title: The Enamovirus P0 protein is a silencing suppressor which inhibits local and systemic RNA silencing through AGO1 degradation.
abstract: The P0 protein of poleroviruses and P1 protein of sobemoviruses suppress the plant's RNA silencing machinery. Here we identified a silencing suppressor protein (SSP), P0(PE), in the Enamovirus Pea enation mosaic virus-1 (PEMV-1) and showed that it and the P0s of poleroviruses Potato leaf roll virus and Cereal yellow dwarf virus have strong local and systemic SSP activity, while the P1 of Sobemovirus Southern bean mosaic virus supresses systemic silencing. The nuclear localized P0(PE) has no discernable sequence conservation with known SSPs, but proved to be a strong suppressor of local silencing and a moderate suppressor of systemic silencing. Like the P0s from poleroviruses, P0(PE) destabilizes AGO1 and this action is mediated by an F-box-like domain. Therefore, despite the lack of any sequence similarity, the poleroviral and enamoviral SSPs have a conserved mode of action upon the RNA silencing machinery.
authors.affiliation: University of Sydney, NSW 2006, Australia.
authors.forename: Adriana F
authors.initials: AF
authors.lastname: Fusaro
authors.forename: Regis L
authors.initials: RL
authors.lastname: Correa
authors.forename: Kenlee
authors.initials: K
authors.lastname: Nakasugi
authors.forename: Craig
authors.initials: C
authors.lastname: Jackson
authors.forename: Lawrence
authors.initials: L
authors.lastname: Kawchuk
authors.forename: Maite F S
authors.initials: MF
authors.lastname: Vaslin
authors.forename: Peter M
authors.initials: PM
authors.lastname: Waterhouse
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism / Q000821:virology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D060565:Argonaute Proteins / Q000235:genetics / Q000378:metabolism*; D020868:Gene Silencing; D052679:Luteoviridae / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000235:genetics / Q000821:virology*; D034622:RNA Interference; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: C117457:AGO1 protein, Arabidopsis; D029681:Arabidopsis Proteins; D060565:Argonaute Proteins; D012097:Repressor Proteins; D014764:Viral Proteins