Regulation of Multiple Stages of Hepadnavirus Replication by the Carboxyl-Terminal Domain of Viral Core Protein in trans

Abstract

Mutational analyses have suggested that the carboxyl-terminal domain (CTD) of hepadnavirus core protein is critical for viral replication. However, results from mutational analyses are open to alternative interpretations. Also, how CTD affects virus replication remains unclear. In this study, we took an alternative approach to mutagenesis by overexpressing CTD alone in cells replicating the virus with the wild-type core protein to determine the roles of CTD in viral replication. Our results revealed that CTD can inhibit multiple stages of viral replication, and its effects may be mediated at least in part through specific host interactions. They suggest that CTD, or its mimics, may have therapeutic potential. Furthermore, our experimental approach should be broadly applicable as a complement to mutagenesis for studying protein functions and interactions while at the same time providing a means to identify the relevant interacting factors.