The nuclear export receptor CRM1/XPO1 and its diverse cargoes

CRM1 (Exportin 1, XPO1), the best-characterized nuclear export receptor, exports hundreds of proteins and various RNA species. Its broad cargo repertoire necessitates versatile binding modes for diverse interaction partners, including nuclear export signal/sequence (NES)-containing cargoes, the GTPase Ran, nucleoporins that line nuclear pore complexes, and accessory proteins that facilitate export complex assembly or disassembly. We review the current knowledge of CRM1's protein and RNA cargoes and examine its modes of interactions in the context of the basic mechanism of nuclear export - NES recognition, recent structural studies that reveal how CRM1 engages cargoes beyond NESs, and allosteric regulation. Finally, we touch on the state of NES/cargo prediction, CRM1's interactions with nucleoporins, and its emerging roles beyond nuclear export.