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.
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.
Paape
Martina
M
University of Rostock, Biology Institute, Albert Einstein Str. 3, 18059 Rostock, Germany.
Solovyev
Andrey G
AG
Erokhina
Tatyana N
TN
Minina
Elena A
EA
Schepetilnikov
Mikhail V
MV
Lesemann
Dietrich-E
DE
Schiemann
Joachim
J
Morozov
Sergey Yu
SY
Kellmann
Jan-W
JW
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*
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