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.