scholarly journals Viral Transport of DNA Damage That Mimics a Stalled Replication Fork

2005 ◽  
Vol 79 (1) ◽  
pp. 569-580 ◽  
Author(s):  
Jaana Jurvansuu ◽  
Kenneth Raj ◽  
Andrzej Stasiak ◽  
Peter Beard
Keyword(s):  
Dna Damage ◽  
Dna Replication ◽  
Cellular Response ◽  
Replication Fork ◽  
Dna Polymerase Delta ◽  
Viral Dna ◽  
Focus Formation ◽  
Viral Dna Replication ◽  
Cross Links ◽  
Cellular Dna

ABSTRACT Adeno-associated virus type 2 (AAV2) infection incites cells to arrest with 4N DNA content or die if the p53 pathway is defective. This arrest depends on AAV2 DNA, which is single stranded with inverted terminal repeats that serve as primers during viral DNA replication. Here, we show that AAV2 DNA triggers damage signaling that resembles the response to an aberrant cellular DNA replication fork. UV treatment of AAV2 enhances the G2 arrest by generating intrastrand DNA cross-links which persist in infected cells, disrupting viral DNA replication and maintaining the viral DNA in the single-stranded form. In cells, such DNA accumulates into nuclear foci with a signaling apparatus that involves DNA polymerase delta, ATR, TopBP1, RPA, and the Rad9/Rad1/Hus1 complex but not ATM or NBS1. Focus formation and damage signaling strictly depend on ATR and Chk1 functions. Activation of the Chk1 effector kinase leads to the virus-induced G2 arrest. AAV2 provides a novel way to study the cellular response to abnormal DNA replication without damaging cellular DNA. By using the AAV2 system, we show that in human cells activation of phosphorylation of Chk1 depends on TopBP1 and that it is a prerequisite for the appearance of DNA damage foci.

scholarly journals Human Parvovirus B19 Utilizes Cellular DNA Replication Machinery for Viral DNA Replication

2017 ◽  
Vol 92 (5) ◽  
Author(s):  
Wei Zou ◽  
Zekun Wang ◽  
Min Xiong ◽  
Aaron Yun Chen ◽  
Peng Xu ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Dna Replication ◽  
Dna Damage Response ◽  
Parvovirus B19 ◽  
Viral Dna ◽  
Viral Dna Replication ◽  
Cycle Arrest ◽  
Damage Response ◽  
Cellular Dna

ABSTRACTHuman parvovirus B19 (B19V) infection of human erythroid progenitor cells (EPCs) induces a DNA damage response and cell cycle arrest at late S phase, which facilitates viral DNA replication. However, it is not clear exactly which cellular factors are employed by this single-stranded DNA virus. Here, we used microarrays to systematically analyze the dynamic transcriptome of EPCs infected with B19V. We found that DNA metabolism, DNA replication, DNA repair, DNA damage response, cell cycle, and cell cycle arrest pathways were significantly regulated after B19V infection. Confocal microscopy analyses revealed that most cellular DNA replication proteins were recruited to the centers of viral DNA replication, but not the DNA repair DNA polymerases. Our results suggest that DNA replication polymerase δ and polymerase α are responsible for B19V DNA replication by knocking down its expression in EPCs. We further showed that although RPA32 is essential for B19V DNA replication and the phosphorylated forms of RPA32 colocalized with the replicating viral genomes, RPA32 phosphorylation was not necessary for B19V DNA replication. Thus, this report provides evidence that B19V uses the cellular DNA replication machinery for viral DNA replication.IMPORTANCEHuman parvovirus B19 (B19V) infection can cause transient aplastic crisis, persistent viremia, and pure red cell aplasia. In fetuses, B19V infection can result in nonimmune hydrops fetalis and fetal death. These clinical manifestations of B19V infection are a direct outcome of the death of human erythroid progenitors that host B19V replication. B19V infection induces a DNA damage response that is important for cell cycle arrest at late S phase. Here, we analyzed dynamic changes in cellular gene expression and found that DNA metabolic processes are tightly regulated during B19V infection. Although genes involved in cellular DNA replication were downregulated overall, the cellular DNA replication machinery was tightly associated with the replicating single-stranded DNA viral genome and played a critical role in viral DNA replication. In contrast, the DNA damage response-induced phosphorylated forms of RPA32 were dispensable for viral DNA replication.

scholarly journals Human Parvovirus B19 Infection Causes Cell Cycle Arrest of Human Erythroid Progenitors at Late S Phase That Favors Viral DNA Replication

2013 ◽  
Vol 87 (23) ◽  
pp. 12766-12775 ◽  
Author(s):  
Yong Luo ◽  
Steve Kleiboeker ◽  
Xuefeng Deng ◽  
Jianming Qiu
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Dna Content ◽  
Parvovirus B19 ◽  
S Phase ◽  
Human Parvovirus B19 ◽  
Viral Dna ◽  
Viral Dna Replication ◽  
Cycle Arrest ◽  
Cellular Dna

Human parvovirus B19 (B19V) infection has a unique tropism to human erythroid progenitor cells (EPCs) in human bone marrow and the fetal liver. It has been reported that both B19V infection and expression of the large nonstructural protein NS1 arrested EPCs at a cell cycle status with a 4 N DNA content, which was previously claimed to be “G2/M arrest.” However, a B19V mutant infectious DNA (M20mTAD2) replicated well in B19V-semipermissive UT7/Epo-S1 cells but did not induce G2/M arrest (S. Lou, Y. Luo, F. Cheng, Q. Huang, W. Shen, S. Kleiboeker, J. F. Tisdale, Z. Liu, and J. Qiu, J. Virol.86:10748–10758, 2012). To further characterize cell cycle arrest during B19V infection of EPCs, we analyzed the cell cycle change using 5-bromo-2′-deoxyuridine (BrdU) pulse-labeling and DAPI (4′,6-diamidino-2-phenylindole) staining, which precisely establishes the cell cycle pattern based on both cellular DNA replication and nuclear DNA content. We found that although both B19V NS1 transduction and infection immediately arrested cells at a status of 4 N DNA content, B19V-infected 4 N cells still incorporated BrdU, indicating active DNA synthesis. Notably, the BrdU incorporation was caused neither by viral DNA replication nor by cellular DNA repair that could be initiated by B19V infection-induced cellular DNA damage. Moreover, several S phase regulators were abundantly expressed and colocalized within the B19V replication centers. More importantly, replication of the B19V wild-type infectious DNA, as well as the M20mTAD2mutant, arrested cells at S phase. Taken together, our results confirmed that B19V infection triggers late S phase arrest, which presumably provides cellular S phase factors for viral DNA replication.

scholarly journals Temporal Regulation of the Mre11-Rad50-Nbs1 Complex during Adenovirus Infection

2009 ◽  
Vol 83 (9) ◽  
pp. 4565-4573 ◽  
Author(s):  
Kasey A. Karen ◽  
Peter J. Hoey ◽  
C. S. H. Young ◽  
Patrick Hearing
Keyword(s):  
Dna Damage ◽  
Dna Replication ◽  
Dna Damage Response ◽  
Adenovirus Infection ◽  
Viral Dna ◽  
Terminal Protein ◽  
Viral Dna Replication ◽  
Mrn Complex ◽  
Viral Dnas ◽  
Damage Response

ABSTRACT Adenovirus infection induces a cellular DNA damage response that can inhibit viral DNA replication and ligate viral genomes into concatemers. It is not clear if the input virus is sufficient to trigger this response or if viral DNA replication is required. Adenovirus has evolved two mechanisms that target the Mre11-Rad50-Nbs1 (MRN) complex to inhibit the DNA damage response. These include E4-ORF3-dependent relocalization of MRN proteins and E4-ORF6/E1B-55K-dependent degradation of MRN components. The literature suggests that degradation of the MRN complex due to E4-ORF6/E1B-55K does not occur until after viral DNA replication has begun. We show that, by the time viral DNA accumulates, the MRN complex is inactivated by either of the E4-induced mechanisms and that, with E4-ORF6/E1B-55K, this inactivation is due to MRN degradation. Our data are consistent with the conclusion that input viral DNA is sufficient to induce the DNA damage response. Further, we demonstrate that when the DNA damage response is active in E4 mutant virus infections, the covalently attached terminal protein is not cleaved from viral DNAs, and the viral origins of replication are not detectably degraded at a time corresponding to the onset of viral replication. The sequences of concatemeric junctions of viral DNAs were determined, which supports the conclusion that nonhomologous end joining mediates viral DNA ligation. Large deletions were found at these junctions, demonstrating nucleolytic procession of the viral DNA; however, the lack of terminal protein cleavage and terminus degradation at earlier times shows that viral genome deletion and concatenation are late effects.

scholarly journals Widespread Phosphorylation of Histone H2AX by Species C Adenovirus Infection Requires Viral DNA Replication

2009 ◽  
Vol 83 (12) ◽  
pp. 5987-5998 ◽  
Author(s):  
Gena J. Nichols ◽  
Jerome Schaack ◽  
David A. Ornelles
Keyword(s):  
Dna Replication ◽  
Effector Proteins ◽  
Adenovirus Infection ◽  
Dna Breaks ◽  
H2ax Phosphorylation ◽  
Viral Dna ◽  
Viral Dna Replication ◽  
Histone H2ax ◽  
Infected Cells ◽  
Cellular Dna

ABSTRACT Adenovirus infection activates cellular DNA damage response and repair pathways. Viral proteins that are synthesized before viral DNA replication prevent recognition of viral genomes as a substrate for DNA repair by targeting members of the sensor complex composed of Mre11/Rad50/NBS1 for degradation and relocalization, as well as targeting the effector protein DNA ligase IV. Despite inactivation of these cellular sensor and effector proteins, infection results in high levels of histone 2AX phosphorylation, or γH2AX. Although phosphorylated H2AX is a characteristic marker of double-stranded DNA breaks, this modification was widely distributed throughout the nucleus of infected cells and was coincident with the bulk of cellular DNA. H2AX phosphorylation occurred after the onset of viral DNA replication and after the degradation of Mre11. Experiments with inhibitors of the serine-threonine kinases ataxia telangiectasia mutated (ATM), AT- and Rad3-related (ATR), and DNA protein kinase (DNA-PK), the kinases responsible for H2AX phosphorylation, indicate that H2AX may be phosphorylated by ATR during a wild-type adenovirus infection, with some contribution from ATM and DNA-PK. Viral DNA replication appears to be the stimulus for this phosphorylation event, since infection with a nonreplicating virus did not elicit phosphorylation of H2AX. Infected cells also responded to high levels of input viral DNA by localized phosphorylation of H2AX. These results are consistent with a model in which adenovirus-infected cells sense and respond to both incoming viral DNA and viral DNA replication.

scholarly journals The large nonstructural protein (NS1) of the human bocavirus 1 (HBoV1) directly interacts with Ku70, which plays an important role in virus replication in human airway epithelia

2021 ◽  
Author(s):  
Liting Shao ◽  
Kang Ning ◽  
Jianke Wang ◽  
Fang Cheng ◽  
Shengqi Wang ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Replication ◽  
Dna Damage Response ◽  
Nonstructural Protein ◽  
Direct Interaction ◽  
Human Bocavirus ◽  
Viral Dna ◽  
Viral Dna Replication ◽  
Human Airway ◽  
Damage Response

Human bocavirus 1 (HBoV1), an autonomous human parvovirus, causes acute respiratory tract infections in young children. HBoV1 infects well-differentiated (polarized) human airway epithelium cultured at an air-liquid interface (HAE-ALI). HBoV1 expresses a large nonstructural protein, NS1, that is essential for viral DNA replication. HBoV1 infection of polarized human airway epithelial cells induces a DNA damage response (DDR) that is critical to viral DNA replication involving DNA repair with error-free Y-family DNA polymerases. HBoV1 NS1 or the isoform NS1-70 per se induces a DDR. In this study, using the second-generation proximity-dependent biotin identification (BioID2) approach, we identified that Ku70 is associated with the NS1-BioID2 pulldown complex through a direct interaction with NS1. Bio-layer Interferometry (BLI) assay determined a high binding affinity of the NS1 with Ku70, which has an equilibrium dissociation constant (K D ) value of 0.16 μM and processes the strongest interaction at the C-terminal domain. The association of Ku70 with NS1 was also revealed during HBoV1 infection of HAE-ALI. Knockdown of Ku70 and overexpression of the C-terminal domain of Ku70 significantly decreased HBoV1 replication in HAE-ALI. Thus, our study provides for the first time a direct interaction of a parvovirus large nonstructural protein NS1 with Ku70. IMPORTANCE Parvovirus infection induces a DNA damage response (DDR) that plays a pivotal role in viral DNA replication. The DDR includes activation of ATM (Ataxia telangiectasia mutated), ATR (ATM- and RAD3-related), and DNA-PKcs (DNA-dependent protein kinase catalytic subunit). The large nonstructural protein (NS1) often plays a role in the induction of DDR; however, how the DDR is induced during parvovirus infection or simply by the NS1 is not well studied. Activation of DNA-PKcs has been shown as one of the key DDR pathways in DNA replication of HBoV1. We identified that HBoV1 NS1 directly interacts with Ku70, but not Ku80, of the Ku70/Ku80 heterodimer at a high affinity. This interaction is also important for HBoV1 replication in HAE-ALI. We propose that the interaction of the NS1 with Ku70 recruits the Ku70/Ku80 complex to the viral DNA replication center, which activates DNA-PKcs and facilitates viral DNA replication.

scholarly journals Adenovirus E1B 55-Kilodalton Protein Targets SMARCAL1 for Degradation during Infection and Modulates Cellular DNA Replication

2019 ◽  
Vol 93 (13) ◽  
Author(s):  
Reshma Nazeer ◽  
Fadi S. I. Qashqari ◽  
Abeer S. Albalawi ◽  
Ann Liza Piberger ◽  
Maria Teresa Tilotta ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Replication ◽  
Viral Replication ◽  
Signaling Pathways ◽  
Dna Damage Response ◽  
Replication Fork ◽  
Dependent Manner ◽  
Damage Response ◽  
Adenovirus E1b ◽  
Cellular Dna

ABSTRACT Here, we show that the cellular DNA replication protein and ATR substrate SMARCAL1 is recruited to viral replication centers early during adenovirus infection and is then targeted in an E1B-55K/E4orf6- and cullin RING ligase-dependent manner for proteasomal degradation. In this regard, we have determined that SMARCAL1 is phosphorylated at S123, S129, and S173 early during infection in an ATR- and CDK-dependent manner, and that pharmacological inhibition of ATR and CDK activities attenuates SMARCAL1 degradation. SMARCAL1 recruitment to viral replication centers was shown to be largely dependent upon SMARCAL1 association with the RPA complex, while Ad-induced SMARCAL1 phosphorylation also contributed to SMARCAL1 recruitment to viral replication centers, albeit to a limited extent. SMARCAL1 was found associated with E1B-55K in adenovirus E1-transformed cells. Consistent with its ability to target SMARCAL1, we determined that E1B-55K modulates cellular DNA replication. As such, E1B-55K expression initially enhances cellular DNA replication fork speed but ultimately leads to increased replication fork stalling and the attenuation of cellular DNA replication. Therefore, we propose that adenovirus targets SMARCAL1 for degradation during infection to inhibit cellular DNA replication and promote viral replication. IMPORTANCE Viruses have evolved to inhibit cellular DNA damage response pathways that possess antiviral activities and utilize DNA damage response pathways that possess proviral activities. Adenovirus has evolved, primarily, to inhibit DNA damage response pathways by engaging with the ubiquitin-proteasome system and promoting the degradation of key cellular proteins. Adenovirus differentially regulates ATR DNA damage response signaling pathways during infection. The cellular adenovirus E1B-55K binding protein E1B-AP5 participates in ATR signaling pathways activated during infection, while adenovirus 12 E4orf6 negates Chk1 activation by promoting the proteasome-dependent degradation of the ATR activator TOPBP1. The studies detailed here indicate that adenovirus utilizes ATR kinase and CDKs during infection to promote the degradation of SMARCAL1 to attenuate normal cellular DNA replication. These studies further our understanding of the relationship between adenovirus and DNA damage and cell cycle signaling pathways during infection and establish new roles for E1B-55K in the modulation of cellular DNA replication.

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