Enables Hsp90 protein binding activity; importin-alpha family protein binding activity; and nuclear import signal receptor activity. Acts upstream of or within ribosomal protein import into nucleus. Located in cytoplasmic stress granule. Part of protein-containing complex. Is expressed in brain; gonad; liver; neural retina; and pancreas. Orthologous to human KPNB1 (karyopherin subunit beta 1). [provided by Alliance of Genome Resources, Apr 2022]