Importin 11 functions in nuclear protein import as nuclear transport receptor. It serves as receptor for nuclear localization signals (NLS) in cargo substrates, and is thought to mediate docking of the importin/substrate complex to the nuclear pore complex (NPC) through binding to nucleoporin and the complex is subsequently translocated through the pore by an energy requiring, Ran-dependent mechanism. At the nucleoplasmic side of the NPC, Ran binds to the importin, the importin/substrate complex dissociates and importin is re-exported from the nucleus to the cytoplasm where GTP hydrolysis releases Ran. The directionality of nuclear import is thought to be conferred by an asymmetric distribution of the GTP- and GDP-bound forms of Ran between the cytoplasm and nucleus (By similarity). Importin 11/IPO11 mediates the nuclear import of UBE2E3, and of RPL12 (By similarity) [taken from the Universal Protein Resource (UniProt) www.uniprot.org/uniprot/Q9UI26].