Exportin 4

A member of the importin β family

General Information

Exportin 4, also referred to as exp4 and XPO4, is a member of the importin β family comprising importins and exportins. These receptor proteins shuttle between the nucleus and the cytoplasm, interact with nuclear pore complexes and bind cargo molecules. Exportin 4 is highly conserved in higher euykaryotes and has been shown to mediate the nuclear export of eIF-5A (eukaryotic translation initiation factor 5A) and Smad 3.
In a recent screen for tumor suppressors an exportin 4 knock-down led to increased tumorigenesis. In addition re-expression of this protein in the exportin 4 deficient cell-line SK-Hep1 efficiently suppressed proliferation.