title: At-4/1, an interactor of the Tomato spotted wilt virus movement protein, belongs to a new family of plant proteins capable of directed intra- and intercellular trafficking.
abstract: The Tomato spotted wilt virus (TSWV) encoded NSm movement protein facilitates cell-to-cell spread of the viral genome through structurally modified plasmodesmata. NSm has been utilized as bait in yeast two-hybrid interaction trap screenings. As a result, a protein of unknown function, called At-4/1, was isolated from an Arabidopsis thaliana GAL4 activation domain-tagged cDNA library. Using polyclonal antibodies against bacterially expressed At-4/1, Western blot analysis of protein extracts isolated from different plant species as well as genome database screenings showed that homologues of At-4/1 seemed to be encoded by many vascular plants. For subcellular localization studies, At-4/1 was fused to green fluorescent protein, and corresponding expression vectors were used in particle bombardment and agroinfiltration assays. Confocal laser scannings revealed that At-4/1 assembled in punctate spots at the cell periphery. The protein accumulated intracellularly in a polarized fashion, appearing in only one-half of a bombarded epidermal cell, and, moreover, moved from cell to cell, forming twin-structured bodies seemingly located at both orifices of the plasmodesmatal pore. In coexpression studies, At-4/1 colocalized with a plant virus movement protein TGBp3 known to reside in endoplasmic reticulum-derived membrane structures located in close vicinity to plasmodesmata. Thus, At-4/1 belongs to a new family of plant proteins capable of directed intra- and intercellular trafficking.
authors.affiliation: University of Rostock, Biology Institute, Albert Einstein Str. 3, 18059 Rostock, Germany.
authors.forename: Martina
authors.initials: M
authors.lastname: Paape
authors.forename: Andrey G
authors.initials: AG
authors.lastname: Solovyev
authors.forename: Tatyana N
authors.initials: TN
authors.lastname: Erokhina
authors.forename: Elena A
authors.initials: EA
authors.lastname: Minina
authors.forename: Mikhail V
authors.initials: MV
authors.lastname: Schepetilnikov
authors.forename: Dietrich-E
authors.initials: DE
authors.lastname: Lesemann
authors.forename: Joachim
authors.initials: J
authors.lastname: Schiemann
authors.forename: Sergey Yu
authors.initials: SY
authors.lastname: Morozov
authors.forename: Jan-W
authors.initials: JW
authors.lastname: Kellmann
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000166:cytology / Q000378:metabolism* / Q000821:virology; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017124:Conserved Sequence; D015723:Gene Library; D049452:Green Fluorescent Proteins / Q000032:analysis; D007150:Immunohistochemistry; D008969:Molecular Sequence Data; D005810:Multigene Family; D018515:Plant Leaves / Q000378:metabolism / Q000821:virology; D053830:Plant Viral Movement Proteins; D030821:Plants, Genetically Modified / Q000166:cytology / Q000378:metabolism / Q000821:virology; D031425:Plasmodesmata / Q000378:metabolism; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000032:analysis; D016415:Sequence Alignment; D014026:Nicotiana / Q000166:cytology / Q000235:genetics; D017865:Tospovirus / Q000378:metabolism*; D020798:Two-Hybrid System Techniques; D014764:Viral Proteins / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; C514342:At-4-1 protein, Arabidopsis; D053830:Plant Viral Movement Proteins; D011993:Recombinant Fusion Proteins; D014764:Viral Proteins; D049452:Green Fluorescent Proteins