title: Ebola virus RNA editing depends on the primary editing site sequence and an upstream secondary structure.
abstract: Ebolavirus (EBOV), the causative agent of a severe hemorrhagic fever and a biosafety level 4 pathogen, increases its genome coding capacity by producing multiple transcripts encoding for structural and nonstructural glycoproteins from a single gene. This is achieved through RNA editing, during which non-template adenosine residues are incorporated into the EBOV mRNAs at an editing site encoding for 7 adenosine residues. However, the mechanism of EBOV RNA editing is currently not understood. In this study, we report for the first time that minigenomes containing the glycoprotein gene editing site can undergo RNA editing, thereby eliminating the requirement for a biosafety level 4 laboratory to study EBOV RNA editing. Using a newly developed dual-reporter minigenome, we have characterized the mechanism of EBOV RNA editing, and have identified cis-acting sequences that are required for editing, located between 9 nt upstream and 9 nt downstream of the editing site. Moreover, we show that a secondary structure in the upstream cis-acting sequence plays an important role in RNA editing. EBOV RNA editing is glycoprotein gene-specific, as a stretch encoding for 7 adenosine residues located in the viral polymerase gene did not serve as an editing site, most likely due to an absence of the necessary cis-acting sequences. Finally, the EBOV protein VP30 was identified as a trans-acting factor for RNA editing, constituting a novel function for this protein. Overall, our results provide novel insights into the RNA editing mechanism of EBOV, further understanding of which might result in novel intervention strategies against this viral pathogen.
authors.affiliation: Department of Medical Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada ; Laboratory of Virology, Rocky Mountain Laboratories, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America.
authors.forename: Masfique
authors.initials: M
authors.lastname: Mehedi
authors.forename: Thomas
authors.initials: T
authors.lastname: Hoenen
authors.forename: Shelly
authors.initials: S
authors.lastname: Robertson
authors.forename: Stacy
authors.initials: S
authors.lastname: Ricklefs
authors.forename: Michael A
authors.initials: MA
authors.lastname: Dolan
authors.forename: Travis
authors.initials: T
authors.lastname: Taylor
authors.forename: Darryl
authors.initials: D
authors.lastname: Falzarano
authors.forename: Hideki
authors.initials: H
authors.lastname: Ebihara
authors.forename: Stephen F
authors.initials: SF
authors.lastname: Porcella
authors.forename: Heinz
authors.initials: H
authors.lastname: Feldmann
mesh_terms: D002460:Cell Line; D029043:Ebolavirus / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D009690:Nucleic Acid Conformation; D017393:RNA Editing / Q000502:physiology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D012367:RNA, Viral / Q000235:genetics / Q000378:metabolism*
chemical_list: D012333:RNA, Messenger; D012367:RNA, Viral