Construction and characterization of herpes simplex type 1 viruses without introns in immediate early gene 1

Everett, Roger D.

doi:10.1099/0022-1317-72-3-651

Cited by 22 publications

(20 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As expected, expression was completely blocked in the presence of cycloheximide. The inhibition of expression by PAA is consistent with previous observations that ICP0 is efficiently expressed late in infection, presumably from replicated molecules (6), and the observation that significant template amplification had occurred by 4 h p.i. (Fig.…”

Section: Vol 79 2005supporting

confidence: 79%

Circularization of the Herpes Simplex Virus Type 1 Genome upon Lytic Infection

Strang

Stow

2005

J Virol

View full text Add to dashboard Cite

For many years, the generally accepted model for the replication of the double-stranded DNA genome of herpes simplex virus type 1 (HSV-1) incorporated initial circularization of linear molecules in the cell nucleus. Ensuing DNA synthesis resulted in the generation of head-to-tail concatemers which were subsequently cleaved into monomeric units and packaged into the nascent viral capsid. Recently, however, it has been proposed that circularization of HSV-1 genomes does not occur at the onset of lytic infection and moreover that this event is specifically inhibited by the HSV-1 transcriptional transactivator, ICP0 (S.A. Jackson and N.A. DeLuca, Proc. Natl. Acad. Sci. USA 100:7871-7876, 2003). To further investigate genome circularization, we have generated HSV-1 derivatives in which the viral a sequences, which contain the cleavage-packaging signals, have been replaced by a minimal packaging element located in the thymidine kinase gene. In contrast to wild-type HSV-1, fusion of the genomic termini of these viruses produces a novel fragment in circular or concatemeric DNA which can be detected by Southern blot hybridization. Utilizing these viruses, we demonstrate that fusion of the genomic termini occurred rapidly upon infection and in the presence of inhibitors of viral DNA or protein synthesis. We provide evidence indicating that the end joining represented circularization rather than concatemerization of input molecules and that circularized molecules functioned as templates for replication. Since the termini of these viruses lack direct repeats, our findings indicate that circularization can be mediated by direct end-to-end ligation of linear input genomes.Herpes simplex virus type 1 (HSV-1), the prototype virus of the family Herpesviridae, possesses a linear double-stranded DNA genome of approximately 153 kbp and is widely used as a model for the study of herpesvirus DNA replication and recombination. Like those of other members of the herpesvirus family, the HSV-1 genome is characterized by the presence of unique and repeated sequences (Fig. 1a). Two covalently joined segments, L and S, each comprise a unique region (U L and U S ) flanked by a set of inverted repeats (TR L and IR L , TR S and IR S , respectively). A region of approximately 400 bp, the a sequence, is present as a direct repeat at the genomic termini and in an inverted orientation at the junction between the L and S segments. The L and S segments of the genome have the capacity to invert relative to each other at high frequency, resulting in the appearance of four equimolar isomeric forms of virion DNA (reviewed in reference 35).Following infection, the HSV-1 genome is released into the nucleus and may either be retained in a latent state or enter into the lytic cycle (reviewed in reference 32). During the establishment of latency in both in vivo and tissue culture systems, the ends of the viral genome become joined, and there is now strong evidence for persistence as a nonreplicating circular episomal form (5,17,18,27,32,34,42). The lytic cyc...

show abstract

Section: Vol 79 2005supporting

confidence: 79%

Circularization of the Herpes Simplex Virus Type 1 Genome upon Lytic Infection

Strang

Stow

2005

J Virol

View full text Add to dashboard Cite

show abstract

“…Thus in conclusion we can state that the structure proposed for the HSV-2 HG52 RL1 gene is correct but like the situation in IE1 (Everett, 1991) deletion of the intron has no apparent effect on the phenotype of the virus. The implication of the RL1 gene being spliced in HSV-2 but not -1 is unclear especially with regards to the presence of an ORF P homologue in HSV-2 strain HG52.…”

mentioning

confidence: 84%

Functional analysis of the herpes simplex virus type 2 strain HG52 RL1 gene: the intron plays no role in virulence.

Ravi

Kennedy

Maclean

1998

Journal of General Virology

View full text Add to dashboard Cite

“…The third line of evidence that ICP0 is a determinant for the initiation of viral gene expression emerged from studies designed initially to determine whether the cDNA of ICP0 could replace the genomic variant. Viruses carrying the cDNA copy were made by two laboratories, and both reported that the cDNA viruses were capable of replication, establishment of latency, and reactivation (35,115,119). A closer examination of one of these mutants revealed that they resembled the wild-type virus in all but one peculiar characteristic.…”

Section: Icp0 Genome Organization and Initiation Of Viral Gene Exprmentioning

confidence: 99%

Role of ICP0 in the Strategy of Conquest of the Host Cell by Herpes Simplex Virus 1

Hagglund

Roizman

2004

J Virol

202

187

View full text Add to dashboard Cite

In early studies, herpes simplex virus 1 (HSV-1) proteins were identified on the basis of two criteria. The first consisted of characterization of proteins contained in virions purified from cells whose proteins were labeled prior to infection. These proteins designated by the prefix VP were numbered in the order of decreasing apparent molecular weight or, conversely, ascending electrophoretic mobility in denaturing gels (147). The second criterion identified putative viral proteins accumulating in infected cells but absent from uninfected cells. These proteins, designated infected-cell proteins (ICPs), were also numbered in order of decreasing apparent molecular weight (73). One protein, however, while clearly apparent only in infected cells, varied with respect to electrophoretic mobility depending on the composition of the denaturing gel (74). This anomalously migrating protein was designated ICP0 (74). In subsequent studies, viral proteins were designated either by their known primary function (e.g., DNA polymerase, etc.) or the position of the gene along the unique long (U L ) or short (U S ) components of the viral genome (105, 107). The original ICP designation, however, was retained primarily for five proteins recognized in early studies as being the products of ␣ or immediate-early genes expressed after infection in the absence of de novo viral protein synthesis (74, 75). The five proteins, ICP0, ICP4, ICP22, ICP27, and ICP47, have been extensively studied, and for the most part, there is at least a semblance of concordance between the phenotype of cells infected with the mutant lacking the gene, the behavior of the protein in transduced cells, and the molecular functions expressed by the protein (reviewed in reference 132). ICP4 is an essential positive and negative regulator of gene expression (reviewed in reference 132). The protein blocks gene expression by binding to high-affinity DNA consensus sites located at transcription initiation sites of at least two genes. The mechanism of gene activation is less understood, although ICP4's affinity for transcription factors and binding to highly degenerate or nonconsensus sites are suggestive of how it might act. ICP27 is also a multifunctional protein whose phenotype can be largely explained by its ability to block RNA splicing but not transport of unspliced RNA early in infection and by its activity as a chaperone of newly made viral mRNA across the nuclear membranes at late times after infection (reviewed in reference 137).Available data indicate that the carboxyl-terminal half of ICP22 enables full expression of a subset of late (␥ 2 ) viral genes by causing cdc2 cyclin-dependent kinase activity to survive the degradation of its physiologic partners cyclins A and B, by an aberrant partnership with the U L 42 DNA polymerase processivity factor (2,5,6,19,141). Optimal transcription of late genes requires binding and posttranslational modification of topoisomerase II␣ by the two proteins (7). The sole known mission of ICP47 is to bind to and preclude TAP1...

show abstract

Construction and characterization of herpes simplex type 1 viruses without introns in immediate early gene 1

Cited by 22 publications

References 32 publications

Circularization of the Herpes Simplex Virus Type 1 Genome upon Lytic Infection

Circularization of the Herpes Simplex Virus Type 1 Genome upon Lytic Infection

Functional analysis of the herpes simplex virus type 2 strain HG52 RL1 gene: the intron plays no role in virulence.

Role of ICP0 in the Strategy of Conquest of the Host Cell by Herpes Simplex Virus 1

Contact Info

Product

Resources

About