The tRNA exporter in vertebrates is called exportin-t. Exportin-t binds directly to its tRNA cargo in the nucleus, a process promoted by the presence of RanGTP. Mutations that affect tRNA's structure inhibit its ability to bind to exportin-t, and consequentially, to be exported, providing the cell with another quality control step.[1] As described above, once the complex has crossed the envelope it dissociates and releases the tRNA cargo into the cytosol.