Abstract
Investigation of the intracellular transport of proteins enables us to understand the molecular mechanisms of signal transduction. Using GFP, we studied the characteristics of nuclear export system in plant cells. A series of GFP fusion genes that nuclear export signal (NES) was added to, was transiently expressed in onion epidermal cells. Although both NES from PKIα (NES1) and NES from tomato HsfA2 (NES2) were effective in the export of GFP from the nucleus, NES2 was more effective. We also examined whether the nuclear export of NES-GFP was mediated by NES-protein receptor, exportin. An inhibitor of exportin, leptomycin B, disturbed the nuclear export of NES-GFP fusion proteins, indicating the involvement of exportin. Thus, this system of NES-GFP seems to be useful in study on the intracellular localization of regulatory proteins in the process of signal transduction.
