ATP-Binding Cassette Transporters/chemistry; Active Transport, Cell Nucleus/physiology; Carrier Proteins/chemistry; Nuclear Pore/chemistry; Nuclear Proteins/chemistry; Nucleocytoplasmic Transport Proteins; RNA, Messenger/metabolism; ATP Binding Cassette Transporter, Subfamily B, Member 2; ATP-Binding Cassette Transporters/metabolism; Amino Acid Sequence; Animals; Binding Sites; Carrier Proteins/genetics; Carrier Proteins/metabolism; Crystallography, X-Ray; Dimerization; Humans; Models, Molecular; Molecular Sequence Data; Mutagenesis, Site-Directed; Nuclear Pore/metabolism; Nuclear Proteins/genetics; Nuclear Proteins/metabolism; Protein Binding; Protein Structure, Tertiary; RNA, Messenger/genetics; Recombinant Fusion Proteins/genetics; Recombinant Fusion Proteins/metabolism; Sequence Alignment; ran GTP-Binding Protein/metabolism