Structural requirements for pre-microRNA binding and nuclear export by Exportin 5.
Journal Article (Journal Article)
The biogenesis and function of mature human microRNAs is dependent on the nuclear export of pre-microRNA precursors by Exportin 5 (Exp5). The precursor for the human miR-30 microRNA, which is a 63 nt long RNA hairpin bearing a 2 nt 3' overhang, forms a specific complex with Exp5 and the Ran-GTP cofactor. Here, we have examined the structural requirements for pre-microRNA binding by Exp5. Our data indicate that pre-miR-30 binding requires an RNA stem of >16 bp and is facilitated by a 3' overhang. Although a blunt-ended derivative of the pre-miR-30 stem-loop remained capable of binding Exp5, 5' overhangs were inhibitory. miR-30 variants that had lost the ability to bind Exp5 effectively were not efficiently exported from the nucleus and were also expressed at reduced levels. Furthermore, formation of a pre-microRNA/Exp5/Ran-GTP complex inhibited exonucleolytic digestion of the pre-miRNA in vitro. Together, these data demonstrate that pre-microRNA binding by Exp5 involves recognition of almost all of the RNA hairpin, with the exception of the terminal loop. Moreover, these results argue that Exp5 binding not only mediates pre-microRNA nuclear export but also prevents nuclear pre-microRNA degradation.
Full Text
Duke Authors
Cited Authors
- Zeng, Y; Cullen, BR
Published Date
- 2004
Published In
Volume / Issue
- 32 / 16
Start / End Page
- 4776 - 4785
PubMed ID
- 15356295
Pubmed Central ID
- PMC519115
Electronic International Standard Serial Number (EISSN)
- 1362-4962
Digital Object Identifier (DOI)
- 10.1093/nar/gkh824
Language
- eng
Conference Location
- England