Expression dynamics and ultrastructural localization of epitope-tagged Abutilon mosaic virus nuclear shuttle and movement proteins in Nicotiana benthamiana cells.
The geminivirus Abutilon mosaic virus (AbMV) encodes two proteins which are essential for viral spread within plants. The nuclear shuttle protein (NSP) transfers viral DNA between the nucleus and cytoplasm, whereas the movement protein (MP) facilitates transport between cells through plasmodesmata and long-distance via phloem. An inducible overexpression system for epitope-tagged NSP and MP in plants yielded unprecedented amounts of both proteins. Western blots revealed extensive posttranslational modification and truncation for MP, but not for NSP. Ultrastructural examination of Nicotiana benthamiana tissues showed characteristic nucleopathic alterations, including fibrillar rings, when epitope-tagged NSP and MP were simultaneously expressed in leaves locally infected with an AbMV DNA A in which the coat protein gene was replaced by a green fluorescent protein encoding gene. Immunogold labelling localized NSP in the nucleoplasm and in the fibrillar rings. MP appeared at the cell periphery, probably the plasma membrane, and plasmodesmata.
Kleinow
Tatjana
T
Institute of Biology, Department of Molecular Biology and Plant Virology, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany. tatjana.kleinow@bio.uni-stuttgart.de
Tanwir
Fariha
F
Kocher
Cornelia
C
Krenz
Björn
B
Wege
Christina
C
Jeske
Holger
H
D053839:Begomovirus / Q000502:physiology*; D002462:Cell Membrane / Q000737:chemistry / Q000648:ultrastructure; D002467:Cell Nucleus / Q000737:chemistry / Q000648:ultrastructure; D003593:Cytoplasm / Q000737:chemistry / Q000648:ultrastructure; D015870:Gene Expression; D046911:Macromolecular Substances / Q000032:analysis; D016253:Microscopy, Immunoelectron / Q000379:methods; D018515:Plant Leaves / Q000737:chemistry; D053830:Plant Viral Movement Proteins / Q000032:analysis; D011499:Protein Processing, Post-Translational; D014026:Nicotiana / Q000737:chemistry* / Q000821:virology*; D014764:Viral Proteins / Q000032:analysis*
D046911:Macromolecular Substances; D053830:Plant Viral Movement Proteins; D014764:Viral Proteins