KPNA2 belongs to the karyopherin alpha family. KPNA2 has a vital part in the nuclear import of proteins with a conventional nuclear localization signal (NLS).
In vitro, KPNA2 bound specifically and directly to substrates having a simple or bipartite NLS motif. KPNA2 stimulated docking of import substrates to the nuclear envelope and together with Ran reconstituted complete nuclear protein import.