title: The functional analysis of distinct tospovirus movement proteins (NSM) reveals different capabilities in tubule formation, cell-to-cell and systemic virus movement among the tospovirus species.
abstract: The lack of infectious tospovirus clones to address reverse genetic experiments has compromised the functional analysis of viral proteins. In the present study we have performed a functional analysis of the movement proteins (NSM) of four tospovirus species Bean necrotic mosaic virus (BeNMV), Chrysanthemum stem necrosis virus (CSNV), Tomato chlorotic spot virus (TCSV) and Tomato spotted wilt virus (TSWV), which differ biologically and molecularly, by using the Alfalfa mosaic virus (AMV) model system. All NSMproteins were competent to: i) support the cell-to-cell and systemic transport of AMV, ii) generate tubular structures on infected protoplast and iii) transport only virus particles. However, the NSMof BeNMV (one of the most phylogenetically distant species) was very inefficient to support the systemic transport. Deletion assays revealed that the C-terminal region of the BeNMV NSM, but not that of the CSNV, TCSV and TSWV NSMproteins, was dispensable for cell-to-cell transport, and that all the non-functional C-terminal NSMmutants were unable to generate tubular structures. Bimolecular fluorescence complementation analysis revealed that the C-terminus of the BeNMV NSMwas not required for the interaction with the cognate nucleocapsid protein, showing a different protein organization when compared with other movement proteins of the '30K family'. Overall, our results revealed clearly differences in functional aspects among movement proteins from divergent tospovirus species that have a distinct biological behavior.
authors.affiliation: Departamento de Biologia Celular, Universidade de Brasília, 70910-900 Brasília, Brazil. Electronic address: m.leastro@gmail.com.
authors.forename: Mikhail O
authors.initials: MO
authors.lastname: Leastro
authors.affiliation: Instituto de Biología Molecular y Celular de Plantas (IBMCP), Consejo Superior de investigaciones Científicas-Universidad Politécnica de Valencia, Valencia, Spain. Electronic address: vpallas@ibmcp.upv.es.
authors.forename: Vicente
authors.initials: V
authors.lastname: Pallás
authors.affiliation: Departamento de Biologia Celular, Universidade de Brasília, 70910-900 Brasília, Brazil. Electronic address: rresende@unb.br.
authors.forename: Renato O
authors.initials: RO
authors.lastname: Resende
authors.affiliation: Instituto de Biología Molecular y Celular de Plantas (IBMCP), Consejo Superior de investigaciones Científicas-Universidad Politécnica de Valencia, Valencia, Spain. Electronic address: jesanche@ibmcp.upv.es.
authors.forename: Jesús A
authors.initials: JA
authors.lastname: Sánchez-Navarro
mesh_terms: D002478:Cells, Cultured; D015870:Gene Expression; D017930:Genes, Reporter; D019590:Nucleocapsid Proteins / Q000378:metabolism; D059828:Plant Cells / Q000821:virology; D010935:Plant Diseases / Q000821:virology; D053830:Plant Viral Movement Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D025941:Protein Interaction Mapping; D011523:Protoplasts / Q000378:metabolism / Q000821:virology; D011993:Recombinant Fusion Proteins; D017865:Tospovirus / Q000502:physiology*; D019065:Virus Assembly; D014779:Virus Replication
chemical_list: D019590:Nucleocapsid Proteins; D053830:Plant Viral Movement Proteins; D011993:Recombinant Fusion Proteins
keywords: AMV system; Cell-to-cell movement; NS(M) functionality; NS(M) protein; Systemic movement; Tospovirus; Tubule formation