Nucleic Acids Research Advance Access first published online on September 8, 2006
This version published online on October 6, 2006
Nucleic Acids Research, doi:10.1093/nar/gkl663
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
© 2006 The Author(s)
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/2.0/uk/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
RNA |
Exportin-5 orthologues are functionally divergent among species
1 Department of Cell Biology and Neuroscience, Graduate School of Medicine, Osaka University 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan 2 Biomolecular Networks Laboratories, Biomolecular Dynamics Group, Graduate School of Frontier Biosciences, Osaka University 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan 3 Department of Target Discovery, GeneCare Research Institute 200 Kajiwara, Kamakura, Kanagawa 247-0063, Japan
*To whom correspondence should be addressed. Tel: +81 6 6879 4605; Fax: +81 6 6879 4609; Email: yyoneda{at}anat3.med.osaka-u.ac.jp
Received July 4, 2006. Revised August 14, 2006. Accepted August 24, 2006.
Exportin-5, an evolutionarily conserved nuclear export factor belonging to the importin-ß family of proteins, is known to play a role in the nuclear export of small noncoding RNAs such as precursors of microRNA, viral minihelix RNA and a subset of tRNAs in mammalian cells. In this study, we show that the exportin-5 orthologues from different species such as human, fruit fly and yeast exhibit diverged functions. We found that Msn5p, a yeast exportin-5 orthologue, binds double-stranded RNAs and that it prefers a shorter 22 nt, double-stranded RNA to 
80 nt pre-miRNA, even though both of these RNAs share a similar terminal structure. Furthermore, we found that Drosophila exportin-5 binds pre-miRNAs and that amongst the exportin-5 orthologues tested, it shows the highest affinity for tRNAs. The knockdown of Drosophila exportin-5 in cultured cells decreased the amounts of tRNA as well as miRNA, whereas the knock down of human exportin-5 in cultured cells affected only miRNA but not tRNA levels. These results indicate that double-stranded RNA binding ability is an inherited functional characteristic of the exportin-5 orthologues and that Drosophila exportin-5 functions as an exporter of tRNAs as well as pre-miRNAs in the fruit fly that lacks the orthologous gene for exportin-t.
*Correspondence may also be addressed to Jun Katahira. Tel: +81 6 6879 4606; Fax: +81 6 6879 4609; Email: katahira{at}anat3.med.osaka-u.ac.jp
Present address: Akira Shimamoto, Department of Cellular and Molecular Biology, Division of Integrated Medical Science, Program for Biomedical Research, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan
The history dates have been corrected.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  C. Okada, E. Yamashita, S. J. Lee, S. Shibata, J. Katahira, A. Nakagawa, Y. Yoneda, and T. Tsukihara A High-Resolution Structure of the Pre-microRNA Nuclear Export Machinery Science, November 27, 2009; 326(5957): 1275 - 1279. [Abstract] [Full Text] [PDF]
|
|