Receptor for the leucine-rich nuclear export signal (NES). Binds cooperatively to the NES on its target protein and to the small GTPase Ran in its active GTP-bound form (PubMed:10652141, PubMed:16766674). Required for the maternal-to-embryonic transition and during gametophyte development (PubMed:18791220). Involved in heat-induced oxidative stress basal resistance (PubMed:20345641). Interacts with RAN1. Expressed ubiquitously, with higher levels in stems, inflorescences and roots (PubMed:10652141, PubMed:20345641). Present in mature pollen grains, unpollinated pistils, and 2-week-old seedlings (PubMed:18791220). Gametophyte defective when both XPO1A and XPO1B are disrupted. Abnormal pollen germination and tube growth, impaired female gametophyte development and embryo lethal (PubMed:18791220). Impaired ability to withstand moderate heat stress (37 degrees Celsius). Enhanced sensitivity to methyl viologen (MV)-induced oxidative stress (PubMed:20345641). Belongs to the exportin family.