GTP-binding protein involved in nucleocytoplasmic transport. Required for the import of protein into the nucleus and also for RNA export. Involved in chromatin condensation and control of cell cycle (By similarity). Found in a nuclear export complex with RanGTP, exportin and pre-miRNA (By similarity). Interacts with RanBP1a and RanBP1b (PubMed:9025305). Interacts with KPNB1 (PubMed:23582042). Induced by salt treatment. Regulated by light. Belongs to the small GTPase superfamily. Ran family.