Abstract
MicroRNAs (miRNAs) are initially expressed as long transcripts that are processed in the nucleus to yield approximately 65-nucleotide (nt) RNA hairpin intermediates, termed pre-miRNAs, that are exported to the cytoplasm for additional processing to yield mature, approximately 22-nt miRNAs. Here, we demonstrate that human pre-miRNA nuclear export, and miRNA function, are dependent on Exportin-5. Exportin-5 can bind pre-miRNAs specifically in vitro, but only in the presence of the Ran-GTP cofactor. Short hairpin RNAs, artificial pre-miRNA analogs used to express small interfering RNAs, also depend on Exportin-5 for nuclear export. Together, these findings define an additional cellular cofactor required for miRNA biogenesis and function.
Publication types
- Research Support, Non-U.S. Gov't
- Research Support, U.S. Gov't, P.H.S.
MeSH terms
- Active Transport, Cell Nucleus
- Cell Line
- Cell Nucleus / genetics
- Cell Nucleus / metabolism*
- Electrophoretic Mobility Shift Assay
- Humans
- Karyopherins / genetics
- Karyopherins / metabolism*
- Luciferases / metabolism
- MicroRNAs / genetics
- MicroRNAs / metabolism*
- Plasmids
- Promoter Regions, Genetic
- RNA / chemistry*
- RNA / metabolism*
- RNA Interference
- RNA Precursors / genetics
- RNA Precursors / metabolism
- RNA Processing, Post-Transcriptional*
- RNA, Messenger / genetics
- RNA, Messenger / metabolism
- ran GTP-Binding Protein / metabolism
Substances
- Karyopherins
- MicroRNAs
- RNA Precursors
- RNA, Messenger
- XPO5 protein, human
- RNA
- Luciferases
- ran GTP-Binding Protein