Functional interaction of varicella zoster virus gene 62 protein with the DNA sequence bound by herpes simplex virus ICP4 protein.

Varicella zoster virus gene 62 protein [defined as the product of open reading frame (ORF)62], like its herpes simplex virus type-1 homolog ICP4 (alpha 4, Vmw175), trans-activates gene expression from the early HSV-1 glycoprotein D promoter. In transient co-transfection assays, trans-activation of gD gene expression by the VZV protein was increased by the presence of cloned alpha 4 binding sites in the promoter. Bacterial extracts containing the 230-amino acid domain of VZV ORF62 homologous to the DNA binding domain of ICP4 (region 2) formed specific complexes with the alpha 4BS DNA sequence. These results indicate that VZV ORF62 protein, like ICP4, binds DNA in a sequence-specific fashion, and the binding may contribute to its mechanism of activation of gene expression.