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Zhang T, Zhao SH, He Y. ZmTDM1 encodes a tetratricopeptide repeat domain protein and is required for meiotic exit in maize. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2024; 117:1517-1527. [PMID: 38047628 DOI: 10.1111/tpj.16579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 11/17/2023] [Accepted: 11/22/2023] [Indexed: 12/05/2023]
Abstract
Elaborate cell-cycle control must be adopted to ensure the continuity of the meiotic second division and termination after that. Despite its importance, however, the genetic controls underlying the meiotic cell cycle have not been reported in maize. Here, we characterized a meiotic cell-cycle controller ZmTDM1, which is a homolog of Arabidopsis TDM1 and encodes a canonical tetratricopeptide repeat domain protein in maize. The Zmtdm1 homozygous plants exhibited complete male sterility and severe female abortion. In Zmtdm1 mutants, cell-cycle progression was almost identical to that of wild type from leptotene to anaphase II. However, chromosomes in the tetrad failed meiotic termination at the end of the second division and underwent additional divisions in succession without DNA replication, reducing the ploidy to less than haploid in the product. In addition, two ZmTDM1-like homologs (ZmTDML1 and ZmTDML2) were not functional in meiotic cell-cycle control. Moreover, ZmTDM1 interacted with RING-type E3 ubiquitin ligase, revealing that it acts as a subunit of the APC/C E3 ubiquitin ligase complex. Overall, our results identified a regulator of meiotic cell cycle in maize and demonstrated that ZmTDM1 is essential for meiotic exit after meiosis II.
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Affiliation(s)
- Ting Zhang
- Institute of Biotechnology, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100097, China
- MOE Key Laboratory of Crop Heterosis and Utilization, National Maize Improvement Center of China, College of Agronomy and Biotechnology, China Agricultural University, Beijing, 100193, China
| | - Shuang-Hui Zhao
- MOE Key Laboratory of Crop Heterosis and Utilization, National Maize Improvement Center of China, College of Agronomy and Biotechnology, China Agricultural University, Beijing, 100193, China
| | - Yan He
- MOE Key Laboratory of Crop Heterosis and Utilization, National Maize Improvement Center of China, College of Agronomy and Biotechnology, China Agricultural University, Beijing, 100193, China
- Key Laboratory of Seed Innovation, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
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2
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Moniruzzaman M, Erazo Garcia MP, Farzad R, Ha AD, Jivaji A, Karki S, Sheyn U, Stanton J, Minch B, Stephens D, Hancks DC, Rodrigues RAL, Abrahao JS, Vardi A, Aylward FO. Virologs, viral mimicry, and virocell metabolism: the expanding scale of cellular functions encoded in the complex genomes of giant viruses. FEMS Microbiol Rev 2023; 47:fuad053. [PMID: 37740576 PMCID: PMC10583209 DOI: 10.1093/femsre/fuad053] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 08/29/2023] [Accepted: 09/21/2023] [Indexed: 09/24/2023] Open
Abstract
The phylum Nucleocytoviricota includes the largest and most complex viruses known. These "giant viruses" have a long evolutionary history that dates back to the early diversification of eukaryotes, and over time they have evolved elaborate strategies for manipulating the physiology of their hosts during infection. One of the most captivating of these mechanisms involves the use of genes acquired from the host-referred to here as viral homologs or "virologs"-as a means of promoting viral propagation. The best-known examples of these are involved in mimicry, in which viral machinery "imitates" immunomodulatory elements in the vertebrate defense system. But recent findings have highlighted a vast and rapidly expanding array of other virologs that include many genes not typically found in viruses, such as those involved in translation, central carbon metabolism, cytoskeletal structure, nutrient transport, vesicular trafficking, and light harvesting. Unraveling the roles of virologs during infection as well as the evolutionary pathways through which complex functional repertoires are acquired by viruses are important frontiers at the forefront of giant virus research.
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Affiliation(s)
- Mohammad Moniruzzaman
- Rosenstiel School of Marine Atmospheric, and Earth Science, University of Miami, Coral Gables, FL 33149, United States
| | - Maria Paula Erazo Garcia
- Department of Biological Sciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA 24061, United States
| | - Roxanna Farzad
- Department of Biological Sciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA 24061, United States
| | - Anh D Ha
- Department of Biological Sciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA 24061, United States
| | - Abdeali Jivaji
- Department of Biological Sciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA 24061, United States
| | - Sangita Karki
- Department of Biological Sciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA 24061, United States
| | - Uri Sheyn
- Department of Biological Sciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA 24061, United States
| | - Joshua Stanton
- Department of Biological Sciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA 24061, United States
| | - Benjamin Minch
- Rosenstiel School of Marine Atmospheric, and Earth Science, University of Miami, Coral Gables, FL 33149, United States
| | - Danae Stephens
- Rosenstiel School of Marine Atmospheric, and Earth Science, University of Miami, Coral Gables, FL 33149, United States
| | - Dustin C Hancks
- Department of Immunology, University of Texas Southwestern Medical Center, 6000 Harry Hines Blvd, Dallas, TX, United States
| | - Rodrigo A L Rodrigues
- Laboratório de Vírus, Departamento de Microbiologia, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, MG, Brazil
| | - Jonatas S Abrahao
- Laboratório de Vírus, Departamento de Microbiologia, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, MG, Brazil
| | - Assaf Vardi
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Frank O Aylward
- Department of Biological Sciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA 24061, United States
- Center for Emerging, Zoonotic, and Arthropod-Borne Infectious Disease, Virginia Tech, Blacksburg, VA 24061, United States
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Panda M, Kalita E, Rao A, Prajapati VK. Mechanism of cell cycle regulation and cell proliferation during human viral infection. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2023; 135:497-525. [PMID: 37061340 DOI: 10.1016/bs.apcsb.2022.11.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Over the history of the coevolution of Host viral interaction, viruses have customized the host cellular machinery into their use for viral genome replication, causing effective infection and ultimately aiming for survival. They do so by inducing subversions to the host cellular pathways like cell cycle via dysregulation of important cell cycle checkpoints by viral encoded proteins, arresting the cell cycle machinery, blocking cytokinesis as well as targeting subnuclear bodies, thus ultimately disorienting the cell proliferation. Both DNA and RNA viruses have been active participants in such manipulation resulting in serious outcomes of cancer. They achieve this by employing different mechanisms-Protein-protein interaction, protein-phosphorylation, degradation, redistribution, viral homolog, and viral regulation of APC at different stages of cell cycle events. Several DNA viruses cause the quiescent staged cells to undergo cell cycle which increases nucleotide pools logistically significantly persuading viral replication whereas few other viruses arrest a particular stage of cell cycle. This allows the latter group to sustain the infection which allows them to escape host immune response and support viral multiplication. Mechanical study of signaling such viral mediated pathways could give insight into understanding the etiology of tumorigenesis and progression. Overall this chapter highlights the possible strategies employed by DNA/RNA viral families which impact the normal cell cycle but facilitate viral infected cell replication. Such information could contribute to comprehending viral infection-associated disorders to further depth.
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Affiliation(s)
- Mamta Panda
- Department of Biochemistry, School of Life Sciences, Central University of Rajasthan, Bandarsindri, Kishangarh, Ajmer, Rajasthan, India
| | - Elora Kalita
- Department of Biochemistry, School of Life Sciences, Central University of Rajasthan, Bandarsindri, Kishangarh, Ajmer, Rajasthan, India
| | - Abhishek Rao
- Department of Biochemistry, School of Life Sciences, Central University of Rajasthan, Bandarsindri, Kishangarh, Ajmer, Rajasthan, India
| | - Vijay Kumar Prajapati
- Department of Biochemistry, School of Life Sciences, Central University of Rajasthan, Bandarsindri, Kishangarh, Ajmer, Rajasthan, India; Department of Biochemistry, School of Biological Sciences, Central University of Punjab, Bathinda, Punjab, India.
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Xiao Q, Dong ZQ, Zhu Y, Zhang Q, Yang X, Xiao M, Chen P, Lu C, Pan MH. Bombyx mori Nucleopolyhedrovirus (BmNPV) Induces G2/M Arrest to Promote Viral Multiplication by Depleting BmCDK1. INSECTS 2021; 12:insects12121098. [PMID: 34940186 PMCID: PMC8708760 DOI: 10.3390/insects12121098] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 11/26/2021] [Accepted: 12/01/2021] [Indexed: 01/01/2023]
Abstract
Simple Summary Baculoviruses arrest the cell cycle in the S or G2/M phase in insect cells, but the exact mechanism of this process still remains obscure. Bombyx mori nucleopolyhedrovirus (BmNPV), one of the best characterized baculoviruses, is an important pathogen in silkworms. In the present study, we determined that downregulation of BmCDK1 and BmCyclin B expression was required for BmNPV-mediated G2/M phase arrest, which plays an essential role in facilitating BmNPV replication. Further investigations showed that BmNPV IAP1 interacted with BmCDK1. The overexpression of the BmNPV iap1 gene led to the accumulation of cells in the G2/M phase, and BmNPV iap1 gene knockdown attenuated the effect of BmNPV-mediated G2/M phase arrest. These findings enhance the understanding of BmNPV pathogenesis, and indicate a novel mechanism through which baculoviruses impact the cell cycle progression. Abstract Understanding virus–host interaction is very important for delineating the mechanism involved in viral replication and host resistance. Baculovirus, an insect virus, can cause S or G2/M phase arrest in insect cells. However, the roles and mechanism of Baculovirus-mediated S or G2/M phase arrest are not fully understood. Our results, obtained using flow cytometry (FCM), tubulin-labeling, BrdU-labeling, and CellTiter 96® AQueous One Solution Cell Proliferation Assay (MTS), showed that Bombyx mori nucleopolyhedrovirus (BmNPV) induced G2/M phase arrest and inhibited cellular DNA replication as well as cell proliferation in BmN-SWU1 cells. We found that BmNPV induced G2/M arrest to support its replication and proliferation by reducing the expression of BmCDK1 and BmCyclin B. Co-immunoprecipitation assays confirmed that BmNPV IAP1 interacted with BmCDK1. BmNPV iap1 was involved in the process of BmNPV-induced G2/M arrest by reducing the content of BmCDK1. Taken together, our results improve the understanding of the virus–host interaction network, and provide a potential target gene that connects apoptosis and the cell cycle.
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Affiliation(s)
- Qin Xiao
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China; (Q.X.); (Z.-Q.D.); (Y.Z.); (Q.Z.); (X.Y.); (M.X.); (P.C.)
- Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, Southwest University, Chongqing 400716, China
| | - Zhan-Qi Dong
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China; (Q.X.); (Z.-Q.D.); (Y.Z.); (Q.Z.); (X.Y.); (M.X.); (P.C.)
- Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, Southwest University, Chongqing 400716, China
| | - Yan Zhu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China; (Q.X.); (Z.-Q.D.); (Y.Z.); (Q.Z.); (X.Y.); (M.X.); (P.C.)
- Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, Southwest University, Chongqing 400716, China
| | - Qian Zhang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China; (Q.X.); (Z.-Q.D.); (Y.Z.); (Q.Z.); (X.Y.); (M.X.); (P.C.)
- Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, Southwest University, Chongqing 400716, China
| | - Xiu Yang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China; (Q.X.); (Z.-Q.D.); (Y.Z.); (Q.Z.); (X.Y.); (M.X.); (P.C.)
- Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, Southwest University, Chongqing 400716, China
| | - Miao Xiao
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China; (Q.X.); (Z.-Q.D.); (Y.Z.); (Q.Z.); (X.Y.); (M.X.); (P.C.)
- Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, Southwest University, Chongqing 400716, China
| | - Peng Chen
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China; (Q.X.); (Z.-Q.D.); (Y.Z.); (Q.Z.); (X.Y.); (M.X.); (P.C.)
- Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, Southwest University, Chongqing 400716, China
| | - Cheng Lu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China; (Q.X.); (Z.-Q.D.); (Y.Z.); (Q.Z.); (X.Y.); (M.X.); (P.C.)
- Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, Southwest University, Chongqing 400716, China
- Correspondence: (C.L.); (M.-H.P.); Tel.: +86-23-6825-0346 (C.L.); +86-23-6825-0076 (M.-H.P.); Fax: +86-23-6825-1128 (C.L. & M.-H.P.)
| | - Min-Hui Pan
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China; (Q.X.); (Z.-Q.D.); (Y.Z.); (Q.Z.); (X.Y.); (M.X.); (P.C.)
- Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, Southwest University, Chongqing 400716, China
- Correspondence: (C.L.); (M.-H.P.); Tel.: +86-23-6825-0346 (C.L.); +86-23-6825-0076 (M.-H.P.); Fax: +86-23-6825-1128 (C.L. & M.-H.P.)
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5
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Lant S, Maluquer de Motes C. Poxvirus Interactions with the Host Ubiquitin System. Pathogens 2021; 10:pathogens10081034. [PMID: 34451498 PMCID: PMC8399815 DOI: 10.3390/pathogens10081034] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/12/2021] [Accepted: 08/13/2021] [Indexed: 12/16/2022] Open
Abstract
The ubiquitin system has emerged as a master regulator of many, if not all, cellular functions. With its large repertoire of conjugating and ligating enzymes, the ubiquitin system holds a unique mechanism to provide selectivity and specificity in manipulating protein function. As intracellular parasites viruses have evolved to modulate the cellular environment to facilitate replication and subvert antiviral responses. Poxviruses are a large family of dsDNA viruses with large coding capacity that is used to synthetise proteins and enzymes needed for replication and morphogenesis as well as suppression of host responses. This review summarises our current knowledge on how poxvirus functions rely on the cellular ubiquitin system, and how poxviruses exploit this system to their own advantage, either facilitating uncoating and genome release and replication or rewiring ubiquitin ligases to downregulate critical antiviral factors. Whilst much remains to be known about the intricate interactions established between poxviruses and the host ubiquitin system, our knowledge has revealed crucial viral processes and important restriction factors that open novel avenues for antiviral treatment and provide fundamental insights on the biology of poxviruses and other virus families.
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6
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Human Immunodeficiency Virus Type 1 Vpr Mediates Degradation of APC1, a Scaffolding Component of the Anaphase-Promoting Complex/Cyclosome. J Virol 2021; 95:e0097120. [PMID: 34011540 DOI: 10.1128/jvi.00971-20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
HIV-1 encodes several accessory proteins-Nef, Vif, Vpr, and Vpu-whose functions are to modulate the cellular environment to favor immune evasion and viral replication. While Vpr was shown to mediate a G2/M cell cycle arrest and provide a replicative advantage during infection of myeloid cells, the mechanisms underlying these functions remain unclear. In this study, we defined HIV-1 Vpr proximity interaction network using the BioID proximity labeling approach and identified 352 potential Vpr partners/targets, including several complexes, such as the cell cycle-regulatory anaphase-promoting complex/cyclosome (APC/C). Herein, we demonstrate that both the wild type and cell cycle-defective mutants of Vpr induce the degradation of APC1, an essential APC/C scaffolding protein, and show that this activity relies on the recruitment of DCAF1 by Vpr and the presence of a functional proteasome. Vpr forms a complex with APC1, and the APC/C coactivators Cdh1 and Cdc20 are associated with these complexes. Interestingly, we found that Vpr encoded by the prototypic HIV-1 NL4.3 does not interact efficiently with APC1 and is unable to mediate its degradation as a result of a N28S-G41N amino acid substitution. In contrast, we show that APC1 degradation is a conserved feature of several primary Vpr variants from transmitted/founder virus. Functionally, Vpr-mediated APC1 degradation did not impact the ability of the protein to induce a G2 cell cycle arrest during infection of CD4+ T cells or enhance HIV-1 replication in macrophages, suggesting that this conserved activity may be important for other aspects of HIV-1 pathogenesis. IMPORTANCE The function of the Vpr accessory protein during HIV-1 infection remains poorly defined. Several cellular targets of Vpr were previously identified, but their individual degradation does not fully explain the ability of Vpr to impair the cell cycle or promote HIV-1 replication in macrophages. Here, we used the unbiased proximity labeling approach, called BioID, to further define the Vpr proximity interaction network and identified several potentially new Vpr partners/targets. We validated our approach by focusing on a cell cycle master regulator, the APC/C complex, and demonstrated that Vpr mediated the degradation of a critical scaffolding component of APC/C called APC1. Furthermore, we showed that targeting of APC/C by Vpr did not impact the known activity of Vpr. Since degradation of APC1 is a conserved feature of several primary variants of Vpr, it is likely that the interplay between Vpr and APC/C governs other aspects of HIV-1 pathogenesis.
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Ehmann R, Brandes K, Antwerpen M, Walter M, V Schlippenbach K, Stegmaier E, Essbauer S, Bugert J, Teifke JP, Meyer H. Molecular and genomic characterization of a novel equine molluscum contagiosum-like virus. J Gen Virol 2020; 102. [PMID: 31922947 PMCID: PMC8515872 DOI: 10.1099/jgv.0.001357] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Cases of pox-like lesions in horses and donkeys have been associated with poxviruses belonging to different genera of the family Poxviridae. These include the orthopoxviruses vaccinia virus (VACV), horsepoxvirus (HPXV) and cowpoxvirus (CPXV), as well as a potentially novel parapoxvirus and molluscum contagiosum virus (MOCV). However, with the exception of VACV, HPXV and CPXV, the genomic characterization of the causative agents remains largely elusive with only single short genome fragments available. Here we present the first full-length genome sequence of an equine molluscum contagiosum-like virus (EMCLV) directly determined from skin biopsies of a horse with generalized papular dermatitis. Histopathological analysis of the lesions revealed severe epidermal hyperplasia with numerous eosinophilic inclusion bodies within keratinocytes. Virions were detected in the lesions in embedded tissue by transmission electron microscopy. The genome sequence determined by next- and third-generation sequencing comprises 166 843 nt with inverted terminal repeats (ITRs) of 3473 nt. Overall, 20 of the predicted 159 ORFs have no equivalents in other poxviruses. Intriguingly, two of these ORFs were identified to encode homologues of mammalian proteins involved in immune signalling pathways, namely secreted and transmembrane protein 1 (SECTM1) and insulin growth factor-like family receptor 1 (IGFLR1), that were not described in any virus family so far. Phylogenetic analysis with all relevant representatives of the Poxviridae suggests that EMCLV should be nominated as a new species within the genus Molluscipoxvirus.
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Affiliation(s)
- Rosina Ehmann
- Bundeswehr Institute of Microbiology, Munich, Germany
| | - K Brandes
- Animal Pathology Augsburg, Augsburg, Germany
| | - M Antwerpen
- Bundeswehr Institute of Microbiology, Munich, Germany
| | - M Walter
- Bundeswehr Institute of Microbiology, Munich, Germany
| | | | | | - S Essbauer
- Bundeswehr Institute of Microbiology, Munich, Germany
| | - J Bugert
- Bundeswehr Institute of Microbiology, Munich, Germany
| | - J P Teifke
- Federal Research Institute for Animal Health, Greifswald - Insel Riems, Germany
| | - H Meyer
- Bundeswehr Institute of Microbiology, Munich, Germany
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Curtis NL, Bolanos-Garcia VM. The Anaphase Promoting Complex/Cyclosome (APC/C): A Versatile E3 Ubiquitin Ligase. Subcell Biochem 2019; 93:539-623. [PMID: 31939164 DOI: 10.1007/978-3-030-28151-9_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/25/2023]
Abstract
In the present chapter we discuss the essential roles of the human E3 ubiquitin ligase Anaphase Promoting Complex/Cyclosome (APC/C) in mitosis as well as the emerging evidence of important APC/C roles in cellular processes beyond cell division control such as regulation of genomic integrity and cell differentiation of the nervous system. We consider the potential incipient role of APC/C dysregulation in the pathophysiology of the neurological disorder Alzheimer's disease (AD). We also discuss how certain Deoxyribonucleic Acid (DNA) and Ribonucleic Acid (RNA) viruses take control of the host's cell division regulatory system through harnessing APC/C ubiquitin ligase activity and hypothesise the plausible molecular mechanisms underpinning virus manipulation of the APC/C. We also examine how defects in the function of this multisubunit protein assembly drive abnormal cell proliferation and lastly argue the potential of APC/C as a promising therapeutic target for the development of innovative therapies for the treatment of chronic malignancies such as cancer.
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Affiliation(s)
- Natalie L Curtis
- Faculty of Health and Life Sciences, Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, OX3 0BP, England, UK
| | - Victor M Bolanos-Garcia
- Faculty of Health and Life Sciences, Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, OX3 0BP, England, UK.
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9
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Fan Y, Sanyal S, Bruzzone R. Breaking Bad: How Viruses Subvert the Cell Cycle. Front Cell Infect Microbiol 2018; 8:396. [PMID: 30510918 PMCID: PMC6252338 DOI: 10.3389/fcimb.2018.00396] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 10/22/2018] [Indexed: 01/10/2023] Open
Abstract
Interactions between the host and viruses during the course of their co-evolution have not only shaped cellular function and the immune system, but also the counter measures employed by viruses. Relatively small genomes and high replication rates allow viruses to accumulate mutations and continuously present the host with new challenges. It is therefore, no surprise that they either escape detection or modulate host physiology, often by redirecting normal cellular pathways to their own advantage. Viruses utilize a diverse array of strategies and molecular targets to subvert host cellular processes, while evading detection. These include cell-cycle regulation, major histocompatibility complex-restricted antigen presentation, intracellular protein transport, apoptosis, cytokine-mediated signaling, and humoral immune responses. Moreover, viruses routinely manipulate the host cell cycle to create a favorable environment for replication, largely by deregulating cell cycle checkpoints. This review focuses on our current understanding of the molecular aspects of cell cycle regulation that are often targeted by viruses. Further study of their interactions should provide fundamental insights into cell cycle regulation and improve our ability to exploit these viruses.
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Affiliation(s)
- Ying Fan
- HKU-Pasteur Research Pole, LKS Faculty of Medicine, School of Public Health, The University of Hong Kong, Hong Kong, Hong Kong.,MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Sumana Sanyal
- HKU-Pasteur Research Pole, LKS Faculty of Medicine, School of Public Health, The University of Hong Kong, Hong Kong, Hong Kong.,LKS Faculty of Medicine, School of Biomedical Sciences, The University of Hong Kong, Hong Kong, Hong Kong
| | - Roberto Bruzzone
- HKU-Pasteur Research Pole, LKS Faculty of Medicine, School of Public Health, The University of Hong Kong, Hong Kong, Hong Kong.,Department of Cell Biology and Infection, Institut Pasteur, Paris, France
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10
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Sarker S, Isberg SR, Milic NL, Lock P, Helbig KJ. Molecular characterization of the first saltwater crocodilepox virus genome sequences from the world's largest living member of the Crocodylia. Sci Rep 2018; 8:5623. [PMID: 29618766 PMCID: PMC5884845 DOI: 10.1038/s41598-018-23955-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Accepted: 03/20/2018] [Indexed: 12/21/2022] Open
Abstract
Crocodilepox virus is a large dsDNA virus belonging to the genus Crocodylidpoxvirus, which infects a wide range of host species in the order Crocodylia worldwide. Here, we present genome sequences for a novel saltwater crocodilepox virus, with two subtypes (SwCRV-1 and -2), isolated from the Australian saltwater crocodile. Affected belly skins of juvenile saltwater crocodiles were used to sequence complete viral genomes, and perform electron microscopic analysis that visualized immature and mature virions. Analysis of the SwCRV genomes showed a high degree of sequence similarity to CRV (84.53% and 83.70%, respectively), with the novel SwCRV-1 and -2 complete genome sequences missing 5 and 6 genes respectively when compared to CRV, but containing 45 and 44 predicted unique genes. Similar to CRV, SwCRV also lacks the genes involved in virulence and host range, however, considering the presence of numerous hypothetical and or unique genes in the SwCRV genomes, it is completely reasonable that the genes encoding these functions are present but not recognized. Phylogenetic analysis suggested a monophyletic relationship between SwCRV and CRV, however, SwCRV is quite distinct from other chordopoxvirus genomes. These are the first SwCRV complete genome sequences isolated from saltwater crocodile skin lesions.
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Affiliation(s)
- Subir Sarker
- Department of Physiology, Anatomy and Microbiology, School of Life Sciences, La Trobe University, Bundoora, VIC 3086, Australia.
| | - Sally R Isberg
- Centre for Crocodile Research, Noonamah, NT, Australia.,School of Psychological and Clinical Sciences, Charles Darwin University, Darwin, NT, Australia
| | - Natalie L Milic
- School of Psychological and Clinical Sciences, Charles Darwin University, Darwin, NT, Australia
| | - Peter Lock
- La Trobe Institute for Molecular Science, La Trobe University, Bundoora, VIC, Australia
| | - Karla J Helbig
- Department of Physiology, Anatomy and Microbiology, School of Life Sciences, La Trobe University, Bundoora, VIC 3086, Australia
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11
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The Host Factor Early Growth Response Gene (EGR-1) Regulates Vaccinia virus Infectivity during Infection of Starved Mouse Cells. Viruses 2018; 10:v10040140. [PMID: 29561772 PMCID: PMC5923434 DOI: 10.3390/v10040140] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2017] [Revised: 02/20/2018] [Accepted: 03/16/2018] [Indexed: 12/16/2022] Open
Abstract
Evolution has equipped poxvirus genomes with the coding capacity for several virus-host interaction products which interfere with host cell gene expression and protein function, creating an adequate intracellular environment for a productive infection. We show here that Vaccinia virus (VACV) induces the expression of the cellular transcription factor EGR-1 (early growth response-1) in Mouse Embryonic Fibroblasts (MEFs) through the MEK (mitogen-activated protein kinase (MAPK)/ERK)/ERK (extracellular signal-regulated kinases) pathway, from 3 to 12 h post infection (h.p.i.). By using starved egr-1 knockout (egr-1−/−) MEFs, we demonstrate that VACV replication is reduced by ~1 log in this cell line. Although western blotting and electron microscopy analyses revealed no difference in VACV gene expression or morphogenesis, the specific infectivity of VACV propagated in egr-1−/− MEFs was lower than virus propagated in wild type (WT) cells. This lower infectivity was due to decreased VACV DNA replication during the next cycle of infection. Taken together, these results revealed that EGR-1 appears to facilitate VACV replication in starved fibroblasts by affecting viral particles infectivity.
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12
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Bennett M, Tu SL, Upton C, McArtor C, Gillett A, Laird T, O’Dea M. Complete genomic characterisation of two novel poxviruses (WKPV and EKPV) from western and eastern grey kangaroos. Virus Res 2017; 242:106-121. [DOI: 10.1016/j.virusres.2017.09.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 09/23/2017] [Accepted: 09/25/2017] [Indexed: 10/18/2022]
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13
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Irwin CR, Hitt MM, Evans DH. Targeting Nucleotide Biosynthesis: A Strategy for Improving the Oncolytic Potential of DNA Viruses. Front Oncol 2017; 7:229. [PMID: 29018771 PMCID: PMC5622948 DOI: 10.3389/fonc.2017.00229] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 09/07/2017] [Indexed: 12/14/2022] Open
Abstract
The rapid growth of tumors depends upon elevated levels of dNTPs, and while dNTP concentrations are tightly regulated in normal cells, this control is often lost in transformed cells. This feature of cancer cells has been used to advantage to develop oncolytic DNA viruses. DNA viruses employ many different mechanisms to increase dNTP levels in infected cells, because the low concentration of dNTPs found in non-cycling cells can inhibit virus replication. By disrupting the virus-encoded gene(s) that normally promote dNTP biosynthesis, one can assemble oncolytic versions of these agents that replicate selectively in cancer cells. This review covers the pathways involved in dNTP production, how they are dysregulated in cancer cells, and the various approaches that have been used to exploit this biology to improve the tumor specificity of oncolytic viruses. In particular, we compare and contrast the ways that the different types of oncolytic virus candidates can directly modulate these processes. We limit our review to the large DNA viruses that naturally encode homologs of the cellular enzymes that catalyze dNTP biogenesis. Lastly, we consider how this knowledge might guide future development of oncolytic viruses.
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Affiliation(s)
- Chad R Irwin
- Faculty of Medicine and Dentistry, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, Canada.,Faculty of Medicine and Dentistry, Li Ka Shing Institute of Virology, University of Alberta, Edmonton, AB, Canada
| | - Mary M Hitt
- Faculty of Medicine and Dentistry, Li Ka Shing Institute of Virology, University of Alberta, Edmonton, AB, Canada.,Faculty of Medicine and Dentistry, Department of Oncology, University of Alberta, Edmonton, AB, Canada
| | - David H Evans
- Faculty of Medicine and Dentistry, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, Canada.,Faculty of Medicine and Dentistry, Li Ka Shing Institute of Virology, University of Alberta, Edmonton, AB, Canada
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14
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Song EJ, Chan MWY, Shin JW, Chen CC. Hard clam extracts induce atypical apoptosis in human gastric cancer cells. Exp Ther Med 2017; 14:1409-1418. [PMID: 28810604 PMCID: PMC5525584 DOI: 10.3892/etm.2017.4630] [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: 03/20/2015] [Accepted: 05/03/2016] [Indexed: 12/13/2022] Open
Abstract
Hard clams (HCs) are a nutritionally high-quality and popular seafood, and are established to be a potent antitumor food. The aim of the present study was to determine whether HC extracts induce apoptosis in the human gastric cancer cell line, AGS. In contrast with previously reported methods of extraction, crude extracts of HC were obtained by freezing and thawing and by a method free of hot water or organic solvents. The composition, quality and properties of the HC extracts were demonstrated to be stable since the extracts that were evaluated by capillary electrophoresis and HPLC analysis at different timepoints were similar. HC extracts also have an inhibitory effect against the survival of AGS cells. Treatment with HC extracts induced a marked sub-G1 DNA peak and reduced the expression of the anti-apoptotic genes BIRC5 and KPNA2. However, hallmarks of classical apoptosis such as DNA fragmentation and apoptotic body formation were not observed, indicating atypical apoptosis. Furthermore, it was revealed that HC extracts interrupted cell cycle progression in AGS cells through altered expression of six cell cycle-associated genes: CDC20, KPNA2, BIRC5, ANAPC2, CDKN1A and RB1. The present findings suggest that HC may contribute to a novel future anticancer agent.
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Affiliation(s)
- Eing-Ju Song
- Department of Bioscience Technology, Chang Jung Christian University, Tainan 71101, Taiwan R.O.C
| | - Michael W Y Chan
- Department of Life Science, Institute of Molecular Biology, National Chung Cheng University, Chiayi 62102, Taiwan R.O.C
| | - Jyh-Wei Shin
- Department of Parasitology, College of Medical, National Cheng Kung University, Tainan 70403, Taiwan R.O.C
| | - Che-Chun Chen
- Department of Aquatic Biosciences, National Chiayi University, Chiayi 60004, Taiwan R.O.C
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15
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Genome-wide analysis of alternative splicing during human heart development. Sci Rep 2016; 6:35520. [PMID: 27752099 PMCID: PMC5067579 DOI: 10.1038/srep35520] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 09/27/2016] [Indexed: 12/16/2022] Open
Abstract
Alternative splicing (AS) drives determinative changes during mouse heart development. Recent high-throughput technological advancements have facilitated genome-wide AS, while its analysis in human foetal heart transition to the adult stage has not been reported. Here, we present a high-resolution global analysis of AS transitions between human foetal and adult hearts. RNA-sequencing data showed extensive AS transitions occurred between human foetal and adult hearts, and AS events occurred more frequently in protein-coding genes than in long non-coding RNA (lncRNA). A significant difference of AS patterns was found between foetal and adult hearts. The predicted difference in AS events was further confirmed using quantitative reverse transcription-polymerase chain reaction analysis of human heart samples. Functional foetal-specific AS event analysis showed enrichment associated with cell proliferation-related pathways including cell cycle, whereas adult-specific AS events were associated with protein synthesis. Furthermore, 42.6% of foetal-specific AS events showed significant changes in gene expression levels between foetal and adult hearts. Genes exhibiting both foetal-specific AS and differential expression were highly enriched in cell cycle-associated functions. In conclusion, we provided a genome-wide profiling of AS transitions between foetal and adult hearts and proposed that AS transitions and deferential gene expression may play determinative roles in human heart development.
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16
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Studies on the Contribution of Human Cytomegalovirus UL21a and UL97 to Viral Growth and Inactivation of the Anaphase-Promoting Complex/Cyclosome (APC/C) E3 Ubiquitin Ligase Reveal a Unique Cellular Mechanism for Downmodulation of the APC/C Subunits APC1, APC4, and APC5. J Virol 2015; 89:6928-39. [PMID: 25903336 DOI: 10.1128/jvi.00403-15] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 04/17/2015] [Indexed: 02/06/2023] Open
Abstract
UNLABELLED Human cytomegalovirus (HCMV) deregulates the cell cycle by several means, including inactivation of the anaphase-promoting complex/cyclosome (APC/C) E3 ubiquitin ligase. Viral proteins UL97 and UL21a, respectively, affect the APC/C by phosphorylation of APC/C coactivator Cdh1 and by inducing the degradation of subunits APC4 and APC5, which along with APC1 form the APC/C platform subcomplex. The aim of this study was to further characterize the mechanism of APC/C inactivation and define the relative contributions of UL21a and UL97 to APC/C substrate accumulation and to viral growth. We show that in uninfected cells, UL21a but not UL97 can disrupt APC/C function, leading to the accumulation of substrates. We find that UL21a is necessary and sufficient to induce the degradation of APC1, in addition to the previously reported APC4 and APC5. We also demonstrate that there is a previously unreported cellular mechanism for a specific decrease in the levels of all three platform subunits, APC1, APC4, and APC5, upon the depletion of any one of these subunits or of subunit APC8. Finally, we show that at a low multiplicity of infection, either UL97 or UL21a can partially complement a growth-defective mutant virus lacking both UL21a and UL97, with significantly greater benefit afforded by the expression of both proteins. This double mutant also can be partially rescued by inactivation of the APC/C using small interfering RNAs against specific subunits. These results further our understanding of HCMV's interaction with the cell cycle machinery and reveal a new cellular pattern of APC/C subunit downmodulation. IMPORTANCE HCMV lytic infection subverts the host cell cycle machinery in multiple ways. A major effect is inactivation of the APC/C, which plays a central role in the control of cell cycle progression. This study provides further insight into the mechanism of inactivation. We discovered that the APC1 subunit, which along with APC4 and APC5 form the platform subcomplex of the APC/C, is an additional target of the degradation induced by HCMV protein UL21a. This study also shows for the first time that there is a unique cellular process in uninfected cells whereby depletion of APC1, APC4, APC5, or APC8 recapitulates the pattern of HCMV-mediated APC/C subunit degradation.
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17
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Fleming SB, Wise LM, Mercer AA. Molecular genetic analysis of orf virus: a poxvirus that has adapted to skin. Viruses 2015; 7:1505-39. [PMID: 25807056 PMCID: PMC4379583 DOI: 10.3390/v7031505] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Revised: 03/17/2015] [Accepted: 03/19/2015] [Indexed: 12/17/2022] Open
Abstract
Orf virus is the type species of the Parapoxvirus genus of the family Poxviridae. It induces acute pustular skin lesions in sheep and goats and is transmissible to humans. The genome is G+C rich, 138 kbp and encodes 132 genes. It shares many essential genes with vaccinia virus that are required for survival but encodes a number of unique factors that allow it to replicate in the highly specific immune environment of skin. Phylogenetic analysis suggests that both viral interleukin-10 and vascular endothelial growth factor genes have been "captured" from their host during the evolution of the parapoxviruses. Genes such as a chemokine binding protein and a protein that binds granulocyte-macrophage colony-stimulating factor and interleukin-2 appear to have evolved from a common poxvirus ancestral gene while three parapoxvirus nuclear factor (NF)-κB signalling pathway inhibitors have no homology to other known NF-κB inhibitors. A homologue of an anaphase-promoting complex subunit that is believed to manipulate the cell cycle and enhance viral DNA synthesis appears to be a specific adaptation for viral-replication in keratinocytes. The review focuses on the unique genes of orf virus, discusses their evolutionary origins and their role in allowing viral-replication in the skin epidermis.
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Affiliation(s)
- Stephen B Fleming
- Department of Microbiology and Immunology, 720 Cumberland St, University of Otago, Dunedin 9016, New Zealand.
| | - Lyn M Wise
- Department of Microbiology and Immunology, 720 Cumberland St, University of Otago, Dunedin 9016, New Zealand.
| | - Andrew A Mercer
- Department of Microbiology and Immunology, 720 Cumberland St, University of Otago, Dunedin 9016, New Zealand.
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18
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Herbert MH, Squire CJ, Mercer AA. Poxviral ankyrin proteins. Viruses 2015; 7:709-38. [PMID: 25690795 PMCID: PMC4353913 DOI: 10.3390/v7020709] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Revised: 02/05/2015] [Accepted: 02/09/2015] [Indexed: 02/08/2023] Open
Abstract
Multiple repeats of the ankyrin motif (ANK) are ubiquitous throughout the kingdoms of life but are absent from most viruses. The main exception to this is the poxvirus family, and specifically the chordopoxviruses, with ANK repeat proteins present in all but three species from separate genera. The poxviral ANK repeat proteins belong to distinct orthologue groups spread over different species, and align well with the phylogeny of their genera. This distribution throughout the chordopoxviruses indicates these proteins were present in an ancestral vertebrate poxvirus, and have since undergone numerous duplication events. Most poxviral ANK repeat proteins contain an unusual topology of multiple ANK motifs starting at the N-terminus with a C-terminal poxviral homologue of the cellular F-box enabling interaction with the cellular SCF ubiquitin ligase complex. The subtle variations between ANK repeat proteins of individual poxviruses suggest an array of different substrates may be bound by these protein-protein interaction domains and, via the F-box, potentially directed to cellular ubiquitination pathways and possible degradation. Known interaction partners of several of these proteins indicate that the NF-κB coordinated anti-viral response is a key target, whilst some poxviral ANK repeat domains also have an F-box independent affect on viral host-range.
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Affiliation(s)
- Michael H Herbert
- School of Biological Sciences, University of Auckland, Auckland 1010, New Zealand.
| | - Christopher J Squire
- School of Biological Sciences, University of Auckland, Auckland 1010, New Zealand.
| | - Andrew A Mercer
- Virus Research Unit, Department of Microbiology and Immunology, University of Otago, Dunedin 9016, New Zealand.
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19
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Maluquer de Motes C, Schiffner T, Sumner RP, Smith GL. Vaccinia virus virulence factor N1 can be ubiquitylated on multiple lysine residues. J Gen Virol 2014; 95:2038-2049. [PMID: 24914067 PMCID: PMC4135091 DOI: 10.1099/vir.0.065664-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Ubiquitylation is a covalent post-translational modification that regulates protein stability and is involved in many biological functions. Proteins may be modified with mono-ubiquitin or ubiquitin chains. Viruses have evolved multiple mechanisms to perturb the cell ubiquitin system and manipulate it to their own benefit. Here, we report ubiquitylation of vaccinia virus (VACV) protein N1. N1 is an inhibitor of the nuclear factor NF-κB and apoptosis that contributes to virulence, has a Bcl-2-like fold, and is highly conserved amongst orthopoxviruses. The interaction between N1 and ubiquitin occurs at endogenous protein levels during VACV infection and following ectopic expression of N1. Biochemical analysis demonstrated that N1 is covalently ubiquitylated, and heterodimers of ubiquitylated and non-ubiquitylated N1 monomers were identified, suggesting that ubiquitylation does not inhibit N1 dimerization. Studies with other VACV Bcl-2 proteins, such as C6 or B14, revealed that although these proteins also interact with ubiquitin, these interactions are non-covalent. Finally, mutagenesis of N1 showed that ubiquitylation occurs in a conventional lysine-dependent manner at multiple acceptor sites because only an N1 allele devoid of lysine residues remained unmodified. Taken together, we described a previously uncharacterized modification of the VACV protein N1 that provided a new layer of complexity to the biology of this virulence factor, and provided another example of the intricate interplay between poxviruses and the host ubiquitin system.
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Affiliation(s)
- Carlos Maluquer de Motes
- Department of Virology, Imperial College London, St Mary's Campus, Norfolk Place, London W2 1PG, UK.,Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Torben Schiffner
- Department of Virology, Imperial College London, St Mary's Campus, Norfolk Place, London W2 1PG, UK
| | - Rebecca P Sumner
- Department of Virology, Imperial College London, St Mary's Campus, Norfolk Place, London W2 1PG, UK.,Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Geoffrey L Smith
- Department of Virology, Imperial College London, St Mary's Campus, Norfolk Place, London W2 1PG, UK.,Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
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20
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Chen X, Anstey AV, Bugert JJ. Molluscum contagiosum virus infection. THE LANCET. INFECTIOUS DISEASES 2013; 13:877-88. [PMID: 23972567 DOI: 10.1016/s1473-3099(13)70109-9] [Citation(s) in RCA: 118] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Molluscum contagiosum virus is an important human skin pathogen: it can cause disfigurement and suffering in children, in adults it is less common and often sexually transmitted. Extensive and persistent skin infection with the virus can indicate underlying immunodeficiency. Traditional ablative therapies have not been compared directly with newer immune-modulating and specific antiviral therapies. Advances in research raise the prospect of new approaches to treatment informed by the biology of the virus; in human skin, the infection is localised in the epidermal layers, where it induces a typical, complex hyperproliferative lesion with an abundance of virus particles but a conspicuous absence of immune effectors. Functional studies of the viral genome have revealed effects on cellular pathways involved in the cell cycle, innate immunity, inflammation, and cell death. Extensive lesions caused by molluscum contagiosum can occur in patients with DOCK8 deficiency-a genetic disorder affecting migration of dendritic and specialised T cells in skin. Sudden disappearance of lesions is the consequence of a vigorous immune response in healthy people. Further study of the unique features of infection with molluscum contagiosum virus could give fundamental insight into the nature of skin immunity.
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Affiliation(s)
- Xiaoying Chen
- Department of Dermatology, Ruijin Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
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21
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Abstract
Viruses commonly manipulate cell cycle progression to create cellular conditions that are most beneficial to their replication. To accomplish this feat, viruses often target critical cell cycle regulators in order to have maximal effect with minimal input. One such master regulator is the large, multisubunit E3 ubiquitin ligase anaphase-promoting complex (APC) that targets effector proteins for ubiquitination and proteasome degradation. The APC is essential for cells to progress through anaphase, exit from mitosis, and prevent a premature entry into S phase. These far-reaching effects of the APC on the cell cycle are through its ability to target a number of substrates, including securin, cyclin A, cyclin B, thymidine kinase, geminin, and many others. Recent studies have identified several proteins from a number of viruses that can modulate APC activity by different mechanisms, highlighting the potential of the APC in driving viral replication or pathogenesis. Most notably, human cytomegalovirus (HCMV) protein pUL21a was recently identified to disable the APC via a novel mechanism by targeting APC subunits for degradation, both during virus infection and in isolation. Importantly, HCMV lacking both viral APC regulators is significantly attenuated, demonstrating the impact of the APC on a virus infection. Work in this field will likely lead to novel insights into viral replication and pathogenesis and APC function and identify novel antiviral and anticancer targets. Here we review viral mechanisms to regulate the APC, speculate on their roles during infection, and identify questions to be addressed in future studies.
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22
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Correa RL, Bruckner FP, de Souza Cascardo R, Alfenas-Zerbini P. The Role of F-Box Proteins during Viral Infection. Int J Mol Sci 2013; 14:4030-49. [PMID: 23429191 PMCID: PMC3588083 DOI: 10.3390/ijms14024030] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Revised: 12/14/2012] [Accepted: 01/17/2013] [Indexed: 01/10/2023] Open
Abstract
The F-box domain is a protein structural motif of about 50 amino acids that mediates protein–protein interactions. The F-box protein is one of the four components of the SCF (SKp1, Cullin, F-box protein) complex, which mediates ubiquitination of proteins targeted for degradation by the proteasome, playing an essential role in many cellular processes. Several discoveries have been made on the use of the ubiquitin–proteasome system by viruses of several families to complete their infection cycle. On the other hand, F-box proteins can be used in the defense response by the host. This review describes the role of F-box proteins and the use of the ubiquitin–proteasome system in virus–host interactions.
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Affiliation(s)
- Régis Lopes Correa
- Department of Genetics, Federal University of Rio de Janeiro, Rio de Janeiro, RJ 21944-970, Brazil; E-Mails: (R.L.C.); (R.S.C.)
| | - Fernanda Prieto Bruckner
- Department of Microbiology/BIOAGRO, Federal University of Viçosa, Viçosa, MG 36570-000, Brazil; E-Mail:
| | - Renan de Souza Cascardo
- Department of Genetics, Federal University of Rio de Janeiro, Rio de Janeiro, RJ 21944-970, Brazil; E-Mails: (R.L.C.); (R.S.C.)
- Department of Microbiology/BIOAGRO, Federal University of Viçosa, Viçosa, MG 36570-000, Brazil; E-Mail:
| | - Poliane Alfenas-Zerbini
- Department of Microbiology/BIOAGRO, Federal University of Viçosa, Viçosa, MG 36570-000, Brazil; E-Mail:
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +55-31-3899-2955; Fax: +55-31-3899-2864
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23
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Proteasome-dependent disruption of the E3 ubiquitin ligase anaphase-promoting complex by HCMV protein pUL21a. PLoS Pathog 2012; 8:e1002789. [PMID: 22792066 PMCID: PMC3390409 DOI: 10.1371/journal.ppat.1002789] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Accepted: 05/22/2012] [Indexed: 01/27/2023] Open
Abstract
The anaphase-promoting complex (APC) is an E3 ubiquitin ligase which controls ubiquitination and degradation of multiple cell cycle regulatory proteins. During infection, human cytomegalovirus (HCMV), a widespread pathogen, not only phosphorylates the APC coactivator Cdh1 via the multifunctional viral kinase pUL97, it also promotes degradation of APC subunits via an unknown mechanism. Using a proteomics approach, we found that a recently identified HCMV protein, pUL21a, interacted with the APC. Importantly, we determined that expression of pUL21a was necessary and sufficient for proteasome-dependent degradation of APC subunits APC4 and APC5. This resulted in APC disruption and required pUL21a binding to the APC. We have identified the proline-arginine amino acid pair at residues 109–110 in pUL21a to be critical for its ability to bind and regulate the APC. A point mutant virus in which proline-arginine were mutated to alanines (PR-AA) grew at wild-type levels. However, a double mutant virus in which the viral ability to regulate the APC was abrogated by both PR-AA point mutation and UL97 deletion was markedly more attenuated compared to the UL97 deletion virus alone. This suggests that these mutations are synthetically lethal, and that HCMV exploits two viral factors to ensure successful disruption of the APC to overcome its restriction on virus infection. This study reveals the HCMV protein pUL21a as a novel APC regulator and uncovers a unique viral mechanism to subvert APC activity. In this study, we report an intriguing mechanism used by human cytomegalovirus (HCMV) to regulate a cellular E3 ubiquitin ligase, the anaphase promoting complex (APC). The ability to hijack the ubiquitin-proteasome system for regulating protein degradation and to manipulate the cell cycle for viral genome synthesis is critical in many viral infections. The APC is a master cell cycle modulator that targets a number of regulatory proteins for proteasomal degradation. It can prevent cells from entry into S-phase, thus creating a hindrance for viruses needing to coerce cells into a cellular environment favorable for viral DNA synthesis. We have identified an HCMV protein, pUL21a, which uses a seemingly counterintuitive mechanism to regulate the APC. It interacts with the APC to target the subunits of this ubiquitin ligase for proteasomal degradation. This causes disruption of the complex and reduces its activity. Furthermore, a virus lacking pUL21a and pUL97, which is another HCMV-encoded APC regulator, was highly attenuated when compared to loss of UL97 alone, suggesting that HCMV uses two proteins to fully disarm the APC. This study identifies a herpesviral protein that uses a unique, proteasome-dependent mechanism to regulate the activity of this prominent cellular E3 ubiquitin ligase.
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Mo M, Shahar S, Fleming SB, Mercer AA. How viruses affect the cell cycle through manipulation of the APC/C. Trends Microbiol 2012; 20:440-8. [PMID: 22727131 DOI: 10.1016/j.tim.2012.05.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Revised: 05/21/2012] [Accepted: 05/28/2012] [Indexed: 02/06/2023]
Abstract
Viruses frequently exploit host cell cycle machineries for their own benefit, often by targeting 'master switches' of cell cycle regulation. By doing so, they achieve maximum effect from minimal input. One such master switch is the anaphase promoting complex or cyclosome (APC/C), a multicomponent ubiquitin ligase and a dominant regulator of the cell cycle. A growing number of viruses have been shown to target the APC/C. Although differing strategies are employed, viral manipulation of the APC/C seems to serve a common purpose, namely, to create an environment supportive of viral replication. Here, the molecular mechanisms employed by these viruses are summarized and discussed.
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Affiliation(s)
- Min Mo
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9016, New Zealand
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25
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Weitzman MD, Lilley CE, Chaurushiya MS. Changing the ubiquitin landscape during viral manipulation of the DNA damage response. FEBS Lett 2011; 585:2897-906. [PMID: 21549706 PMCID: PMC3312807 DOI: 10.1016/j.febslet.2011.04.049] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2011] [Revised: 04/16/2011] [Accepted: 04/19/2011] [Indexed: 02/08/2023]
Abstract
Viruses often induce signaling through the same cellular cascades that are activated by damage to the cellular genome. Signaling triggered by viral proteins or exogenous DNA delivered by viruses can be beneficial or detrimental to viral infection. Viruses have therefore evolved to dissect the cellular DNA damage response pathway during infection, often marking key cellular regulators with ubiquitin to induce their degradation or change their function. Signaling controlled by ubiquitin or ubiquitin-like proteins has recently emerged as key regulator of the cellular DNA damage response. Situated at the interface between DNA damage signaling and the ubiquitin system, viruses can reveal key convergence points in this important cellular pathway. In this review, we examine how viruses harness the diversity of the cellular ubiquitin system to modulate the DNA damage signaling pathway. We discuss the implications of viral infiltration of this pathway for both the transcriptional program of the virus and for the cellular response to DNA damage.
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Affiliation(s)
- Matthew D Weitzman
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA.
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26
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Gustin JK, Moses AV, Früh K, Douglas JL. Viral takeover of the host ubiquitin system. Front Microbiol 2011; 2:161. [PMID: 21847386 PMCID: PMC3147166 DOI: 10.3389/fmicb.2011.00161] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Accepted: 07/14/2011] [Indexed: 01/29/2023] Open
Abstract
Like the other more well-characterized post-translational modifications (phosphorylation, methylation, acetylation, acylation, etc.), the attachment of the 76 amino acid ubiquitin (Ub) protein to substrates has been shown to govern countless cellular processes. As obligate intracellular parasites, viruses have evolved the capability to commandeer many host processes in order to maximize their own survival, whether it be to increase viral production or to ensure the long-term survival of latently infected host cells. The first evidence that viruses could usurp the Ub system came from the DNA tumor viruses and Adenoviruses, each of which use Ub to dysregulate the host cell cycle (Scheffner et al., 1990; Querido et al., 2001). Today, the list of viruses that utilize Ub includes members from almost every viral class, encompassing both RNA and DNA viruses. Among these, there are examples of Ub usage at every stage of the viral life cycle, involving both ubiquitination and de-ubiquitination. In addition to viruses that merely modify the host Ub system, many of the large DNA viruses encode their own Ub modifying machinery. In this review, we highlight the latest discoveries regarding the myriad ways that viruses utilize Ub to their advantage.
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Affiliation(s)
- Jean K Gustin
- Vaccine and Gene Therapy Institute, Oregon Health & Science University Beaverton, OR, USA
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Smolders L, Teodoro JG. Targeting the anaphase promoting complex: common pathways for viral infection and cancer therapy. Expert Opin Ther Targets 2011; 15:767-80. [PMID: 21375465 DOI: 10.1517/14728222.2011.558008] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION The anaphase promoting complex/cyclosome (APC/C) is a ubiquitin ligase involved in regulation of the cell cycle through ubiquitination-dependent substrate proteolysis. Many viral proteins have been shown to interact with the APC/C, derailing cell cycle progression in order to facilitate their own replication. Induction of G(2)/M arrest by viral APC/C inhibition can lead to apoptotic cell death. Some viral proteins cause cytotoxicity specifically in tumour cells, providing evidence that targeting the APC/C could be exploited to selectively eliminate cancer cells. AREAS COVERED In this review, we provide a summary of studies from viral APC/C interactions over the last decade, as well as recent discoveries identifying the APC/C as a promising target in the context of cancer therapy. EXPERT OPINION Current therapeutic strategies inducing mitotic arrest rely on activation of the spindle assembly checkpoint (SAC) for their function. Many cancer cells have a weakened SAC and escape apoptosis through mitotic slippage. Recent evidence has demonstrated that targeting the APC/C, particularly the co-activator Cdc20, might be a better alternative. Tumour cells display greater dependency on APC/C function than normal cells and oncogenic transformation can lead to increased mitotic stress, rendering cancer cells more vulnerable to APC/C inhibition.
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Affiliation(s)
- Linda Smolders
- McGill University, Goodman Cancer Research Centre, Department of Biochemistry, 1160 Pine Avenue West, Room 616, Montreal, Quebec H3A 1A3, Canada
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McLean JR, Chaix D, Ohi MD, Gould KL. State of the APC/C: organization, function, and structure. Crit Rev Biochem Mol Biol 2011; 46:118-36. [PMID: 21261459 DOI: 10.3109/10409238.2010.541420] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The ubiquitin-proteasome protein degradation system is involved in many essential cellular processes including cell cycle regulation, cell differentiation, and the unfolded protein response. The anaphase-promoting complex/cyclosome (APC/C), an evolutionarily conserved E3 ubiquitin ligase, was discovered 15 years ago because of its pivotal role in cyclin degradation and mitotic progression. Since then, we have learned that the APC/C is a very large, complex E3 ligase composed of 13 subunits, yielding a molecular machine of approximately 1 MDa. The intricate regulation of the APC/C is mediated by the Cdc20 family of activators, pseudosubstrate inhibitors, protein kinases and phosphatases and the spindle assembly checkpoint. The large size, complexity, and dynamic nature of the APC/C represent significant obstacles toward high-resolution structural techniques; however, over the last decade, there have been a number of lower resolution APC/C structures determined using single particle electron microscopy. These structures, when combined with data generated from numerous genetic and biochemical studies, have begun to shed light on how APC/C activity is regulated. Here, we discuss the most recent developments in the APC/C field concerning structure, substrate recognition, and catalysis.
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Affiliation(s)
- Janel R McLean
- Howard Hughes Medical Institute, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
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Barry M, van Buuren N, Burles K, Mottet K, Wang Q, Teale A. Poxvirus exploitation of the ubiquitin-proteasome system. Viruses 2010; 2:2356-2380. [PMID: 21994622 PMCID: PMC3185573 DOI: 10.3390/v2102356] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Revised: 09/27/2010] [Accepted: 09/30/2010] [Indexed: 12/19/2022] Open
Abstract
Ubiquitination plays a critical role in many cellular processes. A growing number of viruses have evolved strategies to exploit the ubiquitin-proteasome system, including members of the Poxviridae family. Members of the poxvirus family have recently been shown to encode BTB/kelch and ankyrin/F-box proteins that interact with cullin-3 and cullin-1 based ubiquitin ligases, respectively. Multiple members of the poxvirus family also encode ubiquitin ligases with intrinsic activity. This review describes the numerous mechanisms that poxviruses employ to manipulate the ubiquitin-proteasome system.
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Affiliation(s)
- Michele Barry
- Author to whom correspondence should be addressed: E-Mail: ; Tel.: +1 780 492-0702; Fax: +1 780 492-7521
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Mo M, Fleming SB, Mercer AA. Orf virus cell cycle regulator, PACR, competes with subunit 11 of the anaphase promoting complex for incorporation into the complex. J Gen Virol 2010; 91:3010-5. [PMID: 20826619 DOI: 10.1099/vir.0.026054-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The poxvirus anaphase promoting complex regulator (PACR) promotes viral replication by manipulating the anaphase promoting complex/cyclosome (APC/C), a multisubunit ubiquitin ligase complex with essential roles in cell cycle regulation. PACR has sequence similarities to APC/C subunit 11 (APC11) and associates with APC/C subunits. However, unlike APC11, expression of PACR disrupts APC/C functions. Here, we further investigated the interaction of PACR with APC/C. Following knockdown of APC1, the subunit linking APC11/APC2 to the rest of APC/C, PACR remained bound to APC2 but not to other, distal, subunits of the complex, suggesting PACR associates with APC/C via APC2. This was supported by the demonstration, in vitro, of a direct interaction between PACR and APC2. Moreover, the presence of PACR interfered with interactions between both APC11 and APC2. Based on these observations we propose that PACR competes with APC11 for the incorporation into APC/C.
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Affiliation(s)
- Min Mo
- Department of Microbiology and Immunology, University of Otago, Dunedin 9016, New Zealand
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Inactivation and disassembly of the anaphase-promoting complex during human cytomegalovirus infection is associated with degradation of the APC5 and APC4 subunits and does not require UL97-mediated phosphorylation of Cdh1. J Virol 2010; 84:10832-43. [PMID: 20686030 DOI: 10.1128/jvi.01260-10] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Infection of quiescent cells by human cytomegalovirus (HCMV) elicits severe cell cycle deregulation, resulting in a G(1)/S arrest, which can be partly attributed to the inactivation of the anaphase-promoting complex (APC). As we previously reported, the premature phosphorylation of its coactivator Cdh1 and/or the dissociation of the core complex can account for the inactivation. We have expanded on these results and further delineated the key components required for disabling the APC during HCMV infection. The viral protein kinase UL97 was hypothesized to phosphorylate Cdh1, and consistent with this, phosphatase assays utilizing a virus with a UL97 deletion mutation (ΔUL97 virus) indicated that Cdh1 is hypophosphorylated at early times in the infection. Mass spectrometry analysis demonstrated that UL97 can phosphorylate Cdh1 in vitro, and the majority of the sites identified correlated with previously characterized cyclin-dependent kinase (Cdk) consensus sites. Analysis of the APC core complex during ΔUL97 virus infection showed APC dissociation occurring at the same time as during infection with wild-type virus, suggesting that the UL97-mediated phosphorylation of Cdh1 is not required for this to occur. Further investigation of the APC subunits showed a proteasome-dependent loss of the APC5 and APC4 subunits that was temporally associated with the disassembly of the APC. Immediate early viral gene expression was not sufficient for the degradation of APC4 and APC5, indicating that a viral early gene product(s), possibly in association with a de novo-synthesized cellular protein(s), is involved.
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Gammon DB, Gowrishankar B, Duraffour S, Andrei G, Upton C, Evans DH. Vaccinia virus-encoded ribonucleotide reductase subunits are differentially required for replication and pathogenesis. PLoS Pathog 2010; 6:e1000984. [PMID: 20628573 PMCID: PMC2900304 DOI: 10.1371/journal.ppat.1000984] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2009] [Accepted: 06/03/2010] [Indexed: 11/19/2022] Open
Abstract
Ribonucleotide reductases (RRs) are evolutionarily-conserved enzymes that catalyze the rate-limiting step during dNTP synthesis in mammals. RR consists of both large (R1) and small (R2) subunits, which are both required for catalysis by the R12R22 heterotetrameric complex. Poxviruses also encode RR proteins, but while the Orthopoxviruses infecting humans [e.g. vaccinia (VACV), variola, cowpox, and monkeypox viruses] encode both R1 and R2 subunits, the vast majority of Chordopoxviruses encode only R2 subunits. Using plaque morphology, growth curve, and mouse model studies, we investigated the requirement of VACV R1 (I4) and R2 (F4) subunits for replication and pathogenesis using a panel of mutant viruses in which one or more viral RR genes had been inactivated. Surprisingly, VACV F4, but not I4, was required for efficient replication in culture and virulence in mice. The growth defects of VACV strains lacking F4 could be complemented by genes encoding other Chordopoxvirus R2 subunits, suggesting conservation of function between poxvirus R2 proteins. Expression of F4 proteins encoding a point mutation predicted to inactivate RR activity but still allow for interaction with R1 subunits, caused a dominant negative phenotype in growth experiments in the presence or absence of I4. Co-immunoprecipitation studies showed that F4 (as well as other Chordopoxvirus R2 subunits) form hybrid complexes with cellular R1 subunits. Mutant F4 proteins that are unable to interact with host R1 subunits failed to rescue the replication defect of strains lacking F4, suggesting that F4-host R1 complex formation is critical for VACV replication. Our results suggest that poxvirus R2 subunits form functional complexes with host R1 subunits to provide sufficient dNTPs for viral replication. Our results also suggest that R2-deficient poxviruses may be selective oncolytic agents and our bioinformatic analyses provide insights into how poxvirus nucleotide metabolism proteins may have influenced the base composition of these pathogens. Efficient genome replication is central to the virulence of all DNA viruses, including poxviruses. To ensure replication efficiency, many of the more virulent poxviruses encode their own nucleotide metabolism machinery, including ribonucleotide reductase (RR) enzymes, which act to provide ample DNA precursors for replication. RR enzymes require both large (R1) and small (R2) subunit proteins for activity. Curiously, some poxviruses only encode R2 subunits. Other poxviruses, such as the smallpox vaccine strain, vaccinia virus (VACV), encode both R1 and R2 subunits. We report here that the R2, but not the R1, subunit of VACV RR is required for efficient replication and virulence. We also provide evidence that several poxvirus R2 proteins form novel complexes with host R1 subunits and this interaction is required for efficient VACV replication in primate cells. Our study explains why some poxviruses only encode R2 subunits and identifies a role for these proteins in poxvirus pathogenesis. Furthermore, we provide evidence that mutant poxviruses unable to generate R2 proteins may become entirely dependent upon host RR activity. This may restrict their replication to cells that over-express RR proteins such as cancer cells, making them potential therapeutics for human malignancies.
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Affiliation(s)
- Don B. Gammon
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
| | - Branawan Gowrishankar
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
| | - Sophie Duraffour
- Laboratory of Virology and Rega Institute for Medical Research, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Graciela Andrei
- Laboratory of Virology and Rega Institute for Medical Research, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Chris Upton
- Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - David H. Evans
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
- * E-mail:
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Andrade AA, Brasil BSAF, Pereira ACTC, Ferreira PCP, Kroon EG, Bonjardim CA. Vaccinia virus regulates expression of p21WAF1/Cip1 in A431 cells. Mem Inst Oswaldo Cruz 2010; 105:269-77. [DOI: 10.1590/s0074-02762010000300005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2009] [Accepted: 04/01/2010] [Indexed: 11/22/2022] Open
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