An early regulatory function required in a cell type-dependent manner is expressed by the genomic but not the cDNA copy of the herpes simplex virus 1 gene encoding infected cell protein 0.
An early regulatory function required in a cell type-dependent manner is expressed by the genomic but not the cDNA copy of the herpes simplex virus 1 gene encoding infected cell protein 0.
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细胞类型依赖性方式所需的早期调节功能由编码受感染细胞蛋白 0 的单纯疱疹病毒 1 基因的基因组而不是 cDNA 拷贝表达。
DOI：
10.1128/jvi.76.19.9744-9755.2002
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发表时间：
2002
影响因子：
5.4
通讯作者：
Roizman,Bernard
中科院分区：
文献类型：
--
作者：
Poon,AlicePW;Silverstein,SaulJ;Roizman,Bernard
The α0 genes of herpes simplex virus 1 (HSV-1) contain three exons. Earlier studies have shown that the substitution of genomic sequences with a cDNA copy does not alter the capacity of the virus to replicate or establish latent infection. Other studies have demonstrated that HSV-1 may express alternatively spliced forms of α0 transcripts. The studies reported here centered on a mutant HSV-1(vCPc0) strain in which the genomic copies of the α0 gene were replaced with cDNA copies. From our research, we report the following observations. (i) In contrast to events transpiring in cells infected with wild-type virus, the expression of HSV-1(vCPc0) genes was delayed or restricted to α genes for many hours in rabbit skin cells and to a lesser extent in HEp-2 cells but not in Vero cells. This delay in the expression of HSV-1(vCPc0) β or γ genes was also multiplicity of infection dependent. (ii) Exposure to MG132, a proteasomal inhibitor, before infection with wild-type virus had no significant effect on the accumulation of viral proteins in Vero cells and caused an only slight delay in viral gene expression in rabbit skin cells in a multiplicity of infection-dependent fashion. The drug had no effect when it was added to the medium 3 h after infection. (iii) Rabbit skin or HEp-2 cells exposed to MG132 3 h after infection with the HSV-1(vCPc0) mutant accumulated only α proteins. This restriction was cell type dependent but not multiplicity of infection dependent. (iv) Both the delay in the expression of β and γ genes and the effect of MG132 added to the medium 3 h after infection were rescued by restoration of the intron 1 sequences in the HSV-1(vCPc0) mutant. However, cells transduced by baculoviruses expressing intron 1 RNA did not complement the HSV-1(vCPc0) mutant, suggesting that the function of intron 1 is incisrather than intrans. We came to the following conclusions as a result. (i) Post-α gene expression requires the involvement of the proteasomal pathway in a cell type-dependent manner. Consistent with this requirement, the proapoptotic functions of MG132 are blocked in cells infected before exposure to the drug but not after exposure. (ii) A function encoded by the α0 gene that is absent from the cDNA copy is required for viral gene expression in a cell type- and multiplicity of infection-dependent fashion. The absence of this master function delays but does not ultimately block viral gene expression in the cell lines tested here.
