Journal of Virology (2018) 92 (9 - e02179-17)

Araiz Gallo, Adrian Valli, María Calvo and Juan Antonio García (2018)
A functional link between RNA replication and virion assembly in the Potyvirus Plum pox virus
Journal of Virology 92 (9 - e02179-17)
Abstract: Accurate assembly of viral particles in the potyvirus Plum pox virus (PPV) has been shown to depend on the contribution of the multifunctional viral protein HCPro. In this study, we show that other viral factors, in addition to the capsid protein (CP) and HCPro, are necessary for the formation of stable PPV virions. The CP produced in Nicotiana benthamiana leaves from a subviral RNA termed LONG, which expresses a truncated polyprotein that lacks P1 and HCPro, together with HCPro supplied in trans, was assembled into virus-like particles and remained stable after in vitro incubation. In contrast, deletions in multiple regions of the LONG coding sequence prevented the CP stabilization mediated by HCPro. In particular, we demonstrated that the first 178 amino acids of P3, but not a specific nucleotide sequence coding for them, are required for CP stability and proper assembly of PPV particles. Using a sequential coagroinfiltration assay, we observed that the subviral LONG RNA replicates and locally spreads in N. benthamiana leaves expressing an RNA silencing suppressor. The analysis of the effect of both point and deletion mutations affecting RNA replication in LONG and full-length PPV demonstrated that this process is essential for the assembly of stable viral particles. Interestingly, in spite of this requirement, the CP produced by a nonreplicating viral RNA can be stably assembled into virions as long as it is coexpressed with a replication-proficient RNA. Altogether, these results highlight the importance of coupling encapsidation to other viral processes to secure a successful infection.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Juan Antonio Garcia

Research topic(s) for pests/diseases/weeds:
molecular biology - genes

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Plum pox virus