Establishment of a new cell line for performing sensitive screening of nuclear export inhibitors

Cell nuclear import and export of proteins are among the most important processes for cellular homeostasis. Viruses, including influenza virus and HIV-1 also utilize nuclear export machinery for their propagation. Therefore, the specific inhibition of nuclear export can be a good target for the development of antiviral drugs. This report documents the establishment of Madin-Darby Canine Kidney (MDCK) cells stably expressing GFP-NES fusion protein for the sensitive screening of novel nuclear export inhibitors. Leptomycin B (LMB), an inhibitor for the interaction between substrate nuclear export signal (NES) and cellular export factor, CRM1, was used for evaluating the screening system. The low concentration (30 pg/mL) and short time treatment (~10 min) of LMB resulted in the nuclear accumulation of GFP fluorescence.