title: Heterologous RNA-silencing suppressors from both plant- and animal-infecting viruses support plum pox virus infection.
abstract: HCPro, the RNA-silencing suppressor (RSS) of viruses belonging to the genus Potyvirus in the family Potyviridae, is a multifunctional protein presumably involved in all essential steps of the viral infection cycle. Recent studies have shown that plum pox potyvirus (PPV) HCPro can be replaced successfully by cucumber vein yellowing ipomovirus P1b, a sequence-unrelated RSS from a virus of the same family. In order to gain insight into the requirement of a particular RSS to establish a successful potyviral infection, we tested the ability of different heterologous RSSs from both plant- and animal-infecting viruses to substitute for HCPro. Making use of engineered PPV chimeras, we show that PPV HCPro can be replaced functionally by some, but not all, unrelated RSSs, including the NS1 protein of the mammal-infecting influenza A virus. Interestingly, the capacity of a particular RSS to replace HCPro does not correlate strictly with its RNA silencing-suppression strength. Altogether, our results suggest that not all suppression strategies are equally suitable for efficient escape of PPV from the RNA-silencing machinery. The approach followed here, based on using PPV chimeras in which an under-consideration RSS substitutes for HCPro, could further help to study the function of diverse RSSs in a 'highly sensitive' RNA-silencing context, such as that taking place in plant cells during the process of a viral infection.
authors.affiliation: Centro Nacional de Biotecnología-CSIC, Campus Universidad Autónoma de Madrid, 28049 Madrid, Spain.
authors.forename: Varvara I
authors.initials: VI
authors.lastname: Maliogka
authors.affiliation: Centro Nacional de Biotecnología-CSIC, Campus Universidad Autónoma de Madrid, 28049 Madrid, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Calvo
authors.affiliation: Centro Nacional de Biotecnología-CSIC, Campus Universidad Autónoma de Madrid, 28049 Madrid, Spain.
authors.forename: Alberto
authors.initials: A
authors.lastname: Carbonell
authors.affiliation: Centro Nacional de Biotecnología-CSIC, Campus Universidad Autónoma de Madrid, 28049 Madrid, Spain.
authors.forename: Juan Antonio
authors.initials: JA
authors.lastname: García
authors.affiliation: Centro Nacional de Biotecnología-CSIC, Campus Universidad Autónoma de Madrid, 28049 Madrid, Spain.
authors.forename: Adrian
authors.initials: A
authors.lastname: Valli
mesh_terms: D003546:Cysteine Endopeptidases / Q000235:genetics / Q000378:metabolism*; D015967:Gene Expression Regulation, Viral; D054884:Host-Pathogen Interactions; D009980:Influenza A virus / Q000201:enzymology / Q000235:genetics; D010322:Parvoviridae Infections; D010935:Plant Diseases / Q000821:virology; D017801:Plum Pox Virus / Q000201:enzymology* / Q000235:genetics / Q000502:physiology*; D034622:RNA Interference; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D011995:Recombination, Genetic; D014026:Nicotiana / Q000821:virology; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*; D014779:Virus Replication; D014780:Viruses
chemical_list: D011994:Recombinant Proteins; D014764:Viral Proteins; D003546:Cysteine Endopeptidases; C072775:HC-Pro protein, potyvirus