title: Expression, localization and effects on virulence of the cysteine-rich 8 kDa protein of Potato mop-top virus.
abstract: Potato mop-top virus (PMTV) RNA3 contains a triple gene block (TGB) encoding viral movement proteins and an open reading frame for a putative 8 kDa cysteine-rich protein (CRP). In this study, PMTV CRP was shown to be expressed in the course of virus infection, and a PMTV CRP-specific subgenomic RNA was mapped. CRP has previously been shown to be dispensable for infection of PMTV in Nicotiana benthamiana. In this study, PMTV CRP was found to increase the severity of disease symptoms when expressed from Potato virus X or Tobacco mosaic virus in N. benthamiana and Nicotiana tabacum, suggesting that the protein affects virulence of the virus or might suppress a host defence mechanism. However, PMTV CRP did not show RNA silencing suppression activity in three assays. Host responses to the PMTV CRP expression from different viral genomes ranged from an absence of response to extreme resistance at a single cell level and were dependent on the viral genome. These findings emphasized involvement of viral proteins and/or virus-induced cell components in the plant reaction to CRP. PMTV CRP was predicted to possess a transmembrane segment. CRP fused to the green fluorescent protein was associated with endoplasmic reticulum-derived membranes and induced dramatic rearrangements of the endoplasmic reticulum structure, which might account for protein functions as a virulence factor of the virus.
authors.affiliation: A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow 119899, Russian Federation.|Department of Plant Biology and Forest Genetics, Swedish University of Agricultural Sciences (SLU), Box 7080, SE-750 07 Uppsala, Sweden.
authors.forename: N I
authors.initials: NI
authors.lastname: Lukhovitskaya
authors.affiliation: Department of Plant Biology and Forest Genetics, Swedish University of Agricultural Sciences (SLU), Box 7080, SE-750 07 Uppsala, Sweden.|A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow 119899, Russian Federation.
authors.forename: N E
authors.initials: NE
authors.lastname: Yelina
authors.affiliation: Department of Plant Biology and Forest Genetics, Swedish University of Agricultural Sciences (SLU), Box 7080, SE-750 07 Uppsala, Sweden.
authors.forename: A A
authors.initials: AA
authors.lastname: Zamyatnin
authors.affiliation: A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow 119899, Russian Federation.
authors.forename: M V
authors.initials: MV
authors.lastname: Schepetilnikov
authors.affiliation: A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow 119899, Russian Federation.
authors.forename: A G
authors.initials: AG
authors.lastname: Solovyev
authors.affiliation: Department of Plant Biology and Forest Genetics, Swedish University of Agricultural Sciences (SLU), Box 7080, SE-750 07 Uppsala, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Sandgren
authors.affiliation: A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow 119899, Russian Federation.
authors.forename: S Yu
authors.initials: SY
authors.lastname: Morozov
authors.affiliation: Department of Applied Biology, University of Helsinki, Finland.|Department of Plant Biology and Forest Genetics, Swedish University of Agricultural Sciences (SLU), Box 7080, SE-750 07 Uppsala, Sweden.
authors.forename: J P T
authors.initials: JPT
authors.lastname: Valkonen
authors.affiliation: Department of Plant Biology and Forest Genetics, Swedish University of Agricultural Sciences (SLU), Box 7080, SE-750 07 Uppsala, Sweden.
authors.forename: E I
authors.initials: EI
authors.lastname: Savenkov
mesh_terms: D003545:Cysteine / Q000378:metabolism*; D008970:Molecular Weight; D010935:Plant Diseases / Q000821:virology*; D010942:Plant Viruses / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity*; D034622:RNA Interference; D011198:Solanum tuberosum / Q000821:virology*; D014158:Transcription, Genetic; D014764:Viral Proteins / Q000235:genetics / Q000502:physiology*; D014774:Virulence
chemical_list: D014764:Viral Proteins; D003545:Cysteine