Nucleocytoplasmic transporter involved in the nuclear export of microRNAs (miRNAs). Required for several miRNAs accumulation. Specifically required for miR156 accumulation which targets SPL3, SPL4 and SPL5 transcription factors. Involved in plant development through its role in miRNAs processing. Required for vegetative phase change and vegetative to reproductive phase transition. Functionally dependent on RAN1 binding. Does not seem to be involved in small interfering RNAs (siRNAs) processing. Interacts with RAN1. Nuclear periphery. Expressed in roots, leaves and floral buds. Reduced size of roots and shoot lateral organs. Accelerated vegetative phase change. Increased adaxial trichome density. Disruption of phyllotaxis of the inflorescence. Reduced fertility. Reduced levels of several miRNAs and increased levels of their targeted transcripts. Belongs to the exportin family.