 Once inside the nucleus, interaction with Ran-GTP causes a conformational change in the importin that causes it to dissociate from its cargo.The resulting complex of importin and Ran-GTP then translocates to the cytoplasm, where a protein called Ran Binding Protein (RanBP) separates Ran-GTP from importin.Separation allows access to a GTPase activating protein (GAP) that binds Ran-GTP and induces the hydrolysis of GTP to GDP.