scholarly journals Cellular DNA Ligase I Is Recruited to Cytoplasmic Vaccinia Virus Factories and Masks the Role of the Vaccinia Ligase in Viral DNA Replication

2009 ◽  
Vol 6 (6) ◽  
pp. 563-569 ◽  
Author(s):  
Nir Paran ◽  
Frank S. De Silva ◽  
Tatiana G. Senkevich ◽  
Bernard Moss
Keyword(s):  
Dna Replication ◽  
Vaccinia Virus ◽  
Dna Ligase ◽  
Viral Dna ◽  
Viral Dna Replication ◽  
Dna Ligase I ◽  
Cellular Dna

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.

Immunological characterization of the role of adenovirus terminal protein in viral DNA replication

Virology ◽  
1983 ◽  
Vol 131 (2) ◽  
pp. 287-295 ◽  
Author(s):  
A.W.M. Rijnders ◽  
B.G.M. Van Bergen ◽  
P.C. Van Der Vliet ◽  
J.S. Sussenbach
Keyword(s):  
Dna Replication ◽  
Viral Dna ◽  
Terminal Protein ◽  
Viral Dna Replication ◽  
Immunological Characterization

scholarly journals Kaposi's Sarcoma-Associated Herpesvirus-Encoded Protein Kinase and Its Interaction with K-bZIP

2006 ◽  
Vol 81 (3) ◽  
pp. 1072-1082 ◽  
Author(s):  
Yoshihiro Izumiya ◽  
Chie Izumiya ◽  
Albert Van Geelen ◽  
Don-Hong Wang ◽  
Kit S. Lam ◽  
...  
Keyword(s):  
Dna Replication ◽  
Protein Kinase ◽  
Viral Protein ◽  
Kaposi's Sarcoma ◽  
Kaposi’S Sarcoma ◽  
Viral Transcription ◽  
Viral Dna ◽  
Viral Dna Replication ◽  
Kaposi’S Sarcoma Associated Herpesvirus

ABSTRACT The oncogenic herpesvirus, Kaposi's sarcoma-associated herpesvirus, also identified as human herpesvirus 8, contains genes producing proteins that control transcription and influence cell signaling. Open reading frame 36 (ORF36) of this virus encodes a serine/threonine protein kinase, which is designated the viral protein kinase (vPK). Our recent efforts to elucidate the role of vPK in the viral life cycle have focused on identifying viral protein substrates and determining the effects of vPK-mediated phosphorylation on specific steps in viral replication. The vPK gene was transcribed into 4.2-kb and 3.6-kb mRNAs during the early and late phases of viral reactivation. vPK is colocalized with viral DNA replication/transcription compartments as marked by a polymerase processivity factor, and K-bZIP, a protein known to bind the viral DNA replication origin (Ori-Lyt) and to regulate viral transcription. The vPK physically associated with and strongly phosphorylated K-bZIP at threonine 111, a site also recognized by the cyclin-dependent kinase Cdk2. Both K-bZIP and vPK were corecruited to viral promoters targeted by K-bZIP as well as to the Ori-Lyt region. Phosphorylation of K-bZIP by vPK had a negative impact on K-bZIP transcription repression activity. The extent of posttranslational modification of K-bZIP by sumoylation, a process that influences its repression function, was decreased by vPK phosphorylation at threonine 111. Our data thus identify a new role of vPK as a modulator of viral transcription.

scholarly journals The Vaccinia Virus I3L Gene Product Is Localized to a Complex Endoplasmic Reticulum-Associated Structure That Contains the Viral Parental DNA

2003 ◽  
Vol 77 (10) ◽  
pp. 6014-6028 ◽  
Author(s):  
Sonja Welsch ◽  
Laura Doglio ◽  
Sibylle Schleich ◽  
Jacomine Krijnse Locker
Keyword(s):  
Endoplasmic Reticulum ◽  
Dna Replication ◽  
Vaccinia Virus ◽  
Gene Product ◽  
Close Association ◽  
Viral Dna ◽  
Mrna Accumulation ◽  
Double Labeling ◽  
Viral Dna Replication ◽  
Early Protein

ABSTRACT The vaccinia virus (VV) I3L gene product is a single-stranded DNA-binding protein made early in infection that localizes to the cytoplasmic sites of viral DNA replication (S. C. Rochester and P. Traktman, J. Virol. 72:2917-2926, 1998). Surprisingly, when replication was blocked, the protein localized to distinct cytoplasmic spots (A. Domi and G. Beaud, J. Gen. Virol. 81:1231-1235, 2000). Here these I3L-positive spots were characterized in more detail. By using an anti-I3L peptide antibody we confirmed that the protein localized to the cytoplasmic sites of viral DNA replication by both immunofluorescence and electron microscopy (EM). Before replication had started or when replication was inhibited with hydroxyurea or cytosine arabinoside, I3L localized to distinct cytoplasmic punctate structures of homogenous size. We show that these structures are not incoming cores or cytoplasmic sites of VV early mRNA accumulation. Instead, morphological and quantitative data indicate that they are specialized sites where the parental DNA accumulates after its release from incoming viral cores. By EM, these sites appeared as complex, electron-dense structures that were intimately associated with the cellular endoplasmic reticulum (ER). By double labeling of cryosections we show that they contain DNA and a viral early protein, the gene product of E8R. Since E8R is a membrane protein that is able to bind to DNA, the localization of this protein to the I3L puncta suggests that they are composed of membranes. The results are discussed in relation to our previous data showing that the process of viral DNA replication also occurs in close association with the ER.

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