The infection and viral DNA replication ofBocavirusminute virus of canine in permissive cells and non-permissive cells

2010 ◽  
Vol 34 (8) ◽  
pp. S60-S60
Author(s):  
Yuning Sun ◽  
Fang Li ◽  
Jianming Qiu ◽  
Xiaohong Lu
Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 321
Author(s):  
Ashley N. Della Fera ◽  
Alix Warburton ◽  
Tami L. Coursey ◽  
Simran Khurana ◽  
Alison A. McBride

Persistent infection with oncogenic human papillomavirus (HPV) types is responsible for ~5% of human cancers. The HPV infectious cycle can sustain long-term infection in stratified epithelia because viral DNA is maintained as low copy number extrachromosomal plasmids in the dividing basal cells of a lesion, while progeny viral genomes are amplified to large numbers in differentiated superficial cells. The viral E1 and E2 proteins initiate viral DNA replication and maintain and partition viral genomes, in concert with the cellular replication machinery. Additionally, the E5, E6, and E7 proteins are required to evade host immune responses and to produce a cellular environment that supports viral DNA replication. An unfortunate consequence of the manipulation of cellular proliferation and differentiation is that cells become at high risk for carcinogenesis.


1983 ◽  
Vol 3 (3) ◽  
pp. 315-324 ◽  
Author(s):  
M P Quinlan ◽  
D M Knipe

Two herpes simplex virus proteins, the major capsid protein and the major DNA binding protein, are specifically localized to the nucleus of infected cells. We have found that the major proportion of these proteins is associated with the detergent-insoluble matrix or cytoskeletal framework of the infected cell from the time of their synthesis until they have matured to their final binding site in the cell nucleus. These results suggest that these two proteins may interact with or bind to the cellular cytoskeleton during or soon after their synthesis and throughout transport into the cell nucleus. In addition, the DNA binding protein remains associated with the nuclear skeleton at times when it is bound to viral DNA. Thus, viral DNA may also be attached to the nuclear framework. We have demonstrated that the DNA binding protein and the capsid protein exchange from the cytoplasmic framework to the nuclear framework, suggesting the direct movement of the proteins from one structure to the other. Inhibition of viral DNA replication enhanced the binding of the DNA binding protein to the cytoskeleton and increased the rate of exchange from the cytoplasmic framework to the nuclear framework, suggesting a functional relationship between these events. Inhibition of viral DNA replication resulted in decreased synthesis and transport of the capsid protein. We have been unable to detect any artificial binding of these proteins to the cytoskeleton when solubilized viral proteins were mixed with a cytoskeletal fraction or a cell monolayer. This suggested that the attachment of these proteins to the cytoskeleton represents the actual state of these proteins within the cell.


1983 ◽  
Vol 3 (3) ◽  
pp. 315-324
Author(s):  
M P Quinlan ◽  
D M Knipe

Two herpes simplex virus proteins, the major capsid protein and the major DNA binding protein, are specifically localized to the nucleus of infected cells. We have found that the major proportion of these proteins is associated with the detergent-insoluble matrix or cytoskeletal framework of the infected cell from the time of their synthesis until they have matured to their final binding site in the cell nucleus. These results suggest that these two proteins may interact with or bind to the cellular cytoskeleton during or soon after their synthesis and throughout transport into the cell nucleus. In addition, the DNA binding protein remains associated with the nuclear skeleton at times when it is bound to viral DNA. Thus, viral DNA may also be attached to the nuclear framework. We have demonstrated that the DNA binding protein and the capsid protein exchange from the cytoplasmic framework to the nuclear framework, suggesting the direct movement of the proteins from one structure to the other. Inhibition of viral DNA replication enhanced the binding of the DNA binding protein to the cytoskeleton and increased the rate of exchange from the cytoplasmic framework to the nuclear framework, suggesting a functional relationship between these events. Inhibition of viral DNA replication resulted in decreased synthesis and transport of the capsid protein. We have been unable to detect any artificial binding of these proteins to the cytoskeleton when solubilized viral proteins were mixed with a cytoskeletal fraction or a cell monolayer. This suggested that the attachment of these proteins to the cytoskeleton represents the actual state of these proteins within the cell.


1983 ◽  
Vol 3 (9) ◽  
pp. 1670-1674
Author(s):  
W J Muller ◽  
M A Naujokas ◽  
J A Hassell

The frequency of transformation of rodent fibroblasts by polyomavirus is enhanced by a viral gene product, large T-antigen. However, this effect of large T-antigen cannot be demonstrated with pBR322-cloned viral DNA. Recently, it was discovered that pBR322 contains cis-acting sequences inhibitory to DNA replication in mammalian cells. Because polyomavirus large T-antigen is required for viral DNA replication, we examined the possibility that our inability to demonstrate a requirement for large T-antigen in transformation with pBR322-cloned viral DNA was due to the failure of the chimeric DNA to replicate in the transfected cells. To this end we constructed polyomavirus recombinant molecules with a plasmid (pML-2) that lacks these "poison" sequences and measured their capacity to transform cells. Here we report that recombinant plasmids capable of replicating in the transfected cells transform these cells at frequencies approximately sixfold greater than their replication-defective counterparts.


2021 ◽  
Author(s):  
Weiran Shen ◽  
Zekun Wang ◽  
Kang Ning ◽  
Fang Cheng ◽  
John F. Engelhardt ◽  
...  

Parvoviruses package a linear single-stranded DNA genome with hairpin structures at both ends. It has been thought that terminal hairpin sequences are indispensable for viral DNA replication. Here, we provide evidence that the hairpin-deleted duplex genomes of human bocavirus 1 (HBoV1) replicate in human embryonic kidney (HEK) 293 cells. We propose an alternative model for HBoV1 DNA replication in which the leading strand can initiate strand-displacement without “hairpin-transfer.” The transfection of the HBoV1 duplex genomes that retain a minimal replication origin at the right-end ( OriR ), but with extensive deletions in the right-end hairpin (REH), generated viruses in HEK293 cells at a level 10-20 times lower than the wild-type (WT) duplex genome. Importantly, these viruses that have a genome with various deletions after the OriR , but not the one retaining only the OriR , replicated in polarized human airway epithelia. We discovered that the 18-nt sequence (nt 5,403-5,420) beyond the OriR was sufficient to confer virus replication in polarized human airway epithelia, although its progeny virus production was ∼5 times lower than that of the WT virus. Thus, our study demonstrates that hairpin transfer-independent productive parvovirus DNA replication can occur. Importance Hairpin transfer-independent parvovirus replication was modeled with human bocavirus 1 (HBoV1) duplex genomes whose 5’ hairpin structure was ablated by various deletions. In HEK293 cells, these duplex viral genomes with ablated 5’/hairpin sequence replicated efficiently and generated viruses that productively infected polarized human airway epithelium. Thus, for the first time, we reveal a previously unknown phenomenon that the productive parvovirus DNA replication does not depend on the hairpin sequence at REH to initiate “rolling hairpin” DNA replication. Notably, the intermediates of viral DNA replication, as revealed two-dimensional electrophoresis, from transfections of hairpin sequence-deleted duplex genome and full-length genome in HEK293 cells, as well as from virus infection of polarized human airway epithelia are similar. Thus, the establishment of the hairpin transfer-independent parvoviral DNA replication deepens our understanding in viral DNA replication and may have implications in development of parvovirus-based viral vectors with alternative properties.


1990 ◽  
Vol 10 (9) ◽  
pp. 4996-5001 ◽  
Author(s):  
R Rochford ◽  
C T Davis ◽  
K K Yoshimoto ◽  
L P Villarreal

The cell-specific regulation of DNA replication has important implications for the molecular strategy of cellular gene control. Mouse polyomavirus (Py) DNA replication is examined as a model of cell-specific replication control. Using an FM3A-derived mouse cell line which expresses early viral proteins (FOP cells), we determined the minimal sequence requirements for viral DNA replication. FOP cells were observed to have much simpler enhancer requirements than 3T6 and many other cells and did not need a B enhancer for high levels of DNA replication. Using these cells, we show that the individual or tandem binding sites for several unrelated trans-acting factors which are generally subfunctional as transcriptional enhancers (simian virus 40 A core, TGTGGAATG; EBP20, TGTGGTTTT; PEA1 [an AP-1 analog], GTGACTAA; PEA2, GACCGCAG; and PEA3, AGGAAG) stimulated low levels of Py DNA replication. The ordered dimeric combination of PEA3 and PEA1 factor-binding sites, however, acted synergistically to stimulate viral DNA replication to high wild-type levels. This is in contrast to prior results in which much larger enhancer sequences were necessary for high-level viral DNA replication. PEA3/PEA1-stimulated DNA replication showed a distance and orientation independence relative to the origin, which disagrees with some but not other prior analyses of enhancer-dependent DNA replication. It therefore appears that trans-acting factor-binding sites (enhansons) can generally activate DNA replication and that the AP-1 family of sites may act synergistically with other associated trans-acting factors to strongly affect Py DNA replication in specific cells.


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