In eukaryotic cells, the nuclear genome and its transcriptional apparatus is separated from the site of protein synthesis by the nuclear envelope. Thus, a constant flow of proteins and nucleic acids has to cross the nuclear envelope in both directions. This transport in and out of the nucleus is mediated by nuclear pore complexes (NPCs) and occurs in an energy and signal-dependent manner. Thus, nucleocytoplasmic translocation of macro- molecules across the nuclear envelope appears to be a highly specific and regulated process. Viruses that replicate their genome in the cell nucleus are...

In eukaryotic cells, the nuclear genome and its transcriptional apparatus is separated from the site of protein synthesis by the nuclear envelope. Thus, a constant flow of proteins and nucleic acids has to cross the nuclear envelope in both directions. This transport in and out of the nucleus is mediated by nuclear pore complexes (NPCs) and occurs in an energy and signal-dependent manner. Thus, nucleocytoplasmic translocation of macro- molecules across the nuclear envelope appears to be a highly specific and regulated process. Viruses that replicate their genome in the cell nucleus are...