Interferon-inducible ribonuclease ISG20 inhibits hepatitis B virus replication through directly binding to the epsilon stem-loop structure of viral RNA
HepG2 cells were transfected with pHBV1.3 and equal amount of control vector (lanes 1 & 2) or F-ISG20 (lanes 3 & 4) or F-ISG20D94G (lanes 5 & 6). Cells were harvested 5 days post-transfection and levels of HBV RNA (1st panel from the top) and encapsidated pgRNA (4th panel from the top) were determined by Northern blot hybridization. The assembled HBV capsid was revealed by native capsid gel EIA assay (3rd panel from the top) and the viral DNA in capsid was detected in situ by hybridization (5th panel from the top). HBV core DNA replicative intermediates were extracted and analyzed by Southern blot (6th panel from the top). Expression of FLAG-tagged ISG20 proteins was revealed by Western blot and β-actin served as loading control (bottom two panels). Results from duplicate experiments are presented.