Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.1.21 (thymidine kinase)
 7,561 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A transient assay system was used to identify varicella-zoster virus (VZV)-encoded genes whose products are able to activate the expression of an early gene promoter, the thymidine kinase (tk) promoter, and a late gene promoter, and the glycoprotein I (gpI) promoter. Vero cells were cotransfected with individual cloned DNA fragments spanning the entire VZV genome and with the recombinant construct p1tkCAT which contained the chloramphenicol acetyl transferase (CAT) gene under the control of putative regulatory sequences. Five- to 20-fold increases in the expression p1tkCAT was observed in cotransfections with plasmids containing VZV open reading frame (ORF)4 (map location 0.02-0.03) or ORF62 (0.82-0.86). Expression of p68CAT (contains -682 to +222 bp relative to the AUG of gpI) was also enhanced by the products of ORF4 and ORF62. Synergy between ORF4 and ORF62 products was observed in the activation of p68CAT, resulting in a 22-fold increase in CAT activity. RNA analysis indicated that activation of these promoters was at the transcriptional level. A VZV-encoded "repressor" sequence, containing ORF60 and ORF61, was also identified which repressed expression of p1tkCAT and modulated its activation by ORF4 and ORF62.
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PMID:Mapping of two varicella-zoster virus-encoded genes that activate the expression of viral early and late genes. 255 48

Transient expression assays were performed in Vero cells in order to compare varicella-zoster virus (VZV)-encoded trans-activating proteins [defined by the products of open reading frames (ORF) 4 and 62] with herpes simplex virus type-1 (HSV-1) trans-activating proteins, ICP4 and ICP0, with respect to activation of gene expression. We demonstrate that the product of VZV ORF4 and ORF62 (which are the HSV-1 analogs of ICP27 and ICP4, respectively) stimulate a variety of viral and cellular gene promoters, including the HSV-1 thymidine kinase (tk) promoter. On the other hand, expression of a recombinant vector containing the VZV tk promoter could not be stimulated, by HSV-1 infection or by the HSV-1 ICP4 or ICP0 proteins expressed during cotransfection experiments. These data suggest different mechanisms of activation of the VZV and the HSV-1 tk gene promoters by "trans-activating" factors.
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PMID:Differential regulation by varicella-zoster virus (VZV) and herpes simplex virus type-1 trans-activating genes. 255 49