TY - UNPB

T1 - Plant YTHDF proteins are direct effectors of antiviral immunity against an m6A-containing RNA virus

AU - Martínez-Pérez, Mireya

AU - Aparicio, Frederic

AU - Arribas-Hernández, Laura

AU - Tankmar, Mathias Due

AU - Rennie, Sarah

AU - Brodersen, Peter

AU - Pallas, Vicente

PY - 2022

Y1 - 2022

N2 - In virus-host interactions, nucleic acid-directed first lines of defense that allow viral clearance without compromising growth are of paramount importance. Plants use the RNA interference pathway as such a basal antiviral immune system, but additional RNA-based mechanisms of defense also exist. The infectivity of the plant positive strand RNA virus alfalfa mosaic virus (AMV) relies on demethylation of viral RNA by recruitment of the cellularN6-methyladenosine (m6A) demethylase ALKBH9B, but how demethylation of viral RNA promotes AMV replication remains unknown. Here, we show that inactivation of the cytoplasmic YT521-B homology domain (YTH)-containing m6A-binding proteins, ECT2, ECT3, and ECT5 is sufficient to restore AMV infectivity in partially resistantalkbh9bmutants. We also show that the antiviral function of ECT2 is distinct from its previously demonstrated function in promotion of proliferation of primordial cells, because an ECT2 mutant carrying a small deletion in its intrinsically disordered region is partially compromised for antiviral defense, but not for developmental functions. These results indicate that the m6A-YTH axis constitutes a novel branch of basal antiviral immunity in plants.

AB - In virus-host interactions, nucleic acid-directed first lines of defense that allow viral clearance without compromising growth are of paramount importance. Plants use the RNA interference pathway as such a basal antiviral immune system, but additional RNA-based mechanisms of defense also exist. The infectivity of the plant positive strand RNA virus alfalfa mosaic virus (AMV) relies on demethylation of viral RNA by recruitment of the cellularN6-methyladenosine (m6A) demethylase ALKBH9B, but how demethylation of viral RNA promotes AMV replication remains unknown. Here, we show that inactivation of the cytoplasmic YT521-B homology domain (YTH)-containing m6A-binding proteins, ECT2, ECT3, and ECT5 is sufficient to restore AMV infectivity in partially resistantalkbh9bmutants. We also show that the antiviral function of ECT2 is distinct from its previously demonstrated function in promotion of proliferation of primordial cells, because an ECT2 mutant carrying a small deletion in its intrinsically disordered region is partially compromised for antiviral defense, but not for developmental functions. These results indicate that the m6A-YTH axis constitutes a novel branch of basal antiviral immunity in plants.

U2 - 10.1101/2022.10.19.512835

DO - 10.1101/2022.10.19.512835

M3 - Preprint

BT - Plant YTHDF proteins are direct effectors of antiviral immunity against an m6A-containing RNA virus

ER -