Dynamin-related protein 2 interacts with the membrane-associated methyltransferase domain of plantago asiatica mosaic virus replicase and promotes viral replication

•The MET domain of PlAMV replicase interacts with NbDRP2 in Nicotiana benthamiana.•PlAMV infection induced NbDRP2 gene expression.•The accumulation level of PlAMV was decreased in the NbDRP2 knockdown plants.•PlAMV accumulation was suppressed in protoplasts treated with dynamin inhibitor.•NbDRP2 plays a proviral role during PlAMV replication. Positive-strand RNA viruses replicate their RNA in the viral replication complex, a spherical structure formed by remodeling of host intracellular membranes. This process also requires the interaction between viral membrane-associated replication proteins and host factors. We previously identified the membrane-associated determinant of the replicase of plantago asiatica mosaic virus (PlAMV), a positive-strand RNA virus of the genus Potexvirus, in its methyltransferase (MET) domain, and suggested that its interaction with host factors is required to establish viral replication. Here we identified Nicotiana benthamiana dynamin-related protein 2 (NbDRP2) as an interactor of the MET domain of the PlAMV replicase by co-immunoprecipitation (Co-IP) and mass spectrometry analysis. NbDRP2 is closely related to the DRP2 subfamily proteins in Arabidopsis thaliana, AtDRP2A and AtDRP2B. Confocal microscopy observation and Co-IP confirmed the interaction between the MET domain and NbDRP2. Also, the expression of NbDRP2 was induced by PlAMV infection. PlAMV accumulation was reduced when the expression of NbDRP2 gene was suppressed by virus-induced gene silencing. In addition, PlAMV accumulation was reduced in protoplasts treated with dynamin inhibitor. These results indicate a proviral role of the interaction of NbDRP2 with the MET domain in PlAMV replication.