scholarly journals The function(s) provided by the adenovirus-specified, DNA-binding protein required for viral late gene expression is independent of the role of the protein in viral DNA replication.

1984 ◽  
Vol 49 (1) ◽  
pp. 35-49 ◽  
Author(s):  
S A Rice ◽  
D F Klessig
1979 ◽  
Vol 29 (1) ◽  
pp. 322-327 ◽  
Author(s):  
D J McCorquodale ◽  
J Gossling ◽  
R Benzinger ◽  
R Chesney ◽  
L Lawhorne ◽  
...  

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.


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.


1976 ◽  
Vol 11 (2) ◽  
pp. 79-95 ◽  
Author(s):  
A. J. Levine ◽  
P. C. van der Vliet ◽  
B. Rosenwirth ◽  
C. Anderson ◽  
J. Rabek ◽  
...  

2007 ◽  
Vol 81 (11) ◽  
pp. 6122-6127 ◽  
Author(s):  
Ilja Quadt ◽  
Jan W. M. van Lent ◽  
Dagmar Knebel-Mörsdorf

ABSTRACT Baculovirus DNA binding protein (DBP) binds preferentially single-stranded DNA in vitro and colocalizes with viral DNA replication sites. Here, its putative role as viral replication factor has been addressed by RNA interference. Silencing of DBP in Autographa californica multiple nucleopolyhedrovirus-infected cells increased expression of LEF-3, LEF-4, and P35. In contrast, expression of the structural genes coding for P39 and polyhedrin was suppressed while expression of genes coding for P10 and GP64 was unaffected. In the absence of DBP, viral DNA replication sites were formed, indicating replication of viral DNA. Electron microscopy studies, however, revealed a loss of formation of polyhedra and virus envelopment, suggesting that the primary role of DBP is viral formation rather than viral DNA replication.


2001 ◽  
Vol 75 (9) ◽  
pp. 4048-4055 ◽  
Author(s):  
Gerald R. Kovacs ◽  
Nikos Vasilakis ◽  
Bernard Moss

ABSTRACT The B1 gene of vaccinia virus encodes a serine/threonine protein kinase that is expressed early after infection. Under nonpermissive conditions, temperature-sensitive mutants (ts2 andts25) that map to B1 fail to efficiently replicate viral DNA. Our goal was to extend studies on the function of B1 by determining if the kinase is required for intermediate or late gene expression, two events that ordinarily depend on viral DNA replication. First, we established that early viral gene expression occurred at the nonpermissive temperature. By using a transfection procedure that circumvents the viral DNA replication requirement, we found that reporter genes regulated by an intermediate promoter were transcribed only under conditions permissive for expression of active B1. To assay late gene expression, the T7 RNA polymerase gene was inserted into the genome of ts25 to form ts25/T7. A DNA replication-independent late gene transcription system was established by cotransfecting plasmids containing T7 promoter-driven late gene transcription factors and a late promoter reporter gene intots25/T7-infected cells. Late genes, unlike intermediate genes, were expressed at the nonpermissive temperature. Last, we showed that overexpression of B1 stimulated intermediate but inhibited late gene expression in cells infected with wild-type virus.


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