The IE2 gene products of human cytomegalovirus specifically down-regulate expression from the major immediate-early promoter through a target sequence located near the cap site.

摘要: The 82-kDa IE2 protein of human cytomegalovirus (HCMV) acts as both a powerful nonspecific trans activator heterologous promoters and negative autoregulator HCMV immediate-early gene expression in transient assays. We show here that the highly specific down-regulation effect occurs permissive diploid fibroblast cells well nonpermissive Vero target sequences are conserved within major simian cytomegalovirus. response were localized between -67 +30 IE94 promoter upstream position +9 IE68 promoter. Deletion downstream -14 IE68-CAT abolished phenotype resulted reporter was stimulated instead inhibited by cotransfection with effector DNA. Insertion an oligonucleotide containing from -17 into deletion construction restored autoregulation either orientation. Furthermore, this same transferred full when inserted at +10 nonresponsive IE175 herpes simplex virus. Therefore, signal DNA level must lie these boundaries. Additional analysis oligonucleotides deletions or point mutations revealed essential components positions -12 +5. systems resembles for virus 40 large T antigen acting through located near cap site, but sequence itself bears no resemblance to those utilized other viral systems.