title: The RYMV-encoded viral suppressor of RNA silencing P1 is a zinc-binding protein with redox-dependent flexibility.
abstract: Viral suppressors of RNA interference (VSRs) target host gene silencing pathways, thereby operating important roles in the viral cycle and in host cells, in which they counteract host innate immune responses. However, the molecular mechanisms of VSRs are poorly understood. We provide here biochemical and biophysical features of the dual suppressor/activator VSR P1 protein encoded by the rice yellow mottle virus. In silico analyses of P1 suggested common features with zinc finger proteins and native mass spectrometry unambiguously confirmed that recombinant P1 binds reversibly two zinc atoms, each with a different strength. Additionally, we demonstrate that the reaction of P1 with H2O2 leads to zinc release, disulfide bond formation, and protein oligomerization. A reversible protein modification by redox alterations has only been described for a limited number of zinc finger proteins and has never been reported for VSRs. Those reported here for P1 might be a general feature of Cys-rich VSRs and could be a key regulatory mechanism for the control of RNA silencing.
authors.affiliation: Laboratoire Résistance des Plantes aux Bioagresseurs, IRD de Montpellier, UMR 186 IRD-CIRAD-Université de Montpellier II and CNRS, Montpellier, France.
authors.forename: François-Xavier
authors.initials: FX
authors.lastname: Gillet
authors.forename: Diego Ignacio
authors.initials: DI
authors.lastname: Cattoni
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Petiot-Bécard
authors.forename: François
authors.initials: F
authors.lastname: Delalande
authors.forename: Vianney
authors.initials: V
authors.lastname: Poignavent
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Brizard
authors.forename: Yannick
authors.initials: Y
authors.lastname: Bessin
authors.forename: Alain Van
authors.initials: AV
authors.lastname: Dorsselaer
authors.forename: Nathalie
authors.initials: N
authors.lastname: Declerck
authors.forename: Sarah
authors.initials: S
authors.lastname: Sanglier-Cianférani
authors.forename: Christophe
authors.initials: C
authors.lastname: Brugidou
authors.forename: Florence
authors.initials: F
authors.lastname: Vignols
mesh_terms: D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D019295:Computational Biology; D004220:Disulfides / Q000378:metabolism; D054884:Host-Pathogen Interactions; D006861:Hydrogen Peroxide / Q000378:metabolism; D013058:Mass Spectrometry; D012275:Oryza / Q000276:immunology / Q000821:virology; D010084:Oxidation-Reduction; D055503:Protein Multimerization; D011499:Protein Processing, Post-Translational; D034622:RNA Interference; D012328:RNA Viruses / Q000235:genetics / Q000276:immunology* / Q000502:physiology*; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014779:Virus Replication; D015032:Zinc / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D004220:Disulfides; D014764:Viral Proteins; C017800:zinc-binding protein; D006861:Hydrogen Peroxide; D015032:Zinc