MicroRNA precursors in motion: exportin-5 mediates their nuclear export

Abstract

The discovery of microRNAs (miRNAs) has changed the paradigm of gene regulation, leaving us with numerous exciting questions regarding what these molecules do and how they originate. A model for miRNA biogenesis has emerged recently, yet several key factors - including the identity of the miRNA nuclear export receptor remained unknown. However, recent studies have shown that exportin-5 (Exp5), a Ran-dependent importin-p-related transport receptor, mediates nuclear export of miRNA precursors (pre-miRNAs).