Transcriptional activation of gammaherpesviral oncogene promoters by the hepatitis B viral X protein (HBx).
The latent membrane protein-1 (LMP1) of Epstein-Barr Virus (EBV), saimiri transformation protein (STP) of Herpesvirus saimiri (HVS), and K1 protein of Kaposi's sarcoma-associated herpesvirus (KSHV) are potent gammaherpesvirus oncogenes. To study the possible effects of double viral infection, we investigated the effects of oncogenic early proteins of DNA viruses E1A and E1B (adenovirus-5), E6 and E7 (human papillomavirus-16), HBx (hepatitis B virus), Tag (SV40), and gammaherpesviral oncogene during co-infection in human B-lymphoma (Ramos) and human T-cell leukemia (Jurkat) cell lines. HBx transactivated the promoters of LMP1, STP, and K1 the most, by about six-, three-, and twofold, respectively. Analyses of site-directed mutation and the heterologous promoter system showed that HBx activated the promoter activity of these genes via the NF-kappaB site. These results suggest that HBV (HBx) infection of cells previously infected by gammaherpesviruses transactivates their oncogenes, resulting in possible virus-related disease pathogenesis.
Assogba
Barnabe Dossou
BD
Indang Institute of Molecular Biology, Inje University, Seoul 100-032, Korea.
Paik
Nak Whan
NW
Rho
Hyune Mo
HM
D018142:Gammaherpesvirinae / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D019169:Jurkat Cells; D016328:NF-kappa B / Q000378:metabolism; D009856:Oncogene Proteins, Viral / Q000235:genetics*; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000378:metabolism; D015534:Trans-Activators / Q000378:metabolism*; D015533:Transcriptional Activation; D054334:Viral Regulatory and Accessory Proteins
D016328:NF-kappa B; D009856:Oncogene Proteins, Viral; D012333:RNA, Messenger; D015534:Trans-Activators; D054334:Viral Regulatory and Accessory Proteins; C057628:hepatitis B virus X protein