Transcriptional activation of the promoter of human cytomegalovirus immediate early gene (CMV-IE) by the hepatitis B viral X protein (HBx) through the NF-kappaB site.
The reactivation of latent cytomegalovirus (CMV) in a human by another viral infection may induce virus-related symptoms. Based on this presumption, we investigated the effect of HBx on the activation of the CMV-IE, which is also known as a transactivator and potential oncogene. The HBx transactivated the CMV-IE promoter by up to 4- and 18-fold factors in human liver HepG2 and lung fibroblast MRC-5 cells, respectively. Cotransfection of HBx with each transcription factor presented in the CMV-IE promoter showed that only NF-kappaB synergistically activated the promoter by up to a 14-fold factor. Serial deletion assays and point mutation analysis showed that the third NF-kappaB site (nt -267 to -258) and the second one (nt -162 to -153) appeared as the major responsible site and minor one, respectively, for the transactivation. These results suggest the possibility that the HBV infection of a cell previously infected by CMV would exert influence on the reactivation of the latent cytomegalovirus in a human to induce virus-related symptoms.
Assogba
Barnabe Dossou
BD
Department of Molecular Biology and Research, School of Biological Sciences, Seoul National University, 151-742 Seoul, South Korea.
Choi
Byung Hyune
BH
Rho
Hyune Mo
HM
D001665:Binding Sites; D003587:Cytomegalovirus / Q000235:genetics*; D006515:Hepatitis B virus / Q000378:metabolism*; D006801:Humans; D017874:Immediate-Early Proteins / Q000235:genetics*; D016328:NF-kappa B / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D015534:Trans-Activators / Q000378:metabolism*; D015533:Transcriptional Activation; D014407:Tumor Cells, Cultured; D014764:Viral Proteins; D054334:Viral Regulatory and Accessory Proteins
C088645:IE1 protein, cytomegalovirus; D017874:Immediate-Early Proteins; D016328:NF-kappa B; D015534:Trans-Activators; D014764:Viral Proteins; D054334:Viral Regulatory and Accessory Proteins; C057628:hepatitis B virus X protein