The protein encoded by this gene mediates leucine-rich nuclear export signal (NES)-dependent protein transport. Exportin 1 specifically inhibits the nuclear export of Rev and U snRNAs. It is involved in the control of several cellular processes by controlling the localization of cyclin B, MPAK, and MAPKAP kinase 2. This protein also regulates NFAT and AP-1. [provided by RefSeq, Jul 2008]