Hepatitis C virus E1 protein induces modification of membrane permeability in E. coli cells

The E1 gene of hepatitis C virus (HCV) has been cloned and expressed in BL21(DE3)pLys Escherichia coli strain by pET3a vector to analyze changes in membrane permeability produced by this protein. We showed that the expression of E1 (aa 192-383), as well as of two C-terminal fragments (aa 331-383 and aa 341-383) corresponding to the transmembrane (TM) region of this protein, induced a rapid lysis of cells. On the contrary, the expression of a mutant of E1 (aa 192-340), lacking the last 40 amino acids, did not cause cell lysis. The analysis of permeability changes revealed that modification of membrane permeability to several compounds were observed only in clones expressing E1 and C-terminal fragments, while the synthesis of the C-terminal-deleted mutant had little or no effect on permeability. These findings demonstrate that the TM domain of E1 protein has membrane-active properties that may be involved in some aspects of virus-cell interaction.