Involvement of ribosomal protein L17 and Y-box binding protein 1 in the assembly of hepatitis C virus potentially via their interaction with the 3' untranslated region of the viral genome.

Although basic research on the HCV life cycle has progressed significantly over the past two decades, our understanding of the molecular mechanisms that regulate the process of particle formation, in particular encapsidation of the genome or nucleocapsid assembly, has been limited. We present here, for the first time, that two RNA-binding proteins, RPL17 and YBX1, bind to the 3'X in the 3'UTR of the HCV genome, which potentially acts as a packaging signal, and facilitates the viral particle assembly. Our study revealed that RPL17 and YBX1 exert a positive effect on the interaction between HCV RNA and Core protein, suggesting that the presence of both host factors modulate an RNA structure or conformation suitable for packaging the viral genome. These findings help us to elucidate not only the regulatory mechanism of the particle assembly of HCV but also the function of host RNA-binding proteins during viral infection.