Cytosolic YB-1 and NSUN2 are the only proteins recognizing specific motifs present in mRNAs enriched in exosomes.

Exosomes, membranous vesicles secreted by various cells, are involved in intercellular communication and carry vast repertoires of RNAs and proteins. Processes mediating RNA sorting into exosomes are currently poorly understood. Using bioinformatics approaches, three structural motifs ACCAGCCU, CAGUGAGC and UAAUCCCA have been discovered as enriched in exosomal mRNAs and long noncoding RNAs.