (Q.L.)
| | - Xinyue Zhao
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China; (X.L.); (X.Z.); (J.H.); (S.W.); (X.S.); (Q.L.)
| | - Jinhan He
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China; (X.L.); (X.Z.); (J.H.); (S.W.); (X.S.); (Q.L.)
| | - Sishi Wang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China; (X.L.); (X.Z.); (J.H.); (S.W.); (X.S.); (Q.L.)
| | - Xinfei Shen
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China; (X.L.); (X.Z.); (J.H.); (S.W.); (X.S.); (Q.L.)
| | - Qingfeng Liu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China; (X.L.); (X.Z.); (J.H.); (S.W.); (X.S.); (Q.L.)
| | - Shenlin Wang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China; (X.L.); (X.Z.); (J.H.); (S.W.); (X.S.); (Q.L.)
- Beijing NMR Center, Peking University, Beijing 100087, China
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The γ-tubulin meshwork assists in the recruitment of PCNA to chromatin in mammalian cells. Commun Biol 2021; 4:767. [PMID: 34158617 PMCID: PMC8219688 DOI: 10.1038/s42003-021-02280-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 05/28/2021] [Indexed: 12/27/2022] Open
Abstract
Changes in the location of γ-tubulin ensure cell survival and preserve genome integrity. We investigated whether the nuclear accumulation of γ-tubulin facilitates the transport of proliferating cell nuclear antigen (PCNA) between the cytosolic and the nuclear compartment in mammalian cells. We found that the γ-tubulin meshwork assists in the recruitment of PCNA to chromatin. Also, decreased levels of γ-tubulin reduce the nuclear pool of PCNA. In addition, the γ-tubulin C terminus encodes a PCNA-interacting peptide (PIP) motif, and a γ-tubulin–PIP-mutant affects the nuclear accumulation of PCNA. In a cell-free system, PCNA and γ-tubulin formed a complex. In tumors, there is a significant positive correlation between TUBG1 and PCNA expression. Thus, we report a novel mechanism that constitutes the basis for tumor growth by which the γ-tubulin meshwork maintains indefinite proliferation by acting as an opportune scaffold for the transport of PCNA from the cytosol to the chromatin. Corvaisier et al discover that γ-tubulin and replication protein PCNA forms a complex and that this facilitates recruitment of PCNA to chromatin both during cell division and during the DSB repair response. They identify a PCNA binding motif in γ-tubulin, which when mutated affects replication fork progression, providing insights into the role of the nuclear γ-tubulin meshwork.
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4
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Daniel DC, Johnson EM. PURA, the gene encoding Pur-alpha, member of an ancient nucleic acid-binding protein family with mammalian neurological functions. Gene 2017; 643:133-143. [PMID: 29221753 DOI: 10.1016/j.gene.2017.12.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 12/04/2017] [Accepted: 12/04/2017] [Indexed: 12/20/2022]
Abstract
The PURA gene encodes Pur-alpha, a 322 amino acid protein with repeated nucleic acid binding domains that are highly conserved from bacteria through humans. PUR genes with a single copy of this domain have been detected so far in spirochetes and bacteroides. Lower eukaryotes possess one copy of the PUR gene, whereas chordates possess 1 to 4 PUR family members. Human PUR genes encode Pur-alpha (Pura), Pur-beta (Purb) and two forms of Pur-gamma (Purg). Pur-alpha is a protein that binds specific DNA and RNA sequence elements. Human PURA, located at chromosome band 5q31, is under complex control of three promoters. The entire protein coding sequence of PURA is contiguous within a single exon. Several studies have found that overexpression or microinjection of Pura inhibits anchorage-independent growth of oncogenically transformed cells and blocks proliferation at either G1-S or G2-M checkpoints. Effects on the cell cycle may be mediated by interaction of Pura with cellular proteins including Cyclin/Cdk complexes and the Rb tumor suppressor protein. PURA knockout mice die shortly after birth with effects on brain and hematopoietic development. In humans environmentally induced heterozygous deletions of PURA have been implicated in forms of myelodysplastic syndrome and progression to acute myelogenous leukemia. Pura plays a role in AIDS through association with the HIV-1 protein, Tat. In the brain Tat and Pura association in glial cells activates transcription and replication of JC polyomavirus, the agent causing the demyelination disease, progressive multifocal leukoencephalopathy. Tat and Pura also act to stimulate replication of the HIV-1 RNA genome. In neurons Pura accompanies mRNA transcripts to sites of translation in dendrites. Microdeletions in the PURA locus have been implicated in several neurological disorders. De novo PURA mutations have been related to a spectrum of phenotypes indicating a potential PURA syndrome. The nucleic acid, G-rich Pura binding element is amplified as expanded polynucleotide repeats in several brain diseases including fragile X syndrome and a familial form of amyotrophic lateral sclerosis/fronto-temporal dementia. Throughout evolution the Pura protein plays a critical role in survival, based on conservation of its nucleic acid binding properties. These Pura properties have been adapted in higher organisms to the as yet unfathomable development of the human brain.
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Affiliation(s)
- Dianne C Daniel
- Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, Norfolk, VA 23507, USA
| | - Edward M Johnson
- Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, Norfolk, VA 23507, USA.
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5
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Nali LH, Fink MC, do Olival GS, Moraes L, Callegaro D, Tilbery CP, Vidal JE, Sumita LM, de Oliveira ACP, Romano CM. Polyomavirus detection in multiple sclerosis patients under natalizumab therapy: Profile and frequency of urinary shedding. J Med Virol 2016; 89:528-534. [PMID: 27464945 DOI: 10.1002/jmv.24646] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/17/2016] [Indexed: 11/07/2022]
Abstract
Patients undergoing Natalizumab (NTZ) therapy are at risk of progressive multifocal leukoencephalopathy (PML). Besides John Cunningham virus (JCV), BK polyomavirus might represent an additional concern for such patients since it can also infect CNS cells. Currently, data regarding the presence of anti-JCV antibodies added to previous immunosuppressive therapy and prolonged NTZ therapy has been used to classify patients at risk of developing PML. Here, we investigated the profile shedding of JCV and BKV in multiple sclerosis (MS) patients during treatment with NTZ. Serial blood and urine samples from 97 MS patients receiving either NTZ or β-interferon were investigated for polyomavirus shedding. While all blood samples tested negative, 36% of the patients shed polyomavirus in the urine in at least one time point. From these, 21.7%, 9.3%, and 5.1% shed JCV, BKV, and both polyomavirus, respectively. No difference was observed between the rates of urinary shedding of patients treated with NTZ (38.9%) and patients treated with other drugs (34.5%), also no PML event was diagnosed during the follow-up. Therefore, urinary shedding might not be interfered by therapy condition. In our study, we also observed 14/27 (52%) of anti-JCV antibodies prevalence, and nearly half of them (42%) did not present any event of urinary shedding during the follow-up. J. Med. Virol. 89:528-534, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Luiz Henrique Nali
- Laboratório de Virologia, Instituto de Medicina Tropical de São Paulo, Universidade de São Paulo, São Paulo, Brazil
| | - Maria Cristina Fink
- Laboratório de Virologia, Instituto de Medicina Tropical de São Paulo, Universidade de São Paulo, São Paulo, Brazil
| | - Guilherme S do Olival
- Laboratório de Virologia, Instituto de Medicina Tropical de São Paulo, Universidade de São Paulo, São Paulo, Brazil.,Departamento de Neurologia, Santa Casa de Misericórdia de São Paulo, São Paulo, Brazil
| | - Lenira Moraes
- Hospital das Clínicas de São Paulo-HCFMUSP, São Paulo, Brazil
| | | | - Charles Peter Tilbery
- Departamento de Neurologia, Santa Casa de Misericórdia de São Paulo, São Paulo, Brazil
| | - Jose Ernesto Vidal
- Grupo de Neurociências, Instituto de Infectologia Emílio Ribas, São Paulo, Brazil
| | - Laura Masami Sumita
- Laboratório de Virologia, Instituto de Medicina Tropical de São Paulo, Universidade de São Paulo, São Paulo, Brazil
| | - Augusto C Penalva de Oliveira
- Departamento de Neurologia, Santa Casa de Misericórdia de São Paulo, São Paulo, Brazil.,Grupo de Neurociências, Instituto de Infectologia Emílio Ribas, São Paulo, Brazil
| | - Camila M Romano
- Laboratório de Virologia, Instituto de Medicina Tropical de São Paulo, Universidade de São Paulo, São Paulo, Brazil
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Hirsch HH, Kardas P, Kranz D, Leboeuf C. The human JC polyomavirus (JCPyV): virological background and clinical implications. APMIS 2013; 121:685-727. [PMID: 23781977 DOI: 10.1111/apm.12128] [Citation(s) in RCA: 123] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Accepted: 04/29/2013] [Indexed: 02/06/2023]
Abstract
JC polyomavirus (JCPyV) was the first of now 12 PyVs detected in humans, when in 1964, PyV particles were revealed by electron microscopy in progressive multifocal leukoencephalopathy (PML) tissues. JCPyV infection is common in 35-70% of the general population, and the virus thereafter persists in the renourinary tract. One third of healthy adults asymptomatically shed JCPyV at approximately 50,000 copies/mL urine. PML is rare having an incidence of <0.3 per 100,000 person years in the general population. This increased to 2.4 per 1000 person years in HIV-AIDS patients without combination antiretroviral therapy (cART). Recently, PML emerged in multiple sclerosis patients treated with natalizumab to 2.13 cases per 1000 patients. Natalizumab blocks α4-integrin-dependent lymphocyte homing to the brain suggesting that not the overall cellular immunodeficiency but local failure of brain immune surveillance is a pivotal factor for PML. Recovering JCPyV-specific immune control, e.g., by starting cART or discontinuing natalizumab, significantly improves PML survival, but is challenged by the immune reconstitution inflammatory syndrome. Important steps of PML pathogenesis are undefined, and antiviral therapies are lacking. New clues might come from molecular and functional profiling of JCPyV and PML pathology and comparison with other replicative pathologies such as granule cell neuronopathy and (meningo-)encephalitis, and non-replicative JCPyV pathology possibly contributing to some malignancies. Given the increasing number of immunologically vulnerable patients, a critical reappraisal of JCPyV infection, replication and disease seems warranted.
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Affiliation(s)
- Hans H Hirsch
- Transplantation & Clinical Virology, Department Biomedicine (Haus Petersplatz), University of Basel, Basel, Switzerland.
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7
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Johnson EM, Daniel DC, Gordon J. The pur protein family: genetic and structural features in development and disease. J Cell Physiol 2013; 228:930-7. [PMID: 23018800 PMCID: PMC3747735 DOI: 10.1002/jcp.24237] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Accepted: 09/21/2012] [Indexed: 12/19/2022]
Abstract
The Pur proteins are an ancient family of sequence-specific single-stranded nucleic acid-binding proteins. They bind a G-rich element in either single- or double-stranded nucleic acids and are capable of displacing the complementary C-rich strand. Recently several reports have described Pur family member knockouts, mutations, and disease aberrations. Together with a recent crystal structure of Purα, these data reveal conserved structural features of these proteins that have been adapted to serve functions unique to higher eukaryotes. In humans Pur proteins are critical for myeloid cell development, muscle development, and brain development, including trafficking of mRNA to neuronal dendrites. Pur family members have been implicated in diseases as diverse as cancer, premature aging, and fragile-X mental retardation syndrome.
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Affiliation(s)
- Edward M Johnson
- Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, Norfolk, VA 23507-1696, USA.
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New insights on human polyomavirus JC and pathogenesis of progressive multifocal leukoencephalopathy. Clin Dev Immunol 2013; 2013:839719. [PMID: 23690827 PMCID: PMC3652120 DOI: 10.1155/2013/839719] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Accepted: 03/06/2013] [Indexed: 02/06/2023]
Abstract
John Cunningham virus (JCV) is a member of the Polyomaviridae family. It was first isolated from the brain of a patient with Hodgkin disease in 1971, and since then the etiological agent of the progressive multifocal leukoencephalopathy (PML) was considered. Until the human immunodeficiency virus (HIV) pandemic, PML was rare: in fact HIV-induced immunodeficiency is the most common predisposing factor accounting for 85% of all instances of PML. This data led to intense research on JCV infection and resulted in better understanding of epidemiology and clinic-pathologic spectrum. Recently, cases of PML have been observed after the introduction of monoclonal antibodies, such as natalizumab, rituximab, efalizumab, and infliximab, in the treatment of autoimmune disease, underlining the important role of host immunity in PML pathogenesis. In this review current understanding of the JCV infection and the new findings relating to the pathogenesis of PML has been comprehensively revised, focusing our attention on the interaction between the cellular and viral molecular pathways implicated in the JCV infection and the modulating role of host immune surveillance in the viral reactivation from a latent state.
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Polyomavirus JC in the context of immunosuppression: a series of adaptive, DNA replication-driven recombination events in the development of progressive multifocal leukoencephalopathy. Clin Dev Immunol 2013; 2013:197807. [PMID: 23690820 PMCID: PMC3649189 DOI: 10.1155/2013/197807] [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: 02/03/2013] [Accepted: 03/17/2013] [Indexed: 01/13/2023]
Abstract
Polyomavirus JC (JCV) is the etiological agent of progressive multifocal leukoencephalopathy (PML), a demyelinating infection of oligodendrocytes in the brain. PML, a frequently fatal opportunistic infection in AIDS, has also emerged as a consequence of treatment with several new immunosuppressive therapeutic agents. Although nearly 80% of adults are seropositive, JCV attains an ability to infect glial cells in only a minority of people. Data suggest that JCV undergoes sequence alterations that accompany this ability, and these changes can be derived from an archetype strain by mutation, deletion, and duplication. While the introductory source and primary tissue reservoir of JCV remain unknown, lymphoid cells have been identified as potential intermediaries in progression of JCV to the brain. This review is focused on sequence changes in the noncoding control region (NCCR) of the virus. We propose an adaptive mechanism that involves a sequential series of DNA replication-driven NCCR recombination events involving stalled DNA replication forks at NCCR palindromic secondary structures. We shall describe how the NCCR sequence changes point to a model in which viral DNA replication drives NCCR recombination, allowing JCV adaptation to different cell types in its progression to neurovirulence.
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Nali LHDS, Centrone CDC, Urbano PRP, Penalva-de-Oliveira AC, Vidal JE, Miranda EP, Pannuti CS, Fink MCDDS. High prevalence of the simultaneous excretion of polyomaviruses JC and BK in the urine of HIV-infected patients without neurological symptoms in São Paulo, Brazil. Rev Inst Med Trop Sao Paulo 2012; 54:201-5. [PMID: 22850991 DOI: 10.1590/s0036-46652012000400004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Accepted: 05/25/2012] [Indexed: 01/07/2023] Open
Abstract
OBJECTIVE To evaluate the prevalence of the urinary excretion of BKV and JCV in HIV-infected patients without neurological symptoms. METHODS Urine samples from HIV-infected patients without neurological symptoms were tested for JC virus and BK virus by PCR. Samples were screened for the presence of polyomavirus with sets of primers complementary to the early region of JCV and BKV genome (AgT). The presence of JC virus or BK virus were confirmed by two other PCR assays using sets of primers complementary to the VP1 gene of each virus. Analysis of the data was performed by the Kruskal-Wallis test for numerical data and Pearson or Yates for categorical variables. RESULTS A total of 75 patients were included in the study. The overall prevalence of polyomavirus DNA urinary shedding was 67/75 (89.3%). Only BKV DNA was detected in 14/75 (18.7%) urine samples, and only JCV DNA was detected in 11/75 (14.7%) samples. Both BKV and JCV DNA were present in 42/75 (56.0%) samples. CONCLUSION In this study we found high rates of excretion of JCV, BKV, and simultaneous excretion in HIV+ patients. Also these results differ from the others available on the literature.
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Affiliation(s)
- Luiz Henrique da Silva Nali
- Laboratório de Virologia, Instituto de Medicina Tropical de São Paulo, Universidade de São Paulo, São Paulo, SP, Brazil
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Wright CA, Nance JA, Johnson EM. Effects of Tat proteins and Tat mutants of different human immunodeficiency virus type 1 clades on glial JC virus early and late gene transcription. J Gen Virol 2012; 94:514-523. [PMID: 23152365 DOI: 10.1099/vir.0.047902-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Polyomavirus JC (JCV) is the aetiological agent of progressive multifocal leukoencephalopathy (PML), a frequently fatal infection of the brain afflicting nearly 4% of AIDS patients in the USA. Human immunodeficiency virus type 1 (HIV-1) Tat, acting together with cellular proteins at the JCV non-coding control region (NCCR), can stimulate JCV DNA transcription and replication. Tat in the brain is secreted by HIV-1-infected cells and incorporated by oligodendroglia, cells capable of infection by JCV. Thus far the effects of Tat on JCV have been studied primarily with protein encoded by the HIV-1 B clade most common in North America. Here, we determine the abilities of Tat from different HIV-1 clades to alter JCV early and late gene transcription and DNA replication initiated at the JCV origin. Tat from all clades tested stimulates both JCV early and late gene promoters, with clade B Tat being significantly most effective. Tat proteins from the HIV-1 clades display parallel patterns of differences in their effects on HIV-1 and JCV transcription, suggesting that Tat effects in both cases are mediated by the same cellular proteins. Clade B Tat is most effective at directing Smad mediators of tumour growth factor beta and cellular partner Purα to the NCCR. Tat proteins from all non-B clades inhibit initiation of JCV DNA replication. The effectiveness of HIV-1 clade B Tat at promoting JCV transcriptional and replicative processes highlights a need for further investigation to determine which molecular aspects of Tat from distinct HIV-1 substrains can contribute to the course of PML development in neuroAIDS.
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Affiliation(s)
- Clayton A Wright
- Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, 700 West Olney Road, Norfolk, VA 23510, USA
| | - Jonas A Nance
- Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, 700 West Olney Road, Norfolk, VA 23510, USA
| | - Edward M Johnson
- Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, 700 West Olney Road, Norfolk, VA 23510, USA
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12
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Molecular biology, epidemiology, and pathogenesis of progressive multifocal leukoencephalopathy, the JC virus-induced demyelinating disease of the human brain. Clin Microbiol Rev 2012; 25:471-506. [PMID: 22763635 DOI: 10.1128/cmr.05031-11] [Citation(s) in RCA: 289] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Progressive multifocal leukoencephalopathy (PML) is a debilitating and frequently fatal central nervous system (CNS) demyelinating disease caused by JC virus (JCV), for which there is currently no effective treatment. Lytic infection of oligodendrocytes in the brain leads to their eventual destruction and progressive demyelination, resulting in multiple foci of lesions in the white matter of the brain. Before the mid-1980s, PML was a relatively rare disease, reported to occur primarily in those with underlying neoplastic conditions affecting immune function and, more rarely, in allograft recipients receiving immunosuppressive drugs. However, with the onset of the AIDS pandemic, the incidence of PML has increased dramatically. Approximately 3 to 5% of HIV-infected individuals will develop PML, which is classified as an AIDS-defining illness. In addition, the recent advent of humanized monoclonal antibody therapy for the treatment of autoimmune inflammatory diseases such as multiple sclerosis (MS) and Crohn's disease has also led to an increased risk of PML as a side effect of immunotherapy. Thus, the study of JCV and the elucidation of the underlying causes of PML are important and active areas of research that may lead to new insights into immune function and host antiviral defense, as well as to potential new therapies.
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Shen CJ, Jia YH, Tian RR, Ding M, Zhang C, Wang JH. Translation of Pur-α is targeted by cellular miRNAs to modulate the differentiation-dependent susceptibility of monocytes to HIV-1 infection. FASEB J 2012; 26:4755-64. [PMID: 22835829 DOI: 10.1096/fj.12-209023] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The postentry restriction of HIV-1 replication in monocytes can be relieved when they differentiate to dendritic cells (DCs) or macrophages. Multiple mechanisms have been proposed to interpret the differentiation-dependent susceptibility of monocytes to HIV-1 infection, and the absence of host-cell-encoded essential factors for HIV-1 completing the life cycle may provide an explanation. We have analyzed the gene expression profile in monocytes by mRNA microarray and compared it with that of differentiated DCs. We demonstrated that purine-rich element binding protein α (Pur-α), a host-cell-encoded ubiquitous, sequence-specific DNA- and RNA-binding protein, showed inadequate expression in monocytes, and the translation of Pur-α mRNA was repressed by cell-expressed microRNA (miRNA). These Pur-α-targeted miRNAs modulated the differentiation-dependent susceptibility of monocytes/DCs to HIV-1 infection, because rescue of Pur-α expression by transfection of miRNA inhibitors relieved the restriction of HIV-1 infection in monocytes, and ectopic input of miRNA mimics significantly reduced HIV-1 infection of monocyte-derived DCs (MDDCs). Collectively, our data emphasized that inadequate host factors contribute to HIV-1 restriction in monocytes, and cellular miRNAs modulate differentiation-dependent susceptibility of host cells to HIV-1 infection. Elaboration of HIV-1 restriction in host cells facilitates our understanding of viral pathogenesis and the search for a new antiviral strategy.
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Affiliation(s)
- Chan-Juan Shen
- Key Laboratory of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
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Nukuzuma S, Kameoka M, Sugiura S, Nakamichi K, Nukuzuma C, Miyoshi I, Takegami T. Exogenous human immunodeficiency virus-1 protein, tat, enhances replication of JC virus efficiently in neuroblastoma cell lines. J Med Virol 2012; 84:555-61. [DOI: 10.1002/jmv.23239] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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15
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Broekema NM, Imperiale MJ. Efficient propagation of archetype BK and JC polyomaviruses. Virology 2011; 422:235-41. [PMID: 22099377 DOI: 10.1016/j.virol.2011.10.026] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2011] [Revised: 09/27/2011] [Accepted: 10/28/2011] [Indexed: 01/29/2023]
Abstract
BKPyV and JCPyV are closely related, ubiquitous human pathogens that cause disease in immunocompromised patients. The DNA sequence of the regulatory regions distinguishes two forms of these viruses, designated archetype and rearranged. Although cell culture systems exist for rearranged BKPyV and JCPyV, currently there is no robust cell culture system to study the archetype viruses. Large T antigen (TAg) is a virally encoded protein required to initiate viral DNA synthesis. Because archetype virus produces undetectable levels of TAg, we hypothesized that TAg overexpression would stimulate archetype virus replication. Efficient propagation of the archetype forms of BKPyV and JCPyV was observed in 293TT cells, human embryonic kidney cells overexpressing SV40 TAg. Importantly, the archetypal structure of the regulatory region was maintained during viral growth. Significant replication was not observed for Merkel cell, KI, or WU polyomaviruses. 293TT cells provide a means of propagating archetype BKPyV and JCPyV for detailed study.
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Affiliation(s)
- Nicole M Broekema
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109-5620, USA.
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Friedrich BM, Dziuba N, Li G, Endsley MA, Murray JL, Ferguson MR. Host factors mediating HIV-1 replication. Virus Res 2011; 161:101-14. [PMID: 21871504 DOI: 10.1016/j.virusres.2011.08.001] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Revised: 08/05/2011] [Accepted: 08/08/2011] [Indexed: 10/17/2022]
Abstract
Human immunodeficiency virus type 1(HIV-1) infection is the leading cause of death worldwide in adults attributable to infectious diseases. Although the majority of infections are in sub-Saharan Africa and Southeast Asia, HIV-1 is also a major health concern in most countries throughout the globe. While current antiretroviral treatments are generally effective, particularly in combination therapy, limitations exist due to drug resistance occurring among the drug classes. Traditionally, HIV-1 drugs have targeted viral proteins, which are mutable targets. As cellular genes mutate relatively infrequently, host proteins may prove to be more durable targets than viral proteins. HIV-1 replication is dependent upon cellular proteins that perform essential roles during the viral life cycle. Maraviroc is the first FDA-approved antiretroviral drug to target a cellular factor, HIV-1 coreceptor CCR5, and serves to intercept viral-host protein-protein interactions mediating entry. Recent large-scale siRNA and shRNA screens have revealed over 1000 candidate host factors that potentially support HIV-1 replication, and have implicated new pathways in the viral life cycle. These host proteins and cellular pathways may represent important targets for future therapeutic discoveries. This review discusses critical cellular factors that facilitate the successive steps in HIV-1 replication.
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Affiliation(s)
- Brian M Friedrich
- Department of Internal Medicine, Division of Infectious Diseases, University of Texas Medical Branch, Galveston, Texas 77555-0435, United States.
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Nukuzuma S, Nakamichi K, Kameoka M, Sugiura S, Nukuzuma C, Miyoshi I, Takegami T. Efficient propagation of progressive multifocal leukoencephalopathy-type JC virus in COS-7-derived cell lines stably expressing Tat protein of human immunodeficiency virus type 1. Microbiol Immunol 2010; 54:758-62. [PMID: 21223365 DOI: 10.1111/j.1348-0421.2010.00278.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The high incidence of progressive multifocal leukoencephalopathy (PML) in AIDS patients compared with many other immunosuppressive diseases suggests that HIV-1 infection is strictly related to the activation of JC virus (JCV) propagation. In this report, propagation of PML-type JCV in COS-7-derived cell lines stably expressing HIV-1 Tat (COS-tat cells) has been examined. In COS-tat cells, production of viral particles and replication of genomic DNA were markedly increased compared to COS-7 cells, as judged by HA and real-time PCR analyses. These results demonstrate that COS-tat cells provide a useful model system for studying HIV-1 Tat-mediated propagation of PML-type JCV.
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Affiliation(s)
- Souichi Nukuzuma
- Department of Microbiology, Kobe Institute of Health, Minatojima-Nakamachi, Kobe, Hyogo, Japan.
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18
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Wortman MJ, Hanson LK, Martínez-Sobrido L, Campbell AE, Nance JA, García-Sastre A, Johnson EM. Regulation of PURA gene transcription by three promoters generating distinctly spliced 5-prime leaders: a novel means of fine control over tissue specificity and viral signals. BMC Mol Biol 2010; 11:81. [PMID: 21062477 PMCID: PMC2992531 DOI: 10.1186/1471-2199-11-81] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2010] [Accepted: 11/09/2010] [Indexed: 12/17/2022] Open
Abstract
Background Purα is an evolutionarily conserved cellular protein participating in processes of DNA replication, transcription, and RNA transport; all involving binding to nucleic acids and altering conformation and physical positioning. The distinct but related roles of Purα suggest a need for expression regulated differently depending on intracellular and external signals. Results Here we report that human PURA (hPURA) transcription is regulated from three distinct and widely-separated transcription start sites (TSS). Each of these TSS is strongly homologous to a similar site in mouse chromosomal DNA. Transcripts from TSS I and II are characterized by the presence of large and overlapping 5'-UTR introns terminated at the same splice receptor site. Transfection of lung carcinoma cells with wild-type or mutated hPURA 5' upstream sequences identifies different regulatory elements. TSS III, located within 80 bp of the translational start codon, is upregulated by E2F1, CAAT and NF-Y binding elements. Transcription at TSS II is downregulated through the presence of adjacent consensus binding elements for interferon regulatory factors (IRFs). Chromatin immunoprecipitation reveals that IRF-3 protein binds hPURA promoter sequences at TSS II in vivo. By co-transfecting hPURA reporter plasmids with expression plasmids for IRF proteins we demonstrate that several IRFs, including IRF-3, down-regulate PURA transcription. Infection of NIH 3T3 cells with mouse cytomegalovirus results in a rapid decrease in levels of mPURA mRNA and Purα protein. The viral infection alters the degree of splicing of the 5'-UTR introns of TSS II transcripts. Conclusions Results provide evidence for a novel mechanism of transcriptional control by multiple promoters used differently in various tissues and cells. Viral infection alters not only the use of PURA promoters but also the generation of different non-coding RNAs from 5'-UTRs of the resulting transcripts.
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Affiliation(s)
- Margaret J Wortman
- Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, 700 W, Olney Road, Norfolk, VA 23507, USA.
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Graebsch A, Roche S, Niessing D. X-ray structure of Pur-alpha reveals a Whirly-like fold and an unusual nucleic-acid binding surface. Proc Natl Acad Sci U S A 2009; 106:18521-6. [PMID: 19846792 PMCID: PMC2765457 DOI: 10.1073/pnas.0907990106] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Indexed: 01/23/2023] Open
Abstract
The PUR protein family is a distinct and highly conserved class that is characterized by its sequence-specific RNA- and DNA-binding. Its best-studied family member, Pur-alpha, acts as a transcriptional regulator, as host factor for viral replication, and as cofactor for mRNP localization in dendrites. Pur-alpha-deficient mice show severe neurologic defects and die after birth. Nucleic-acid binding by Pur-alpha is mediated by its central core region, for which no structural information is available. We determined the x-ray structure of residues 40 to 185 from Drosophila melanogaster Pur-alpha, which constitutes a major part of the core region. We found that this region contains two almost identical structural motifs, termed "PUR repeats," which interact with each other to form a PUR domain. DNA- and RNA-binding studies confirmed that PUR domains are indeed functional nucleic-acid binding domains. Database analysis show that PUR domains share a fold with the Whirly class of nucleic-acid binding proteins. Structural analysis combined with mutational studies suggest that a PUR domain binds nucleic acids through two independent surface regions involving concave beta-sheets. Structure-based sequence alignment revealed that the core region harbors a third PUR repeat at its C terminus. Subsequent characterization by small-angle x-ray scattering (SAXS) and size-exclusion chromatography indicated that PUR repeat III mediates dimerization of Pur-alpha. Surface envelopes calculated from SAXS data show that the Pur-alpha dimer consisting of repeats I to III is arranged in a Z-like shape. This unexpected domain organization of the entire core domain of Pur-alpha has direct implications for ssDNA/ssRNA and dsDNA binding.
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Affiliation(s)
- Almut Graebsch
- Institute of Structural Biology, Helmholtz Zentrum München, German Research Center for Environmental Health, Marchionini-Strasse 25, Munich, 81377, Germany; and
- Department of Chemistry and Biochemistry, Gene Center Munich and Center for Integrated Protein Science CIPSM, Ludwig-Maximilians-University Munich, Feodor-Lynen-Strasse 25, Munich, 81377, Germany
| | - Stéphane Roche
- Institute of Structural Biology, Helmholtz Zentrum München, German Research Center for Environmental Health, Marchionini-Strasse 25, Munich, 81377, Germany; and
- Department of Chemistry and Biochemistry, Gene Center Munich and Center for Integrated Protein Science CIPSM, Ludwig-Maximilians-University Munich, Feodor-Lynen-Strasse 25, Munich, 81377, Germany
| | - Dierk Niessing
- Institute of Structural Biology, Helmholtz Zentrum München, German Research Center for Environmental Health, Marchionini-Strasse 25, Munich, 81377, Germany; and
- Department of Chemistry and Biochemistry, Gene Center Munich and Center for Integrated Protein Science CIPSM, Ludwig-Maximilians-University Munich, Feodor-Lynen-Strasse 25, Munich, 81377, Germany
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20
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Nukuzuma S, Kameoka M, Sugiura S, Nakamichi K, Nukuzuma C, Miyoshi I, Takegami T. Archetype JC virus efficiently propagates in kidney-derived cells stably expressing HIV-1 Tat. Microbiol Immunol 2009; 53:621-8. [PMID: 19903262 DOI: 10.1111/j.1348-0421.2009.00166.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Pathogenic JCV with rearranged regulatory regions (PML-type) causes PML, a demyelinating disease, in the brains of immunocompromised patients. On the other hand, archetype JCV persistently infecting the kidney is thought to be converted to PML-type virus during JCV replication in the infected host under immunosuppressed conditions. In addition, Tat protein, encoded by HIV-1, markedly enhances the expression of a reporter gene under control of the JCV late promoter. In order to examine the influence of Tat on JCV propagation, we used kidney-derived COS-7 cells, which only permit archetype JCV, and established COS-tat cells, which express HIV-1 Tat stably. We found that the extent of archetype JCV propagation in COS-tat cells is significantly greater than in COS-7 cells. On the other hand, COS-7 cells express SV40 T antigen, which is a strong stimulator of archetype JCV replication. The expression of SV40 T antigen was enhanced by HIV-1 Tat slightly according to real-time RT-PCR, this was not closely related to JCV replication in COS-tat cells. The efficiency of JCV propagation depended on the extent of expression of functional Tat. To our knowledge, this is the first report of increased production of archetype JCV in a culture system using cell lines stably expressing HIV-1 Tat. We propose here that COS-tat cells are a useful tool for studying the role of Tat in archetype JCV replication in the development of PML.
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Affiliation(s)
- Souichi Nukuzuma
- Department of Microbiology, Kobe Institute of Health, 4-6, Minatojima-Nakamachi, Chuo-ku, Kobe, Hyogo 650-0046, Japan.
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21
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Abstract
Polyomaviruses are a growing family of small DNA viruses with a narrow tropism for both the host species and the cell type in which they productively replicate. Species host range may be constrained by requirements for precise molecular interactions between the viral T antigen, host replication proteins, including DNA polymerase, and the viral origin of replication, which are required for viral DNA replication. Cell type specificity involves, at least in part, transcription factors that are necessary for viral gene expression and restricted in their tissue distribution. In the case of the human polyomaviruses, BK virus (BKV) replication occurs in the tubular epithelial cells of the kidney, causing nephropathy in kidney allograft recipients, while JC virus (JCV) replication occurs in the glial cells of the central nervous system, where it causes progressive multifocal leukoencephalopathy. Three new human polyomaviruses have recently been discovered: MCV was found in Merkel cell carcinoma samples, while Karolinska Institute Virus and Washington University Virus were isolated from the respiratory tract. We discuss control mechanisms for gene expression in primate polyomaviruses, including simian vacuolating virus 40, BKV, and JCV. These mechanisms include not only modulation of promoter activities by transcription factor binding but also enhancer rearrangements, restriction of DNA methylation, alternate early mRNA splicing, cis-acting elements in the late mRNA leader sequence, and the production of viral microRNA.
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22
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Stettner MR, Nance JA, Wright CA, Kinoshita Y, Kim WK, Morgello S, Rappaport J, Khalili K, Gordon J, Johnson EM. SMAD proteins of oligodendroglial cells regulate transcription of JC virus early and late genes coordinately with the Tat protein of human immunodeficiency virus type 1. J Gen Virol 2009; 90:2005-2014. [PMID: 19420158 DOI: 10.1099/vir.0.011072-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
JC virus (JCV) is the aetiological agent of progressive multifocal leukoencephalopathy (PML), a fatal, demyelinating disease of the brain affecting people with AIDS. Although immunosuppression is involved in infection of the brain by JCV, a direct influence of human immunodeficiency virus type 1 (HIV-1) has also been established. The Tat protein of HIV-1 has been implicated in activation of the cytokine transforming growth factor (TGF)-beta in HIV-1-infected cells and in stimulating JCV gene transcription and DNA replication in oligodendroglia, the primary central nervous system cell type infected by JCV in PML. This study demonstrated that Tat can cooperate with SMAD proteins, the intracellular effectors of TGF-beta, at the JCV DNA control region (CR) to stimulate JCV gene transcription. Tat stimulated JCV early gene transcription in KG-1 oligodendroglial cells when expressed via transfection or added exogenously. Using chromatin immunoprecipitation, it was shown that exogenous Tat enhanced binding of SMAD2, -3 and -4 and their binding partner Fast1 to the JCV CR in living cells. When SMAD2, -3 and -4 were expressed together, Tat, expressed from plasmid pTat, stimulated transcription from both early and late gene promoters, with the early promoter exhibiting stimulation of >100-fold. Tat, SMAD4 and JCV large T-antigen were all visualized in oligodendroglial cells at the border of an active PML lesion in the cerebral frontal lobe. These results revealed a positive reinforcement system in which the SMAD mediators of the TGF-beta system act cooperatively with Tat to stimulate JCV gene transcription.
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Affiliation(s)
- Michelle R Stettner
- Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, 700 West Olney Road, Norfolk, VA 23501, USA
| | - Jonas A Nance
- Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, 700 West Olney Road, Norfolk, VA 23501, USA
| | - Clayton A Wright
- Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, 700 West Olney Road, Norfolk, VA 23501, USA
| | - Yayoi Kinoshita
- Departments of Pathology and Neuroscience, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - Woong-Ki Kim
- Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, 700 West Olney Road, Norfolk, VA 23501, USA
| | - Susan Morgello
- Departments of Pathology and Neuroscience, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - Jay Rappaport
- Department of Neuroscience and Center for Neurovirology, Temple University School of Medicine, Philadelphia, PA 19122, USA
| | - Kamel Khalili
- Department of Neuroscience and Center for Neurovirology, Temple University School of Medicine, Philadelphia, PA 19122, USA
| | - Jennifer Gordon
- Department of Neuroscience and Center for Neurovirology, Temple University School of Medicine, Philadelphia, PA 19122, USA
| | - Edward M Johnson
- Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, 700 West Olney Road, Norfolk, VA 23501, USA
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23
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White MK, Johnson EM, Khalili K. Multiple roles for Puralpha in cellular and viral regulation. Cell Cycle 2009; 8:1-7. [PMID: 19182532 DOI: 10.4161/cc.8.3.7585] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Pur-alpha is a ubiquitous multifunctional protein that is strongly conserved throughout evolution, binds to both DNA and RNA and functions in the initiation of DNA replication, control of transcription and mRNA translation. In addition, it binds to several cellular regulatory proteins including the retinoblastoma protein, E2F-1, Sp1, YB-1, cyclin T1/Cdk9 and cyclin A/Cdk2. These observations and functional studies provide evidence that Puralpha is a major player in the regulation of the cell cycle and oncogenic transformation. Puralpha also binds to viral proteins such as the large T-antigen of JC virus (JCV) and the Tat protein of human immunodeficiency virus-1 (HIV-1) and plays a role in the cross-communication of these viruses in the opportunistic polyomavirus JC (JCV) brain infection, progressive multifocal leukoencephalopathy (PML). The creation of transgenic mice with inactivation of the PURA gene that encodes Puralpha has revealed that Puralpha is critical for postnatal brain development and has unraveled an essential role of Puralpha in the transport of specific mRNAs to the dendrites and the establishment of the postsynaptic compartment in the developing neurons. Finally, the availability of cell cultures from the PURA knockout mice has allowed studies that have unraveled a role for Puralpha in DNA repair.
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Affiliation(s)
- Martyn K White
- Department of Neuroscience, Center for Neurovirology, Temple University School of Medicine, Philadelphia, Pennsylvania, USA
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24
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Kinoshita Y, Johnson EM, Gordon RE, Negri-Bell H, Evans MT, Coolbaugh J, Rosario-Peralta Y, Samet J, Slusser E, Birkenbach MP, Daniel DC. Colocalization of MCM8 and MCM7 with proteins involved in distinct aspects of DNA replication. Microsc Res Tech 2008; 71:288-97. [DOI: 10.1002/jemt.20553] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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25
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Abstract
Many human neurological diseases involve demyelination of the central and/or peripheral nervous systems. These include the hereditary leukodystrophies--which have a genetic basis; multiple sclerosis (MS)--where the underlying cause of demyelination remains unknown; and progressive multifocal leukoencephalopathy (PML)--where the etiology is well-established as being viral. The human neurotropic polyomavirus--JC virus (JCV)--is the etiologic agent of PML, a fatal demyelinating disease of the central nervous system that occurs mainly in immunosuppressed patients, especially those with HIV/AIDS. JCV belongs to the polyomavirus family of tumor viruses that are characterized by non-enveloped icosahedral capsids containing small, circular, double-stranded DNA genomes. Serological studies have shown that JCV is widespread throughout the human population, but infections are usually restricted by the immune system, particularly cell-mediated immunity, causing the virus to enter a latent phase. An important corollary of this is that situations of severe immunosuppression may permit JCV to replicate and are thus a risk factor for PML.
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Affiliation(s)
- K Khalili
- Center for Neurovirology and Cancer Biology, College of Science and Technology, Temple University, Philadelphia, PA 19122, USA.
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26
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Schaffer K, Sheehy N, Coughlan S, Bergin C, Hall WW. JC virus in the Irish population: significant increase of genotype 2 in immunocompromised individuals. J Neurovirol 2006; 12:39-46. [PMID: 16595373 DOI: 10.1080/13550280600614965] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The human polyomavirus JC virus (JCV) is ubiquitous and can be shed in the urine of more than 40% of the healthy population. Amplification and sequencing of JCV from urine has allowed a distinctive map of the distribution of JCV genotypes worldwide. To define the frequency of JCV urinary excretion and genotype distribution in Ireland, urines from 121 healthy individuals and from 94 immunocompromised individuals (human immunodeficiency virus [HIV]-positive patients and rheumatoid arthritis patients) were collected. JCV DNA was detected by polymerase-chain reaction (PCR) with subsequent nucleotide sequencing of a fragment of the major capsid protein (VP1). JCV was detected in 20.7% of healthy individuals and was found significantly more often in the urine of HIV-positive patients (54.2%; P < .001) and rheumatoid arthritis patients (54.4%; P < .001). In healthy Irish individuals genotype 1 was the predominant genotype in 62.5%, followed by genotype 4 in 16.7% and genotype 2 in 12.5%. In contrast, genotype 2 was significantly more often isolated from the urine of both HIV-positive patients (60%) and rheumatoid arthritis patients (54.4%; P < .01). The pattern of genotype distribution among healthy Irish individuals is in agreement with data reported from other European countries, whereas the overall level of JCV urinary excretion is lower. Previous studies have found genotype 2 significantly more often in cerebrospinal (CSF) samples of patients with progressive multifocal leukoencephalopathy (PML). Here the authors report an increased frequency of genotype 2 in urine samples of immunocompromised non-PML patients. This finding further underlines the hypothesis that there could be biologic differences between JCV genotypes.
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Affiliation(s)
- Kirsten Schaffer
- Department of Medical Microbiology, Centre for Research in Infectious Diseases, National Virus Reference Laboratory, University College Dublin, Dublin, Ireland.
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27
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Khalili K, Gordon J, White MK. The polyomavirus, JCV and its involvement in human disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2006; 577:274-87. [PMID: 16626043 DOI: 10.1007/0-387-32957-9_20] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The human neurotropic polyomavirus, JC virus (JCV), is the etiologic agent of progressive multifocal leukoencephalopathy (PML), a fatal demyelinating disease of the central nervous system that occurs mainly in immunosuppressed patients. JCV has also been found to be associated with human tumors of the brain and other organs. In this chapter, we describe JC virus and its role in human diseases.
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Affiliation(s)
- Kamel Khalili
- Center for Neurovirology and Cancer Biology, Temple University, Philadelphia, Pennsylvania, USA
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28
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White MK, Gorrill TS, Khalili K. Reciprocal transactivation between HIV-1 and other human viruses. Virology 2006; 352:1-13. [PMID: 16725168 DOI: 10.1016/j.virol.2006.04.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2006] [Revised: 03/14/2006] [Accepted: 04/06/2006] [Indexed: 01/08/2023]
Abstract
A variety of rare clinical syndromes are seen with strikingly increased prevalence in HIV-1-infected individuals, many with underlying viral etiologies. The emergence of these diseases in AIDS reflects a reduction in the ability of the immune system to mount an adequate defense against viruses in general due to the damage inflicted to the immune system by HIV-1 infection. However, in many cases, it has been found that HIV-1 can enhance the level of expression and hence the life cycle of other viruses independently of immunosuppression through specific interactions with the viruses. This can occur either directly by HIV-1 proteins such as Tat enhancing the activity of heterologous viral promoters, and/or indirectly by HIV-1 inducing the expression of cytokines and activation of their downstream signaling that eventually promotes the multiplication of the other virus. In a reciprocal manner, the effects of other viruses can enhance the pathogenicity of HIV-1 infection in individuals with AIDS through stimulation of the HIV-1 promoter activity and genome expression. The purpose of this review is to examine the cross-interactions between these viruses and HIV-1.
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Affiliation(s)
- Martyn K White
- Center for Neurovirology, Department of Neuroscience, Temple University School of Medicine, 1900 North 12th Street, 015-96, Room 203, Philadelphia, PA 19122, USA.
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Fedele CG, Polo C, Tenorio A, Niubò J, Ciardi MR, Pérez JL. Analysis of the transcriptional control region of JC polyomavirus in cerebrospinal fluid from HIV-negative patients with progressive multifocal leucoencephalopathy. J Med Virol 2006; 78:1271-5. [PMID: 16927288 DOI: 10.1002/jmv.20697] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The human polyomavirus JC (JCV) is the causative agent of progressive multifocal leukoencephalopathy (PML), a fatal demyelinating disease of the central nervous system (CNS). JCV has a hyper-variable non-coding transcriptional control region (TCR), which contains the origin of replication and the promoters of viral transcription and replication. The archetype form of TCR-JCV is frequently found in the urine and kidneys of healthy and immunocompromised subjects. However, the rearranged forms, possibly generated by deletion and duplication of segments of the archetype sequence, are found in the peripheral blood, cerebrospinal fluid (CSF), and brain of PML patients. Most experience on this setting has come from the human immunodeficiency virus (HIV) pandemic. Little has been described on the JCV-TCR sequences from PML-HIV-negative patients affected by other immunosuppressive disorders. The aim of this study was to analyze the JCV-TCR detected in CSF samples from 12 HIV-negative immunosuppressed patients suffering from PML and to investigate the possible role of genomic organization in the different incidences of PML in HIV-positive and HIV-negative patients. The results confirm that the JCV-TCR rearrangements play a crucial role in the development of PML, although they do not account for the higher frequency of the disease in HIV infection. These data support the hypothesis that, independently of the rearrangement patterns of JCV-TCR, the direct action of HIV together with other as yet unidentified cellular determinants can be a key to explaining the high rate of PML in HIV infection with respect to other underlying immunosuppressive conditions.
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Affiliation(s)
- Cesare Giovanni Fedele
- Diagnostic Microbiology Service Centro Nacional de Microbiología, Majadahonda, Madrid, Spain.
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30
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Eberwein P, Hansen LL, Agostini HT. Genotypes of JC virus, DNA of cytomegalovirus, and proviral DNA of human immunodeficiency virus in eyes of acquired immunodeficiency syndrome patients. J Neurovirol 2005; 11:58-65. [PMID: 15804960 DOI: 10.1080/13550280590900391] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
JC virus (JCV) is a human polyomavirus that exists in at least eight different genotypes as a result of coevolution with different human populations all over the world. Well adapted to its host, it usually persists in the kidneys and possibly the brain. If the host becomes immunodeficient, JCV can cause the fatal demyelinating disease progressive multifocal leukoencephalopathy (PML). There is increasing evidence that JCV is transactivated by cytomegalovirus (CMV) and the human immunodeficiency virus (HIV). Both CMV and HIV can infect the retina of acquired immunodeficiency syndrome (AIDS) patients, causing severe necrosis in the case of CMV retinitis or a mild HIV-associated vasculopathy, with bleeding and cotton wool spots. The authors therefore investigated by polymerase chain reaction (PCR) whether DNA of these three viruses was detectable in paraffin-embedded eyes of AIDS patients with a clinical history of CMV retinitis. From a total of 65 eyes, JCV was detected in 21 (32%). Thirty-six (55%) were positive for CMV and 6 (9%) for proviral DNA of HIV. JCV and CMV were found in 13 eyes, JCV and HIV in 3 eyes, CMV and HIV in 1 eye, and DNA from all three viruses in 1 eye. The JCV genotypes were types 1A, 2A, 2E, 3, and 4. In 21 eyes of patients without AIDS, only one sample was JCV positive. In conclusion, JCV DNA can be detected in ocular tissue of AIDS patients at a significantly higher level than in eyes of nonimmunosuppressed patients. Further investigations will help to decide if JCV contributes to the retinopathy caused by CMV and HIV.
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Affiliation(s)
- Philipp Eberwein
- Department of Ophthalmology, University of Freiburg, Freiburg, Germany
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31
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Wortman MJ, Johnson EM, Bergemann AD. Mechanism of DNA binding and localized strand separation by Pur alpha and comparison with Pur family member, Pur beta. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2005; 1743:64-78. [PMID: 15777841 DOI: 10.1016/j.bbamcr.2004.08.010] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2004] [Revised: 08/19/2004] [Accepted: 08/20/2004] [Indexed: 11/18/2022]
Abstract
Pur alpha is a single-stranded (ss) DNA- and RNA-binding protein with three conserved signature repeats that have a specific affinity for guanosine-rich motifs. Pur alpha unwinds a double-stranded oligonucleotide containing purine-rich repeats by maintaining contact with the purine-rich strand and displacing the pyrimidine-rich strand. Mutational analysis indicates that arginine and aromatic residues in the repeat region of Pur alpha are essential for both ss- and duplex DNA binding. Pur alpha binds either linearized or supercoiled plasmid DNA, generating a series of regularly spaced bands in agarose gels. This series is likely due to localized unwinding by quanta of Pur alpha since removal of Pur alpha in the gel eliminates the series and since Pur alpha binding increases the sensitivity of plasmids to reaction with potassium permanganate, a reaction specific for unwound regions. Pur alpha binding to linear duplex DNA creates binding sites for the phage T4 gp32 protein, an ss-DNA binding protein that does not itself bind linearized DNA. In contrast, Pur beta lacking the Pur alpha C-terminal region binds supercoiled DNA but not linearized DNA. Similarly, a C-terminal deletion of Pur alpha can bind supercoiled pMYC7 plasmid, but cannot bind the same linear duplex DNA segment. Therefore, access to linear DNA initially requires C-terminal sequences of Pur alpha.
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Affiliation(s)
- Margaret J Wortman
- Department of Pathology, Mount Sinai School of Medicine, New York, NY 10029, USA
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Liu H, Barr SM, Chu C, Kohtz DS, Kinoshita Y, Johnson EM. Functional interaction of Puralpha with the Cdk2 moiety of cyclin A/Cdk2. Biochem Biophys Res Commun 2005; 328:851-7. [PMID: 15707957 DOI: 10.1016/j.bbrc.2005.01.038] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2005] [Indexed: 11/19/2022]
Abstract
Puralpha is a sequence-specific single-stranded nucleic acid-binding protein and a member of the highly conserved Pur family. Puralpha has been shown to colocalize with cyclin A/Cdk2 and to coimmunoprecipitate with cyclin A during S-phase. Here we show that this interaction is mediated by a specific affinity of Puralpha for Cdk2. In pull-down assays GST-Puralpha efficiently binds Cdk2 and Cdk1, binds Cdk4 less efficiently, and does not display binding to Cdk6. Puralpha stimulates several-fold the phosphorylation in vitro of histone H1 by cyclin A/Cdk2, produced from baculovirus constructs. Double chromatin immunoprecipitation using antibodies to Cdk2 and Puralpha reveals that both proteins colocalize in HeLa cells to DNA segments upstream of the c-MYC gene. Pur family member Purgamma colocalizes with Cdk2 to a specific DNA segment in this region.
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Affiliation(s)
- Hong Liu
- Department of Pathology, Mount Sinai School of Medicine, New York, NY 10029, USA
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Daniel DC, Kinoshita Y, Khan MA, Del Valle L, Khalili K, Rappaport J, Johnson EM. Internalization of exogenous human immunodeficiency virus-1 protein, Tat, by KG-1 oligodendroglioma cells followed by stimulation of DNA replication initiated at the JC virus origin. DNA Cell Biol 2005; 23:858-67. [PMID: 15684713 DOI: 10.1089/dna.2004.23.858] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
JC virus (JCV) is the etiological agent of an opportunistic brain infection, progressive multifocal leukoencephalopathy (PML), in AIDS. PML is fatal in approximately 4% of HIV-infected individuals, and although the overall incidence has fallen due to highly aggressive antiretroviral therapy (HAART), this percent has remained steady. It has been shown that the Tat protein of human immunodeficiency virus-1 (HIV-1) interacts in cells with cellular protein Puralpha. This interaction can stimulate transcription of both HIV-1 and JCV genes. HIV-1, however, infects primarily microglia and astrocytes in the brain, whereas JCV infects primarily oligodendrocytes. Although HIV-1 has been shown capable of infecting oligodendrocytes in vitro (Albright et al., 1996), no instance of viral coinfection of such cells with JCV has been reported. Tat is known to be secreted from cells in which it is made. Here we ask whether such exogenous Tat can influence JCV replication in oligodendrocytes. We find that glial cells infected with either HIV-1 or JCV are in proximity at the outer edge of PML lesions. Exogenous Tat is avidly incorporated into cultured KG-1 oligodendroglioma cells over a 72-h period and is colocalized with endogenous Puralpha both nuclear and juxtanuclear. At concentrations in the medium well below the pM range, Tat stimulates several-fold the replication in vivo of DNA initiated at the JCV origin. These results define a pathway by which a protein made by HIV-1 can directly affect the course of infection by another disease-causing virus.
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Affiliation(s)
- Dianne C Daniel
- Department of Pathology, Mount Sinai School of Medicine, New York, New York 10029, USA
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Kinoshita Y, Johnson EM. Site-specific Loading of an MCM Protein Complex in a DNA Replication Initiation Zone Upstream of the c-MYC Gene in the HeLa Cell Cycle. J Biol Chem 2004; 279:35879-89. [PMID: 15190069 DOI: 10.1074/jbc.m401640200] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The MCM proteins participate in an orderly association, beginning with the origin recognition complex, that culminates in the initiation of chromosomal DNA replication. Among these, MCM proteins 4, 6, and 7 constitute a subcomplex that reportedly possesses DNA helicase activity. Little is known about DNA sequences initially bound by these MCM proteins or about their cell cycle distribution in the chromatin. We have determined the locations of certain MCM and associated proteins by chromatin immunoprecipitation (ChIP) in a zone of initiation of DNA replication upstream of the c-MYC gene in the HeLa cell cycle. MCM7 and its clamp-loading partner Cdc6 are highly specifically colocalized by ChIP and re-ChIP in G(1) and early S on a 198-bp segment located near the center of the initiation zone. ChIP and Re-ChIP colocalizes MCM7 and ORC1 to the same segment specifically in late G(1). MCM proteins 6 and 7 can be coimmunoprecipitated throughout the cell cycle, whereas MCM4 is reduced in the complex in late S and G(2), reappearing upon mitosis. MCM7 is not visualized by immunohistochemistry on metaphase chromosomes. MCM7 is recruited to multiple sites in chromatin in S and G(2), at which time it is not detected with ORC1. The rate of dissemination is surprisingly slow and is unlikely to be simply attributed to progression with replication forks. Results indicate sequence-specific loading of MCM proteins onto DNA in late G(1) followed by a recruitment to multiple sites in chromatin subsequent to replication.
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Affiliation(s)
- Yayoi Kinoshita
- Department of Pathology, Mount Sinai School of Medicine, New York, New York 10029, USA
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Enam S, Sweet TM, Amini S, Khalili K, Del Valle L. Evidence for Involvement of Transforming Growth Factor β1 Signaling Pathway in Activation of JC Virus in Human Immunodeficiency Virus 1–Associated Progressive Multifocal Leukoencephalopathy. Arch Pathol Lab Med 2004; 128:282-91. [PMID: 14987161 DOI: 10.5858/2004-128-282-efiotg] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Abstract
Context.—Progressive multifocal leukoencephalopathy is a fatal demyelinating disease of the central nervous system frequently seen in patients with impaired immune systems, particularly acquired immunodeficiency syndrome. JC virus (JCV), a human neurotropic polyomavirus, is the etiologic infectious agent of this disease.
Objective.—The significantly higher incidence of progressive multifocal leukoencephalopathy in patients with acquired immunodeficiency syndrome than in patients with other immunosuppressive conditions suggests that molecular interactions between human immunodeficiency virus 1 and JCV, via the Tat protein, are responsible for the activation of the JCV enhancer/promoter and the development of progressive multifocal leukoencephalopathy. An indirect mechanism through activation of cytokines, such as transforming growth factor β1 and Smads 3 and 4, may also be responsible for the enhancement of JCV gene expression.
Design.—Immunohistochemical analysis in progressive multifocal leukoencephalopathy samples and chloramphenicol acetyl transferase assays on cell cultures were performed to corroborate this hypothesis.
Results.—The JCV capsid protein VP-1 was found in the nuclei of oligodendrocytes and in the nuclei and cytoplasm of bizarre astrocytes. Human immunodeficiency virus proteins, including p24 and Tat, were detected in the cytoplasm of astrocytes. Tat, but not p24, was detected in oligodendrocytes, suggesting that extracellular Tat accumulates in the nuclei of oligodendrocytes, where JCV gene transcription takes place. High levels of transforming growth factor β1 and Smads 3 and 4 were detected in JCV-infected oligodendrocytes. Results from in vitro studies confirm activation of the JCV early and late promoters by Smads 3 and 4.
Conclusions.—These observations support our model, suggesting that the induction of transforming growth factor β1 by human immunodeficiency virus 1 Tat can stimulate its downstream factors, including Smads 3 and 4, which in turn augment transcription of the JCV promoter in glial cells.
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Affiliation(s)
- Sahnila Enam
- Center for Neurovirology and Cancer Biology, College of Science and Technology, Temple University, Philadelphia, Pa, USA
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Pietropaolo V, Videtta M, Fioriti D, Mischitelli M, Arancio A, Orsi N, Degener AM. Rearrangement patterns of JC virus noncoding control region from different biological samples. J Neurovirol 2004; 9:603-11. [PMID: 14602573 DOI: 10.1080/13550280390246507] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The JC virus (JCV) is generally considered the etiological agent of progressive multifocal leukoencephalopathy (PML), a demyelinating brain illness, often associated with immunosuppression and significantly frequent in acquired immunodeficiency syndrome (AIDS) patients. The primary infection by JCV is usually asymptomatic and the virus can remain in a latent status in the kidney. As a consequence of immunological alterations of the host, the virus can show a genetic variability in the noncoding control region (NCCR) due to deletions, duplications, and insertions as compared with the archetype. The NCCR of the archetype strain can be divided into six regions, named boxes A to F. In this study, the authors evaluated the presence of the JCV genome in different biological samples, such as urine, peripheral blood mononuclear cells (PBMCs) and cerebral spinal fluid (CSF) by means of polymerase chain reaction (PCR). After sequencing of the PCR fragments, the NCCR structure of isolated JCV strains was analyzed in order to verify the presence of different viral variants. An analysis of the homology and of the multiple alignment of the obtained sequences in comparison with the archetype strain has been carried out. The results indicated the presence of different rearrangements among the analyzed samples. Whereas in the urine, the NCCR structure always appeared very similar to that of the archetype, in the PBMCs and CSF, the NCCR sequences showed specific and characteristic rearrangements as compared to the archetype. These different rearrangements could be correlated with the emerging of an NCCR organization more suitable for the development of PML.
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Affiliation(s)
- V Pietropaolo
- Department of Public Health Sciences, University of Rome "La Sapienza," Rome, Italy.
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Khalili K, Del Valle L, Muralidharan V, Gault WJ, Darbinian N, Otte J, Meier E, Johnson EM, Daniel DC, Kinoshita Y, Amini S, Gordon J. Puralpha is essential for postnatal brain development and developmentally coupled cellular proliferation as revealed by genetic inactivation in the mouse. Mol Cell Biol 2003; 23:6857-75. [PMID: 12972605 PMCID: PMC193944 DOI: 10.1128/mcb.23.19.6857-6875.2003] [Citation(s) in RCA: 136] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The single-stranded DNA- and RNA-binding protein, Puralpha, has been implicated in many biological processes, including control of transcription of multiple genes, initiation of DNA replication, and RNA transport and translation. Deletions of the PURA gene are frequent in acute myeloid leukemia. Mice with targeted disruption of the PURA gene in both alleles appear normal at birth, but at 2 weeks of age, they develop neurological problems manifest by severe tremor and spontaneous seizures and they die by 4 weeks. There are severely lower numbers of neurons in regions of the hippocampus and cerebellum of PURA(-/-) mice versus those of age-matched +/+ littermates, and lamination of these regions is aberrant at time of death. Immunohistochemical analysis of MCM7, a protein marker for DNA replication, reveals a lack of proliferation of precursor cells in these regions in the PURA(-/-) mice. Levels of proliferation were also absent or low in several other tissues of the PURA(-/-) mice, including those of myeloid lineage, whereas those of PURA(+/-) mice were intermediate. Evaluation of brain sections indicates a reduction in myelin and glial fibrillary acidic protein labeling in oligodendrocytes and astrocytes, respectively, indicating pathological development of these cells. At postnatal day 5, a critical time for cerebellar development, Puralpha and Cdk5 were both at peak levels in bodies and dendrites of Purkinje cells of PURA(+/+) mice, but both were absent in dendrites of PURA(-/-) mice. Puralpha and Cdk5 can be coimmunoprecipitated from brain lysates of PURA(+/+) mice. Immunohistochemical studies reveal a dramatic reduction in the level of both phosphorylated and nonphosphorylated neurofilaments in dendrites of the Purkinje cell layer and of synapse formation in the hippocampus. Overall results are consistent with a role for Puralpha in developmentally timed DNA replication in specific cell types and also point to a newly emerging role in compartmentalized RNA transport and translation in neuronal dendrites.
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Affiliation(s)
- Kamel Khalili
- Center for Neurovirology and Cancer Biology, College of Science and Technology, Temple University, Philadelphia, Pennsylvania 19122, USA.
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Smith RWP, Nasheuer HP. Initiation of JC virus DNA replication in vitro by human and mouse DNA polymerase alpha-primase. EUROPEAN JOURNAL OF BIOCHEMISTRY 2003; 270:2030-7. [PMID: 12709063 DOI: 10.1046/j.1432-1033.2003.03579.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Host species specificity of the polyomaviruses simian virus 40 (SV40) and mouse polyomavirus (PyV) has been shown to be determined by the host DNA polymerase alpha-primase complex involved in the initiation of both viral and host DNA replication. Here we demonstrate that DNA replication of the related human pathogenic polyomavirus JC virus (JCV) can be supported in vitro by DNA polymerase alpha-primase of either human or murine origin indicating that the mechanism of its strict species specificity differs from that of SV40 and PyV. Our results indicate that this may be due to differences in the interaction of JCV and SV40 large T antigens with the DNA replication initiation complex.
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Affiliation(s)
- Richard W P Smith
- Abteilung Biochemie, Institut für Molekulare Biotechnologie, Jena, Germany
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Sweet TM, Del Valle L, Khalili K. Molecular biology and immunoregulation of human neurotropic JC virus in CNS. J Cell Physiol 2002; 191:249-56. [PMID: 12012320 DOI: 10.1002/jcp.10096] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The human polyomavirus, JC virus (JCV), provides an excellent model system to investigate the reciprocal interaction of the immune and nervous systems. Infection with JCV occurs during childhood and the virus remains in the latent state with no apparent clinical symptoms. However, under immunosuppressed conditions, the virus enters the lytic cycle and upon cytolytic destruction of glial cells, causes the fatal demyelinating disease of the central nervous system (CNS), named progressive multifocal leukoencephalopathy (PML). In this short review, we discuss the molecular pathogenesis of PML by highlighting the role of the immune system in modulating JCV gene activation and replication, and the latency/reactivation of this virus upon immunosuppression. Further, due to the higher incidence of PML among AIDS patients, we further elaborate on the cross-talk between JCV and HIV-1 by direct and indirect pathways that lead to enhanced expression of the JCV genome.
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Affiliation(s)
- Thersa M Sweet
- Center for Neurovirology and Cancer Biology, Temple University, Philadelphia, Pennsylvania 19122, USA
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