The alpha 0 genes of @entity3307 ) 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 @entity281 . Other studies have demonstrated that @entity3307 may express alternatively spliced forms of alpha 0 transcripts. The studies reported here centered on a mutant @entity3307 (vCPc0) strain in which the genomic copies of the alpha 0 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 @entity3307 (vCPc0) genes was delayed or restricted to alpha genes for many hours in @entity95 skin cells and to a lesser extent in HEp-2 cells but not in Vero cells. This delay in the expression of @entity3307 (vCPc0) beta or gamma genes was also multiplicity of @entity281 dependent. (ii) Exposure to @entity16626 , a proteasomal inhibitor, before @entity281 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 @entity95 skin cells in a multiplicity of @entity281 -dependent fashion. The drug had no effect when it was added to the medium 3 h after @entity281 . (iii) @entity95 skin or HEp-2 cells exposed to @entity16626 3 h after @entity281 with the @entity3307 (vCPc0) mutant accumulated only alpha proteins. This restriction was cell type dependent but not multiplicity of @entity281 dependent. (iv) Both the delay in the expression of beta and gamma genes and the effect of @entity16626 added to the medium 3 h after @entity281 were rescued by restoration of the intron 1 sequences in the @entity3307 (vCPc0) mutant. However, cells transduced by baculoviruses expressing intron 1 RNA did not complement the @entity3307 (vCPc0) mutant, suggesting that the function of intron 1 is in cis rather than in trans. We came to the following conclusions as a result. (i) Post-alpha gene expression requires the involvement of the proteasomal pathway in a cell type-dependent manner. Consistent with this requirement, the proapoptotic functions of @entity16626 are blocked in cells infected before exposure to the drug but not after exposure. (ii) A function encoded by the alpha 0 gene that is absent from the cDNA copy is required for viral gene expression in a cell type- and multiplicity of @entity281 -dependent fashion. The absence of this master function delays but does not ultimately block viral gene expression in the cell lines tested here.

An early regulatory function required in a cell type-dependent manner is expressed by the genomic but not the cDNA copy of the XXXX gene encoding infected cell protein 0.

@entity281 :: ('MESH:D007239', 'Disease') :: ['infection', 'latent infection'] @entity16626 :: ('MESH:C072553', 'Chemical') :: ['MG132'] @entity3307 :: ('10298', 'Species') :: ['herpes simplex virus 1 (HSV-1', 'HSV-1'] @entity95 :: ('9986', 'Species') :: ['rabbit', 'Rabbit']
@entity3307 :: (10298,Species) :: ['herpes simplex virus 1']
