RNA helicase domains of viral origin in proteins of insect retrotransposons: possible source for evolutionary advantages
- Published
- Accepted
- Subject Areas
- Entomology, Genomics, Molecular Biology, Virology
- Keywords
- Retrotransposon, Horizontal Gene Transfer, Herbivory, Gene silencing, Long Interspersed Nuclear Element, Insect genome, Viral RNA helicase
- Copyright
- © 2017 Morozov et al.
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
- Cite this article
- 2017. RNA helicase domains of viral origin in proteins of insect retrotransposons: possible source for evolutionary advantages. PeerJ Preprints 5:e3101v1 https://doi.org/10.7287/peerj.preprints.3101v1
Abstract
Recently, a novel phenomenon of horizontal gene transfer of helicase-encoding sequence from positive-stranded RNA viruses to LINE transposons in insect genomes was described. TRAS family transposons encoding an ORF2 protein, which comprised all typical functional domains and an additional helicase domain, were found to be preserved in many families during the evolution of the order Lepidoptera. In the present paper, in species of orders Hemiptera and Orthoptera, we found helicase domain-encoding sequences integrated into ORF1 of retrotransposons of the Jockey family. RNA helicases encoded by transposons of TRAS and Jockey families represented separate brunches in a phylogenetic tree of helicase domains and thus could be considered as independently originated in the evolution of insect transposons. Transcriptome database analyses revealed that both TRAS and Jockey transposons encoding the helicase domain represented transcribed genome sequences. Moreover, the transposon-encoded helicases were found to contain the full set of conserved motifs essential for their enzymatic activities. Taking into account the previously reported ability of RNA helicase encoded by TRAS ORF2 to suppress post-transcriptional RNA silencing, we propose possible scenarios of evolutionary fixation of actively expressed functional helicases of viral origin in insect retrotransposons as genetic elements advantageous for both transposons and their insect hosts.
Author Comment
This is a submission to PeerJ for review.