We previously identified an RNA transport element (RTE) present at a high copy number in the mouse genome. Here, we show that a related element, RTE-D, is part of a mobile LTR-retrotransposon, which belongs to a family of intracisternal A-particle related elements (IAP). We demonstrate that RTE-D is essential for the mobility of the retrotransposon and it can be substituted by other known RNA export signals. RTE-deficient IAP transcripts are retained in the nucleus, while the RTE-containing transcripts accumulate in the cytoplasm allowing Gag protein expression. RTE-D acts as a posttranscriptional control element in a heterologous reporter mRNA and is activated by the cellular RNA binding protein 15 (RBM15), as reported for the previously described RTE. We identified a complex family of RTE-containing IAPs in mouse and mapped the active RTE-D-containing IAPs to the Mmr10 group of LTR-retrotransposons. These data reveal that, despite a complex evolutionary history, retroelements and retroviruses share the dependency on posttranscriptional regulation.
Zolotukhin, A. S., Schneider, R., Uranishi, H., Bear, J., Tretyakova, I., Michalowski, D., … Felber, B. K. (2008). The RNA transport element RTE is essential for IAP LTR-retrotransposon mobility. Virology, 377(1), 88–99. https://doi.org/10.1016/j.virol.2008.04.002