Portland State University. Department of Biology
Term of Graduation
Date of Publication
Master of Science (M.S.) in Biology
Myc oncogenes, Herpes simplex virus, Genetic regulation
1 online resource (v, 99 pages)
The purpose of this investigation was to identify the regulatory elements involved in the transactivation of the human c-myc gene by herpes simplex virus type-1 (HSV-1). This study mainly focused on a major c-myc promoter P2 (Fig. 1). Transient expression assays were carried out with a reporter plasmid, that contained either a wild type (+66wt c-myc) or mutant (+66 mt E2F, +66mt CT -I2) c-myc promoter fused to the chloramphenicol acetyltransferase (CAT) gene, cotransfected with effector plasmids that contained the HSV-1 immediate early (IE) genes ( encoding IE proteins, ICP4, ICP0, ICP27). The transient expression assays revealed that the HSV-1 IE protein, ICP4, was a major effector in transactivation of the human c-myc P2 promoter by HSV-1, and ICPO provided a synergistic effect with ICP4. Cis-acting elements E2F and CT-12, which were potential binding sites for cellular transcription factors E2F and Spl respectively, were shown to be important in HSV-1 induced c-myc transactivation. In addition, these assays indicated that ICPO influences ICP4 mediated activation through these two sites. Electrophoretic mobility shift assays, oligonucleotide competition assays, and footprinting analysis together demonstrated that viral proteins didn't directly interact with P2 promoter region. Three cellular transcription factors, Spl, E2F, and YYl, however, specifically interacted with the P2 promoter region, of which, Spl and its related proteins SpX bound to several other sites in addition of CT-I2 site.
Moreover, SpX also appeared to interact with another cellular factor that bound together with it on the P2 promoter region, and a second unknown cellular factor was also observed to interact with P2 promoter region.
Wu, Xian, "Investigation of Transactivation of the Human C-Myc Gene by Herpes Simplex Virus Type 1" (1997). Dissertations and Theses. Paper 6328.