Effect of Staurosporine on the Intracellular Localization of Hepatitis B Virus Core Protein

Abstract

protein is also including in the HBV genome targeting into the nucleus through modulating carboxyl residues by
phosphorylation. Nuclear localication Signal (NLS) in HBV core protein is inside the virion structure and it must be
unmasked in order to function, perhaps by phosphorylation. Phosphorylation of of HBV core protein in turn could
begin to alter capsid conformation. Staurosporine is a natural product originally isolated from bacterium
Streptomyces staurosporeus. Staurosporine was discovered to have biological activities ranging from anti-fungal to
anti-hypertensive. The interest in these activities resulted in a large investigative effort in chemistry and biology and
the discovery of the potential for anti-cancer treatment. The main biological activity of Staurosporine is the inhibition
of protein kinases through the prevention of ATP binding to the kinase. In the present study, we have studied the
intracellular localization of EGFP-Core fusion protein with triple HBV core and SV-40 nuclear localization signal at
its carboxyl terminal in presence and absence of Staurosporine. We also to study the effect of Staurosporine treatment
on the intracellular localization of EGFP-Core fusion protein in the hepatocyte cells line of HepG2 cell. Results
showed that effect of Staurosporine is prevent the nuclear localization of EGFP-Core fusion protein into nucleus
through an inhibition of the phosphorylation of core protein. Stauroporine also prevents cell division so that passive
trapping of core protein is inhibited.