Control of expression of the herpes simplex virus-induced deoxypyrimidine triphosphatase in cells infected with mutants of herpes simplex virus types 1 and 2 and intertypic recombinants

Abstract

Infection of cells with herpes simplex virus type 1 (HSV-1) induces high levels of deoxypyrimidine triphosphatase. The majority of the enzyme activity is found in infected cell nuclei. A similar activity is induced by HSV type 2 (HSV-2) which, in contrast to the HSV-1 enzyme, fractionates to more than 99% in the soluble cytoplasmic extract. Of a series of temperature-sensitive mutants of HSV-1 studied, only the immediate-early mutants in complementation group 1-2 (strain 17 mutants tsD and tsK and strain KOS mutant tsB2) induced reduced levels of triphosphatase at nonpermissive temperature. Of a series of temperature-sensitive mutants of HSV-2 strain HG52, ts9 and tsl3 failed to induce wild-type levels of the enzyme at nonpermissive temperature; ts9 was the most defective mutant with regard to triphosphatase expression of both herpes simplex virus serotypes. After shift-up from permissive to nonpermissive temperature, triphosphatase activity in cells infected with ts9 decreased rapidly, whereas all other mutants continued to exhibit enzyme levels comparable with controls kept at the permissive temperature. The type 1-specific nuclear expression of the triphosphatase was mapped physically by the use of HSV-1 x HSV-2 intertypic recombinants, based on enzyme levels different by more than two orders of magnitude found in nuclei of HSV-1-and HSV-2-infected cells. The locus for the type-specific expression maps between 0.67 and 0.68 fractional length on the HSV genome.

Integrative functional genomics decodes herpes simplex virus 1

“…5g). UL50 dUTPase activity in PRV-infected cells was reported to be nuclear 41 , while it appears to be predominantly cytoplasmic with HSV-2 42 and nearly equally distributed in HSV-1. We conclude that NTEs initiating from non-AUG start codons are common in alphaherpesvirus proteomes.…”

Identification and characterization of pseudorabies virus dUTPase

“…In contrast, bovine herpesvirus 1 dUTPase activity has been shown to be localized mainly in the cytoplasm but was also detectable in the nuclear fraction (17). HSV-1 dUTPase was found in the nucleus, whereas HSV-2 dUTPase appears to be confined to the cytoplasm of infected cells (32). Since all herpesviruses replicate in the nucleus, the significance of these different findings is unknown at present.…”

“…To assay whether PrV UL50 indeed encodes a protein with dUTPase activity (32), confluent monolayers of 2 ϫ 10 7 MDBK cells were infected with either wild-type PrV Ka, PrV UL50 Ϫ , or PrV UL50resc at a multiplicity of infection of 1 or mock infected and incubated for 20 h at 37ЊC. Thereafter, dUTPase activity was assayed in nuclear and cytoplasmic fractions.…”

Kinetic properties and stereospecificity of the monomeric dUTPase from herpes simplex virus type 1

“…Herpesviruses constitute a heterogeneous group; dUTPases encoded by herpesviruses from fish [18, 19]appear to conform to the homotrimeric model. The mammalian herpesviruses [20–26]are monomeric and have in general longer polypeptide chains [27, 28]with a rearranged order of the conserved sequence motifs [29], implying that the three‐dimensional structures of these enzymes are widely different. Therefore, characterization of a dUTPase from a mammalian herpesvirus would be of immediate interest.…”