An extensive survey of phytoviral RNA 3' uridylation identifies extreme variations and virus-specific patterns.
Fiche publication
Date publication
mai 2023
Journal
Plant physiology
Auteurs
Membres identifiés du Cancéropôle Est :
Mme KOECHLER Sandrine
Tous les auteurs :
Joly AC, Garcia S, Hily JM, Koechler S, Demangeat G, Garcia D, Vigne E, Lemaire O, Zuber H, Gagliardi D
Lien Pubmed
Résumé
Viral RNAs can be uridylated in eucaryotic hosts. However, our knowledge of uridylation patterns and roles remains rudimentary for phytoviruses. Here, we report global 3' terminal RNA uridylation profiles for representatives of the main families of positive single-stranded RNA phytoviruses. We detected uridylation in all 47 viral RNAs investigated here, revealing its prevalence. Yet, uridylation levels of viral RNAs varied from 0.2% to 90%. Unexpectedly, most poly(A) tails of grapevine fanleaf virus (GFLV) RNAs, including encapsidated tails, were strictly mono-uridylated, which corresponded to an unidentified type of viral genomic RNA extremity. This mono-uridylation appears beneficial for GFLV because it becomes dominant when plants are infected with non-uridylated GFLV transcripts. We found that GFLV RNA mono-uridylation is independent of the known TUTases HEN1 SUPPRESSOR 1 (HESO1) and UTP:RNA URIDYLYLTRANSFERASE 1 (URT1) in Arabidopsis (Arabidopsis thaliana). By contrast, both TUTases uridylate other viral RNAs like turnip crinkle virus (TCV) and turnip mosaic virus (TuMV) RNAs. Interestingly, TCV and TuMV degradation intermediates were differentially uridylated by HESO1 and URT1. Although the lack of both TUTases did not prevent viral infection, we detected degradation intermediates of TCV RNA at higher levels in a Arabidopsis heso1 urt1 mutant, suggesting that uridylation participates in clearing viral RNA. Collectively, our work unveils an extreme diversity of uridylation patterns across phytoviruses and constitutes a valuable resource to further decipher pro- and anti-viral roles of uridylation.
Mots clés
GFLV, RNA degradation, TUTase, TuMV, Uridylation, grapevine, nepovirus, ssRNA phytovirus
Référence
Plant Physiol. 2023 05 13;: