scholarly journals Transcription Program of Red Sea Bream Iridovirus as Revealed by DNA Microarrays

2005 ◽  
Vol 79 (24) ◽  
pp. 15151-15164 ◽  
Author(s):  
Dang Thi Lua ◽  
Motoshige Yasuike ◽  
Ikuo Hirono ◽  
Takashi Aoki

ABSTRACT Red sea bream iridovirus (RSIV) has been identified as the causative agent of a serious disease in red sea bream and at least 30 other marine fish species. We developed a viral DNA microarray containing 92 putative open reading frames of RSIV to monitor the viral gene transcription program over the time course of an in vitro infection and to classify RSIV transcripts into temporal kinetic expression classes. The microarray analysis showed that viral genes commenced expression as early as 3 h postinfection (p.i.) and this was followed by a rapid escalation of gene expression from 8 h p.i. onwards. Based on the expression of some enzymes associated with viral DNA replication, the DNA replication of RSIV appeared to begin at around 8 h p.i. in infected cells in vitro. Using a de novo protein synthesis inhibitor (cycloheximide) and a viral DNA replication inhibitor (phosphonoacetic acid), 87 RSIV transcripts could be classified into three temporal kinetic classes: nine immediate-early (IE), 40 early (E), and 38 late (L) transcripts. The gene expression of RSIV occurred in a temporal kinetic cascade with three stages (IE, E, and L). Although the three classes of transcripts were distributed throughout the RSIV genome, E transcripts appeared to cluster in at least six discrete regions and L transcripts appeared to originate from seven discrete regions. The microarray data were statistically confirmed by using a t test, and were also clustered into groups based on similarity in the gene expression patterns by using a cluster program.

2019 ◽  
Vol 94 (2) ◽  
Author(s):  
Xiaomei Wang ◽  
Peng Xu ◽  
Fang Cheng ◽  
Yi Li ◽  
Zekun Wang ◽  
...  

ABSTRACT Human bocavirus 1 (HBoV1), which belongs to the genus Bocaparvovirus of the Parvoviridae family, causes acute respiratory tract infections in young children. In vitro, HBoV1 infects polarized primary human airway epithelium (HAE) cultured at an air-liquid interface (HAE-ALI). HBoV1 encodes a small nonstructural protein, nuclear protein 1 (NP1), that plays an essential role in the maturation of capsid protein (VP)-encoding mRNAs and viral DNA replication. In this study, we determined the broad interactome of NP1 using the proximity-dependent biotin identification (BioID) assay combined with mass spectrometry (MS). We confirmed that two host mRNA processing factors, DEAH-box helicase 15 (DHX15) and cleavage and polyadenylation specificity factor 6 (CPSF6; also known as CFIm68), a subunit of the cleavage factor Im complex (CFIm), interact with HBoV1 NP1 independently of any DNA or mRNAs. Knockdown of CPSF6 significantly decreased the expression of capsid protein but not that of DHX15. We further demonstrated that NP1 directly interacts with CPSF6 in vitro and colocalizes within the virus replication centers. Importantly, we revealed a novel role of CPSF6 in the nuclear import of NP1, in addition to the critical role of CPSF6 in NP1-facilitated maturation of VP-encoding mRNAs. Thus, our study suggests that CPSF6 interacts with NP1 to escort NP1 imported into the nucleus for its function in the modulation of viral mRNA processing and viral DNA replication. IMPORTANCE Human bocavirus 1 (HBoV1) is one of the significant pathogens causing acute respiratory tract infections in young children worldwide. HBoV1 encodes a small nonstructural protein (NP1) that plays an important role in the maturation of viral mRNAs encoding capsid proteins as well as in viral DNA replication. Here, we identified a critical host factor, CPSF6, that directly interacts with NP1, mediates the nuclear import of NP1, and plays a role in the maturation of capsid protein-encoding mRNAs in the nucleus. The identification of the direct interaction between viral NP1 and host CPSF6 provides new insights into the mechanism by which a viral small nonstructural protein facilitates the multiple regulation of viral gene expression and replication and reveals a novel target for potent antiviral drug development.


Aquaculture ◽  
2019 ◽  
Vol 512 ◽  
pp. 734283 ◽  
Author(s):  
Tran Nguyen Duy Khoa ◽  
Viliame Waqalevu ◽  
Akinobu Honda ◽  
Kazuhiro Shiozaki ◽  
Tomonari Kotani

2016 ◽  
Vol 91 (3) ◽  
Author(s):  
Filomena Grosso ◽  
Peter Stoilov ◽  
Clifford Lingwood ◽  
Martha Brown ◽  
Alan Cochrane

ABSTRACT The dependence of adenovirus on the host pre-RNA splicing machinery for expression of its complete genome potentially makes it vulnerable to modulators of RNA splicing, such as digoxin and digitoxin. Both drugs reduced the yields of four human adenoviruses (HAdV-A31, -B35, and -C5 and a species D conjunctivitis isolate) by at least 2 to 3 logs by affecting one or more steps needed for genome replication. Immediate early E1A protein levels are unaffected by the drugs, but synthesis of the delayed protein E4orf6 and the major late capsid protein hexon is compromised. Quantitative reverse transcription-PCR (qRT-PCR) analyses revealed that both drugs altered E1A RNA splicing (favoring the production of 13S over 12S RNA) early in infection and partially blocked the transition from 12S and 13S to 9S RNA at late stages of virus replication. Expression of multiple late viral protein mRNAs was lost in the presence of either drug, consistent with the observed block in viral DNA replication. The antiviral effect was dependent on the continued presence of the drug and was rapidly reversible. RIDK34, a derivative of convallotoxin, although having more potent antiviral activity, did not show an improved selectivity index. All three drugs reduced metabolic activity to some degree without evidence of cell death. By blocking adenovirus replication at one or more steps beyond the onset of E1A expression and prior to genome replication, digoxin and digitoxin show potential as antiviral agents for treatment of serious adenovirus infections. Furthermore, understanding the mechanism(s) by which digoxin and digitoxin inhibit adenovirus replication will guide the development of novel antiviral therapies. IMPORTANCE Despite human adenoviruses being a common and, in some instances, life-threating pathogen in humans, there are few well-tolerated therapies. In this report, we demonstrate that two cardiotonic steroids already in use in humans, digoxin and digitoxin, are potent inhibitors of multiple adenovirus species. A synthetic derivative of the cardiotonic steroid convallotoxin was even more potent than digoxin and digitoxin when tested with HAdV-C5. These drugs alter the cascade of adenovirus gene expression, acting after initiation of early gene expression to block viral DNA replication and synthesis of viral structural proteins. These findings validate a novel approach to treating adenovirus infections through the modulation of host cell processes.


2007 ◽  
Vol 81 (19) ◽  
pp. 10699-10711 ◽  
Author(s):  
Malen A. Link ◽  
Priscilla A. Schaffer

ABSTRACT Two in-frame, C-terminal isoforms of the herpes simplex virus type 1 (HSV-1) origin binding protein (OBP), OBPC-1 and OBPC-2, and a unique C-terminal transcript, UL8.5, are specified by HSV-1 DNA. As the first isoform identified, OBPC-1 was initially assumed to be the product of the UL8.5 transcript. Recent evidence has demonstrated, however, that OBPC-1 is a cathepsin B-mediated cleavage product of OBP, suggesting that OBPC-2 is the product of the UL8.5 transcript. Because both OBPC-1 and -2 contain the majority of the OBP DNA binding domain, we hypothesized that both may be involved in regulating origin-dependent, OBP-mediated viral DNA replication. In this paper, we demonstrate that OBPC-2 is, indeed, the product of the UL8.5 transcript. The translational start site of OBPC-2 was mapped, and a virus (M571A) that does not express this protein efficiently was constructed. Using M571A, we have shown that OBPC-2 is able to bind origin DNA, even though it lacks seven N-terminal amino acid residues of the previously mapped OBP DNA binding domain, resulting in a revision of the limits of the OBP DNA binding domain. Consistent with their proposed roles in regulating viral DNA replication, OBPC-1 and -2 act together to down-regulate viral DNA replication in vitro. During functional studies in vivo, OBPC-2 was identified as a factor that increases mortality in the mouse ocular model of HSV-1 infection.


Aquaculture ◽  
2016 ◽  
Vol 464 ◽  
pp. 8-16 ◽  
Author(s):  
Md. Sakhawat Hossain ◽  
Shunsuke Koshio ◽  
Manabu Ishikawa ◽  
Saichiro Yokoyama ◽  
Nadia Mahjabin Sony ◽  
...  

mBio ◽  
2014 ◽  
Vol 5 (4) ◽  
Author(s):  
Zhipeng Yan ◽  
Kevin F. Bryant ◽  
Sean M. Gregory ◽  
Magdalena Angelova ◽  
David H. Dreyfus ◽  
...  

ABSTRACTThe catalytic site of the HIV integrase is contained within an RNase H-like fold, and numerous drugs have been developed that bind to this site and inhibit its activity. Herpes simplex virus (HSV) encodes two proteins with potential RNase H-like folds, the infected cell protein 8 (ICP8) DNA-binding protein, which is necessary for viral DNA replication and exhibits recombinase activityin vitro, and the viral terminase, which is essential for viral DNA cleavage and packaging. Therefore, we hypothesized that HIV integrase inhibitors might also inhibit HSV replication by targeting ICP8 and/or the terminase. To test this, we evaluated the effect of 118-D-24, a potent HIV integrase inhibitor, on HSV replication. We found that 118-D-24 inhibited HSV-1 replication in cell culture at submillimolar concentrations. To identify more potent inhibitors of HSV replication, we screened a panel of integrase inhibitors, and one compound with greater anti-HSV-1 activity, XZ45, was chosen for further analysis. XZ45 significantly inhibited HSV-1 and HSV-2 replication in different cell types, with 50% inhibitory concentrations that were approximately 1 µM, but exhibited low cytotoxicity, with a 50% cytotoxic concentration greater than 500 µM. XZ45 blocked HSV viral DNA replication and late gene expression. XZ45 also inhibited viral recombination in infected cells and ICP8 recombinase activityin vitro. Furthermore, XZ45 inhibited human cytomegalovirus replication and induction of Kaposi’s sarcoma herpesvirus from latent infection. Our results argue that inhibitors of enzymes with RNase H-like folds may represent a general antiviral strategy, which is useful not only against HIV but also against herpesviruses.IMPORTANCEThe herpesviruses cause considerable morbidity and mortality. Nucleoside analogs have served as effective antiviral agents against the herpesviruses, but resistance can arise through viral mutation. Second-line anti-herpes drugs have limitations in terms of pharmacokinetic properties and/or toxicity, so there is a great need for additional drugs for treatment of herpesviral infections. This study showed that the HIV integrase inhibitors also block herpesviral infection, raising the important potential of a new class of anti-herpes drugs and the prospect of drugs that combat both HIV and the herpesviruses.


2010 ◽  
Vol 84 (12) ◽  
pp. 6153-6162 ◽  
Author(s):  
Mei Yu ◽  
Eric B. Carstens

ABSTRACT Autographa californica multiple nucleopolyhedrovirus (AcMNPV) lef-3 is one of nine genes required for viral DNA replication in transient assays. LEF-3 is predicted to contain several domains related to its functions, including nuclear localization, single-strand DNA binding, oligomerization, interaction with P143 helicase, and interaction with a viral alkaline nuclease. To investigate the essential nature of LEF-3 and the roles it may play during baculovirus DNA replication, a lef-3 null bacmid (bKO-lef3) was constructed in Escherichia coli and characterized in Sf21 cells. The results showed that AcMNPV lef-3 is essential for DNA replication, budded virus production, and late gene expression in vivo. Cells transfected with the lef-3 knockout bacmid produced low levels of early proteins (P143, DNA polymerase, and early GP64) and no late proteins (P47, VP39, or late GP64). To investigate the functional role of domains within the LEF-3 open reading frame in the presence of the whole viral genome, plasmids expressing various LEF-3 truncations were transfected into Sf21 cells together with bKO-lef3 DNA. The results showed that expression of AcMNPV LEF-3 amino acids 1 to 125 was sufficient to stimulate viral DNA replication and to support late gene expression. Expression of Choristoneura fumiferana MNPV lef-3 did not rescue any LEF-3 functions. The construction of a LEF-3 amino acid 1 to 125 rescue bacmid revealed that this region of LEF-3, when expressed in the presence of the rest of the viral genome, stimulated viral DNA replication and late and very late protein expression, as well as budded virus production.


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