RNA synthesis in polyoma virus-infected cells. I. Pattern of formation of polyribosome-associated messenger RNA during productive infection

1970 ◽  
Vol 48 (10) ◽  
pp. 1104-1112 ◽  
Author(s):  
William P. Cheevers ◽  
Rose Sheinin
Keyword(s):  
Dna Replication ◽  
Messenger Rna ◽  
Rna Synthesis ◽  
Polyoma Virus ◽  
Productive Infection ◽  
Mrna Synthesis ◽  
Viral Dna ◽  
Experimental Conditions ◽  
Embryo Cells ◽  
Infected Cells

Experimental conditions have been established for selective measurement of the synthesis of mRNA in mouse embryo cells. Using such conditions, it was found that productive infection of these cells by polyoma virus resulted in stimulation of mRNA synthesis. The pattern of induction of mRNA synthesis was biphasic, characterized by distinct "early" and "late" periods, as denoted by the time of initiation of progeny viral DNA replication. The formation of "early" mRNA was first detected at 9–11 h postinfection, 6 h prior to the time of onset of virus-induced synthesis of cell DNA and 9 h prior to initiation of polyoma DNA replication. The initiation of synthesis of "late" mRNA was approximately coincident with the onset of formation of viral DNA. Most of the newly synthesized "early" and "late" mRNA was of relatively small size (8–12 S) and was associated with polyribosomes which sedimented at less than 180 S. The proportion of the total "late" mRNA which was virus-specific was three times higher than that of the total "early" mRNA; however, the mRNA synthesized both "early" and "late" was predominantly cell-specific.

Messenger RNA Synthesis in Mumps-Virus-Infected Cells

1980 ◽  
Vol 8 (4) ◽  
pp. 441-442
Author(s):  
BERT K. RIMA ◽  
SAMUEL J. MARTIN
Keyword(s):  
Messenger Rna ◽  
Rna Synthesis ◽  
Mumps Virus ◽  
Infected Cells

scholarly journals Vpr Is Required for Efficient Nef Expression from Unintegrated Human Immunodeficiency Virus Type 1 DNA

2007 ◽  
Vol 81 (19) ◽  
pp. 10515-10523 ◽  
Author(s):  
Betty Poon ◽  
Michael A. Chang ◽  
Irvin S. Y. Chen
Keyword(s):  
Human Immunodeficiency Virus ◽  
Viral Rna ◽  
Productive Infection ◽  
Hiv Replication ◽  
Viral Dna ◽  
Hiv Tat ◽  
Immunodeficiency Virus ◽  
Unintegrated Dna ◽  
Infected Cells

ABSTRACT Unintegrated human immunodeficiency virus (HIV) DNA are viral DNA products formed naturally during HIV replication. While the integrated proviral DNA form is transcriptionally active and results in productive infection, unintegrated DNA is also capable of expression of viral RNA and proteins. Previously, we showed that HIV Vpr enhances expression from integrase-defective HIV. Here we show that Vpr activation of expression is partially dependent upon the presence of a transcriptionally active HIV promoter and results in increased transcription of unspliced gag and spliced nef viral RNA. While Tat is detectable during infection with integrase-defective HIV, Tat levels are not affected by the presence of Vpr. Mutation studies reveal that Tat is dispensable for the Vpr-mediated enhancement of expression from unintegrated DNA. We find that virion-associated Vpr is sufficient for Nef expression from unintegrated viral DNA, resulting in the efficient downregulation of CD4 from the surface of infected cells. These results provide a mechanism by which Nef expression from unintegrated HIV type 1 DNA expression occurs.

Attempts to Find a Specific Intranuclear Location for Replicating Polyoma Virus DNA

1973 ◽  
Vol 51 (9) ◽  
pp. 1225-1228 ◽  
Author(s):  
E. Frost ◽  
P. Bourgaux
Keyword(s):  
Nuclear Membrane ◽  
Mouse Embryo ◽  
Protein Complexes ◽  
Polyoma Virus ◽  
Large Structure ◽  
Viral Dna ◽  
Embryo Cells

Attempts were made to localize the site of replication of polyoma virus DNA in mouse embryo cells. Although newly synthesized viral DNA was clearly confined within the nucleus, no evidence was found to indicate that replication takes place either on the nuclear membrane, or in the nucleolus, or in association with any other large structure. In all nuclear fractions examined, the mature and replicative forms of the viral DNA were found in the same proportions, but as parts of DNA–protein complexes with unique sedimentation properties.

scholarly journals A Dominant-Negative Herpesvirus Protein Inhibits Intranuclear Targeting of Viral Proteins: Effects on DNA Replication and Late Gene Expression

2000 ◽  
Vol 74 (21) ◽  
pp. 10122-10131 ◽  
Author(s):  
Elizabeth E. McNamee ◽  
Travis J Taylor ◽  
David M. Knipe
Keyword(s):  
Gene Expression ◽  
Dna Replication ◽  
Viral Replication ◽  
Gene Transcription ◽  
Dominant Negative ◽  
Late Gene ◽  
Late Gene Expression ◽  
Viral Dna ◽  
Late Genes ◽  
Infected Cells

ABSTRACT The d105 dominant-negative mutant form of the herpes simplex virus 1 (HSV-1) single-stranded DNA-binding protein, ICP8 (d105 ICP8), inhibits wild-type viral replication, and it blocks both viral DNA replication and late gene transcription, although to different degrees (M. Gao and D. M. Knipe, J. Virol. 65:2666–2675, 1991; Y. M. Chen and D. M. Knipe, Virology 221:281–290, 1996). We demonstrate here that this protein is also capable of preventing the formation of intranuclear prereplicative sites and replication compartments during HSV infection. We defined three patterns of ICP8 localization using indirect immunofluorescence staining of HSV-1-infected cells: large replication compartments, small compartments, and no specific intranuclear localization of ICP8. Cells that form large replication compartments replicate viral DNA and express late genes. Cells that form small replication compartments replicate viral DNA but do not express late genes, while cells without viral replication compartments are incapable of both DNA replication and late gene expression. The d105 ICP8 protein blocks formation of prereplicative sites and large replication compartments in 80% of infected cells and formation of large replication compartments in the remaining 20% of infected cells. The phenotype ofd105 suggests a correlation between formation of large replication compartments and late gene expression and a role for intranuclear rearrangement of viral DNA and bound proteins in activation of late gene transcription. Thus, these results provide evidence for specialized machinery for late gene expression within replication compartments.

scholarly journals Transcription of bacteriophage T4 deoxyribonucleic acid in vitro

1969 ◽  
Vol 115 (3) ◽  
pp. 353-361 ◽  
Author(s):  
John O. Bishop ◽  
Forbes W. Robertson
Keyword(s):  
Rna Polymerase ◽  
Messenger Rna ◽  
Rna Synthesis ◽  
Deoxyribonucleic Acid ◽  
Bacteriophage T4 ◽  
Rna Sequences ◽  
Experimental Conditions ◽  
E Coli ◽  
New Methods

1. RNA was synthesized in vitro from a template of bacteriophage T4 DNA, in the presence of Mn2+. A comparison was made of the RNA synthesized by purified RNA polymerase from two sources, Micrococcus lysodeikticus and Escherichia coli; these are referred to as Micrococcus cRNA and E. coli cRNA respectively (where cRNA indicates RNA synthesized in vitro by using purified RNA polymerase and a DNA primer). 2. Both types of RNA were self-complementary as judged by resistance to digestion with ribonuclease after self-annealing, Micrococcus cRNA being more self-complementary (40%) than was E. coli cRNA (30%). The cRNA was found to be much less self-complementary if Mg2+ was present during RNA synthesis instead of Mn2+. 3. Micrococcus cRNA hybridized with a larger part of bacteriophage T4 DNA than did E. coli cRNA. The E. coli cRNA competed with only part (70%) of the Micrococcus cRNA in hybridization-competition experiments. It is concluded that more sequences of bacteriophage T4 DNA are transcribed by Micrococcus polymerase than by E. coli polymerase. 4. The RNA sequences synthesized by Micrococcus RNA polymerase but not by E. coli RNA polymerase are shown by hybridization competition to compete with specifically late bacteriophage T4 messenger RNA sequences. The relevance of this finding to the control of transcription is discussed. 5. In an Appendix, new methods are described for the analysis of hybridization-saturation and -competition experiments. Particular attention is paid to the effects produced if different RNA sequences are present at different relative concentrations. 6. By using cRNA isolated from an enzymically synthesized DNA–RNA hybrid, it is estimated that, of the DNA that is complementary to cRNA, only about half can become hybridized with cRNA under the experimental conditions used.

scholarly journals Autographa californica Multiple Nucleopolyhedrovirus LEF-2 Is a Capsid Protein Required for Amplification but Not Initiation of Viral DNA Replication

2010 ◽  
Vol 84 (10) ◽  
pp. 5015-5024 ◽  
Author(s):  
Carol P. Wu ◽  
Yi-Ju Huang ◽  
Jen-Yeu Wang ◽  
Yueh-Lung Wu ◽  
Huei-Ru Lo ◽  
...  
Keyword(s):  
Dna Replication ◽  
Autographa Californica ◽  
Host Cells ◽  
Growth Curve Analysis ◽  
Late Gene Expression ◽  
Viral Dna ◽  
Viral Dna Replication ◽  
Virus Particles ◽  
Multiple Nucleopolyhedrovirus ◽  
Infected Cells

ABSTRACT The late expression factor 2 gene (lef-2) of baculovirus Autographa californica multiple nucleopolyhedrovirus (AcMNPV) has been identified as one of the factors essential for origin-dependent DNA replication in transient expression assays and has been shown to be involved in late/very late gene expression. To study the function of lef-2 in the life cycle of AcMNPV, lef-2 knockout and repair bacmids were generated by homologous recombination in Escherichia coli. Growth curve analysis showed that lef-2 was essential for virus production. Interestingly, a DNA replication assay indicated that lef-2 is not required for the initiation of viral DNA replication and that, rather, it is required for the amplification of DNA replication. lef-2 is also required for the expression of late and very late genes, as the expression of these genes was abolished by lef-2 deletion. Temporal and spatial distributions of LEF-2 protein in infected cells were also analyzed, and the data showed that LEF-2 protein was localized to the virogenic stroma in the nuclei of the infected cells. Analysis of purified virus particles revealed that LEF-2 is a viral protein component of both budded and occlusion-derived virions, predominantly in the nucleocapsids of the virus particles. This observation suggests that LEF-2 may be required immediately after virus entry into host cells for efficient viral DNA replication.

Electrical conductivity dispersion as a probe of membrane modifications in mouse polyomavirus infected cells in culture

1996 ◽  
Vol 16 (1) ◽  
pp. 41-48 ◽  
Author(s):  
Adalberto Bonincontro ◽  
Anna Iacoangeli ◽  
Gianfranco Risuleo
Keyword(s):  
Electrical Conductivity ◽  
Dna Replication ◽  
Cell Membrane ◽  
Virus Titer ◽  
Experimental Conditions ◽  
Membrane Conductivity ◽  
Cells In Culture ◽  
Infected Cells ◽  
Murine Polyomavirus

In this report we investigate the inhibition of membrane conductivity, due to the murine polyomavirus infection in permissive cells in culture. We define experimental conditions to have reproducible results and demonstrate that the intensity of the effects on the cell membrane, depends upon the virus titer used in the infection. Finally, the virus dependent effects disappear if the infection is performed in the presence of a drug that inhibits polymavirus DNA replication.

scholarly journals Adenovirus Protein VII Functions throughout Early Phase and Interacts with Cellular Proteins SET and pp32

2005 ◽  
Vol 79 (4) ◽  
pp. 2474-2483 ◽  
Author(s):  
Yuming Xue ◽  
Jeffrey S. Johnson ◽  
David A. Ornelles ◽  
Judy Lieberman ◽  
Daniel A. Engel
Keyword(s):  
Dna Replication ◽  
Dna Synthesis ◽  
Chromatin Immunoprecipitation ◽  
Early Phase ◽  
Rna Synthesis ◽  
Dna Binding Protein ◽  
Cellular Proteins ◽  
Viral Dna ◽  
And Function

ABSTRACT Adenovirus protein VII is the major component of the viral nucleoprotein core. It is a highly basic nonspecific DNA-binding protein that condenses viral DNA inside the capsid. We have investigated the fate and function of protein VII during infection. “Input” protein VII persisted in the nucleus throughout early phase and the beginning of DNA replication. Chromatin immunoprecipitation revealed that input protein VII remained associated with viral DNA during this period. Two cellular proteins, SET and pp32, also associated with viral DNA during early phase. They are components of two multiprotein complexes, the SET and INHAT complexes, implicated in chromatin-related activities. Protein VII associated with SET and pp32 in vitro and distinct domains of protein VII were responsible for binding to the two proteins. Interestingly, protein VII was found in novel nuclear dot structures as visualized by immunofluorescence. The dots likely represent individual infectious genomes in association with protein VII. They appeared within 30 min after infection and localized in the nucleus with a peak of intensity between 4 and 10 h postinfection. After this, their intensity decreased and they disappeared between 16 and 24 h postinfection. Interestingly, disappearance of the dots required ongoing RNA synthesis but not DNA synthesis. Taken together these data indicate that protein VII has an ongoing role during early phase and the beginning of DNA replication.

Sign in / Sign up

Export Citation Format

Share Document