Study of viral nuclear transport: system based on the ''Fluorescence Resonance Energy Transfer'' (FRET)

Background Most DNA viruses replicate inside the nucleus. In nondividing cells the viral genome enters the nucleus via the nuclear pores. Nuclear import of viral genomes is an active process, which is mediated by a variety of different nuclear localization signals (NLS), being exposed on the surface of genome-associated proteins. Knowledge on viral nuclear transport is very limited as the quantitative impact of the attached viral proteins is often restricted. In cellulo experiments are frequently impaired by the different expression levels of the analyzed proteins making it difficult to quantify the import reaction.