title: The Agrobacterium tumefaciens virulence protein VirE3 is a transcriptional activator of the F-box gene VBF.
abstract: During Agrobacterium tumefaciens-mediated transformation of plant cells a part of the tumour-inducing plasmid, T-DNA, is integrated into the host genome. In addition, a number of virulence proteins are translocated into the host cell. The virulence protein VirE3 binds to the Arabidopsis thaliana pBrp protein, a plant-specific general transcription factor of the TFIIB family. To study a possible role for VirE3 in transcriptional regulation, we stably expressed virE3 in A. thaliana under control of a tamoxifen-inducible promoter. By RNA sequencing we showed that upon expression of virE3 the RNA levels of 607 genes were increased more than three-fold and those of 132 genes decreased more than three-fold. One of the strongly activated genes was that encoding VBF (At1G56250), an F-box protein that may affect the levels of the VirE2 and VIP1 proteins. Using Arabidopsis cell suspension protoplasts we showed that VirE3 stimulates the VBF promoter, especially when co-expressed with pBrp. Although pBrp is localized at the external surface of plastids, co-expression of VirE3 and pBrp in Arabidopsis cell suspension protoplasts resulted in the accumulation of pBrp in the nucleus. Our results suggest that VirE3 affects the transcriptional machinery of the host cell to favour the transformation process.
authors.affiliation: Department of Molecular and Developmental Genetics, Institute of Biology, Leiden University, Sylviusweg 72, 2333BE, Leiden, The Netherlands.
authors.forename: Xiaolei
authors.initials: X
authors.lastname: Niu
authors.affiliation: Department of Molecular and Developmental Genetics, Institute of Biology, Leiden University, Sylviusweg 72, 2333BE, Leiden, The Netherlands.
authors.forename: Meiliang
authors.initials: M
authors.lastname: Zhou
authors.affiliation: Department of Molecular and Developmental Genetics, Institute of Biology, Leiden University, Sylviusweg 72, 2333BE, Leiden, The Netherlands.
authors.forename: Christiaan V
authors.initials: CV
authors.lastname: Henkel
authors.affiliation: Department of Molecular and Developmental Genetics, Institute of Biology, Leiden University, Sylviusweg 72, 2333BE, Leiden, The Netherlands.
authors.forename: G Paul H
authors.initials: GP
authors.lastname: van Heusden
authors.affiliation: Department of Molecular and Developmental Genetics, Institute of Biology, Leiden University, Sylviusweg 72, 2333BE, Leiden, The Netherlands.
authors.forename: Paul J J
authors.initials: PJ
authors.lastname: Hooykaas
mesh_terms: D016960:Agrobacterium tumefaciens / Q000472:pathogenicity*; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D011523:Protoplasts / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D017423:Sequence Analysis, RNA; D014157:Transcription Factors / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D015533:Transcriptional Activation; D014170:Transformation, Genetic; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
chemical_list: D029681:Arabidopsis Proteins; D001426:Bacterial Proteins; D014157:Transcription Factors; D037521:Virulence Factors; C474201:transcription factor IIB-related protein, Arabidopsis
keywords: Agrobacterium tumefaciens; Arabidopsis thaliana; F-box protein; RNAseq; VBF; VirE3