title: Mapping of functional region conferring nuclear localization and karyopherin α-binding activity of the C2 protein of bhendi yellow vein mosaic virus.
abstract: Bhendi yellow vein mosaic disease is caused by a complex consisting of a monopartite begomovirus associated with a β-satellite. The C2 protein of bhendi yellow vein mosaic virus (BYVMV) is a suppressor of post-transcriptional gene silencing and also functions as a transcriptional activator. To explore the molecular mechanisms of its nuclear trafficking and self-interaction, fusion proteins of fluorescent proteins with wild-type or mutated constructs of BYVMV C2 were expressed in tobacco protoplasts. Analyses revealed that the BYVMV C2 nuclear localization signal (NLS) was located in the N terminus of the protein, comprising aa 17-31 of C2. NLSs are recognized by a class of soluble transport receptors termed karyopherins α and β. The BYVMV C2 NLS was found to be necessary for this protein's interaction with its nuclear import mediator, karyopherin α, ensuring its nuclear localization. Nevertheless, when deleted, C2 was found in both the cytoplasm and the nucleus, suggesting NLS-independent nuclear import of this protein. Homotypic interaction of BYVMV C2 was also found, which correlates with the nuclear localization needed for efficient activation of transcription.
authors.affiliation: Department of Plant Biotechnology, School of Biotechnology, Madurai Kamaraj University, Madurai, India.
authors.forename: Sam A
authors.initials: SA
authors.lastname: Chandran
authors.affiliation: Department of Genetics and Vegetable Research, Agricultural Research Organization, The Volcani Center, PO Box 6, Bet Dagan 50250, Israel.
authors.forename: Yael
authors.initials: Y
authors.lastname: Levy
authors.affiliation: Department of Genetics and Vegetable Research, Agricultural Research Organization, The Volcani Center, PO Box 6, Bet Dagan 50250, Israel.
authors.forename: Anahit
authors.initials: A
authors.lastname: Mett
authors.affiliation: Department of Genetics and Vegetable Research, Agricultural Research Organization, The Volcani Center, PO Box 6, Bet Dagan 50250, Israel.
authors.forename: Eduard
authors.initials: E
authors.lastname: Belausov
authors.affiliation: Department of Plant Biotechnology, School of Biotechnology, Madurai Kamaraj University, Madurai, India.
authors.forename: Usha
authors.initials: U
authors.lastname: Ramakrishnan
authors.affiliation: Department of Genetics and Vegetable Research, Agricultural Research Organization, The Volcani Center, PO Box 6, Bet Dagan 50250, Israel.
authors.forename: Yedidya
authors.initials: Y
authors.lastname: Gafni
mesh_terms: D020816:Amino Acid Motifs; D053839:Begomovirus / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D019913:Nuclear Localization Signals; D010935:Plant Diseases / Q000821:virology*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D021381:Protein Transport; D014026:Nicotiana / Q000378:metabolism / Q000821:virology; D014764:Viral Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D028901:alpha Karyopherins / Q000235:genetics / Q000378:metabolism*
chemical_list: D019913:Nuclear Localization Signals; D010940:Plant Proteins; D014764:Viral Proteins; D028901:alpha Karyopherins