Bax-induced cell death in tobacco is similar to the hypersensitive response.
Bax, a death-promoting member of the Bcl-2 family of proteins, triggered cell death when expressed in plants from a tobacco mosaic virus vector. Analysis of Bax deletion mutants demonstrated a requirement for the BH1 and BH3 domains in promoting rapid cell death, whereas deletion of the carboxyl-terminal transmembrane domain completely abolished the lethality of Bax in plants. The phenotype of cell death induced by Bax closely resembled the hypersensitive response induced by wild-type tobacco mosaic virus in tobacco plants carrying the N gene. The cell death-promoting function of Bax in plants correlated with accumulation of the defense-related protein PR1, suggesting Bax activated an endogenous cell-death program in plants. In support of this view, both N gene- and Bax-mediated cell death was blocked by okadaic acid, an inhibitor of protein phosphatase activity. The ability of Bax to induce cell death and a defense reaction in plants suggests that some features of animal and plant cell death processes may be shared.
Lacomme
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Department of Virology, Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, United Kingdom.
Santa Cruz
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D000818:Animals; D017209:Apoptosis; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000235:genetics; D051379:Mice; D018613:Microscopy, Confocal; D008928:Mitochondria / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure; D019590:Nucleocapsid Proteins / Q000235:genetics / Q000502:physiology; D019319:Okadaic Acid / Q000494:pharmacology; D010641:Phenotype; D010947:Plants, Toxic; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000502:physiology*; D019253:Proto-Oncogene Proteins c-bcl-2; D014026:Nicotiana / Q000166:cytology* / Q000502:physiology*; D014027:Tobacco Mosaic Virus / Q000235:genetics / Q000502:physiology*; D014158:Transcription, Genetic; D051028:bcl-2-Associated X Protein
C494827:Bax protein, mouse; D008164:Luminescent Proteins; D019590:Nucleocapsid Proteins; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; D049452:Green Fluorescent Proteins; D019319:Okadaic Acid