Unknown

Dataset Information

0

Exportin-5 orthologues are functionally divergent among species.


ABSTRACT: Exportin-5, an evolutionarily conserved nuclear export factor belonging to the importin-beta 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 approximately 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.

SUBMITTER: Shibata S 

PROVIDER: S-EPMC1635293 | biostudies-literature |

REPOSITORIES: biostudies-literature

Similar Datasets

| S-EPMC7305131 | biostudies-literature
| S-EPMC1266296 | biostudies-literature
| S-EPMC4915192 | biostudies-literature
| S-EPMC7351251 | biostudies-literature
| S-EPMC8185449 | biostudies-literature
| S-EPMC6938507 | biostudies-literature
| S-EPMC2045677 | biostudies-literature
| S-EPMC4288972 | biostudies-literature
| S-EPMC2064598 | biostudies-literature
| S-EPMC3464624 | biostudies-literature