title: Modification of plant Rac/Rop GTPase signalling using bacterial toxin transgenes.
abstract: Bacterial protein toxins which modify Rho GTPase are useful for the analysis of Rho signalling in animal cells, but these toxins cannot be taken up by plant cells. We demonstrate in vitro deamidation of Arabidopsis Rop4 by Escherichia coli Cytotoxic Necrotizing Factor 1 (CNF1) and glucosylation by Clostridium difficile toxin B. Expression of the catalytic domain of CNF1 caused modification and activation of co-expressed Arabidopsis Rop4 GTPase in tobacco leaves, resulting in hypersensitive-like cell death. By contrast, the catalytic domain of toxin B modified and inactivated co-expressed constitutively active Rop4, blocking the hypersensitive response caused by over-expression of active Rops. In transgenic Arabidopsis, both CNF1 and toxin B inhibited Rop-dependent polar morphogenesis of leaf epidermal cells. Toxin B expression also inhibited Rop-dependent morphogenesis of root hairs and trichome branching, and resulted in root meristem enlargement and dwarf growth. Our results show that CNF1 and toxin B transgenes are effective tools in Rop GTPase signalling studies.
authors.affiliation: Faculty of Biology, Institute for Biology II/Botany, Albert-Ludwigs-University of Freiburg, Schänzlestrasse 1, 79104, Freiburg, Germany.
authors.forename: Manoj K
authors.initials: MK
authors.lastname: Singh
authors.affiliation: Faculty of Biology, Institute for Biology II/Botany, Albert-Ludwigs-University of Freiburg, Schänzlestrasse 1, 79104, Freiburg, Germany.
authors.forename: Fugang
authors.initials: F
authors.lastname: Ren
authors.affiliation: Institute for Clinical and Experimental Pharmacology and Toxicology, Albert-Ludwigs-University of Freiburg, Albertstrasse 25, 79104, Freiburg, Germany.
authors.forename: Torsten
authors.initials: T
authors.lastname: Giesemann
authors.affiliation: Faculty of Biology, Institute for Biology II/Botany, Albert-Ludwigs-University of Freiburg, Schänzlestrasse 1, 79104, Freiburg, Germany.
authors.forename: Cristina
authors.initials: C
authors.lastname: Dal Bosco
authors.affiliation: Faculty of Biology, Institute for Biology II/Botany, Albert-Ludwigs-University of Freiburg, Schänzlestrasse 1, 79104, Freiburg, Germany.
authors.forename: Taras P
authors.initials: TP
authors.lastname: Pasternak
authors.affiliation: Faculty of Biology, Institute for Biology II/Botany, Albert-Ludwigs-University of Freiburg, Schänzlestrasse 1, 79104, Freiburg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Blein
authors.affiliation: Department of Environmental Agronomy and Crop Science, University of Padova, Via Romea, 16, Agripolis, 35020, Legnaro, Padova, Italy.
authors.forename: Benedetto
authors.initials: B
authors.lastname: Ruperti
authors.affiliation: Institute for Clinical and Experimental Pharmacology and Toxicology, Albert-Ludwigs-University of Freiburg, Albertstrasse 25, 79104, Freiburg, Germany.
authors.forename: Gudula
authors.initials: G
authors.lastname: Schmidt
authors.affiliation: Institute for Clinical and Experimental Pharmacology and Toxicology, Albert-Ludwigs-University of Freiburg, Albertstrasse 25, 79104, Freiburg, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Aktories
authors.affiliation: Faculty of Biology, Institute for Biology II/Botany, Albert-Ludwigs-University of Freiburg, Schänzlestrasse 1, 79104, Freiburg, Germany.|Freiburg Initiative for Systems Biology (FRISYS), Albert-Ludwigs-University of Freiburg, Schänzlestrasse 1, 79104, Freiburg, Germany.
authors.forename: Arthur J
authors.initials: AJ
authors.lastname: Molendijk
authors.affiliation: Faculty of Biology, Institute for Biology II/Botany, Albert-Ludwigs-University of Freiburg, Schänzlestrasse 1, 79104, Freiburg, Germany.|Freiburg Initiative for Systems Biology (FRISYS), Albert-Ludwigs-University of Freiburg, Schänzlestrasse 1, 79104, Freiburg, Germany.|Centre of Biological Systems Analysis, Albert-Ludwigs-University of Freiburg, Habsburgerstrasse 49, 79104, Freiburg, Germany.|Freiburg Institute for Advanced Sciences (FRIAS), Albert-Ludwigs-University of Freiburg, Albertstrasse 19, 79104, Freiburg, Germany.|Centre for Biological Signalling Studies (BIOSS), Albert-Ludwigs-University of Freiburg, Albertstrasse 19, 79104, Freiburg, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Palme
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001427:Bacterial Toxins / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D019441:Plant Epidermis / Q000166:cytology / Q000378:metabolism; D018515:Plant Leaves / Q000166:cytology / Q000378:metabolism; D018517:Plant Roots / Q000254:growth & development / Q000378:metabolism; D030821:Plants, Genetically Modified; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism; D020744:rac GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D001427:Bacterial Toxins; D019204:GTP-Binding Proteins; C511948:Rop4 protein, Arabidopsis; D020744:rac GTP-Binding Proteins