title: An RNA virus-encoded zinc-finger protein acts as a plant transcription factor and induces a regulator of cell size and proliferation in two tobacco species.
abstract: Plant viruses cause a variety of diseases in susceptible hosts. The disease symptoms often include leaf malformations and other developmental abnormalities, suggesting that viruses can affect plant development. However, little is known about the mechanisms underlying virus interference with plant morphogenesis. Here, we show that a C-4 type zinc-finger (ZF) protein, p12, encoded by a carlavirus (chrysanthemum virus B) can induce cell proliferation, which results in hyperplasia and severe leaf malformation. We demonstrate that the p12 protein activates expression of a regulator of cell size and proliferation, designated upp-L (upregulated by p12), which encodes a transcription factor of the basic/helix-loop-helix family sufficient to cause hyperplasia. The induction of upp-L requires translocation of the p12 protein into the nucleus and ZF-dependent specific interaction with the conserved regulatory region in the upp-L promoter. Our results establish the role of the p12 protein in modulation of host cell morphogenesis. It is likely that other members of the conserved C-4 type ZF family of viral proteins instigate reprogramming of plant development by mimicking eukaryotic transcriptional activators.
authors.affiliation: Department of Plant Biology and Forest Genetics, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linean Center for Plant Biology, SE-75007 Uppsala, Sweden.
authors.forename: Nina I
authors.initials: NI
authors.lastname: Lukhovitskaya
authors.forename: Anna D
authors.initials: AD
authors.lastname: Solovieva
authors.forename: Santosh K
authors.initials: SK
authors.lastname: Boddeti
authors.forename: Srinivas
authors.initials: S
authors.lastname: Thaduri
authors.forename: Andrey G
authors.initials: AG
authors.lastname: Solovyev
authors.forename: Eugene I
authors.initials: EI
authors.lastname: Savenkov
mesh_terms: D021581:Active Transport, Cell Nucleus; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism*; D017788:Carlavirus / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity*; D002467:Cell Nucleus / Q000378:metabolism / Q000821:virology; D049109:Cell Proliferation; D048429:Cell Size; D031202:Chrysanthemum / Q000235:genetics / Q000378:metabolism / Q000821:virology*; D058503:Mesophyll Cells / Q000378:metabolism / Q000821:virology; D008969:Molecular Sequence Data; D059828:Plant Cells / Q000378:metabolism; D063245:Plant Development; D010935:Plant Diseases / Q000821:virology; D018515:Plant Leaves / Q000166:cytology / Q000378:metabolism / Q000821:virology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism* / Q000821:virology; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism; D016335:Zinc Fingers
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D010940:Plant Proteins; D014764:Viral Proteins