title: Post-transcriptional regulation of GORK channels by superoxide anion contributes to increases in outward-rectifying K⁺ currents.
abstract: · Ion fluxes are ubiquitous processes in the plant and animal kingdoms, controlled by fine-tuned regulations of ion channel activity. Yet the mechanism that cells employ to achieve the modification of ion homeostasis at the molecular level still remains unclear. This is especially true when it comes to the mechanisms that lead to cell death. · In this study, Arabidopsis thaliana cells were exposed to ozone (O₃). Ion flux variations were analyzed by electrophysiological measurements and their transcriptional regulation by RT-PCR. Reactive oxygen species (ROS) generation was quantified by luminescence techniques and caspase-like activities were investigated by laser confocal microscopy. · We highlighted the delayed activation of K(+) outward-rectifying currents after an O₃ -induced oxidative stress leading to programmed cell death (PCD). Caspase-like activities are detected under O₃ exposure and could be decreased by K(+) channel blocker. Molecular experiments revealed that the sustained activation of K(+) outward current could be the result of an unexpected O₂ ·⁻ post-transcriptional regulation of the guard cell outward-rectifying K(+) (GORK) channels. · This consists of a likely new mode of regulating the processing of the GORK mRNA, in a ROS-dependent manner, to allow sustained K(+) effluxes during PCD. These data provide new mechanistic insights into K(+) channel regulation during an oxidative stress response.
authors.affiliation: Univ Paris Diderot, Sorbonne Paris Cité, Institut des Energies de Demain (IED), Paris, France.|LEM, Institut de Biologie des Plantes, Bât 630, 91405, Orsay, France.
authors.forename: Daniel
authors.initials: D
authors.lastname: Tran
authors.affiliation: UPMC, UR5 - PCMP, 9 Quai St Bernard, 75005, Paris, France.
authors.forename: Hayat
authors.initials: H
authors.lastname: El-Maarouf-Bouteau
authors.affiliation: LINV - Department of Plant Soil & Environmental Science, University of Florence, Florence, Italy.
authors.forename: Marika
authors.initials: M
authors.lastname: Rossi
authors.affiliation: Univ Paris Diderot, Sorbonne Paris Cité, Institut des Energies de Demain (IED), Paris, France.|LEM, Institut de Biologie des Plantes, Bât 630, 91405, Orsay, France.
authors.forename: Bernadette
authors.initials: B
authors.lastname: Biligui
authors.affiliation: Univ Paris Diderot, Sorbonne Paris Cité, Institut des Energies de Demain (IED), Paris, France.|LEM, Institut de Biologie des Plantes, Bât 630, 91405, Orsay, France.
authors.forename: Joël
authors.initials: J
authors.lastname: Briand
authors.affiliation: LINV - Department of Plant Soil & Environmental Science, University of Florence, Florence, Italy.|Graduate School of Environmental Engineering, University of Kitakyushu 1-1, Hibikino, Wakamatsu-ku, Kitakyushu, 808-0135, Japan.|Univ Paris Diderot, Sorbonne Paris Cité, Paris Interdisciplinary Energy Research Institute (PIERI), Paris, France.
authors.forename: Tomonori
authors.initials: T
authors.lastname: Kawano
authors.affiliation: LINV - Department of Plant Soil & Environmental Science, University of Florence, Florence, Italy.|Univ Paris Diderot, Sorbonne Paris Cité, Paris Interdisciplinary Energy Research Institute (PIERI), Paris, France.
authors.forename: Stefano
authors.initials: S
authors.lastname: Mancuso
authors.affiliation: Univ Paris Diderot, Sorbonne Paris Cité, Institut des Energies de Demain (IED), Paris, France.|LEM, Institut de Biologie des Plantes, Bât 630, 91405, Orsay, France.|LINV - Department of Plant Soil & Environmental Science, University of Florence, Florence, Italy.
authors.forename: François
authors.initials: F
authors.lastname: Bouteau
mesh_terms: D017398:Alternative Splicing / Q000187:drug effects / Q000235:genetics; D017360:Arabidopsis / Q000166:cytology / Q000187:drug effects / Q000235:genetics* / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D061945:Caspase Inhibitors / Q000494:pharmacology; D020169:Caspases / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects; D002478:Cells, Cultured; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D015640:Ion Channel Gating / Q000187:drug effects; D010126:Ozone / Q000494:pharmacology; D054046:Plant Stomata / Q000166:cytology; D026902:Potassium Channel Blockers / Q000494:pharmacology; D015221:Potassium Channels / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013481:Superoxides / Q000494:pharmacology*; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D029681:Arabidopsis Proteins; D061945:Caspase Inhibitors; C584663:GORK protein, Arabidopsis; D026902:Potassium Channel Blockers; D015221:Potassium Channels; D012333:RNA, Messenger; D013481:Superoxides; D010126:Ozone; D020169:Caspases