title: A transcription enhancer in the Herpesvirus saimiri genome.
abstract: Herpesvirus saimiri, an oncogenic agent of New World primates, has a linear double-stranded DNA genome of approximately 155 kb. To test its genome for the presence of a transcription enhancer, we have mixed randomly fragmented H. saimiri DNA with non-infectious, linear SV40 DNA lacking the 72-bp repeat enhancer region (the so-called SV40 enhancer trap) and co-transfected this DNA mixture into monkey CV-1 cells. Viable SV40-like viruses were generated by intracellular ligation/repair processes with short H. saimiri DNA fragments. One recombinant, SVHS-2, had integrated a 377-bp enhancer segment from the righthand region of the H. saimiri genome, 7 kb upstream of DNA sequences encoding an immediate-early mRNA. This enhancer sequence is contained within the non-repetitive portions of the viral genome known to be preserved episomally in all lymphoid tumor cell lines. Further recombinant viruses (SVHS-14, SVHS-7, and SVHS-8) essentially contain subsets of the 377-bp insert. Unlike in the previous enhancer trap experiments, where heterologous enhancers were incorporated without any sequence alterations, SVHS-14 and SVHS-7 have suffered short internal deletions of a very similar segment of the H. saimiri insert. This renders the enhancer more active, implying that the deleted segment, while it may have a role in the herpesvirus infection cycle, exerts a negative effect within the isolated enhancer.
mesh_terms: D000957:Antigens, Viral, Tumor / Q000235:genetics; D001483:Base Sequence; D002872:Chromosome Deletion; D002874:Chromosome Mapping; D004742:Enhancer Elements, Genetic; D005786:Gene Expression Regulation; D005809:Genes, Regulator; D006567:Herpesvirus 2, Saimiriine / Q000235:genetics*; D011995:Recombination, Genetic; D012689:Sequence Homology, Nucleic Acid; D013539:Simian virus 40 / Q000235:genetics; D014158:Transcription, Genetic
chemical_list: D000957:Antigens, Viral, Tumor