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Schulz TF, Freise A, Stein SC. Kaposi sarcoma-associated herpesvirus latency-associated nuclear antigen: more than a key mediator of viral persistence. Curr Opin Virol 2023; 61:101336. [PMID: 37331160 DOI: 10.1016/j.coviro.2023.101336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 05/03/2023] [Accepted: 05/22/2023] [Indexed: 06/20/2023]
Abstract
Kaposi sarcoma-associated herpesvirus (KSHV), or human herpesvirus-8, is an oncogenic herpesvirus. Its latency-associated nuclear antigen (LANA) is essential for the persistence of KSHV in latently infected cells. LANA mediates replication of the latent viral genome during the S phase of a dividing cell and partitions episomes to daughter cells by attaching them to mitotic chromosomes. It also mediates the establishment of latency in newly infected cells through epigenetic mechanisms and suppresses the activation of the productive replication cycle. Furthermore, LANA promotes the proliferation of infected cell by acting as a transcriptional regulator and by modulating the cellular proteome through the recruitment of several cellular ubiquitin ligases. Finally, LANA interferes with the innate and adaptive immune system to facilitate the immune escape of infected cells.
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Affiliation(s)
- Thomas F Schulz
- Institute of Virology, Hannover Medical School, Germany; Cluster of Excellence 2155 RESIST, Germany; German Center for Infection Research, Hannover-Braunschweig Site, Germany.
| | - Anika Freise
- Institute of Virology, Hannover Medical School, Germany
| | - Saskia C Stein
- Institute of Virology, Hannover Medical School, Germany; Cluster of Excellence 2155 RESIST, Germany
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2
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Curtis NL, Ruda GF, Brennan P, Bolanos-Garcia VM. Deregulation of Chromosome Segregation and Cancer. ANNUAL REVIEW OF CANCER BIOLOGY 2020. [DOI: 10.1146/annurev-cancerbio-030419-033541] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The mitotic spindle assembly checkpoint (SAC) is an intricate cell signaling system that ensures the high fidelity and timely segregation of chromosomes during cell division. Mistakes in this process can lead to the loss, gain, or rearrangement of the genetic material. Gross chromosomal aberrations are usually lethal but can cause birth and development defects as well as cancer. Despite advances in the identification of SAC protein components, important details of the interactions underpinning chromosome segregation regulation remain to be established. This review discusses the current understanding of the function, structure, mode of regulation, and dynamics of the assembly and disassembly of SAC subcomplexes, which ultimately safeguard the accurate transmission of a stable genome to descendants. We also discuss how diverse oncoviruses take control of human cell division by exploiting the SAC and the potential of this signaling circuitry as a pool of drug targets to develop effective cancer therapies.
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Affiliation(s)
- Natalie L. Curtis
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford OX3 0BP, United Kingdom
| | - Gian Filippo Ruda
- Target Discovery Institute and Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7BN, United Kingdom
| | - Paul Brennan
- Target Discovery Institute and Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7BN, United Kingdom
| | - Victor M. Bolanos-Garcia
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford OX3 0BP, United Kingdom
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De Leo A, Calderon A, Lieberman PM. Control of Viral Latency by Episome Maintenance Proteins. Trends Microbiol 2019; 28:150-162. [PMID: 31624007 DOI: 10.1016/j.tim.2019.09.002] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 08/30/2019] [Accepted: 09/05/2019] [Indexed: 12/12/2022]
Abstract
The human DNA tumor viruses Epstein-Barr virus (EBV), Kaposi's sarcoma-associated herpesvirus (KSHV), and human papillomavirus (HPV) share the common property of persisting as multicopy episomes in the nuclei of rapidly dividing host cells. These episomes form the molecular basis for viral latency and are etiologically linked to virus-associated cancers. Episome maintenance requires epigenetic programming to ensure the proper control of viral gene expression, DNA replication, and genome copy number. For these viruses, episome maintenance requires a dedicated virus-encoded episome maintenance protein (EMP), namely LANA (KSHV), EBNA1 (EBV), and E2 (HPV). Here, we review common features of these viral EMPs and discuss recent advances in understanding how they contribute to the epigenetic control of viral episome maintenance during latency.
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Yan L, Majerciak V, Zheng ZM, Lan K. Towards Better Understanding of KSHV Life Cycle: from Transcription and Posttranscriptional Regulations to Pathogenesis. Virol Sin 2019; 34:135-161. [PMID: 31025296 PMCID: PMC6513836 DOI: 10.1007/s12250-019-00114-3] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 03/14/2019] [Indexed: 02/08/2023] Open
Abstract
Kaposi’s sarcoma-associated herpesvirus (KSHV), also known as human herpesvirus-8 (HHV-8), is etiologically linked to the development of Kaposi’s sarcoma, primary effusion lymphoma, and multicentric Castleman’s disease. These malignancies often occur in immunosuppressed individuals, making KSHV infection-associated diseases an increasing global health concern with persistence of the AIDS epidemic. KSHV exhibits biphasic life cycles between latent and lytic infection and extensive transcriptional and posttranscriptional regulation of gene expression. As a member of the herpesvirus family, KSHV has evolved many strategies to evade the host immune response, which help the virus establish a successful lifelong infection. In this review, we summarize the current research status on the biology of latent and lytic viral infection, the regulation of viral life cycles and the related pathogenesis.
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Affiliation(s)
- Lijun Yan
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Vladimir Majerciak
- National Cancer Institute, National Institutes of Health, Frederick, MD, 21702, USA
| | - Zhi-Ming Zheng
- National Cancer Institute, National Institutes of Health, Frederick, MD, 21702, USA.
| | - Ke Lan
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, 430072, China.
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Zhang F, Liang D, Lin X, Zou Z, Sun R, Wang X, Liang X, Kaye KM, Lan K. NDRG1 facilitates the replication and persistence of Kaposi's sarcoma-associated herpesvirus by interacting with the DNA polymerase clamp PCNA. PLoS Pathog 2019; 15:e1007628. [PMID: 30811506 PMCID: PMC6411202 DOI: 10.1371/journal.ppat.1007628] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 03/11/2019] [Accepted: 02/08/2019] [Indexed: 02/07/2023] Open
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV) latently infects host cells and establishes lifelong persistence as an extra-chromosomal episome in the nucleus. To persist in proliferating cells, the viral genome typically replicates once per cell cycle and is distributed into daughter cells. This process involves host machinery utilized by KSHV, however the underlying mechanisms are not fully elucidated. In present study, we found that N-Myc downstream regulated gene 1 (NDRG1), a cellular gene known to be non-detectable in primary B cells and endothelial cells which are the major cell types for KSHV infection in vivo, was highly upregulated by KSHV in these cells. We further demonstrated that the high expression of NDRG1 was regulated by latency-associated nuclear antigen (LANA), the major viral latent protein which tethers the viral genome to host chromosome and plays an essential role in viral genome maintenance. Surprisingly, knockdown of NDRG1 in KSHV latently infected cells resulted in a significant decrease of viral genome copy number in these cells. Interestingly, NDRG1 can directly interact with proliferating cell nuclear antigen (PCNA), a cellular protein which functions as a DNA polymerase clamp during DNA replication. Intriguingly, we found that NDRG1 forms a complex with LANA and PCNA and serves as a scaffold protein bridging these two proteins. We further demonstrated that NDRG1 is critical for mediating LANA to recruit PCNA onto terminal repeat (TR) of KSHV genome, and facilitates viral DNA replication and episome persistence. Taken together, our findings suggest that NDRG1 plays an important role in KSHV viral genome replication, and provide new clues for understanding of KSHV persistence.
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Affiliation(s)
- Fang Zhang
- CAS Key Laboratory of Molecular Virology & Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Deguang Liang
- CAS Key Laboratory of Molecular Virology & Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Xiaoxi Lin
- CAS Key Laboratory of Molecular Virology & Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Zhe Zou
- CAS Key Laboratory of Molecular Virology & Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Rui Sun
- CAS Key Laboratory of Molecular Virology & Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Xing Wang
- CAS Key Laboratory of Molecular Virology & Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Xiaozhen Liang
- CAS Key Laboratory of Molecular Virology & Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Kenneth M. Kaye
- Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA, United States of America
| | - Ke Lan
- State Key Laboratory of Virology, College of Life Sciences, Medical Research Institute, Wuhan University, Wuhan, China
- * E-mail:
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Shugoshin 1 is dislocated by KSHV-encoded LANA inducing aneuploidy. PLoS Pathog 2018; 14:e1007253. [PMID: 30212568 PMCID: PMC6136811 DOI: 10.1371/journal.ppat.1007253] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 07/31/2018] [Indexed: 11/30/2022] Open
Abstract
Shugoshin-1 (Sgo1) protects the integrity of the centromeres, and H2A phosphorylation is critical for this process. The mitotic checkpoint kinase Bub1, phosphorylates H2A and ensures fidelity of chromosome segregation and chromosome number. Oncogenic KSHV induces genetic alterations through chromosomal instability (CIN), and its essential antigen LANA regulates Bub1. We show that LANA inhibits Bub1 phosphorylation of H2A and Cdc20, important for chromosome segregation and mitotic signaling. Inhibition of H2A phosphorylation at residue T120 by LANA resulted in dislocation of Sgo1, and cohesin from the centromeres. Arrest of Cdc20 phosphorylation also rescued degradation of Securin and Cyclin B1 at mitotic exit, and interaction of H2A, and Cdc20 with Bub1 was inhibited by LANA. The N-terminal nuclear localization sequence domain of LANA was essential for LANA and Bub1 interaction, reversed LANA inhibited phosphorylation of H2A and Cdc20, and attenuated LANA-induced aneuploidy and cell proliferation. This molecular mechanism whereby KSHV-induced CIN, demonstrated that the NNLS of LANA is a promising target for development of anti-viral therapies targeting KSHV associated cancers. KSHV is a known oncogenic herpes virus associated with human malignancies and lymphoproliferative disorders, which includes Kaposi’s sarcoma, Primary effusion lymphoma, and Multicentric Castleman’s disease. KSHV disrupts the G1 and G2/M checkpoints through multiple pathways. Whether KSHV can directly interfere with spindle checkpoints is not known. Impairment of the mitotic checkpoint protein Bub1 leads to CIN and oncogenesis through displacement of Shugoshin-1. KSHV associated diseases have genetic alterations which are driven by chromosomal instability (CIN), as seen in numerous viral-associated cancer cells. Here we examined the molecular mechanism behind KSHV-induced CIN. We showed that the latent antigen LANA, encoded by KSHV, inhibits Bub1 phosphorylation of H2A and Cdc20, and this led to the dislocation of Shugoshin-1. Our studies demonstrated the direct induction of aneuploidy by LANA. The NNLS domain of LANA serves as an anchor for LANA to promote its multiple functions. We also showed that the NNLS polypeptide can antagonize LANA’s inhibition on Bub1 kinase function, and so rescue the aneuploidy induced by LANA. Development of this property of NNLS is potentially useful for targeted elimination of KSHV-associated cancers.
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Wang Q, Li Y, Dong H, Wang L, Peng J, An T, Yang X, Tian Z, Cai X. Identification of host cellular proteins that interact with the M protein of a highly pathogenic porcine reproductive and respiratory syndrome virus vaccine strain. Virol J 2017; 14:39. [PMID: 28222748 PMCID: PMC5320790 DOI: 10.1186/s12985-017-0700-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 02/06/2017] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND The highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) continues to pose one of the greatest threats to the swine industry. M protein is the most conserved and important structural protein of PRRSV. However, information about the host cellular proteins that interact with M protein remains limited. METHODS Host cellular proteins that interact with the M protein of HP-PRRSV were immunoprecipitated from MARC-145 cells infected with PRRSV HuN4-F112 using the M monoclonal antibody (mAb). The differentially expressed proteins were identified by LC-MS/MS. The screened proteins were used for bioinformatics analysis including Gene Ontology, the interaction network, and the enriched KEGG pathways. Some interested cellular proteins were validated to interact with M protein by CO-IP. RESULTS The PRRSV HuN4-F112 infection group had 10 bands compared with the control group. The bands included 219 non-redundant cellular proteins that interact with M protein, which were identified by LC-MS/MS with high confidence. The gene ontology and Kyoto encyclopedia of genes and genomes (KEGG) pathway bioinformatic analyses indicated that the identified proteins could be assigned to several different subcellular locations and functional classes. Functional analysis of the interactome profile highlighted cellular pathways associated with protein translation, infectious disease, and signal transduction. Two interested cellular proteins-nuclear factor of activated T cells 45 kDa (NF45) and proliferating cell nuclear antigen (PCNA)-that could interact with M protein were validated by Co-IP and confocal analyses. CONCLUSIONS The interactome data between PRRSV M protein and cellular proteins were identified and contribute to the understanding of the roles of M protein in the replication and pathogenesis of PRRSV. The interactome of M protein will aid studies of virus/host interactions and provide means to decrease the threat of PRRSV to the swine industry in the future.
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Affiliation(s)
- Qian Wang
- Division of Swine Infectious Diseases, National Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No.678, Haping street, Xiangfang District, Harbin, 150069, China
| | - Yanwei Li
- National Engineering Research Center of Veterinary Biologics, Harbin, 150001, China
| | - Hong Dong
- Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agribiotechnology, China Agricultural University, Beijing, 100193, China
| | - Li Wang
- Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agribiotechnology, China Agricultural University, Beijing, 100193, China
| | - Jinmei Peng
- Division of Swine Infectious Diseases, National Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No.678, Haping street, Xiangfang District, Harbin, 150069, China
| | - Tongqing An
- Division of Swine Infectious Diseases, National Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No.678, Haping street, Xiangfang District, Harbin, 150069, China
| | - Xufu Yang
- North Guangdong Collaborative Innovation and Development Center of Pig Farming and Disease Control, Shaoguan University, Shaoguan, 512005, China
| | - Zhijun Tian
- Division of Swine Infectious Diseases, National Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No.678, Haping street, Xiangfang District, Harbin, 150069, China.
| | - Xuehui Cai
- Division of Swine Infectious Diseases, National Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No.678, Haping street, Xiangfang District, Harbin, 150069, China.
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Gupta N, Thakker S, Verma SC. KSHV encoded LANA recruits Nucleosome Assembly Protein NAP1L1 for regulating viral DNA replication and transcription. Sci Rep 2016; 6:32633. [PMID: 27599637 PMCID: PMC5013526 DOI: 10.1038/srep32633] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 08/11/2016] [Indexed: 11/17/2022] Open
Abstract
The establishment of latency is an essential for lifelong persistence and pathogenesis of Kaposi’s sarcoma-associated herpesvirus (KSHV). Latency-associated nuclear antigen (LANA) is the most abundantly expressed protein during latency and is important for viral genome replication and transcription. Replication-coupled nucleosome assembly is a major step in packaging the newly synthesized DNA into chromatin, but the mechanism of KSHV genome chromatinization post-replication is not understood. Here, we show that nucleosome assembly protein 1-like protein 1 (NAP1L1) associates with LANA. Our binding assays revealed an association of LANA with NAP1L1 in KSHV-infected cells, which binds through its amino terminal domain. Association of these proteins confirmed their localization in specific nuclear compartments of the infected cells. Chromatin immunoprecipitation assays from NAP1L1-depleted cells showed LANA-mediated recruitment of NAP1L1 at the terminal repeat (TR) region of the viral genome. Presence of NAP1L1 stimulated LANA-mediated DNA replication and persistence of a TR-containing plasmid. Depletion of NAP1L1 led to a reduced nucleosome positioning on the viral genome. Furthermore, depletion of NAP1L1 increased the transcription of viral lytic genes and overexpression decreased the promoter activities of LANA-regulated genes. These results confirmed that LANA recruitment of NAP1L1 helps in assembling nucleosome for the chromatinization of newly synthesized viral DNA.
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Affiliation(s)
- Namrata Gupta
- Department of Microbiology and Immunology, School of Medicine, University of Nevada, Reno, NV 89557, USA
| | - Suhani Thakker
- Department of Microbiology and Immunology, School of Medicine, University of Nevada, Reno, NV 89557, USA
| | - Subhash C Verma
- Department of Microbiology and Immunology, School of Medicine, University of Nevada, Reno, NV 89557, USA
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Major Histocompatibility Complex Class II HLA-DRα Is Downregulated by Kaposi's Sarcoma-Associated Herpesvirus-Encoded Lytic Transactivator RTA and MARCH8. J Virol 2016; 90:8047-58. [PMID: 27356905 DOI: 10.1128/jvi.01079-16] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 06/07/2016] [Indexed: 12/27/2022] Open
Abstract
UNLABELLED Kaposi's sarcoma-associated herpesvirus (KSHV) maintains two modes of life cycle, the latent and lytic phases. To evade the attack of the cell host's immune system, KSHV switches from the lytic to the latent phase, a phase in which only a few of viral proteins are expressed. The mechanism by which KSHV evades the attack of the immune system and establishes latency has not been fully understood. Major histocompatibility complex class II (MHC-II) molecules are key components of the immune system defense mechanism against viral infections. Here we report that HLA-DRα, a member of the MHC-II molecules, was downregulated by the replication and transcription activator (RTA) protein encoded by KSHV ORF50, an important regulator of the viral life cycle. RTA not only downregulated HLA-DRα at the protein level through direct binding and degradation through the proteasome pathway but also indirectly downregulated the protein level of HLA-DRα by enhancing the expression of MARCH8, a member of the membrane-associated RING-CH (MARCH) proteins. Our findings indicate that KSHV RTA facilitates evasion of the virus from the immune system through manipulation of HLA-DRα. IMPORTANCE Kaposi's sarcoma-associated herpesvirus (KSHV) has a causal role in a number of human cancers, and its persistence in infected cells is controlled by the host's immune system. The mechanism by which KSHV evades an attack by the immune system has not been well understood. This work represents studies which identify a novel mechanism by which the virus can facilitate evasion of an immune system. We now show that RTA, the replication and transcription activator encoded by KSHV (ORF50), can function as an E3 ligase to degrade HLA-DRα. It can directly bind and induce degradation of HLA-DRα through the ubiquitin-proteasome degradation pathway. In addition to the direct regulation of HLA-DRα, RTA can also indirectly downregulate the level of HLA-DRα protein by upregulating transcription of MARCH8. Increased MARCH8 results in the downregulation of HLA-DRα. Furthermore, we also demonstrate that expression of HLA-DRα was impaired in KSHV de novo infection.
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Juillard F, Tan M, Li S, Kaye KM. Kaposi's Sarcoma Herpesvirus Genome Persistence. Front Microbiol 2016; 7:1149. [PMID: 27570517 PMCID: PMC4982378 DOI: 10.3389/fmicb.2016.01149] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 07/11/2016] [Indexed: 12/17/2022] Open
Abstract
Kaposi’s sarcoma-associated herpesvirus (KSHV) has an etiologic role in Kaposi’s sarcoma, primary effusion lymphoma, and multicentric Castleman’s disease. These diseases are most common in immunocompromised individuals, especially those with AIDS. Similar to all herpesviruses, KSHV infection is lifelong. KSHV infection in tumor cells is primarily latent, with only a small subset of cells undergoing lytic infection. During latency, the KSHV genome persists as a multiple copy, extrachromosomal episome in the nucleus. In order to persist in proliferating tumor cells, the viral genome replicates once per cell cycle and then segregates to daughter cell nuclei. KSHV only expresses several genes during latent infection. Prominent among these genes, is the latency-associated nuclear antigen (LANA). LANA is responsible for KSHV genome persistence and also exerts transcriptional regulatory effects. LANA mediates KSHV DNA replication and in addition, is responsible for segregation of replicated genomes to daughter nuclei. LANA serves as a molecular tether, bridging the viral genome to mitotic chromosomes to ensure that KSHV DNA reaches progeny nuclei. N-terminal LANA attaches to mitotic chromosomes by binding histones H2A/H2B at the surface of the nucleosome. C-terminal LANA binds specific KSHV DNA sequence and also has a role in chromosome attachment. In addition to the essential roles of N- and C-terminal LANA in genome persistence, internal LANA sequence is also critical for efficient episome maintenance. LANA’s role as an essential mediator of virus persistence makes it an attractive target for inhibition in order to prevent or treat KSHV infection and disease.
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Affiliation(s)
- Franceline Juillard
- Departments of Medicine, Brigham and Women's Hospital, Harvard Medical School Boston, MA, USA
| | - Min Tan
- Departments of Medicine, Brigham and Women's Hospital, Harvard Medical School Boston, MA, USA
| | - Shijun Li
- Departments of Medicine, Brigham and Women's Hospital, Harvard Medical School Boston, MA, USA
| | - Kenneth M Kaye
- Departments of Medicine, Brigham and Women's Hospital, Harvard Medical School Boston, MA, USA
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Jha HC, Sun Z, Upadhyay SK, El-Naccache DW, Singh RK, Sahu SK, Robertson ES. KSHV-Mediated Regulation of Par3 and SNAIL Contributes to B-Cell Proliferation. PLoS Pathog 2016; 12:e1005801. [PMID: 27463802 PMCID: PMC4963126 DOI: 10.1371/journal.ppat.1005801] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 07/09/2016] [Indexed: 12/23/2022] Open
Abstract
Studies have suggested that Epithelial-Mesenchymal Transition (EMT) and transformation is an important step in progression to cancer. Par3 (partitioning-defective protein) is a crucial factor in regulating epithelial cell polarity. However, the mechanism by which the latency associated nuclear antigen (LANA) encoded by Kaposi's Sarcoma associated herpesvirus (KSHV) regulates Par3 and EMTs markers (Epithelial-Mesenchymal Transition) during viral-mediated B-cell oncogenesis has not been fully explored. Moreover, several studies have demonstrated a crucial role for EMT markers during B-cell malignancies. In this study, we demonstrate that Par3 is significantly up-regulated in KSHV-infected primary B-cells. Further, Par3 interacted with LANA in KSHV positive and LANA expressing cells which led to translocation of Par3 from the cell periphery to a predominantly nuclear signal. Par3 knockdown led to reduced cell proliferation and increased apoptotic induction. Levels of SNAIL was elevated, and E-cadherin was reduced in the presence of LANA or Par3. Interestingly, KSHV infection in primary B-cells led to enhancement of SNAIL and down-regulation of E-cadherin in a temporal manner. Importantly, knockdown of SNAIL, a major EMT regulator, in KSHV cells resulted in reduced expression of LANA, Par3, and enhanced E-cadherin. Also, SNAIL bound to the promoter region of p21 and can regulate its activity. Further a SNAIL inhibitor diminished NF-kB signaling through upregulation of Caspase3 in KSHV positive cells in vitro. This was also supported by upregulation of SNAIL and Par3 in BC-3 transplanted NOD-SCID mice which has potential as a therapeutic target for KSHV-associated B-cell lymphomas.
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Affiliation(s)
- Hem C. Jha
- Department of Otorhinolaryngology-Head and Neck Cancer, and Tumor Virology Program and Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Zhiguo Sun
- Department of Otorhinolaryngology-Head and Neck Cancer, and Tumor Virology Program and Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Santosh K. Upadhyay
- Department of Otorhinolaryngology-Head and Neck Cancer, and Tumor Virology Program and Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Darine W. El-Naccache
- Department of Otorhinolaryngology-Head and Neck Cancer, and Tumor Virology Program and Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Rajnish K. Singh
- Department of Otorhinolaryngology-Head and Neck Cancer, and Tumor Virology Program and Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Sushil K. Sahu
- Department of Otorhinolaryngology-Head and Neck Cancer, and Tumor Virology Program and Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Erle S. Robertson
- Department of Otorhinolaryngology-Head and Neck Cancer, and Tumor Virology Program and Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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12
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Rahayu R, Ohsaki E, Omori H, Ueda K. Localization of latency-associated nuclear antigen (LANA) on mitotic chromosomes. Virology 2016; 496:51-58. [PMID: 27254595 DOI: 10.1016/j.virol.2016.05.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 04/28/2016] [Accepted: 05/24/2016] [Indexed: 01/25/2023]
Abstract
In latent infection of Kaposi's sarcoma-associated herpesvirus (KSHV), viral gene expression is extremely limited and copy numbers of viral genomes remain constant. Latency-associated nuclear antigen (LANA) is known to have a role in maintaining viral genome copy numbers in growing cells. Several studies have shown that LANA is localized in particular regions on mitotic chromosomes, such as centromeres/pericentromeres. We independently examined the distinct localization of LANA on mitotic chromosomes during mitosis, using super-resolution laser confocal microscopy and correlative fluorescence microscopy-electron microscopy (FM-EM) analyses. We found that the majority of LANA were not localized at particular regions such as telomeres/peritelomeres, centromeres/pericentromeres, and cohesion sites, but at the bodies of condensed chromosomes. Thus, LANA may undergo various interactions with the host factors on the condensed chromosomes in order to tether the viral genome to mitotic chromosomes and realize faithful viral genome segregation during cell division.
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Affiliation(s)
- Retno Rahayu
- Division of Virology, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka 565-0871, Japan
| | - Eriko Ohsaki
- Division of Virology, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka 565-0871, Japan
| | - Hiroko Omori
- Central Instrumentation Laboratory Research Institute for Microbial Diseases (BIKEN), Osaka University, Osaka 565-0871, Japan
| | - Keiji Ueda
- Division of Virology, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka 565-0871, Japan.
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Wei F, Gan J, Wang C, Zhu C, Cai Q. Cell Cycle Regulatory Functions of the KSHV Oncoprotein LANA. Front Microbiol 2016; 7:334. [PMID: 27065950 PMCID: PMC4811921 DOI: 10.3389/fmicb.2016.00334] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 03/03/2016] [Indexed: 12/13/2022] Open
Abstract
Manipulation of cell cycle is a commonly employed strategy of viruses for achieving a favorable cellular environment during infection. Kaposi’s sarcoma-associated herpesvirus (KSHV), the primary etiological agent of several human malignancies including Kaposi’s sarcoma, and primary effusion lymphoma, encodes several oncoproteins that deregulate normal physiology of cell cycle machinery to persist with endothelial cells and B cells and subsequently establish a latent infection. During latency, only a small subset of viral proteins is expressed. Latency-associated nuclear antigen (LANA) is one of the latent antigens shown to be essential for transformation of endothelial cells in vitro. It has been well demonstrated that LANA is critical for the maintenance of latency, episome DNA replication, segregation and gene transcription. In this review, we summarize recent studies and address how LANA functions as an oncoprotein to steer host cell cycle-related events including proliferation and apoptosis by interacting with various cellular and viral factors, and highlight the potential therapeutic strategy of disrupting LANA-dependent signaling as targets in KSHV-associated cancers.
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Affiliation(s)
- Fang Wei
- ShengYushou Center of Cell Biology and Immunology, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University Shanghai, China
| | - Jin Gan
- MOE & MOH Key Laboratory of Medical Molecular Virology, School of Basic Medicine, Shanghai Medical College, Fudan University Shanghai, China
| | - Chong Wang
- MOE & MOH Key Laboratory of Medical Molecular Virology, School of Basic Medicine, Shanghai Medical College, Fudan University Shanghai, China
| | - Caixia Zhu
- MOE & MOH Key Laboratory of Medical Molecular Virology, School of Basic Medicine, Shanghai Medical College, Fudan University Shanghai, China
| | - Qiliang Cai
- MOE & MOH Key Laboratory of Medical Molecular Virology, School of Basic Medicine, Shanghai Medical College, Fudan University Shanghai, China
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Purushothaman P, Dabral P, Gupta N, Sarkar R, Verma SC. KSHV Genome Replication and Maintenance. Front Microbiol 2016; 7:54. [PMID: 26870016 PMCID: PMC4740845 DOI: 10.3389/fmicb.2016.00054] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 01/12/2016] [Indexed: 12/04/2022] Open
Abstract
Kaposi's sarcoma associated herpesvirus (KSHV) or human herpesvirus 8 (HHV8) is a major etiological agent for multiple severe malignancies in immune-compromised patients. KSHV establishes lifetime persistence in the infected individuals and displays two distinct life cycles, generally a prolonged passive latent, and a short productive or lytic cycle. During latent phase, the viral episome is tethered to the host chromosome and replicates once during every cell division. Latency-associated nuclear antigen (LANA) is a predominant multifunctional nuclear protein expressed during latency, which plays a central role in episome tethering, replication and perpetual segregation of the episomes during cell division. LANA binds cooperatively to LANA binding sites (LBS) within the terminal repeat (TR) region of the viral episome as well as to the cellular nucleosomal proteins to tether viral episome to the host chromosome. LANA has been shown to modulate multiple cellular signaling pathways and recruits various cellular proteins such as chromatin modifying enzymes, replication factors, transcription factors, and cellular mitotic framework to maintain a successful latent infection. Although, many other regions within the KSHV genome can initiate replication, KSHV TR is important for latent DNA replication and possible segregation of the replicated episomes. Binding of LANA to LBS favors the recruitment of various replication factors to initiate LANA dependent DNA replication. In this review, we discuss the molecular mechanisms relevant to KSHV genome replication, segregation, and maintenance of latency.
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Affiliation(s)
- Pravinkumar Purushothaman
- Department of Microbiology and Immunology, School of Medicine, University of Nevada, Reno Reno, NV, USA
| | - Prerna Dabral
- Department of Microbiology and Immunology, School of Medicine, University of Nevada, Reno Reno, NV, USA
| | - Namrata Gupta
- Department of Microbiology and Immunology, School of Medicine, University of Nevada, Reno Reno, NV, USA
| | - Roni Sarkar
- Department of Microbiology and Immunology, School of Medicine, University of Nevada, Reno Reno, NV, USA
| | - Subhash C Verma
- Department of Microbiology and Immunology, School of Medicine, University of Nevada, Reno Reno, NV, USA
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