Hepatitis B virus (HBV) is an enveloped virus and contains a partially double-stranded relaxed circular DNA (RC-DNA) genome. After entry into hepatocytes, HBV RC-DNA is transported to the nucleus and converted into a covalently closed circular molecule cccDNA. The cccDNA is the template for transcription of all viral RNAs including the pregenomic RNA (pgRNA), encoding for 7 viral proteins: large, middle, and small envelope proteins (LHBs, MHBs, and SHBs) that form the surface antigen (HBsAg), the core antigen (HBcAg), the e antigen (HBeAg), the HBV polymerase, and the regulatory protein X (HBx). The pgRNA interacts with the viral polymerase protein to initiate the encapsidation into the core particles. Through endoplasmic reticulum, the core particles finish assembling with the envelope proteins and are released. HBV infection leads to a wide spectrum of liver diseases raging from chronic hepatitis, cirrhosis to hepatocellular carcinoma. The mechanism of liver injury is still not clear. However, HBV proteins target host proteins, involved in a variety of functions, thus regulating transcription, cellular signaling cascades, proliferation, differentiation, and apoptosis.
Murata M, Matsuzaki K, Yoshida K, Sekimoto G, Tahashi Y, Mori S, Uemura Y, Sakaida N, Fujisawa J, Seki T, Kobayashi K, Yokote K, Koike K, Okazaki K
Title
Hepatitis B virus X protein shifts human hepatic transforming growth factor (TGF)-beta signaling from tumor suppression to oncogenesis in early chronic hepatitis B.
Hepatitis B viral HBx induces matrix metalloproteinase-9 gene expression through activation of ERK and PI-3K/AKT pathways: involvement of invasive potential.
Hepatitis B virus polymerase inhibits RIG-I- and Toll-like receptor 3-mediated beta interferon induction in human hepatocytes through interference with interferon regulatory factor 3 activation and dampening of the interaction between TBK1/IKKepsilon and DDX3.
