title: Identification of a nuclear localization signal and nuclear export signal of the umbraviral long-distance RNA movement protein.
abstract: The 27 kDa protein encoded by ORF3 of Groundnut rosette virus (GRV) is required for viral RNA protection and movement of viral RNA through the phloem. Localization studies have revealed that this protein is located in nuclei, preferentially targeting nucleoli. We have demonstrated that amino acids (aa) 108-122 of the GRV ORF3 protein contain an arginine-rich nuclear localization signal. Arginine-to-asparagine substitutions in this region decreased the level of the ORF3 protein accumulation in nuclei. A leucine-rich nuclear export signal (NES) was located at aa 148-156 of the GRV ORF3 protein. Leucine-to-alanine substitutions in this region resulted in a dramatic increase in GRV ORF3 protein accumulation in both nuclei and nucleoli. Consistent with this, we also showed that the previously identified NES of BR1 protein of Squash leaf curl virus can functionally replace the leucine-rich region of GRV ORF3 in nuclear export.
authors.affiliation: Horticulture Research International, Wellesbourne, Warwick CV35 9EF, UK.|Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, UK.
authors.forename: Eugene V
authors.initials: EV
authors.lastname: Ryabov
authors.affiliation: Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, UK.
authors.forename: Sang Hyon
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, UK.
authors.forename: Michael
authors.initials: M
authors.lastname: Taliansky
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000235:genetics; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001692:Biological Transport; D002466:Cell Nucleolus / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016366:Open Reading Frames; D010935:Plant Diseases / Q000821:virology; D018515:Plant Leaves / Q000821:virology; D012328:RNA Viruses / Q000378:metabolism*; D012367:RNA, Viral / Q000378:metabolism*; D014026:Nicotiana / Q000821:virology; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D012367:RNA, Viral; D014764:Viral Proteins