Abstract
Positive-sense RNA viruses have a small genome with very limited coding capacity and are highly dependent on host components to fulfill their life cycle. Recent studies have suggested that DEAD-box RNA helicases play vital roles in many aspects of RNA metabolism. To explore the possible role of the RNA helicases in viral infection, we used the Turnip mosaic virus (TuMV)-Arabidopsis pathosystem. The Arabidopsis genome encodes more than 100 putative RNA helicases (AtRH). Over 41 Arabidopsis T-DNA insertion mutants carrying genetic lesions in the corresponding 26 AtRH genes were screened for their requirement in TuMV infection. TuMV infection assays revealed that virus accumulation significantly decreased in the Arabidopsis mutants of three genes, AtRH9, AtRH26, and PRH75. In the present work, AtRH9 was further characterized. Yeast two-hybrid and bimolecular fluorescence complementation (BiFC) assays showed that AtRH9 interacted with the TuMV NIb protein, the viral RNA-dependent RNA polymerase. Moreover, the subcellular distribution of AtRH9 was altered in the virus-infected cells, and AtRH9 was recruited to the viral replication complex. These results suggest that Arabidopsis AtRH9 is an important component of the TuMV replication complex, possibly recruited via its interaction with NIb.
Highlights
The VRC of all positive-sense RNA viruses is intimately associated with intracellular membranous structures[17]
To elucidate the role of AtRH genes in viral infection, Arabidopsis T-DNA insertion lines corresponding to 42 AtRH genes were selected from the TAIR database
Seed stocks of 128 Arabidopsis T-DNA insertion lines corresponding to these 42 AtRH genes were obtained from the Arabidopsis Biological Resource Center (ABRC)
Summary
The VRC of all positive-sense RNA viruses is intimately associated with intracellular membranous structures[17]. Two additional cellular RNA helicases, e.g., the eIF4AIII-like yeast FAL1 and the DDX5-like Dbp[3] and their orthologs in Arabidopsis, AtRH2 and AtRH5, have been shown to be present in the tombusvirus VRCs34. In the case of potyviruses, an Arabidopsis DEAD-box RNA helicase, AtRH8 and a Prunus persica DDX-like protein, PpDDXL, have been identified to interact with potyviral VPg. AtRH8 co-localizes with the viral replication vesicles, suggesting AtRH8 is likely involved in viral genome translation and replication[24]. AtRH8 co-localizes with the viral replication vesicles, suggesting AtRH8 is likely involved in viral genome translation and replication[24] These studies demonstrate the essential roles of DDXs in virus infections. We describe our characterization of Arabidopsis AtRH9 and present evidence that AtRH9 interacts with TuMV NIb and is recruited to the VRC to promote TuMV infection
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
