Hepatitis C virus structural proteins reside in the endoplasmic reticulum as well as in the intermediate compartment/cis-Golgi complex region of stably transfected cells.

The intracellular localization of hepatitis C virus structural proteins was analyzed by confocal immunofluorescence microscopy, cell fractionation, and immunoelectron microscopy in stably transfected cells that do not overexpress the viral proteins. The results strongly suggest that at steady state the structural proteins reside not only in the endoplasmic reticulum but also in the intermediate compartment and cis-Golgi complex region. By analogy with other viral systems, this finding raises the possibility that the intermediate compartment and cis-Golgi complex play a role in the assembly and budding of hepatitis C virus.