The genome-linked protein VPg of plant viruses — a protein with many partners

For some plant positive-sense RNA viruses, a protein known as VPg (short for virus protein, genome linked) is covalently linked to the 5′ end of the viral RNA. The VPg is an intrinsically disordered protein, and this property would confer an ability to bind several proteins. Accordingly, the potyvirus VPg interacts with many proteins, notably host factors involved in protein synthesis within viral replication factories or within the nucleus. The number of protein partners, the clustering of the various interactions centering around it, the biological importance for some of these interactions (e.g. VPg–eIF4E) and the intrinsically disordered state of the protein are all elements that support the notion that VPg is a hub protein that controls many processes leading to virus production and spread.

► The plant VPg is an intrinsically disordered protein. ► The potyvirus VPg interacts with many viral and host proteins within viral replication factories or the nucleus. ► Several interactions are clustered around this viral protein and some of them (e.g. VPg–eIF4E) are essential for virus infection. ► VPg is a hub protein that likely controls many processes leading to virus production and spread.