Hepetitis C Virus Non-Structural Protein NS5A Interacts With USF2

Hepatitis C Virus(HCV) is a major causative agent for public health problem worldwide.Infection of HCV often leads to chronic hepatitis,which may progress to liver cirrhosis,liver dysfunction and hepatocellular carcinoma.The understanding of the mechanism for HCV pathogenesis so far is still limited.A growing number of evidence has shown that the interactions between viral proteins and host cellular proteins may play an important role in HCV pathogenesis.Among the stuctural and non-structural proteins,the non-structural protin5A NS5A has been paid extensive attention.A number of studies have demonstrated that NS5A play various roles in cellular signal transduction,protein trafficking,anti-apoptosis and other cellular events,most of which may ultimately result in persistent viral infection.To gain further insight into the molecular mechanism,we screened ahuman fetal liver cDNA library to find out its cellar partners and their physiological functions.We show that NS5A is a key factor for the assembly of infectious HCV particles.We specifically identify the C-terminal domain Ⅱ,Ⅲ as the primary determinant in NS5A for particle formation.We have understood the interaction between NS5A domain Ⅱ-Ⅲ and USF2by yeast two-hybrid system screening the human liver cDNA library,considering the importance of physiological function of the two proteins,we have performance GST pulldown and co-IP,but the result cannot suggested that NS5A domain Ⅱ-Ⅲ can interact with USF2,we need the other experientments to proof it.