Three C-terminal phosphorylation sites in the Abutilon mosaic virus movement protein affect symptom development and viral DNA accumulation.
The Abutilon mosaic virus (AbMV, Geminiviridae) DNA B component encodes a movement protein (MP), which facilitates viral transport within plants and affects pathogenicity. The presence of phosphorylated serine and threonine residues was confirmed for MP expressed in yeast and Nicotiana benthamiana by comparative Western blot analysis using phospho-amino acid- and MP-specific immunodetection. Mass spectrometry of yeast-derived MP identified three phosphorylation sites located in the C-terminal domain (Thr-221, Ser-223 and Ser-250). To assess their functional relevance in plants, several point mutations were generated in the MP gene of DNA B, which replace Thr-221, Ser-223 and Ser-250, either singly or in combinations, with either an uncharged alanine or a phosphorylation-mimicking aspartate residue. When co-inoculated with DNA A, all mutants were infectious. In systemically infected plants the symptoms and/or viral DNA accumulation were significantly altered for several of the mutants.
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
Nischang
Marc
M
Beck
Alexander
A
Kratzer
Ulrich
U
Tanwir
Fariha
F
Preiss
Werner
W
Kepp
Gabi
G
Jeske
Holger
H
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001483:Base Sequence; D053839:Begomovirus / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity; D001665:Binding Sites / Q000235:genetics; D004279:DNA, Viral / Q000235:genetics / Q000378:metabolism; D005814:Genes, Viral; D019660:Malvaceae / Q000821:virology*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010766:Phosphorylation; D010935:Plant Diseases / Q000821:virology; D053830:Plant Viral Movement Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017354:Point Mutation; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012568:Schizosaccharomyces / Q000235:genetics / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D053719:Tandem Mass Spectrometry; D014026:Nicotiana / Q000821:virology
D004279:DNA, Viral; D053830:Plant Viral Movement Proteins; D011994:Recombinant Proteins