Scholars Archive

Title

Methylation of rRNA as a host defense against rampant group II intron retrotransposition

Authors

Marlene Belfort, University at Albany, State University of New York
Olga Novikova, University at Albany, State University of New York
Dan Fabris, University at Albany, State University of New York
Reza Nemati, University at Albany, State University of New York
Nicholas J. Schiraldi, University at Albany, State University of New York
E. Jake Bailey, University at Albany, State University of New York
Carol Lyn Piazza, University at Albany, State University of New York
Dorie Smith, University at Albany, State University of New York
Justin M. Waldern, University at Albany, State University of New York

Preview

Document Type

Article

Publication Date

2-22-2021

DOI

https://doi.org/10.1186/s13100-021-00237-z

Abstract

Background: Group II introns are mobile retroelements, capable of invading new sites in DNA. They are self-splicing ribozymes that complex with an intron-encoded protein to form a ribonucleoprotein that targets DNA after splicing. These molecules can invade DNA site-specifically, through a process known as retrohoming, or can invade ectopic sites through retrotransposition. Retrotransposition, in particular, can be strongly influenced by both environmental and cellular factors.

Results: To investigate host factors that influence retrotransposition, we performed random insertional mutagenesis using the ISS1 transposon to generate a library of over 1000 mutants in Lactococcus lactis, the native host of the Ll.LtrB group II intron. By screening this library, we identified 92 mutants with increased retrotransposition frequencies (RTP-ups). We found that mutations in amino acid transport and metabolism tended to have increased retrotransposition frequencies. We further explored a subset of these RTP-up mutants, the most striking of which is a mutant in the ribosomal RNA methyltransferase rlmH, which exhibited a reproducible 20-fold increase in retrotransposition frequency. In vitro and in vivo experiments revealed that ribosomes in the rlmH mutant were defective in the m3Ψ modification and exhibited reduced binding to the intron RNA.

Conclusions: Taken together, our results reinforce the importance of the native host organism in regulating group II intron retrotransposition. In particular, the evidence from the rlmH mutant suggests a role for ribosome modification in limiting rampant retrotransposition.

Comments

This is the Publisher’s PDF of the following article made available by Mobile DNA: Waldern, J.M., Smith, D., Piazza, C.L. et al. Methylation of rRNA as a host defense against rampant group II intron retrotransposition. Mobile DNA 12, 9 (2021). https://doi.org/10.1186/s13100-021-00237-z

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

Recommended Citation

Belfort, Marlene; Novikova, Olga; Fabris, Dan; Nemati, Reza; Schiraldi, Nicholas J.; Bailey, E. Jake; Piazza, Carol Lyn; Smith, Dorie; and Waldern, Justin M., "Methylation of rRNA as a host defense against rampant group II intron retrotransposition" (2021). Biological Sciences Faculty Scholarship. 15.
https://scholarsarchive.library.albany.edu/biology_fac_scholar/15