Hepatitis B viral core protein activates the hepatitis B viral enhancer II/pregenomic promoter through the nuclear factor κB binding site

Abstract

We here demonstrated that the hepatitis B viral (HBV) core protein (HBc) functions as a transcriptional activator on the pregenomic promoter of HBV. Detailed analyses on the HBV pregenomic promoter by serial deletion, mutation, and heterologous promoter system showed that the site responsible for activation was the nuclear factor κB (NF-κB) binding site (GGGACGTACT, nucleotides 1408-1417) upstream of the enhancer II/pregenomic promoter. The electrophoretic mobility shift assay using the HBc-transfected HepG2 nuclear extracts showed that the HBc enhanced the NF-κB DNA-binding ability. These results suggest that the HBc functions as a positive regulator, which may enhance viral replication in hepatocytes.Key words: hepatitis B viral core protein (HBc), transcriptional activation, EnII/Cp, NF-κB.